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Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995 (1995)

Chapter: 2 Nutrient Requirements of the Laboratory Rat

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Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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2
Nutrient Requirements of the Laboratory Rat

The laboratory rat (Rattus norvegicus) has long been favored as an experimental model for nutritional research because of its moderate size, profligate reproduction, adaptability to diverse diets, and tractable nature. It is now the species of choice for many experimental objectives because of the large body of available data and the development of strains with specific characteristics that facilitate the study of disease and other processes.

ORIGIN OF THE LABORATORY RAT

The laboratory rat is a domesticated Norway rat, which in nature is one of the most widespread and abundant of the more than 70 species of the genus Rattus (family Muridae). The albinos of the Norway rat were first domesticated in Europe in the early 19th century and came into use as experimental animals shortly thereafter (Lindsey, 1979). The Norway rat is not indigenous to Europe; however, it is believed to have originated in Asia and to have taken advantage of human movement in expanding its range worldwide (Nowak, 1991). The origin and historical development of the major strains of laboratory rats have been reviewed by Lindsey (1979).

In the wild, the Norway rat exhibits both territorial and colonial behavior and typically occupies underground burrows (Calhoun, 1963). Females produce 1 to 12 litters per year, and those in a colony nurture their young collectively. The Norway rat is omnivorous, eating a wide variety of seeds, grains, and other plant matter as well as invertebrates and small vertebrates (Nowak, 1991). Other than the fact that it lacks a gallbladder, the rat's digestive tract resembles that of other omnivorous rodents in that the stomach contains both nonglandular and glandular regions, the small intestine is of moderate length, and the cecum is relatively well developed (Bivin et al., 1979; Vorontsov, 1979).

GROWTH AND REPRODUCTIVE PERFORMANCE

Growth and reproductive performance are two key indicators of dietary adequacy. It is important that investigators monitor performance of experimental animals in relation to expected patterns of weight gain and reproduction. Given the large number of strains and different genotypes, it is not possible to describe a single growth pattern or reproductive performance applicable to all laboratory rats. Poiley (1972) summarized body weight gains from birth to about 24 weeks of age for 18 inbred strains and 3 outbred strains of rats. Examples of his mean values for 5 major inbred strains (Brown Norway, Fischer 344, Long-Evans, Osborne-Mendel, and Sprague-Dawley) are illustrated in Figure 2-1. Males gain weight more quickly and become larger than females of the same strain, but there are considerable differences in growth rates and adult body mass among the strains. In view of ongoing genetic selection of the strains of rats, and improvements in diets, the mean growth rates shown in Figure 2-1 may not represent desired performance at present. However, Reeves et al. (1993a) found similar growth rates in Sprague-Dawley rats fed a commercial rat diet for 16 weeks. Investigators should obtain expected or desired growth curves for their experimental rats from the supplier or breeding colony from which animals originate.

Reproductive characteristics such as age at the time reproduction begins, fertility, litter size, growth rates of suckling young, and preweaning mortality also vary among strains. C. T. Hansen (Veterinary Resources Program, National Center for Research Resources, National Institutes of Health, personal communication, 1993) recently summarized selected reproductive parameters of rat strains maintained in breeding colonies at the National Institutes of Health, including 37 monogamously mated inbred strains, 42 harem-mated congenic strains, 5 harem-mated mutant

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

FIGURE 2-1 Mean body weight of male and female rats of five inbred strains: □, Brown Norway; ◇, Fischer 344; ▹, Long-Evans; ■, Osborne-Mendel; and ◆, Sprague-Dawley. SOURCE: Data adapted from Poiley (1972).

stocks, and 3 monogamously mated outbred stocks. Differences in the percentage of sterile matings, litter size, and preweaning mortality were evident among major inbred strains such as Brown Norway, Fischer 344, Osborne-Mendel, Sprague-Dawley, and Wistar (Table 2-1). Outbred strains tended to have higher reproductive performance (Table 2-1). Thus the expected reproductive performance of rats in experimental studies may vary according to strain and system of breeding.

ESTIMATION OF NUTRIENT REQUIREMENTS

Although the nutrient requirements of the laboratory rat are better known than those of other laboratory animals, there can be considerable disparity in estimated requirements as a consequence of the criteria used (Baker, 1986). For example, the amounts of nutrients required to sustain maximum growth of young rats may be different from the

TABLE 2-1 Some Reproductive Characteristics of Representative Strains of Inbred and Outbred Rat Colonies Maintained at the National Institutes of Health

Strain

Sterile

Matings

(%)

Mean

Litter

Size

Preweaning

Mortality

(%)

Inbred strain

Brown Norway

30

5.9

1

Fischer 344

14

7.6

10

Osborne-Mendel

38

7.6

9

Sprague-Dawley

16

4.4

6

Wistar

31

7.9

8

Outbred strain

Osborne-Mendel

6

7.4

6

Sprague-Dawley

2

7.1

2

NOTE: Both strains are from monogamously mated stocks.

 

SOURCE: Data summarized and provided by C. T. Hansen (Veterinary Resources Program, National Center for Research Resources, National Institutes of Health, personal communication, 1993).

amounts needed to maintain tissue concentrations or to maximize functional measures such as enzyme activities. Moreover, nutrient requirements are not static; they change according to developmental state, reproductive activity, and age. There is also evidence of differences in requirements between males and females as well as among various inbred and outbred strains. The nutrient requirements listed in this chapter represent average values, but they may not suffice in all circumstances. There is a need for further research that will identify the sources of variation in nutrient requirements.

Recommended nutrient concentrations in this report have not been increased to allow a margin of safety for variation in dietary ingredients or for differences among rats. The data on which requirements are based were reported from many different laboratories that used various colony management practices. One may assume that the recommendations are adequate for rats in most laboratory conditions, but particular experimental protocols such as maintenance of germ-free colonies or testing of experimental drugs (see Chapter 1) may alter the requirements for one or more nutrients. In some cases sufficient data were available to differentiate the nutrient requirements for adult maintenance from those for growing, pregnant, or lactating rats; hence, estimates of requirements are provided for maintenance, growth, and reproduction (Table 2-2). If data available were insufficient to determine requirements, adequate concentrations are reported on the basis of long-term feeding. If cited papers provided nutrient intakes per day but did not specify dietary concentrations, the values have been converted to dietary content by assuming a dietary intake of 15 g/rat/day for growing rats or adult rats at maintenance, 15 to 20 g/rat/day during pregnancy, and 30 to 40 g/rat/day during lactation.

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

TABLE 2-2 Estimated Nutrient Requirements for Maintenance, Growth, and Reproduction of Rats

 

 

Amount, per kg diet

 

 

Nutrient

Unit

Maintenance

Growth

Reproduction (Female)

Fat

g

50.0

50.0

50.0

Linoleic acid (n-6)

g

a

6.0a

3.0a

Linolenic acid (n-3)

g

R

R

R

Protein

g

50.0b

150.0b

150.0

Amino Acidsc

 

 

 

 

Arginine

g

ND

4.3

4.3

Aromatic AAsd

g

1.9

10.2

10.2

Histidine

g

0.8

2.8

2.8

Isoleucine

g

3.1

6.2

6.2

Leucine

g

1.8

10.7

10.7

Lysine

g

1.1

9.2

9.2

Methionine + cystinee

g

2.3

9.8

9.8

Threonine

g

1.8

6.2

6.2

Tryptophan

g

0.5

2.0

2.0

Valine

g

2.3

7.4

7.4

Other (including nonessentials)

g

f

66.0

66.0

Minerals

 

 

 

 

Calcium

g

g

5.0

6.3

Chlorideh

g

g

0.5

0.5

Magnesium

g

g

0.5

0.6

Phosphorus

g

g

3.0

3.7

Potassiumh

g

g

3.6

3.6

Sodium

g

g

0.5

0.5

Copper

mg

g

5.0

8.0

Iron

mg

g

35.0

75.0

Manganese

mg

g

10.0

10.0

Zinci

mg

g

12.0

25.0

Iodine

µg

g

150.0

150.0

Molybdenum

µg

g

150.0

150.0

Selenium

µg

g

150.0

400.00

Vitamins

 

 

 

 

A (retinol)j

mg

g

0.7

0.7

D (cholecalciferol)k

mg

g

0.025

0.025

E (RRR-α-tocopherol)l

mg

g

18.0

18.0

K (phylloquinone)

mg

g

1.0

1.0

Biotin (d-biotin)

mg

g

0.2

0.2

Choline (free base)

mg

g

750.0

750.0

Folic acid

mg

g

1.0

1.0

Niacin (nicotinic acid)

mg

g

15.0

15.0

Pantothenate (Ca-d-pantothenate)

mg

g

10.0

10.0

Riboflavin

mg

g

3.0

4.0

Thiamin (thiamin-HCl)m

mg

g

4.0

4.0

B6 (pyridoxine)n

mg

g

6.0

6.0

B12

µg

g

50.0

50.0

NOTE: Nutrient requirements are expressed on an as-fed basis for diets containing 10% moisture and 3.8–4.1 kcal ME/g (16–17 kJ ME/g) and should be adjusted for diets of differing moisture and energy concentrations. Unless otherwise specified, the listed nutrient concentrations represent minimal requirements and do not include a margin of safety. Higher concentrations for many nutrients may be warranted in natural-ingredient diets. R, required but no concentration determined; other long-chain n-3 polyunsaturated fatty acids may substitute for linolenic acid. ND, not determined.

a Females require only 2 g/kg linoleate for growth. Separate requirements for maintenance have not been determined for linoleate. Requirements presented for growth will meet maintenance requirements.

b Estimates based on highly digestible protein of balanced amino acid composition (e.g., lactalbumin).

c Asparagine, glutamic acid, and proline may be required for very rapid growth (see text).

d Phenylalanine plus tyrosine. Tyrosine may supply up to 50 percent of aromatic acid requirement.

e Cystine may supply up to 50% of the methionine plus cystine requirement on a weight basis.

f 41.3 g/kg diet as a mixture of glycine, L-alanine, and L-serine.

g Separate requirements for maintenance have not been determined for minerals and vitamins. Requirements presented for growth will meet maintenance requirements.

h Estimate represents adequate amount, rather than true requirement.

i Higher concentration is required when ingredients that contain phytate (such as soybean meal) are included in the diet.

j Equivalent to 2,300 IU/g. Requirement may also be met by 1.3 mg β -carotene/kg diet. Higher vitamin A concentration is needed under conditions of stress (e.g., surgical recovery).

k Equivalent to 1,000 IU/kg.

l Equivalent to 27 IU/kg. Higher concentration may be required if high-fat diets are fed.

m Higher concentration may be required with low-protein, high-carbohydrate diets.

n Estimate represents adequate amount, rather than true requirements.

EXAMPLES OF DIETS FOR RATS

The type of diet and its nutrient composition will vary according to experimental objectives (see Chapter 1). Most practical diets include nutrient concentrations that exceed requirements as a margin of safety. Examples of natural-ingredient diets based on detailed formula specifications and used successfully to maintain rat colonies at the National Institutes of Health and at other facilities are provided in Table 2-3. The ingredient specifications, however, have not been updated for some years and are not entirely in agreement with recommendations in this report.

As indicated in Chapter 1, natural-ingredient diets do not offer the same control over nutrient concentrations or potential contaminants as do purified diets. An example of a purified diet that has often been used in rat studies is given in Table 2-4. However, as there has been concern about the standardization and concentrations of some constituents, as well as the clinical observation of nephrocalcinosis in females when this diet is used (Reeves, 1989; Reeves et al., 1993a), a change in formulation is warranted. A committee of the American Institute of Nutrition (AIN) has reformulated and tested new purified diets for the

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

TABLE 2-3 Examples of Natural-Ingredient Diets Used for Rat and Mouse Breeding Colonies at the National Institutes of Health

Ingredient

Conventional

(NIH-07)

Autoclavable

(NIH-31)

Basic Diet, g/kg diet

Dried skim milk

50.0

 

Fish meal (60% protein)

100.0

90.0

Soybean meal (48% protein)

120.0

50.0

Alfalfa meal, dehydrated (17% protein)

40.0

20.0

Corn gluten meal (60% protein)

30.0

20.0

Ground #2 yellow shelled corn

245.0

210.0

Ground hard winter wheat

230.0

355.0

Ground whole oats

 

100.0

Wheat middlings

100.0

100.0

Brewer's dried yeast

20.0

10.0

Dry molasses

15.0

 

Soybean oil

25.0

15.0

Salt

5.0

5.0

Dicalcium phosphate

12.5

15.0

Ground limestone

5.0

5.0

Mineral premix

1.2

2.5

Vitamin premix

1.3

2.5

Mineral Premix, mg/kg diet

Cobalt (as cobalt carbonate)

0.44

0.44

Copper (as copper sulfate)

4.40

4.40

Iron (as iron sulfate)

132.30

66.20

Manganese (as manganous oxide)

66.20

110.00

Zinc (as zinc oxide)

17.60

11.00

Iodine (as calcium iodate)

1.54

1.65

Vitamin Premix, per kg diet

Stabilized vitamin A palmitate or stearate

6,060.00 IU

24,300.00 IU

Vitamin D3 (D-activated animal sterol)

5,070.00 IU

4,190.00 IU

Vitamin K (menadione activity)

3.09 mg

22.10 mg

All-rac-α-tocopheryl acetate

22.10 mg

16.50 mg

Choline chloride

617.00 mg

772.00 mg

Folic acid

2.43 mg

1.10 mg

Niacin

33.10 mg

22.10 mg

Ca-d-pantothenate

19.80 mg

27.60 mg

Pyridoxine-HCl

1.87 mg

2.21 mg

Riboflavin supplement

3.75 mg

5.51 mg

Thiamin mononitrate

11.0 mg

71.7 mg

d-Biotin

0.15 mg

0.13 mg

Vitamin B12 supplement

0.004 mg

0.015 mg

NOTE: Amounts listed for mineral and vitamin premixes represent the mass or IU of the specific mineral element or vitamin rather than the added compounds.

SOURCES: Knapka (1983), Knapka et al. (1974), and National Institutes of Health (1982).

growth (AIN-93G) and maintenance (AIN-93M) of rats and mice (Reeves et al., 1993a,b; Reeves et al., 1994). These diets are included in Table 2-5.

ENERGY

Purified diets containing 5 to 10 percent fat have gross

TABLE 2-4 Example of a Commonly Used Purified Diet (AIN-76A) for Rats

Ingredient

Amount, g/kg diet

Basic Diet

Sucrose

500.0

Casein (≥85% protein)

200.0

Cronstarch

150.0

Corn oil (including 0.01-0.02% antioxidanta)

50.0

Fiber source (cellulose-type)

50.0

Mineral mix (listed below)

35.0

Vitamin mix (listed below)

10.0

DL-Methionine

3.0

Choline bitartrate

2.0

Mineral Premix

Calcium phosphate, dibasic (CaHPO4)

500.00

Potassium citrate, monohydrate (K3C6H5O7·H2O)

220.00

Sodium chloride

74.00

Potassium sulfate

52.00

Magnesium oxide

24.00

Ferric citrate (16-17% Fe)

6.00

Manganous carbonate (43–48% Mn)

3.50

Zinc carbonate (70% ZnO)

1.60

Chromium potassium sulfate [CrK(SO4)2·12H2O]

0.55

Cupric carbonate (53–55% Cu)

0.30

Potassium iodate (KIO3)

0.01

Sodium selenite (Na2SeO3·5H2O)

0.01

Sucrose, finely powdered

118.03

Vitamin premix

Nicotinic acid or nicotinamide

3.000

Calcium d-pantothenate

1.600

Pyridoxine-HCL

0.700

Thiamin-HCl

0.600

Riboflavin

0.600

Folic acid

0.200

d-Biotin

0.020

Cyanocobalamin (vitamin B12)

0.001

Retinyl palmitate or acetate (vitamin A)

+b

α-Tocopheryl acetate (vitamin E)

+c

Cholecalciferol (vitamin D3)

0.0025

Menaquinone (vitamin K)

0.005

Sucrose, finely powdered

To make <1,000 g

SOURCE: American Institute of Nutrition (1977, 1980).

a Betahydroxytoluene or Santoquin.

b As stabilized powder to provide 400,000 IU vitamin A activity (120,000 retinol equivalents).

c As stabilized powder to provide 5,000 IU vitamin E activity.

energy (GE) values of about 4.0 to 4.5 Mcal/kg (17 to 19 MJ/kg). The digestible energy (DE) of most purified diets ranges from 90 to 95 percent of GE (Hartsook et al., 1973; McCraken, 1975; Deb et al., 1976). The metabolizable energy (ME) varies from 90 to 95 percent of DE (Hartsook et al., 1973; Pullar and Webster, 1974; McCraken, 1975; Deb et al., 1976). These values may be somewhat lower when diets formulated from natural-ingredients are used

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

TABLE 2-5 Examples of Recently Tested Purified Diets for Rapid Growth of Young Rats and Mice or for Maintenance of Adult Rats and Mice

Ingredient

Growth

(AIN-93G)

Maintenance

(AIN-93M)

Basic Diet, g/kg diet

Cornstarch

397.486

465.692

Casein (≥85%)

200.000

140.000

Dextrinized cornstarcha

132.000

155.000

Sucrose

100.000

100.000

Soybean oil (no additives)

70.000

40.000

Fiber source (cellulose)b

50.000

50.000

Mineral mix (listed below)

35.000

35.000

Vitamin mix (listed below)

10.000

10.000

L-Cystine

3.000

1.800

Choline bitartrate (41.1% choline)

2.500

2.500

Tert-butylhydroquinone (TBHQ)

0.014

0.008

Mineral Premix, g/kg mixc

Calcium carbonate, anhydrous (40.0% Ca)

357.00

357.00

Potassium phosphate, monobasic

(22.8% P, 28.7% K)

196.00

250.00

Potassium sulfate (44.9% K, 18.4% S)

46.60

46.60

Potassium citrate tri-K, monohydrate, (36.2% K)

70.78

28.00

Sodium chloride (39.3% Na, 60.7% Cl)

74.00

74.00

Magnesium oxide (60.3% Mg)

24.00

24.00

Ferric citrate (16.5% Fe)

6.06

6.06

Zinc carbonate (52.1% Zn)

1.65

1.65

Manganous carbonate (47.8% Mn)

0.63

0.63

Cupric carbonate (57.5% Cu)

0.30

0.30

Potassium iodate (59.3% I)

0.01

0.01

Sodium selenate anhydrous (41.8% Se)

0.01025

0.01025

Ammonium paramolybdate 4 hydrate (54.3% Mo)

0.00795

0.00795

Sodium meta-silicate 9 hydrate (9.88% Si)

1.4500

1.4500

Chromium potassium sulfate 12 hydrate (10.4% Cr)

0.2750

0.2750

Lithium chloride (16.4% Li)

0.0174

0.0174

Boric acid (17.5% B)

0.0815

0.0815

Sodium fluoride (45.2% F)

0.0635

0.0635

Nickel carbonate (45% Ni)

0.0318

0.0318

Ammonium vanadate (43.6% V)

0.0066

0.0066

Powdered sucrose

221.0260

209.8060

Vitamin Premix, g/kg mixd

Nicotinic acid

3.000

3.000

Calcium pantothenate

1.600

1.600

Pyridoxine-HCI

0.700

0.700

Thiamin-HCI

0.600

0.600

Riboflavin

0.600

0.600

Folic acid

0.200

0.200

d-Biotin

0.020

0.020

Vitamin B12 (cyanocobalamin 0.1% in mannitol)

2.500

2.500

All-rac-α-tocopheryl acetate (500 IU/g)e

15.000

15.000

Retinyl palmitate (500,000 IU/g)e

0.800

0.800

Vitamin D3 (cholecalciferol 400,000 IU/g) Vitamin K1 (phylloquinone)

0.075

0.075

Powdered sucrose

974.655

974.655

a Ninety percent tetrasaccharides or higher oligosaccharides such as Dyetrose (Dyets Inc., Bethlehem, PA) Lo-Dex (American Maize Co., Hammond, NJ) or equivalent.

b Solka-Floc 200 FCC (FS&D Corp., St. Louis, MO) or equivalent.

c Mineral mix for growth referred to as AIN-93G-MX and for maintenance as AIN-93M-MX.

d Vitamin mixes referred to as AIN-93-VX

e Dry gelatin-matrix form.

SOURCE: Adapted from Reeves et al. (1993b).

(Yang et al., 1969; Peterson and Baumgardt, 1971a). The addition of cellulose to natural-ingredient diets decreases energy digestibility (Yang et al., 1969; Peterson and Baumgardt, 1971a) even though 15 to 60 percent of the cellulose is digested (Conrad et al., 1958; Yang et al., 1969; Peterson and Baumgardt, 1971b). Some of the decrease in energy digestibility is caused by the low digestibility of cellulose and some is caused by increased fecal nitrogen losses (Meyer, 1956).

In general the rat will consume food to meet its energy requirement (Brody, 1945; Mayer et al., 1954; Sibbald et al., 1956, 1957; Yoshida et al., 1958; Peterson and Baumgardt, 1971b; Kleiber, 1975). Yoshida et al. (1958) reported that the daily caloric intake remained constant when the diet contained from 0 to 30 percent fat. A proportionate increase in consumption of diet occurs when the diet is diluted with inert materials. A maximum concentration of 40 percent dilution of the diet could be made for weanling female rats before caloric intake was reduced, whereas 50 percent dilution could be made for mature females (Peterson and Baumgardt, 1971b). The energy requirement of the lactating female is high, and dilution of the diet with only 10 percent of inert material results in a significant decrease in DE intake (Peterson and Baumgardt, 1971b). Inadequate dietary protein may decrease energy intake (Menaker and Navia, 1973).

Temperature, age, and activity influence the energy requirement of the rat. The lower critical temperature of the fasting rat is 30°C (Swift and Forbes, 1939; Brody, 1945; Kleiber, 1975). The lower critical temperature is that environmental temperature below which heat production must be increased to maintain body temperature. The basal metabolic rate of the rat can be estimated from the general formula

where Hkcal is the heat production in kcal per day, BW is the body weight in kilograms, and 72 is the average heat production (kcal) per kg0.75 of 26 groups of rats studied (Kleiber, 1975). This formula is valid only for estimating the basal heat production of mature animals. If kilojoules (kJ) are used as the unit of energy, the formula is Hj = 301 BWkg0.75.

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

MAINTENANCE

The maintenance energy requirement can be generally defined as that portion of the total energy requirement that is separate from the needs for growth, pregnancy, and lactation. Animals fed at maintenance are in energy equilibrium. Advantages and disadvantages of the methods by which the maintenance energy requirement may be estimated have been reviewed by van Es (1972). The maintenance energy requirement is usually expressed as energy required per unit of body weight in kilograms to the 0.75 power (BWkg0.75), and is based on the work of Brody (1945) and Kleiber (1975).

An estimate of the maintenance requirement for the adult rat (300 g) can be made by increasing the value for basal heat production (300 BWkg0.75; Kleiber et al., 1956) by approximately 20 percent (Morrison, 1968) to cover the expected requirement for activity in a laboratory setting. This value, which is in net energy units, can be converted to ME units by dividing by 0.75, based on an efficiency of 75 percent in conversion of ME to net energy (McCraken, 1975). The daily maintenance energy requirement in ME units for adult rats, based on these assumptions, is 114 kcal ME/BWkg0.75 (477 kJ ME/BWkg0.75). This value is remarkably similar to direct estimates of the maintenance energy requirement in ME units at 100 kcal (418 kJ; Pullar and Webster, 1974), 106 kcal (444 kJ; McCraken, 1975), 130 kcal (544 kJ; Deb et al., 1976), and 91 kcal (381 kJ; Ahrens, 1967). However, the requirement for fat rats (e.g., obese Zucker) is approximately 15 percent lower than the requirement for normal rats (Pullar and Webster, 1974; Deb et al., 1976). As this difference in maintenance energy requirement between the adult normal and adult obese Zucker is not determined by body weight, the practice of estimating maintenance energy requirement solely from body weight must be used with caution (Pullar and Webster, 1974; Webster et al., 1980).

It is well established that resting heat production per BWkg0.75 is greater in working and producing animals than in nonworking animals (Brody, 1945). A portion of this difference is attributable to differences in amount of intake. Walker and Garrett (1971) demonstrated that a decrease in food intake of rats results in a decrease in energy expenditure and in the maintenance energy requirement.

Previous plane of nutrition also influences maintenance energy requirement. Rats fed at a high plane of nutrition (39.6 g/BWkg0.75/day) for a 3-week period had a 38 percent greater heat production when compared to rats on a low plane (28.8 g/BWkg0.75/day) of nutrition (Koong et al., 1985). Experiments with sheep indicate that changes in organ mass associated with amount of intake and sequence of feeding may be largely responsible for altered heat production (Koong et al., 1985). Thus an accurate prediction of the maintenance energy requirement of the rat requires consideration of the amount of intake, previous nutritional history, physiological state, and other factors including the composition of the body (see Baldwin and Bywater, 1984, for a review). Nonetheless, data suggest that maintenance energy requirements of the rat will be met in most cases by consumption of 112 kcal/BW kg0.75/day (470 kJ/BWkg0.75/day).

GROWTH

It is difficult to estimate the energy requirement for growth because of variation in the composition of weight gain (Meyer, 1958; Schemmel et al., 1972; Hartsook et al., 1973; McCraken, 1975; Deb et al., 1976) and in the energetic efficiency of net protein and fat synthesis. Kielanowski (1965) used a multiple regression model that partitioned total ME intake (MEI) into a component proportional to body weight, representing maintenance energy requirement, a component proportional to energy gain as fat, and a component proportional to energy gain as protein or lean body mass. Separation of the efficiencies of energy gain in fat and lean is problematic, however, leading to inconsistent and sometimes biologically impossible results (see Chapter 3, which deals with the mouse). Pullar and Webster (1974) attempted to circumvent some of these difficulties by using obese and lean Zucker rats, which partition energy differently between gain in fat and in lean at all stages of growth. The energetic efficiencies of fat and net protein synthesis were estimated at 65 and 43 percent, respectively. These estimates assumed that the maintenance energy requirement remained constant. In a subsequent experiment that did not require assumptions about maintenance energy requirements, Pullar and Webster (1977) determined the energetic efficiencies of fat and net protein deposition as 73.5 and 44.4 percent, respectively. Kielanowski (1976) concluded from a review of previous work that the energetic efficiency of net protein deposition in growing rats is approximately 43 percent.

The requirement of the rat for maintenance and growth can be met by diets with a wide range of energy densities. Peterson and Baumgardt (1971b) reported that weanling and mature rats consumed 225 and 150 kcal DE/BWkg0.75 (940 and 630 kJ/BWkg0.75), respectively, when the energy density of the diet varied from 2.5 to 5.0 kcal DE/g (10.5 to 20.9 kJ/g). When the energy density in the diet fell below 2.9 kcal/g (12.1 kJ/g), the weanling rat could not meet its energy requirement. The mature rat could meet its energy requirement until DE density fell to values below 2.5 kcal DE/g (10.5 kJ/g). These values are equivalent to diluting the diet with 40 and 50 percent inert material for weanling and mature rats, respectively. During the 4-week growth period after weaning at 21 days postpartum, the average daily energy requirement is at least 227 kcal/BWkg0.75) and may be greater. A diet con-

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

taining at least 3.6 kcal ME/g (15.0 kJ ME/g) will meet the energy requirement for maintenance and growth if rats are allowed free access to food and the diet is not deficient in other nutrients.

GESTATION AND LACTATION

The energy requirement for gestation appears to be 10 to 30 percent greater than that of the mature but nonreproductive female rat (Morrison, 1956; Menaker and Navia, 1973). Food intake of rats fed diets adequate in protein increased 10 to 20 percent (Menaker and Navia, 1973) or 20 to 30 percent during the first days of gestation and up to 140 percent by days 16 to 18 of gestation (Morrison, 1956). Total heat production in pregnant rats increased approximately 10 percent above that of nonpregnant female rats (Brody et al., 1938; Kleiber and Cole, 1945; Morrison, 1956; Champigny, 1963). Approximately one-third of the 100 to 201 kcal (420 to 840 kJ) stored during gestation is deposited in fetal tissues (Morrison, 1956). Restriction of the diet during gestation decreases the size and viability of the young and may induce resorption (Perisse and Salmon-Legagneur, 1960; Berg, 1965). Protein appears to be more critical than energy for satisfactory reproduction (Hsueh et al., 1967; Menaker and Navia, 1973).

The daily ME requirement of the rat is about 143 kcal/BWkg0.75 (600 kJ/BWkg0.75) in early gestation and may increase to 265 kcal/BWkg0.75 (1,110 kJ/BWkg0.75) during the later stages of gestation. Lactating rats consume from two to four times more energy than nonlactating female rats, and the magnitude of increase depends on the number of offspring being nursed (Nelson and Evans, 1961; Peterson and Baumgardt, 1971b; Menaker and Navia, 1973; Grigor et al., 1984). Some of the increase in measured intake late in the lactation period may be caused by the consumption of diet by the litter, but this is not significant until about 15 to 17 days postpartum. In spite of the large increase in feed consumption, however, rats are generally in negative energy balance at peak lactation. Losses of both body fat and protein can occur. In general it appears that lipid is stored in the maternal body during gestation and then mobilized to support the lactation process (Sampson and Janson, 1984). Naismith et al. (1982) concluded that hormonal factors were responsible for the storage of lipid during gestation and the mobilization of body fat during lactation. They suggested that body fat supplies a major portion of the energy required to support lactation. Sainz et al. (1986) fed lactating rats diets containing 12, 24, and 36 percent protein and 4.50, 4.37, and 4.04 kcal ME/g (18.8, 18.3, and 16.9 kJ/g). Although fed ad libitum, the lactating rats lost body fat from days 7 to 14 of lactation regardless of diet. It is difficult to establish an energy ''requirement" for the lactating rat based on body energy change. At peak lactation, rats rearing 8 pups produced about 41 g milk/day, representing a milk energy output of about 239 kcal/BWkg0.75/day (1,000 kJ/BWkg0.75 /day) (Kametaka et al., 1974; Oftedal, 1984). It is likely that during peak lactation, the dam's daily ME requirement to support lactation will be at least 311 kcal/BWkg0.75 (1,300 kJ/BWkg0.75), but the ME requirement will vary with litter size.

LIPIDS

Lipid is an important component of the rat diet because it provides essential fatty acids (EFA) and a concentrated energy source, aids in the absorption of fat-soluble vitamins, and enhances diet acceptability.

ESSENTIAL FATTY ACIDS

n-6 Fatty Acids

The rat requires fatty acids from the n-6 family as a component of membranes, for optimal membrane-bound enzyme function, and to serve as a precursor for prostaglandin formation (Mead, 1984; Dupont, 1990; Clandinin et al., 1991). Linoleic acid [18:2(n-6)] cannot be synthesized endogenously but can be elongated and desaturated to form arachidonic acid [20:4(n-6)]; thus, the requirement for n-6 fatty acids can be met through dietary linoleic acid. Early estimates of the requirement for n-6 fatty acids were made by using growth and skin condition as response criteria. The requirement for growing male rats was estimated to be 50 to 100 mg/day and that of growing female rats to be 10 to 20 mg/day (Greenberg et al., 1950). That the requirement differs between sexes is in agreement with early observations that male rats are more susceptible than female rats to the development of EFA deficiency signs (Loeb and Burr, 1947). A series of later experiments indicated that other lipid components of the diet [e.g., oleic acid (Lowry and Tinsley, 1966) and cholesterol (Holman and Peiffer, 1960)] increased the need for n-6 fatty acids. Also, Holman (1960) demonstrated that more linoleic acid is needed in high-lipid diets versus low-lipid diets in order to meet the EFA requirement of the rat. Therefore it has become common practice to express the requirement as a percent of dietary ME rather than as a percent of diet weight. The Δ6 desaturase enzyme involved in the synthesis of long-chain polyunsaturated fatty acids uses the fatty acid substrates in the following order: n-3 > n-6 > n-9 (Johnston, 1985).

Holman (1960) found that the ratio of 20:3(n-9) to 20:4(n-6) (also called the triene:tetraene ratio) was relatively constant in tissues until clinical signs of EFA deficiency began to develop. Because this biochemical measure was both objective and relatively stable (the precise ratio varied

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

slightly among tissues), Holman (1960) initiated the use of the triene:tetraene ratio to indicate inadequate EFA status. Diets high in n-3 fatty acids also lower the triene concentration (Morhauer and Holman, 1963; Rahm and Holman, 1964) because of the competition for desaturation mentioned above. Therefore the triene:tetraene ratio is a valid indicator of EFA status only when n-6 fatty acids are the principal unsaturated dietary fatty acids. Pudelkewicz et al. (1986) used this technique (in conjunction with dermatitis and growth) to estimate the linoleic acid requirement of growing female and male rats to be 0.5 percent and 1.3 percent of dietary ME, respectively.

The requirement for pregnancy is met by diets adequate for growth, while that for lactation is somewhat higher. Deuel et al. (1954) conducted two experiments to estimate these requirements. In the first experiment, 0, 10, 40, 100, 200, 400, and 1,000 mg cottonseed oil (approximately 50 percent linoleic acid) were fed daily. The number of litters born and the average number of pups per litter increased and then plateaued at 10 and 100 mg dietary cottonseed oil (e.g., 5 and 50 mg linoleate), respectively. When pure linoleate was fed as the fat source in a second experiment in which rats were provided with 0, 2.5, 5.0, 10, 20, 40, and 80 mg linoleate daily, the maximum litters born and average number of pups per litter increased and then plateaued at 2.5 and 20 mg linoleate, respectively. This higher amount of linoleic acid intake will be achieved if the pregnant rat consumes 18 g/day and the diet contains 0.25 percent of dietary ME as linoleic acid.

The requirement for lactation also can be estimated from these experiments. Indicators of successful lactation (the maximum average weight per pup in a litter at 21 days and minimum percent mortality between 3 and 21 days) reached a plateau between 100 to 200 mg cottonseed oil (50 to 100 mg linoleate) in the first experiment. In the second experiment, these criteria for successful lactation reached a maximum at 80 mg of linoleate. Because greater amounts of linoleate were not tested, it is not possible to determine whether the optimal requirement for lactation is more than 80 mg/day. In addition, the authors did not indicate the range of experimental error; therefore, a precise requirement cannot be established. Assuming a requirement of 100 mg linoleate/day, a lactating rat consuming 35 g diet/day will consume sufficient linoleate for lactation (100 mg/day) if the diet contains 0.68 percent of dietary ME as linoleate (approximately 0.30 percent of the diet).

Bourre et al. (1990) proposed that the n-6 fatty acid requirement be established as the percent of dietary linoleate that results in a constant concentration of tissue arachidonic acid. They found that constant concentrations of arachidonic acid were achieved at 150 mg (nerve tissue), 300 mg (testicle), 800 mg (kidney), and 1,200 mg (liver, lung, heart) linoleate/100 g diet. The minimal requirement then was expressed as 1,200 mg linoleic acid/100 g diet (or approximately 2.5 percent of dietary ME) because some tissues require a higher concentration of arachidonic acid to reach a plateau. Because the authors did not relate the arachidonic acid concentration plateau to any functional phenomena, the validity of this method of estimating the n-6 fatty acid requirement remains to be established.

n-3 Fatty Acids

The essentiality of the n-3 fatty acids has been equivocal until recently. It was initially demonstrated that the n-3 fatty acid, α-linolenic acid [18:3(n-3)], could substitute, in part, for the requirement of n-6 fatty acids (Greenberg et al., 1950). Tinoco et al. (1971) failed to show any change in growth of rats raised for three generations on diets lacking in n-3 fatty acids in comparison to litter mates fed diets containing 1.25 percent linoleate and 0.25 percent linolenate. However, the sequestering of n-3 fatty acids in specific tissues (retina, cerebral cortex, testis, sperm; Tinoco, 1982) and the tenacity with which they retain these fatty acids, despite the variation in dietary concentration (Crawford et al., 1976), led many researchers to speculate that n-3 fatty acids were required for some function in the body.

Bernsohn and Spitz (1974) fed rats lipid-free diets for 4 months and measured slightly decreased amounts (38 percent of control values) of monoamine oxidase and 5'-mononucleotidase in cerebral cortex that responded to dietary α-linolenic but not to linoleic acid. Retinal function may be negatively impacted in offspring of rats fed a low linolenate oil for two to three generations (Okuyama et al., 1987). Lamptey and Walker (1976) found reduced exploratory behavior in second generation rats fed safflower oil. A large percent of safflower oil is linoleic acid, and a very small percent is linolenic acid. This was confirmed in studies by Enslen et al. (1991) who showed a reduction in exploratory behavior in 16- to 18-week-old rats from dams fed safflower oil 6 weeks prior to mating and throughout gestation and lactation. These researchers found that when rats were switched to α-linolenic acid at weaning, they did not recover exploratory behavior, further suggesting a specific requirement for n-3 fatty acids during development.

Yamamoto et al. (1987, 1988) found a reduction in brightness discrimination learning in offspring from rats fed safflower oil through two generations in comparison to rats similarly fed perulla oil, a rich source of α-linolenic acid.

Bourre et al. (1989) measured impairment of nerve terminal Na+, K+ -ATPase activity, brain 5'-nucleotidase, and 2',3'-cyclic nucleotide-3'-phosphodiesterase in offspring from rats fed 1.8 percent sunflower oil in comparison to those from dams fed 1.9 percent soybean oil through two generations. They estimated the requirement for n-3 fatty

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

acids as the least amount of α-linolenic acid in the diet that resulted in a higher concentration of brain n-3 fatty acids. Using this methodology, they estimated a requirement of 2 g/kg food (or 0.4 percent of the total dietary ME). These experiments indicate that n-3 fatty acids are required; further study is needed to determine the amount below which functional impairment occurs.

Although a requirement has not been defined, it may be advisable to include a source of n-3 fatty acids when dietary oils such as sunflower or safflower are fed through two or more generations. Homeostatic mechanisms appear to sequester n-3 fatty acids to protect the rat from n-3 deficiency during short-term dietary deprivation.

SIGNS OF EFA DEFICIENCY

A deficiency of EFA results in a plethora of gross clinical signs, anatomical changes, and physiological changes as discussed by Holman (1968, 1970). Classical overt signs include diminished growth, dermatitis, caudal necrosis, fatty liver, impaired reproduction, increased triene:tetraene ratio in the tissue and blood, and increased permeability of skin, with impaired water balance. There are many other less noticeable but equally severe changes that have been reported, including kidney lesions and a decrease in urine volume (Sinclair, 1952), lipid-containing macrophages in the lung (Bernick and Alfin-Slater, 1963), increased metabolic rate (Wesson and Burr, 1931), decreased capillary resistance (Kramar and Levine, 1953), and aberrant ventricular conduction (Caster and Ahn, 1963).

The EFA content of the rat's diet prior to the feeding of EFA-deficient diets affects reserve stores of EFA (Guggenheim and Jurgens, 1944). Weanling rats rapidly exhibit signs of EFA deficiency after consuming a lipid-free diet for 9 to 12 weeks, while mature rats may require an extensive period of starvation, then refeeding of a lipid-free diet in order to develop EFA deficiency signs (Barki et al., 1947). Dermal signs resulting from EFA deficiency were reported after feeding adult rats a lipid-free diet for 35 weeks (Aaes-Jorgensen et al., 1958). Pups from dams fed EFA-deficient diets exhibit the most severe signs of EFA deficiency and usually die within 3 days to 3 weeks after birth, depending on the duration of the EFA feeding to the dam (Guggenheim and Jurgens, 1944; Kummerow et al., 1952). Other dietary factors [e.g., cholesterol (Holman and Peiffer, 1960) and 18:2(n-6) trans,trans fatty acid (Hill et al., 1979; Kinsella et al., 1979)] accelerate the development of EFA deficiency in rats fed EFA-deficient diets. Males may develop signs of EFA deficiency more quickly than females because males have a greater EFA requirement than do females (Morhauer and Holman, 1963; Pudelkewicz et al., 1968). Prevention of coprophagy will accelerate the development of EFA deficiency in rats fed lipid-free diets (Barnes et al., 1959a).

The relative capacities of n-6 and n-3 fatty acids to alleviate some of the deficiency signs are shown in Table 2-6. The classical signs of EFA deficiency appear to be more amenable to amelioration by n-6 fatty acids. It was hypothesized that the sole function of linoleic acid was as a precursor to arachidonic acid [20:4(n-6)] (Rahm and Holman, 1964; Yamanaka et al., 1980). Linoleic acid concentration is much lower than that of arachidonic acid in membrane lipids (Sprecher, 1991). However, linoleate-rich O-acyl sphingolipids have been identified in the epidermis of pigs and humans (Gray et al., 1978). The structures of pig and human epidermal acyl ceramide and acyl glucosyl ceramide were confirmed by Wertz et al. (1986). Hansen and Hensen (1985) fed EFA-deficient rats oleic [18:1(n-9)], linoleic [18:2(n-6)], columbinic [18:3(n-6)], α-linolenic [18:3(n-3)], and arachidonic [20:4(n-6)] acid esters and measured epidermal sphingolipids and trans-epidermal water loss. Only n-6 fatty acid esters restored the water barrier; however, among n-6 fatty acids, only linoleate was esterified in substantial amounts in the sphingolipids. The authors suggested that columbinate and arachidonate result in linoleate mobilization from other tissues for incorporation into the epidermal sphingolipids. The relationship between linoleate-containing epidermal sphingolipids and trans-epidermal water loss awaits further study.

DIGESTIBILITY OF LIPIDS

Most commercial sources of dietary lipid consist exclusively of triglycerides and contain a high percentage of 18-carbon fatty acids. During digestion, lipase activity releases fatty acids from the 1 and 3 positions of the triglyceride. Free fatty acids and 2-monoacyl glycerol are absorbed.

Digestibility differs among lipid sources. Crockett and Deuel (1947) demonstrated that lipid digestibility was reduced when the melting point of the lipid was greater than 50° C. Fatty acid composition also may affect digestibility. Mattson (1959) showed that digestibility was reduced with increasing content of simple triglycerides (same fatty acid at each position) composed of 18-carbon saturated fatty acids. Saturated fatty acids and monounsaturated trans-fatty acids of 18-carbon chain length or longer are poorly

TABLE 2-6 Relative Ability of n-6 and n-3 Fatty Acids to Alleviate Several Signs of EFA Deficiency in Rats

Sign

Ability to Alleviate Sign

Diminished growth

n-6 better able than n-3

Impaired reproduction

n-6 will alleviate; n-3 ineffective

Dermatitis

n-6 will alleviate; n-3 ineffective

Increased triene:tetraene ratio in tissues and blood

n-6 equal to n-3

Capillary fragility

n-6 equal to n-3

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

absorbed as free fatty acids but easily absorbed in the 2-monoacyl glycerol form (Linscher and Vergroeson, 1988). Increasing the number of double bonds in the fatty acid improved absorption; increasing the fatty acid chain length decreased absorption (Chen et al., 1985, 1987a). Very long-chain n-3 fatty acids were poorly hydrolyzed in in vitro experiments (Brockerhoff et al., 1966; Bottino et al., 1967) but were well absorbed in unesterified forms (Chen et al., 1985).

The rate of triglyceride digestion and subsequent absorption of fatty acids depends on the nature of the fatty acid (chain length and number and position of double bonds) and its molar frequency and position in the triglyceride (Apgar et al., 1987; Nelson and Ackman, 1988). Tables of fatty acid composition of dietary fats that include their positional specificity are available (Small, 1991).

Utilization of dietary lipid may be affected by other dietary components (Vahouny, 1982; Carey et al., 1983). Estimates of utilization by using the lipid source in the absence of other dietary ingredients may not correctly define the utilization of lipid in a complex diet. Nelson and Ackman (1988) reviewed the literature on the use of ethyl esters of lipid to study absorption and concluded that absorption and transport may not be identical to naturally occurring (triglyceride) lipid sources. The digestibility of many dietary lipids has been determined and certain of these experimental results are summarized in Table 2-7.

DIETARY LIPID CONCENTRATION

Better growth, reproduction, and lactation performance result when rats are fed diets in which lipid content is increased from 5 to 40 percent (Deuel et al., 1947). These observations and those of Forbes et al. (1946a,b) led Deuel (1950, 1955) to conclude that 30 percent lipid is the optimal dietary concentration. These response criteria alone are no longer considered sufficient to establish the optimal amount of dietary lipid.

Maximum growth also is associated with a decrease in longevity (French et al., 1953). Rats fed diets containing 10 or 20 percent corn oil had higher growth rates of a transplantable mammary tumor than those fed diets containing 2 or 5 percent corn oil (Kollmorgen et al., 1983). Rolls and Rowe (1982) demonstrated diminished growth and survival of pups suckled by dams fed high-lipid diets. Another study showed that rats consuming diets containing 3 or 20 percent lipid had superior reproduction (total numbers of offspring; percent of young weaned) compared to rats consuming diets containing 36 and 50 percent lipid (Richardson et al., 1964). It appears, then, that maximum growth should not be the only predictor of optimal dietary lipid content.

Data from the following experiments serve as justification for maintaining the previously recommended amount of 5 percent dietary lipid for both males and females during rapid growth and for adult females during reproduction and lactation (National Research Council, 1978). Swift and Black (1949) showed that the greatest improvement in energy retention occurred when dietary lipid content was increased from 2 to 5 percent; additional increments in energy retention were smaller when lipid content was above 5 percent. Deuel et al. (1947) reported that the greatest reduction in number of days required to reach puberty occurred when the percentage of lipid in the diet was increased from 0 to 5 percent. Relatively small changes occurred when lipid was greater than 5 percent of the diet. Burns et al. (1951) demonstrated that 5 percent lipid was satisfactory for absorption of carotene and vitamin A. Loosli et al. (1944) reported only slight improvement in weight gain of rat pups when lactating females were fed diets that contained more than 5 percent lipid. Furthermore, many lipids provide sufficient EFA when included in the diet at these concentrations. Reeves et al. (1993b: pp. 1941-1942) noted the following:

Bourre et al. (1989, 1990) used the method of dietary titration of 18:2(n-6) and 18:3(n-3) to determine linoleic and linolenic acid requirements, respectively. They used tissue saturation of 20:4(n-6) and 22:6(n-3) to make the assessments and concluded that 12 g of linoleic acid and 2 g of α-linolenic acid per kilogram of diet were the minimal requirements for the rat. This amounts to approximately 3 percent soybean oil in the diet. However, to reach the plateau for maximal concentrations of these fatty acids in many tissues of growing rats, an amount of fat equivalent to 5-6 percent soybean oil was required.

Lee et al. (1989) suggest that a n-6:n-3 ratio of five and a polyunsaturate:saturate (P:S) ratio of two are the points of greatest influence on tissue lipids and eicosanoid production. Bourre et al. (1989) suggested that the optimal n-6:n-3 ratio is between one and six. Soybean oil is a source of dietary fat that may meet these criteria. The oil contains about 14 percent saturated fatty acids, 23 percent monounsaturated fatty acids, 51 percent linoleic acid, and 7 percent linolenic acid. This gives a n-6:n-3 ratio of seven, and a P:S ratio of approximately four. The fatty acid composition of commercial lipid sources must be monitored because of the widespread practice of hydrogenation and the emergence of new cultivars with different fatty acid compositions.

CARBOHYDRATES

Although no definite carbohydrate requirement has been established, rats perform best with glucose or glucose precursors (such as other sugars, glycerol, glucogenic amino acids) in their diets. Diets containing 90 percent of dietary ME from fatty acids and 10 percent from protein were unable to support growth of young male rats. The substitution of neutral fats (soybean oil) for fatty acids or the addition of glycerol equivalent to that in the triglyceride allowed growth but not at rates equivalent to that achieved

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

TABLE 2-7 Digestibility of Some Selected Dietary Fats

Test Fat

Fat in Diet

Fat Digestibility, %

Test Animal and Method

Experiment 1 (Hoagland and Snider, 1943)

Butterfat

5%

87.9*

Male albino weanling rats

 

15%

90.2*

 

Mutton, tallow

5%

74.2

 

 

15%

85.0*¹

 

Cocoa butter

5%

63.3§

 

 

15%

81.6

 

Soybean oil

5%

98.7

 

 

15%

98.3

 

Corn oil

5%

97.5

 

 

15%

98.3

 

Coconut oil

5%

98.9

 

 

15%

96.5

 

Experiment 2 (Crockett and Devel, 1947)

Margarine (mp = 34° C)

15%

97.0

Adult female rats; calculations similar to Experiment 1

Bland lard (mp = 43° C)

15%

94.3

 

Hydrogenated lard (mp = 55° C)

15%

63.2*

 

Experiment 3 (Apgar et al., 1987)

Corn oil

5%

92.9*

Male weanling Sprague-Dawley rats; calculations similar to Experiment 1

 

10%

96.7

 

 

20%

96.3

 

Cocoa butter

5%

58.8

 

 

10%

60.3

 

 

20%

71.7

 

Experiment 4 (Chen et al., 1987b)

Corn oil

170 mg

100.0

Adult male Wistar rats, 250–350 g; lipid emulsion infused via duodenal catheters; lipid collected as lymph from thoracic duct catheters; method measures absorption; corn oil set as control = 100%

Palm kernal oil

170 mg

82.3

 

Cocoa butter

130 mg

63.0*

 

Experiment 5 (Chen et al., 1989)

Corn oil

170 mg

100.0

Same as Experiment 4

Menhaden oil

170 mg

56.6*

 

Max EPA® (eicosapentanoic acid-containing fish oil concentrate)

170 mg

47.1*

 

NOTE: Different symbols following measurements in the "Fat Digestibility" column indicate that digestibility mean differs significantly (P < 0.5).

with a 78 percent starch diet (Konijn et al., 1970; Carmel et al., 1975). When carbohydrate-free diets containing 80 percent of dietary ME from fatty acids and 20 percent from protein were fed, rats were capable of weight gain, but growth increased when the diet was supplemented with glucose or neutral fats (Goldberg, 1971; Akrabawi and Salji, 1973). Rats fed low-protein (10 percent of dietary ME), carbohydrate-free diets were hypoglycemic and demonstrated abnormal glucose tolerance curves (Konijn et al., 1970; Carmel et al., 1975); rats fed higher protein (18 percent of dietary ME), carbohydrate-free diets had normal blood glucose concentrations but still demonstrated slightly abnormal glucose tolerance curves (Goldberg, 1971). When neutral fats replaced fatty acids in carbohydrate-free diets (20 percent of dietary ME from protein), growth did not improve when rats were allowed to eat ad libitum but was greater with diets containing the neutral fats when rats were meal-fed once daily (Akrabawi and Salji, 1973).

Over wide ranges of dietary fat:carbohydrate ratios (0.2 to 1.4, ME basis), the heat increment was found to be constant at 47.5 percent of ME, indicating that carbohydrate and lipid are used with equal efficiency (Hartsook et al., 1973).

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

A large number of carbohydrates can be used by the rat. Those most commonly used in rat diets include glucose, fructose, sucrose, starch, dextrins, and maltose. (See "Fiber" section for a discussion of fiber sources.) These carbohydrate sources support similar rates of growth; however, in diets adequate in other respects, fructose (and sucrose as a source of fructose) can lead to several abnormalities when compared to glucose or glucose-based polymers. Because the initial metabolic steps in fructose utilization are mediated by fructokinase and aldolase B, fructose metabolism bypasses the control of glycolysis at phosphofructokinase and, thus, increases the flux through glycolysis. Feeding of fructose or sucrose leads to increases in liver weight, liver lipid, liver glycogen, and activities of liver lipogenic enzymes: glucose-6-phosphate dehydrogenase, malic enzyme, ATP citrate lyase, and fatty acid synthetase (Worcester et al., 1979; Narayan and McMullen, 1980; Michaelis et al., 1981; Cha and Randall, 1982; Herzberg and Rogerson, 1988a,b). Hypertriglyceridemia associated with fructose feeding has been attributed to both increased hepatic synthesis (Herzberg and Rogerson, 1988b) and decreased peripheral clearance (Hirano et al., 1988) of triglyceride. Increases in kidney weight and nephrocalcinosis also were observed when diets containing 55 percent sucrose (Kang et al., 1979) or 63 percent fructose (Koh et al., 1989) were fed. Starch was more easily metabolized than sucrose by rats fed low-protein diets (12.5 percent casein; Khan and Munira, 1978) or protein-free diets (Yokogoshi et al., 1980). Essential fatty acid deficiencies may be exacerbated by high sucrose diets (Trugnan et al., 1985).

Poor performance and cataract formation occurred in rats fed lactose or galactose (Day and Pigman, 1957); diarrhea was also observed in weanling rats fed α- or β-lactose (Baker et al., 1967). Xylose is toxic to rats; lens opacity and diarrhea were observed in rats fed diets containing 15 percent or more xylose (Booth et al., 1953). Sorbose, a slowly absorbed sugar, decreases feed intake and growth rate when added to rat diets but appears to supply the rat with a significant amount of energy, presumably, in part, as end products of hindgut fermentation (Furuse et al., 1989). Mannose (up to 8 percent of the diet) improved growth of rats fed a carbohydrate-free diet, suggesting that it can be metabolized, at least in low concentrations (Keymer et al., 1983). Leucrose [D-glucosyl-α(1–5)D-fructopyranose, a bond isomer of sucrose] appears to be metabolized as well as sucrose (Ziesenitz et al., 1989). Of the sugar alcohols, lactitol and xylitol decrease feed intake and growth when added to diets at 16 percent of dry matter, although rats appear to adapt, at least in part, to these two sugar alcohols within 2 weeks (Grenby and Phillips, 1989). Sorbitol can be metabolized by rat liver (Ertel et al., 1983).

A series of experiments defined the rats' need for carbohydrate for successful reproduction. In all these experiments a low-protein diet was required in order to demonstrate the need for carbohydrate. Rats fed carbohydrate-free diets [ME = 4.25 kcal/g (17.8 kJ/g), 12 percent of dietary ME from protein] were unable to maintain pregnancy. Although 78 percent of embryos were normal following 6 days of gestation for rats fed carbohydrate-free diets (compared to 91 percent for controls), only 25 percent (control = 89 percent) were classified as normal following 8 days and 0.6 percent (control = 90 percent) following 10 days of the carbohydrate-free diet. By day 12 of gestation, all embryos from rats fed carbohydrate-free diets had been resorbed (Taylor et al., 1983). A carbohydrate-free diet [ME = 4.11 kcal/g (17.2 kJ/g), 10 percent of dietary ME from protein] fed to gestating rats had to be supplemented with 4 percent carbohydrate (as glucose or an equivalent amount of glycerol) to maintain pregnancy to term, 6 to 8 percent glucose to produce normal maternal weight gain and normal fetal weight, and 12 percent glucose to produce fetal liver glycogen concentrations one-half as large as controls fed a 62 percent carbohydrate diet (Koski et al., 1986). Survival was poor for pups from dams fed low-glucose diets (9.5 percent protein) from day 9 of gestation through day 7 of lactation. From dams fed 6 percent or less glucose, no pups survived 7 days postpartum. From those dams fed 8 or 12 percent glucose, pup survival at 7 days was 6 and 30 percent, respectively. Control pups whose dams were fed 62 percent glucose diets had 93 percent survival (Koski and Hill, 1986). Poor rat pup survival caused by feeding dams a low (4 percent)-glucose diet (10 percent of calories from protein) could be markedly improved by feeding dams a high-carbohydrate diet for the final 2 days of gestation and through lactation (Koski and Hill, 1990). Lactation is not supported by carbohydrate-free diets. Milk production can occur for rats fed 6 percent glucose diets, but the milk contains low concentrations of carbohydrate and lipid, which is associated with retarded postnatal growth of pups (Koski et al., 1990). In general, fructose appears to be an adequate source of carbohydrate in diets fed to pregnant rats. However, when low (4 percent)-carbohydrate diets are fed during lactation, neither fructose- nor glycerol-supplemented diets will support deposition of as much fetal liver glycogen as 4 percent glucose diets (Fergusson and Koski, 1990). Essential fatty acid deficiencies may be more likely to occur in gestating rats fed sucrose-based (61.5 percent) diets than in those fed glucose-based diets (Cardot et al., 1987).

PROTEIN AND AMINO ACIDS

In establishing the protein requirements at different stages of life, three factors must be considered: (1) energy concentration in the diet, (2) amino acid composition of the protein (see Appendix Table 2), and (3) bioavailability of the amino acids.

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

PROTEIN AND GROWTH

Protein requirements are most accurately expressed as a protein:energy ratio to take into account the large differences in energy concentration that may occur among diets. In earlier studies that used egg protein as a highly digestible and balanced source of amino acids, the minimal amount of protein required for maximum weight gain in young rats was 25 to 31 mg/kcal GE (6.0 to 7.4 mg/kJ GE) (Hamilton, 1939; Barnes et al., 1946; Hoagland et al., 1948; Mitchell and Beadles, 1952). Similar results were obtained with pure amino acid mixtures (Rose et al., 1948) and with casein supplemented with sulfur amino acids (Breuer et al., 1963; Hartsook and Mitchell, 1956); as expected, greater amounts of protein were required when unsupplemented casein was used (Yoshida et al., 1957). These data indicate that a dietary protein concentration of 10 to 15 percent is required for maximum growth when a low-fiber diet containing a balanced amino acid pattern, 5 percent fat and 4 kcal ME/g (17 kJ ME/g), is fed. The 1978 edition of this report concluded that the protein requirement for maximum growth of the rat is 12 percent when highly digestible protein of balanced amino acid pattern is used.

Computation of the percentage of dietary protein required for maximum growth when the diet contains a mixture of proteins requires that both the content and bioavailability of the amino acids in the different proteins be considered. Historically, most methods have assumed that protein quality is constant over a range of dietary protein concentrations. For example, in the slope-ratio procedure, test proteins are fed at several concentrations and the value of a protein is determined by linear regression (Hegsted and Chang, 1965). However, the value of protein as used for maintenance differs from the value of protein as used for growth, and the difference is not linear (Phillips, 1981; Finke et al., 1987a,b, 1989; Mercer et al., 1989; Schulz, 1991). Finke et al. (1987a,b, 1989) used a four-parameter logistical model to describe the effect of utilization of protein from a variety of sources on growth rates and nitrogen gain of young rats (Sprague-Dawley strain). Although 1.11 times more casein than lactalbumin was required to achieve 95 percent of the maximum nitrogen gain, 1.43 times more casein than lactalbumin was required to achieve maintenance or zero nitrogen gain. In another comparison, twice as much soybean protein as lactalbumin was required to support 95 percent of the maximum nitrogen gain, but only 1.54 times as much soybean protein was required to meet maintenance needs. Thus, use of nonlinear models to describe an animal's growth response to dietary protein or protein mixtures indicates that the relative value of protein is not constant and that the value of a protein for maintenance may not predict its value for growth. This may be an expression of the different amino acid patterns required for maintenance versus growth. Finally, nonlinear response models, in which marginal efficiency (response per unit input) changes with response level, seem to be more accurate than linear (constant marginal efficiency, i.e., broken stick) models in predicting the relative capacity of proteins to support maximum gain or nitrogen retention.

In determining the relative value of proteins to support growth using nonlinear models, it is important to include test diets that produce a maximal response or response plateau so that the "diminishing-returns" portion of the response curve can be defined. The weight gain response per unit of protein added (diminishing-returns) is expected to vary with type of dietary protein. By applying a saturation kinetics model, Mercer et al. (1989) used data from Peters and Harper (1985) to demonstrate that 19 percent unsupplemented casein (about 17 percent crude protein) in the diet was necessary to give 95 percent of the maximum growth response and that about 26 percent unsupplemented casein (23 percent crude protein) was needed to produce 100 percent of the maximum growth response. Given that 1.11 times as much casein as lactalbumin is required to support maximum gain, the requirement for 95 percent maximum growth response of rats fed lactalbumin is about 15 percent crude protein. This concentration is adopted as the protein requirement for rats fed a diet containing a balanced protein source and 4 kcal ME/g (17 kJ ME/g). Additional studies with nonlinear-response models and rapidly growing rat strains are needed to refine this requirement. In practice, natural-ingredient diets that contain 18 to 25 percent crude protein have supported high rates of postweaning growth.

PROTEIN AND MAINTENANCE

Although protein requirement declines with age after weaning, the problem has not been studied extensively (Forbes and Rao, 1959; Hartsook and Mitchell, 1956). Hartsook and Mitchell (1956) estimated from carcass analyses that the requirement declined from about 28 percent of the diet (14 mg net protein1/kJ GE) at 30 days of age to 10 percent (about 5 mg net protein/kJ GE) at 50 days of age. The higher value agrees with that calculated from analysis of rat milk (Luckey et al., 1954). Using carcass nitrogen as the dependent variable, Sheehan et al. (1981) found that a dietary protein concentration averaging 4 percent was required for 12-month-old Sprague-Dawley female rats. Baldwin and Griminger (1985) were able to maintain nitrogen balance in 12- and 24-month-old male rats with an amino acid mixture simulating casein provided in the diet at 4.5 percent to 6.0 percent. Dibak et al. (1986) found that minimal concentrations of casein and wheat

1  

"Net protein" is protein retained in the body for use in maintenance and production.

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

gluten of 4.86 percent and 7.12 percent were required for positive nitrogen balance of 6-month-old male rats. Therefore the maintenance requirement is about 5 percent protein when the source is of high-quality. In natural-ingredient diets a concentration of 7 percent crude protein is suggested by Bricker and Mitchell (1947).

AMINO ACIDS AND GROWTH

As with estimation of the protein requirement, it is necessary to consider the energy concentration of the diets when estimating the amount of each amino acid needed to support growth (Wretlind and Rose, 1950; Rosenberg and Culik, 1955). The sample amino acid patterns given in Table 2-8 are intended for use in a diet that contains 5 percent fat. Extrapolation of the requirements to diets of different caloric densities can probably be safely made by maintaining a constant amino acid:energy ratio and allowing for variations in amino acid digestibility (Kornberg and Endicott, 1946; Guthneck et al., 1953; Schweigert and Guthneck, 1953, 1954; Lushbough et al., 1957; Rogers and Harper, 1965).

Amino acid requirements are related to dietary protein concentration (Grau, 1948; Almquist, 1949; Brinegar et al., 1950; Becker et al., 1957; Bressani and Mertz, 1958). In general, the requirement for an amino acid, expressed as a percent of the diet, tends to increase as dietary protein

TABLE 2-8 Examples of Amino Acid Patterns Used in Studies with Purified Diets Containing 5 Percent Fat

 

Amount

 

Amino Acid

g/kg diet

mg/g nitrogen

Arginine

4.3

254

Histidine

2.8

163

Isoleucine

6.2

367

Leucine

10.7

626

Lysine

9.2

540

Methionine

6.5

381

Cystine

3.3

190

Phenylalanine

6.8

397

Tyrosine

3.4

198

Threonine

6.2

366

Tryptophan

2.0

115

Valine

7.4

435

Alanine

4.0

235

Aspartic acid

4.0

235

Glutamic acid

40.0

2,351

Glycine

6.0

353

Proline

4.0

235

Serine

4.0

235

Asparagine

4.0

235

NOTE: This pattern was demonstrated by Gahl et al. (1991) to support weight gain of 6 g/day for 65 g rats over a 21-day period.

concentration increases but may remain constant or decrease slightly when expressed as percent of protein (Forbes et al., 1955; Bressani and Mertz, 1958).

As with protein quality assessment, a nonlinear model best describes the growth response of rats fed varying amounts of amino acids (Yoshida and Ashida, 1969; Heger and Frydrych, 1985; Gahl et al., 1991). A nonlinear model most accurately describes the diminishing-returns portion of the response curve. Heger and Frydrych (1985) and Gahl et al. (1991) used different nonlinear models to assess the maintenance and maximum response of young rats to dietary concentrations of individual amino acids. Gahl et al. (1991) added incrementally a mixture of amino acids to the diet to obtain a growth response rather than adding a test amino acid to a diet devoid of that test amino acid to obtain a growth response. The test amino acid was incorporated into the amino acid mixture at a concentration 35 percent below that of the other amino acids. Addition of incremental amounts of the mixture to the diet was used to obtain a growth response to the test amino acid. This approach ensured that the limiting amino acid remained first limiting. Figure 2-2 shows the response curves for nitrogen gain as a function of lysine and sulfur amino acid intake. These curves were generated from data reported by Gahl et al. (1991) and Benevenga et al. (1994). Similar curves for each indispensable amino acid were used to generate the requirement estimated to support growth (Table 2-9). Estimates were also made for the amount of amino acid required for nitrogen gain based on carcass nitrogen gain. The estimated amino acid requirements based on nitrogen gain were 1.1 to 1.7 times those required for weight gain. Because weight gain per se does not reflect a change in body composition, nitrogen gain may be a more dependable response criterion. The substitution value of tyrosine for phenylalanine and cystine for methionine could not be estimated from the results used to generate the requirements shown in Table 2-9. The replacement of phenylalanine by tyrosine was determined by Stockland et al. (1971) by comparing the growth of rats fed diets containing phenylalanine alone as part of an amino acid mix and with five phenylalanine:tyrosine ratios. They found the requirement for phenylalanine alone was 0.70 percent of the diet, while that for phenylalanine plus tyrosine was 0.69 percent of the diet. Tyrosine without phenylalanine would not support growth, and at least 0.38 percent L-phenylalanine had to be in the diet for tyrosine to be of benefit. Tyrosine could provide 45 percent of the aromatic amino acid requirement. Estimates of the replacement value of cystine for methionine have been made (Sowers et al., 1972; Stockland et al., 1973). The requirement for methionine alone was 0.49 percent of the diet and cystine could replace 48 to 58 percent of methionine. The diet had to have at least 0.17 percent methionine for cystine to be of benefit. Rat growth was between 4 and 5.5 g/day in these studies. The estimates

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

FIGURE 2-2 Nitrogen gain response curves generated using the parameter estimates for the logistic equation as described by Gahl et al. (1991) for rats fed diets limiting in one indispensable amino acid. Each data point represents the mean (SEM) for four rats.

of these replacement values may not be applicable to rats with high growth potential such as those used by Gahl et al. (1991).

The estimates for indispensible amino acids reported in earlier editions of this publication are, on average, 23 percent lower than the current estimates (see Table 2-9 for comparisons). The reasons for this difference is the methods used to estimate the requirement. Estimates reported earlier (National Research Council, 1972, 1978) were based on significant differences between means by use of a multiple-range test, which produced values similar to results obtained with broken-stick models. Estimates made in this way will be lower than those made by the four-parameter logistical model and, as observed in the guinea pig (Chapter 5), may underestimate the requirement for indispensable amino acids by about 20 percent. A reanalysis of the original data of Benevenga et al. (1994) using these two analytical approaches gave the following requirement estimates, as grams per kilogram of diet, for 95 percent of Rmax (maximum rate) for growth versus multiple-range tests of group

TABLE 2-9 Comparison of National Research Council Estimates of Indispensable Amino Acid Requirements of Rats for Growth

 

Amount, g/kg diet

 

 

L-Amino Acid

NRC, 1972

NRC, 1978

This Report

Arginine

6.0

6.0

4.3

Histidine

3.0

3.0

2.8

Isoleucine

5.5

5.0

6.2

Leucine

7.5

7.5

10.7

Lysine

9.0

7.0

9.2

Methioninea

6.0

6.0

9.8

Phenylalanineb

8.0

8.0

10.2

Threonine

5.0

5.0

6.2

Tryptophan

1.5

1.5

2.0

Valine

6.0

6.0

7.4

NOTE: Comparison is based on diet with 90 percent dry matter.

a One-half of L-methionine may be replaced by L-cystine (see NRC, 1978).

b One-half of L-phenylalanine may be replaced by L-tyrosine (see NRC, 1978).

means, respectively: arginine, 4.3, 2.7; histidine, 2.8, 2.3; isoleucine, 6.2, 5.3; leucine, 10.7, 7.9; lysine, 9.2, 7.4; total sulfur amino acids, 9.7, 7.5; total aromatic amino acids, 10.1, 7.2; threonine, 6.2, 4.5; tryptophan, 2.0, 1.6; valine, 7.4, 7.5 (M. Gahl and N. J. Benevenga, University of Wisconsin, personal communication, 1994).

The difference between the total nitrogen requirement and the essential amino acid nitrogen requirement should be made up with mixtures of nonessential amino acids. Stucki and Harper (1962) reported that amino acid diets that contained both essential and nonessential amino acids supported greater growth in rats than diets that contained only essential amino acids. Ratios of essential amino acid nitrogen to nonessential amino acid nitrogen of 0.5 to 4.0 were satisfactory in diets that contained 9.4 to 15.0 percent protein. Arginine, asparagine, glutamic acid, and proline must be included in the nonessential amino acid mixture to support maximum growth (Breuer et al., 1964; Hepburn and Bradley, 1964; Ranhotra and Johnson, 1965; Rogers and Harper, 1965; Adkins et al., 1966; Breuer et al., 1966; Newburg et al., 1975). The responses to these amino acids are presumed to reflect the inability of the rat to synthesize the quantities required for rapid growth. However, as pointed out by Breuer et al. (1964) and Crosby and Cline (1973), rats appear to adapt to diets devoid of certain of the nonessential amino acids and resume nearly maximum growth.

It is evident that specific requirements for the nonessential amino acids cannot be given because of the metabolic relationships among them. Therefore, the values given in Table 2-8 represent a pattern that has been used successfully in studies with purified diets. The value of 40.0 g/kg for glutamic acid is based on the data of Hepburn and

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

Bradley (1964) and Breuer et al. (1964); that for asparagine is 4.0 g/kg, as found by Breuer et al. (1966) to be required for maximum growth. Proline at 4 g/kg is the concentration used by Adkins et al. (1966). To raise the dietary crude protein limit to that planned, a mixture of alanine, glycine, and serine can be used.

Amino acid imbalances and antagonisms can result in increased requirements for individual amino acids, an area reviewed by Harper et al. (1970) and Benevenga and Steele (1984). The effects of imbalances and antagonisms on the requirement for maximum growth may be small or nonexistent if dietary protein concentration is adequate, but the effect in diets that contain suboptimal concentrations of protein may be considerable. The immediate response of an imbalance is decreased food intake (Harper et al., 1970).

AMINO ACIDS AND MAINTENANCE

The determination of amino acid requirements for adult rats is difficult because of the flat dose-response curves that occur for many amino acids (Smith and Johnson, 1967; Said and Hegsted, 1970). The indispensable amino acid requirements for maintenance of adult rats are based on reports by Benditt et al. (1950), Smith and Johnson (1967), and Said and Hegsted (1970). The data for each amino acid from these reports were averaged and are expressed on the basis of metabolic body size as follows (mg/BWkg0.75): histidine, 23.5; isoleucine, 90.4; leucine, 53.1; lysine, 32.2; methionine, 67.2; phenylalanine, 54.5; threonine, 53.1; tryptophan, 15.6; and valine, 67.1. Assuming a basal energy requirement of 117 kcal/BWkg0.75 (490 kJ/BWkg0.75) for a 300-g rat, these data have been incorporated into Table 2-2 as g/kg of diet.

GESTATION AND LACTATION

Nelson and Evans (1953) reported that 5 percent protein as unsupplemented casein was the minimum amount needed to support reproduction, while optimal performance occurred at 15 to 20 percent. Later, Nelson and Evans (1958) reported that 18 percent casein supported maximum growth in suckling young but that 24 percent was required to provide for weight gain in the dam during lactation. Supplementary cystine was added to both diets. Sucrose was used as the source of carbohydrate, a factor that may have influenced food intake, and thus protein utilization, at the lower protein concentrations in their studies (Harper and Elvehjem, 1957; Harper and Spivey, 1958). Gander and Schultze (1955) reported that 15 to 16 percent protein derived from a combination of casein, methionine, and mixed cereals supported reproduction and lactation in rats. More recently, Turner et al. (1987) compared the protein requirements for growth and reproduction in Sprague-Dawley female rats. Protein intakes of 8.6 percent (as whole-egg powder) delayed puberty but met the needs for subsequent reproductive function except pup weight. Concentrations of 15.6 percent (the highest used in their study) were needed for maximum growth from weaning to breeding. Subsequent response surface analysis revealed that a concentration of 21 percent would have been needed for maximum responses with a minimum concentration of between 9 to 11 percent whole-egg powder. It seems that the net protein requirement for gestation and lactation as a percentage of the diet does not differ significantly from that for growth of weanling rats (see Table 2-2).

The amino acid requirements for gestation and lactation have not been studied in depth. A concentration of 0.11 percent tryptophan in diets that contained 1 or 2 percent nitrogen (6.25 to 12.5 percent crude protein) was found to be adequate to support normal pregnancy in rats (Lojkin, 1967). Nelson and Evans (1958) reported that the sulfur amino acid requirement for lactation was 1 percent of the diet, one-half of which could come from cystine. Newburg and Fillios (1979) reported an apparent requirement for dietary asparagine in pregnant rats because its omission from the diet may have been associated with impaired neurological development of pups. Data are inadequate at this time to conclude that the concentration of amino acids in the diet required to support gestation and lactation exceed that required for growth in young rats.

SIGNS OF PROTEIN DEFICIENCY

Protein deficiency in young rats results in reduced growth, anemia, hypoproteinemia, depletion of body protein, muscular wasting, emaciation, and, if sufficiently severe, death. In adults a loss of weight and body nitrogen occurs (Cannon, 1948), and chronic deficiency may lead to edema (Alexander and Sauberlich, 1957). Estrus becomes irregular and may cease, fetal resorption occurs, and newborns are weak or dead. A lack of protein for pregnant and lactating rats may result in offspring that are stunted in growth (Hsueh et al., 1967) and have reduced concentrations of DNA and RNA in various tissues (Zeman and Stanbrough, 1969; Ahmad and Rahman, 1975). Low-protein diets also result in reduced food intake (Black et al., 1950). The reproductive capacity of the male is impaired by consumption of diets with inadequate concentrations of protein (Goettsch, 1949).

Removal of a single indispensable amino acid results in an immediate reduction in feed consumption, a situation that can return to normal within a day after replacement of that amino acid. A lack of an indispensable amino acid in the diet tends to be reflected in the concentration of the amino acid in the blood plasma (Longnecker and Hause, 1959; Kumta and Harper, 1962). Lack of specific amino acids has been reported to manifest as specific signs:

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×
  • lack of tryptophan—cataract formation, corneal vascularization, and alopecia (Cannon, 1948; Meister, 1957);

  • lack of lysine—dental caries, impaired bone calcification, blackened teeth, hunched stance, and ataxia (Harris et al., 1943; Cannon, 1948; Kligler and Krehl, 1952; Bavetta and McClure, 1957; Likins et al., 1957; Meister, 1957);

  • lack of methionine—fatty liver (Follis, 1958);

  • lack of arginine—increased excretion of urinary urea, citrate, and orotate (Milner et al., 1974) and increased plasma and liver glutamate and glutamine (Gross et al., 1991).

The accumulation of a porphyrin-like pigment on the nose and paws has been observed in rats deficient in tryptophan, methionine, and histidine (Cole and Robson, 1951; Forbes and Vaughan, 1954), but this condition is also observed in other deficiency states.

MINERALS

Recommended mineral intakes have often been based on estimates of the amounts of minerals that promote maximum growth in short-term studies with little consideration of potential toxicological problems and of nutrient interactions. However, high safety margins added to recommended intakes of one mineral may affect requirements for another. For example, ingestion of extra calcium has been found to decrease absorption of iron and zinc (Greger, 1982, 1989), and excess intake of manganese may decrease iron utilization as these two elements are antagonistic (Davis et al., 1990).

Because of concerns about the consequences of feeding purified diets to rats for more than 6 months in studies on aging, hypertension, and cancer, a separate discussion of the role of dietary minerals in the development of nephrocalcinosis follows the discussions of the individual minerals.

MACROMINERALS

Six mineral elements occur in living tissues in substantial amounts and are commonly called ''macrominerals" to distinguish them from mineral elements present in lesser quantities and designated as "trace elements." Although this distinction arose historically because of difficulties in the accurate analysis of the latter (Underwood and Mertz, 1987), it is still of some practical use because the trace elements are typically added to diets in premixes rather than via the formulated proportions of the primary ingredients.

Calcium and Phosphorus

The dietary requirements for calcium and phosphorus are closely linked and depend on the availability of each mineral from the dietary source. In the 1978 edition of Nutrient Requirements of Laboratory Animals , the recommendation for the minimal concentration of calcium and phosphorus to maximize bone calcification during growth was 5 and 4 g/kg, respectively. This gives a Ca:P molar ratio of 0.96. However, Bernhart et al. (1969) had shown previously that adequate mineralization could be accomplished with smaller amounts of dietary calcium and phosphorus. They held the dietary molar ratio of Ca:P to 0.91 and noted that Sprague-Dawley rats attained maximum weight gain when fed diets containing as little as 1.6 g Ca/kg, but the rats required at least 3.5 g Ca/kg to attain maximum body accumulation of calcium. In the same experiment, the amount of dietary phosphorus required to maximize body weight was ³1.5 g/kg, and to maximize body phosphorus concentration it was ³3.5 g/kg. Several groups of investigators have observed normal growth and tissue concentrations of calcium and phosphorus in bones and other tissues of rats (RIVm:TOX and Sprague-Dawley strains) fed from 2.85 to 3.2 g P/kg diet (Kaup et al., 1991b; Shah and Belonje, 1991). Ritskes-Hoitinga et al. (1993) fed rats 2.0 and 4.0 g P/kg diet with 5.2 g Ca/kg diet and 0.6 g Mg/kg diet for three successive generations. They found that 2.0 g P/kg diet sustained reproduction but delayed bone mineralization in offspring. Kaup et al. (1991b) noted that growth and bone calcium concentrations in male Sprague-Dawley rats fed 2.8 g P/kg diet increased as dietary calcium concentrations increased from 2.1 to 3.4 g Ca/kg diet but were similar for rats fed 3.6 and 4.4 Ca/kg diet.

These studies suggest that dietary concentrations of calcium and phosphorus at 3.5 and 3.0 g/kg, respectively, with a molar ratio 0.9, would be sufficient. However, other studies have shown that a larger Ca:P ratio is required to prevent specific abnormalities in Sprague-Dawley rats. Draper et al. (1972), for example, showed that a molar ratio of 1.5 was better than 0.8 for the prevention of osteoporosis.

Variations in calcium and phosphorus intake have been associated with soft tissue calcification, especially nephrocalcinosis, in rats. However, a variety of other dietary factors can influence the development of nephrocalcinosis.

The recommendations for calcium and phosphorus intakes reflect the somewhat conflicting needs to maximize growth and maximize bone calcium and phosphorus concentrations without inducing nephrocalcinosis. A Ca:P molar ratio of 1.3 is needed to prevent nephrocalcinosis in female rats. However, a dietary phosphorus concentration of more than 2.0 g/kg diet is needed to prevent inadequate bone mineralization in successive generations. Therefore, the recommended concentrations of dietary calcium and

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

phosphorus under normal conditions for growth and maintenance of nonlactating rats are 5.0 and 3.0 g/kg, respectively.

Considering the demands placed on the dams during lactation, it might be prudent to increase the amount of dietary calcium and phosphorus during this period. It has been estimated that a lactating dam will produce 70 mL of milk per day (Brommage, 1989). This amounts to approximately 200 mg calcium and 140 mg phosphorus transferred to milk in a 24-hour period. Brommage (1989) showed that this demand for calcium and phosphorus was compensated for by increases in food intake and dramatic increases in intestinal absorption of these minerals. Ritskes-Hoitinga et al. (1993) showed that 2 g P/kg diet, compared to 4 g P/kg, sustained reproductive performance but delayed growth and bone mineralization in successive generations of female rats. To help relieve some of the stress of lactation, it is recommended that the dietary calcium and phosphorus be increased by 25 percent (6.3 g Ca, 3.7 g P/kg diet) during this period. This could be especially helpful for those females used in continuous-breeding programs. It should be mentioned, however, that when lactating and nonlactating rats were given a choice of diets containing various concentrations of calcium and phosphorus, the lactating rats chose a diet that contained a Ca:P molar ratio of 2, whereas the nonlactating rats chose a diet that contained a ratio of 1.5 (Brommage and DeLuca, 1984).

Factors Affecting Calcium and Phosphorus Requirements Certain dietary factors can affect the biological availability of calcium and phosphorus and thus affect requirements for them in the diet. When these factors are present in the diet, appropriate adjustments to the dietary concentrations of calcium or phosphorus should be made. Low concentrations of vitamin D in the diet will reduce the absorption of calcium. Kaup et al. (1990) showed reduced phosphorus absorption in rats fed 10 g Ca/kg diet when compared to those fed only 2.5 g/kg. High dietary phosphorus will in turn reduce the apparent absorption of calcium (Schoenmakers et al., 1989) but may depend on the concentration of dietary magnesium (Bunce et al., 1965). Increasing the amount of fat in the diet from 5 to 20 percent reduced phosphorus absorption in older rats but not young rats (Kaup et al., 1990). High-fat diets also have been shown to decrease the absorption of calcium in mature rats but not young rats (Kane et al., 1949; Kaup et al., 1990). Calcium absorption is decreased in rats fed diets containing sources of oxalate (Weaver et al., 1987; Peterson et al., 1992), and phosphorus availability is reduced in diets containing phytate (inositol hexaphosphate) (Taylor, 1980; Moore et al., 1984). Some protein sources, including soybean protein isolates and other plant products, contain phytate. Phosphorus availability from these products should be considered when they are used in an animal's diet.

Other factors enhance calcium or phosphorus absorption. Bergstra et al. (1993) showed that the absorption of phosphorus was stimulated in rats fed diets high in fructose. Dietary disaccharides such as lactose and sucrose stimulate calcium absorption in rat intestine (Armbrecht and Wasserman, 1976). However, dietary lactose was better than sucrose in improving bone growth and development in intact vitamin D-deficient rats (Miller et al., 1988). Buchowski and Miller (1991) showed that 20 percent lactose added to diets containing a variety of calcium sources such as calcium carbonate, milk, and cheese significantly increased the amount of calcium in the tibia compared to rats fed diets without lactose. The enhancement was evident in 21-day-old rats fed the diets for 8 days but not in older rats.

Protein sources contain varying amounts of phosphorus, and the bioavailability of this phosphorus may not be the same in all sources. It is advisable, therefore, to analyze the source before using it in the diet and to be aware of whether the phosphorus is biologically available. Although few data are available in rats (Moore et al., 1984), data obtained for common feedstuffs in other species may be useful (National Research Council, 1988, 1994).

Signs of Calcium and Phosphorus Deficiency Boelter and Greenberg (1941, 1943) fed 0.1 g Ca/kg diet to young rats for 8 weeks. The rats exhibited growth retardation, decreased food consumption, increased basal metabolic rate, reduced activity and sensitivity, osteoporosis, rear leg paralysis, and internal hemorrhage. Males failed to mate; females did not lactate properly. Day and McCollum (1939) fed 0.17 g P/kg diet to young rats. The animals survived up to 9 weeks and exhibited lethargy, pain, and cessation of bone growth with massive losses of calcium in urine.

When Sprague-Dawley rats were fed diets with moderate restrictions in calcium (2.1 to 3.4 g Ca/kg diet) for 28 days, the rats grew normally but had reduced bone weight and bone calcium concentrations (Kaup et al., 1991b). Improved calcium absorption and reduced urinary calcium losses allowed the rats to compensate for these marginally low calcium intakes, but these mechanisms would not be sufficient to prevent growth retardation if lesser amounts of calcium had been fed.

Chloride

Voris and Thacker (1942) obtained a reduction of 25 percent in growth in a 10-week, paired-feeding comparison of rats fed 0.2 g Cl/kg diet as compared to 2.9 g Cl/kg diet. Picciano (1970) found no increase in weight gain of young rats fed 2 g Cl/kg compared to rats fed 0.5 g Cl/kg. Miller (1926) reported that 5 mg/day (0.17 to 0.25 g Cl/kg diet) was acceptable for reproduction and lactation. On the basis of these limited studies, the estimated requirement is 0.5 g

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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Cl/kg diet, but future work may indicate this can be reduced.

Signs of Chloride Deficiency The rat tenaciously conserves its supply of tissue chloride by reducing drastically the urinary excretion within hours of consuming a diet deficient in the element. As a result, the signs of deficiency develop slowly. Rats fed 0.12 g Cl/kg diet exhibited poor growth, reduced efficiency of feed utilization, reduced blood chloride, reduced urinary chloride excretion, and increased blood CO2 content (Greenberg and Cuthbertson, 1942). Rats fed 0.5 g Cl/kg diet for more than 70 days had reduced growth, reduced tissue chloride concentrations, and extensive kidney damage; but some rats survived for more than a year (Cuthbertson and Greenberg, 1945).

Signs of Chloride Toxicity Rats are also relatively insensitive to excess dietary chloride as judged by growth and tissue composition. Dahl (salt sensitive) and Sprague-Dawley rats fed excess chloride (15.6 to 26.6 g Cl/kg diet) as sodium or potassium chloride grew normally with unchanged chloride concentrations in kidneys and muscle (Whitescarver et al., 1986; Kaup et al., 1991a,c). However, the Sprague-Dawley rats fed 15.6 g Cl/kg had elevated blood pressure and enlarged kidneys (Kaup et al., 1991a,c). Dahl (salt sensitive) rats fed 4.86 g Cl/kg as NaCl also had elevated blood pressures, while rats fed a basal diet or a diet supplemented with NaHCO3 did not (Kotchen et al., 1983).

Magnesium

Magnesium is required for numerous physiological functions in the rat. The amount required in the diet for adequate nutrition of the rat depends on numerous factors that affect availability of magnesium—the most important being the amount of dietary calcium, phosphorus, and vitamin D present. McAleese and Forbes (1961) found that a diet containing 0.1 g Mg/kg supported normal growth in weanling Sprague-Dawley rats. However, a diet containing 0.35 to 0.425 g/kg was required to maintain normal plasma magnesium concentrations of approximately 20 mg/L. More recently, Brink et al. (1991) found no significant difference in plasma magnesium between rats fed 0.4 and 0.6 g/kg diet; however, bone magnesium concentration was slightly (5 percent) but significantly higher in rats fed 0.6 g Mg/kg diet. On the other hand, rats fed only 0.2 g Mg/kg diet had significantly lower plasma and bone concentrations of magnesium than those fed 0.6 g/kg; 20 and 10 percent differences, respectively. Previously, Martindale and Heaton (1964) reported that 0.4 g Mg/kg was not sufficient to maintain normal bone and serum magnesium in adult Sprague-Dawley rats.

Other studies have shown questionable extremes for magnesium requirement. For example, Smith and Field (1963) estimated that a diet containing 0.05 g Mg/kg would replace endogenous losses in hooded Lister rats, but Clark and Belanger (1967) observed that a diet containing 2.5 g Mg/kg was needed for normal bone histology in Holtzman rats. These extremes may be the result of dietary factors that affect magnesium bioavailability. Brink et al. (1991) showed that magnesium absorption in rats fed diets with soybean protein was significantly less than in rats fed similar diets but with casein. Apparently this effect was caused by the presence of phytate in the soybean protein because when phytate was added to a casein diet, there was a similar reduction in absorption of magnesium. On the other hand, when lactose was added to the casein diet, magnesium absorption was enhanced.

Dietary calcium and phosphorus also affect magnesium requirement. O'Dell et al. (1960) showed that high-phosphorus diets enhanced the signs of magnesium deficiency in rats. Bunce et al. (1965) found that magnesium absorption was reduced by high dietary phosphorus. High dietary calcium also will depress magnesium absorption (O'Dell et al., 1960; Hardwick et al., 1987). Brink et al. (1992) have shown, however, that the effects of calcium and phosphorus on magnesium absorption is probably caused by the two minerals complexing magnesium in the gut lumen and rendering it insoluble. They showed that calcium was ineffective when phosphorus was not present and vice versa. [For an excellent review of factors affecting magnesium absorption, see Hardwick et al. (1991).]

Based on the review of these studies, and keeping the dietary calcium concentration at 5 g/kg and phosphorus at 3 g/kg, the dietary requirement for magnesium for growing and mature, nonpregnant rats is set at 0.5 g/kg diet. However, if diets contain factors, such as phytate, that might reduce the absorption of magnesium, a slightly higher dietary concentration might be required. In addition, because of the demands of lactation, an increase in dietary magnesium during this period is recommended. Wang et al. (1971) found that Sprague-Dawley rats were able to sustain gestation and lactation whether fed 0.8 g Mg/kg or 1.9 g Mg/kg diet.

Signs of Magnesium Deficiency Signs of magnesium deficiency in growing Sprague-Dawley rats include vasodilation, hyperirritability, cardiac arrhythmias, spasticity, and fatal clonic convulsions. Vasodilation occurred after about 1 week and often disappeared and reappeared spontaneously. Convulsions occurred between 21 and 30 days (Kunkel and Pearson, 1948; Ko et al., 1962). In Sprague-Dawley rats renal calcification was common and was detected within 2 days after initiating a markedly deficient diet (Reeves and Forbes, 1972).

Tufts and Greenberg (1938) reported that lactating females fed a deficient diet bred successfully but did not

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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suckle their young. Hurley et al. (1976a,b) reported that magnesium-deficient Sprague-Dawley dams resorbed their fetuses or bore malformed pups; they suggested that the malformations resulted from a concomitant zinc deficiency.

Potassium

In two studies, rats grew normally when fed 1.7 to 1.8 g K/kg diet (Kornberg and Endicott, 1946; Grunert et al., 1950). Two other studies indicated that rats may require 5 to 6 g K/kg diet during lactation (Heppel and Schmidt, 1949; Nelson and Evans, 1961); however, diets designed by the American Institute of Nutrition (1977) that contain 3.6 g K/kg support adequate growth and reproduction. Studies to determine potassium requirements for the rat are limited. Until more extensive research has been done, the minimal requirement is estimated to be 3.6 g K/kg diet. The dietary concentration of potassium may be increased to 5 g/kg during lactation, but such an increase does not seem necessary based on available data.

The potassium requirement of different strains of rats may vary. Sato et al. (1991) showed that increasing the dietary potassium to 42 g/kg diet protected spontaneously hypertensive rats against elevation of blood pressure induced by the ingestion of 8 percent sodium chloride. However, Sprague-Dawley rats developed elevated blood pressure when fed 15.5 g Cl/kg diet either as sodium chloride or potassium chloride (Kaup et al., 1991a,b).

Signs of Potassium Deficiency Insufficient potassium markedly reduces appetite and growth. Animals become lethargic and comatose and may die within 3 weeks. They have an untidy appearance, cyanosis, short fur-like hair, diarrhea, distended abdomens with ascites, and are frequently hydrothoracic. Rats fed diets containing 1 g K/kg diet had a symmetrical loss of hair along the back and a 50 percent reduction in hair per follicular group (Robbins et al., 1965). Pathological lesions are widespread with potassium depletion (Schrader et al., 1937; Kornberg and Endicott, 1946; Newberne, 1964). The initial noninflammatory degeneration of myocardial fibers is followed by necrosis and cellular infiltration. Renal lesions include cast formation in proximal convoluted tubules, sloughing of tubular epithelium in the medulla, and accumulation of hyalin droplets in the epithelium of the collecting tubules.

Signs of Potassium Toxicity Pearson (1948) fed weanling rats 5 percent potassium in the diet as potassium bicarbonate, and after 3 weeks observed reduced growth rate. More than 60 percent mortality was observed when dietary magnesium was low and only 17 percent when magnesium was adequate. Drescher et al. (1958) showed electrocardiograph changes when potassium intake exceeded 10 mg/kg body weight. Potassium toxicity can cause hypertrophy of the adrenal zona glomerulosa, sodium depletion, and increased density of mitochondrial cristae in the kidney tubules (Hartroft and Sowa, 1964; Sealey et al., 1970; Pfaller et al., 1974).

Sodium

Grunert et al. (1950) estimated the sodium requirement of the rat to be 0.50 g Na/kg and to be independent of potassium intake. Forbes (1966) found that 0.48 g Na/kg diet was inadequate for maximum weight gain of weanling Sprague-Dawley rats over a 28-day period but that 2.20 g Na/kg gave maximum gains. Intermediate concentrations were not tested.

Pregnant Sprague-Dawley females fed low-sodium diets (0.3 g Na/kg diet) ate less food and showed languor and debility, particularly during the last week of pregnancy; however, reproduction was not seriously impaired (Kirksey and Pike, 1962). Ganguli et al. (1969a,b) suggested that the sodium requirement for gestation and lactation was 0.50 g Na/kg diet. The estimated requirement for growth, maintenance, gestation, and lactation is 0.5 g Na/kg diet.

Signs of Sodium Deficiency The classic sodium deficiency syndrome was described by Orent-Keiles et al. (1937). Rats fed a diet that contained 20 mg Na/kg diet exhibited growth retardation, corneal lesions, and soft bones. Males became infertile after 2 to 3 months, and sexual maturity was delayed in females. Death ensued in 4 to 6 months. At a concentration of 70 mg Na/kg diet, Kahlenberg et al. (1937) noted reduced appetite, poor growth, increased heat production, and reduced stores of energy, fat, and protein.

Signs of Sodium Toxicity Rats are relatively insensitive to excess sodium as indicated by growth and tissue composition. Sprague-Dawley rats fed 10.1 to 11.2 g Na/kg diet as chloride, sulfate, carbonate, and bicarbonate salts grew normally and had concentrations of sodium in bones and kidneys similar to rats fed a basal diet but had higher concentrations of sodium in bone than rats fed the potassium forms of these salts (Kaup et al., 1991a). However, ingestion of excess sodium as NaCl is associated with elevated blood pressure in several different rat strains, including Sprague-Dawley, Dahl (salt sensitive), Dahl (salt resistant treated with deoxycorticosterone acetate), and spontaneously hypertensive rats (SHR) (Kaup et al., 1991a,c; Tobian, 1991).

TRACE MINERALS

Of the many trace mineral elements found in foods, only seven—copper, iodine, iron, manganese, molybdenum, se-

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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lenium, and zinc—have been unequivocally demonstrated to be required by rats. Although there is some evidence that other mineral elements (such as chromium, lithium, nickel, sulfur, and vanadium) may be required, further research is needed to establish requirement amounts. These other elements are treated in the discussion "Potentially Beneficial Dietary Constituents."

Copper

There is a general consensus that weanling and adult rats housed individually in wire-bottom stainless steel cages have a dietary copper requirement on the order of 5 to 6 mg/kg diet, the value used in the AIN-76A and AIN-93 diets. Johnson et al. (1993) fed weanling male Sprague-Dawley rats casein-starch-based purified diets containing copper concentrations ranging from 0.2 to 5.4 mg/kg for 5 weeks. They found that numerous functional measures of copper status (including platelet cytochrome c oxidase activity, serum ceruloplasmin activity, plasma copper, copper, and zinc-superoxide dismutase activity) were depressed in rats fed diets with copper concentrations at or below 3 mg/kg.

Studies by Klevay and Saari (1993) showed similar results. When weanling male rats were fed dietary copper ranging from 0.2 to 5.2 mg/kg diet for 5 weeks, the concentrations of copper in liver and heart and serum ceruloplasmin activity were depressed in rats fed copper concentrations at less than 4 mg/kg diet. However, Failla et al. (1988) could find no significant differences in copper status of Lewis rats fed an egg white-starch-based purified diet containing 2.1 or 7.0 mg Cu/kg diet. When similar rats were fed diets with sucrose instead of starch, indicators of copper status were significantly reduced at dietary concentrations up to 2.9 mg Cu/kg when compared to diets containing 7.1 mg Cu/kg. These studies suggest that the minimal dietary requirement for copper, to maintain adequate copper status in young growing rats of different strains and different dietary conditions, is more than 4 mg/kg diet.

Spoerl and Kirchgessner (1975a,b) reported that increasing dietary copper from 5 to 8 mg/kg during pregnancy and lactation resulted in an improvement in serum copper, serum ceruloplasmin activity, and liver copper concentrations in dams and their offspring. Cerklewski (1979) reported higher copper concentrations in milk on day 14 postpartum and in pup liver on day 21 postpartum when dams were fed diets containing 9 versus 6 mg Cu/kg diet during pregnancy and lactation. The functional significance of the higher tissue copper concentrations was not investigated.

Based on these data, a dietary copper concentration of 5 mg/kg diet is recommended for growth and maintenance for a variety of rat strains and under different dietary conditions. A dietary concentration of 8 mg Cu/kg diet is recommended for pregnancy and lactation. It should be noted that the requirement for growth and maintenance has not changed from that reported in the 1978 edition of this volume. However, the requirement recommended for pregnancy and lactation has increased from 5 to 8 mg Cu/kg diet. High dietary concentrations of zinc, cadmium, and ascorbic acid may increase the dietary requirement for copper (Davis and Mertz, 1987).

Signs of Copper Deficiency Copper deficiency develops rapidly in young rats and slowly in adult rats fed diets containing less than 1 mg Cu/kg. The copper deficiency develops more rapidly when fructose or sucrose is fed than when starch is fed, and males show a greater sensitivity to copper deficiency than females with respect to both the severity of signs and the duration of time until the onset of signs of deficiency (Fields et al., 1986; Koh, 1990; C.G. Lewis et al., 1990). Copper deficiency during early development can result in significant abnormalities in the cardiovascular, nervous, skeletal, reproductive, immune, and hematopoietic systems (Keen et al., 1982; Davis and Mertz, 1987). Weanling and adult rats fed copper-deficient diets can develop alternations in platelet function, impairments in both the acquired and innate arms of the immune system, altered exocrine pancreatic morphology and function, anemia (if dietary iron is marginal), alterations in thromboxane and prostaglandin synthesis, and impaired cardiovascular function (Cohen et al., 1985; Koller et al., 1987; Kramer et al., 1988; Dubick et al., 1989; Johnson and Dufault, 1989; Babu and Failla, 1990a,b; Allen et al., 1991; Medeiros et al., 1992; Saari, 1992). Weanling rats fed diets containing less than 2.7 mg Cu/kg show impaired neutrophil function within 5 weeks (Babu and Failla, 1990a).

Signs of Copper Toxicity Rats are particularly tolerant of high concentrations of dietary copper. Boyden et al. (1938) observed no adverse effects after feeding rats diets containing 500 mg Cu/kg, rats fed diets containing 2,000 mg/kg showed marked weight loss, and diets in excess of 4,000 mg/kg resulted in severe anorexia and starvation. Evidence of liver and kidney pathology in rats fed diets containing more than 1,000 mg/kg has been reported (Haywood, 1979; Czarnecki et al., 1984; Haywood, 1985).

Iodine

Iodine is regarded as essential for the rat. Utilization of dietary iodine is very high, and absorption occurs all along the gastrointestinal tract. It is concentrated by many tissues (Gross, 1962) but functions primarily as an integral part of the thyroid hormones. The few studies done to determine the iodine requirement generally agree that it is between 100 and 200 µg/kg diet (Levine et al., 1933; Remington and Remington, 1938; Halverson et al., 1945; Parker et al.,

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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1951). Parker et al. (1951) found that 100 to 230 µg I/kg diet was satisfactory for reproduction; natural-ingredient diets that contained 330 µg/kg supported reproduction (Kellerman, 1934). The 1978 edition of this report set the iodine requirement at 150 µg/kg diet. Many commercially available natural-ingredient diets contain this amount and support adequate growth and reproductive performance in rats. There have been no recent studies to suggest that this concentration should be changed.

Signs of Iodine Deficiency The most obvious sign of iodine deficiency in the rat is enlargement of the thyroid glands with the formation of trabecular-type nodules (Taylor and Poulson, 1956). Iodine-deficient rats also had more coarse and less dense hair than controls. Iodine deficiency results in impaired reproduction (Feldmann, 1960). One biochemical sign of iodine deficiency is a decrease in serum concentrations of the thyroid hormone thyroxine (T4) (Abrams and Larsen, 1973); another is a dramatic increase in the concentrations of serum thyrotropin (Pazos-Moura et al., 1991). An increase in the activity of liver type I iodothyronine deiodinase also occurs in iodine-deficient rats. Arthur et al. (1991) showed that the activity of this enzyme in rats fed less than 100 µg I/kg diet was 60 percent higher than in controls fed 1,000 µg/kg.

Signs of Iodine Toxicity The rat has a relatively high tolerance for dietary iodine. Adult female rats fed 500 to 2,000 mg/kg diet during pregnancy had increased neonatal mortality (Ammerman et al., 1964). However, when fed concentrations approaching 500 mg/kg diet, female rats had decreased milk production. The fertility of male rats fed as much as 2,500 mg I/kg diet for 200 days from birth was not affected.

Iron

For weanling and adult rats the iron requirement for growth and maintenance of maximum hemoglobin concentration is on the order of 35 mg/kg (McCall et al., 1962a; Ahlström and Jantti, 1969). For reproduction McCall et al. (1962b) reported that a diet containing 240 mg Fe/kg was adequate for maximum weight gain and hemoglobin concentrations. Ahlström and Jantti (1969) reported that considerably less iron was needed for reproduction: 28 mg Fe/kg for maximum hemoglobin concentration and 58 mg/kg for maximum iron stores in the offspring. Lin and Kirksey (1976) reported that growing, pregnant rats required between 10 and 50 mg Fe/kg diet for maximum hemoglobin concentration and between 50 and 250 mg/kg for maximum fetal liver iron stores. Shepard et al. (1980) reported that diets containing less than 10 mg/kg resulted in loss of embryos and fetuses. Kochanowski and Sherman (1983) have argued that although 35 mg Fe/kg diet is adequate to maximize maternal weight gain and hemoglobin concentrations during pregnancy and lactation, iron concentrations between 75 and 250 mg/kg diet are needed for optimal iron status at the end of lactation and between 150 and 250 mg Fe/kg are needed to maximize iron stores in the pups. Given the above, the recommended dietary iron concentration during pregnancy and lactation is 75 mg/kg diet.

Signs of Iron Deficiency In addition to anemia, iron-deficient rats can be characterized by multiple abnormalities including hyperlipidemia and low tissue carnitine concentrations (Bartholmey and Sherman, 1986), growth failure, elevated resting metabolic rate (Tobin and Beard, 1990; Borel et al., 1991), reduced exercise capacity (Willis et al., 1990), low milk folate concentrations (O'Connor et al., 1990), a compromised immune system including impaired phagocytosis and natural killer cell activity, and reduced antibody production (Hallquist et al., 1992; Kochanowski and Sherman, 1984, 1985).

Signs of Iron Toxicity The general term used to describe iron toxicity in animals is "iron overload." Chronic consumption of large amounts of dietary iron results in an accumulation of large quantities of iron in various cells and tissues, especially the liver. Wu et al. (1990) fed young (4 month old) and old (20 month old) rats 25 g elemental Fe/kg diet as finely powdered carbonyl iron and found detrimental effects on growth and maintenance of body weight. Within 2 weeks of feeding the high-iron diet, young rats had stopped gaining weight and old rats had lost 12 percent of their body weight. Weight of the old rats continued to decrease for up to 10 weeks of feeding. Large increases in the concentrations of iron in liver and spleen were seen in both age groups. Reductions in concentrations of serum, liver, and heart copper were also observed in the iron-overloaded rats. Britton et al. (1991) observed similar results in rats fed 30 g Fe/kg diet. These large amounts of tissue iron result in lipid peroxidation and cellular damage (Houglum et al., 1990; Wu et al., 1990).

Manganese

There is a paucity of studies that address manganese requirements in rats. Holtkamp and Hill (1950) reported that the optimal manganese intake for growth is between 2 and 5 mg/kg diet; when dietary manganese concentration was increased to 40 mg/kg, the average weight gain was less than in the group fed 5 mg/kg diet. In contrast, Anderson and Parker (1955) reported a faster growth rate in weanling rats fed 50 mg Mn/kg compared to rats fed 5 mg/kg. The manganese requirement for reproduction has not been firmly established. Diets containing 1 mg Mn/kg are inadequate for normal reproduction; litters from dams fed

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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this concentration of manganese are characterized by ataxia (due to inner ear defects), skeletal defects, and a high incidence of early postnatal death (Hurley and Keen, 1987). Litters from dams fed diets containing 3 mg Mn/kg have normal survival and growth rates; however, depending on the strain, they can still be characterized by a high incidence of ataxia (Baly et al., 1986; Hurley and Keen, 1987). An increased incidence of ataxia was not observed in litters from Sprague-Dawley dams fed diets containing 5 mg Mn/kg (C. L. Keen, University of California, Davis, personal communication, 1992). The above data suggest that a dietary concentration of 5 mg Mn/kg is probably adequate for normal growth and development. However, because there is a significant difference in how different strains respond to dietary manganese intake (Hurley and Bell, 1974; Kawano et al., 1987), the requirement is set at 10 mg/kg. It should be noted that this is lower than the recommendation of 50 mg/kg (National Research Council, 1978); however, given the lack of data supporting the need for such a high concentration of manganese in the diet, coupled with the possible negative effects of excess manganese on iron metabolism (Davis et al., 1990), reduction in the manganese requirement is warranted.

High concentrations of dietary iron, calcium, phosphorus, and copper have been reported to increase the requirement for dietary manganese (Hurley and Keen, 1987; Johnson and Korynta, 1992).

Signs of Manganese Deficiency Diets containing less than 1 mg Mn/kg can result in reduced food consumption, poor growth, bone abnormalities, and early mortality. Reproduction can be impaired and is characterized by testicular degeneration in the male and by a delay in the opening of the vaginal orifice and defective ovulation in the female. If reproduction occurs, litters are characterized by ataxia, skeletal defects, marked abnormalities in glucose and lipid metabolism, and a high frequency of early postnatal death (Hurley and Keen, 1987). Manganese deficiency in weanling and adult rats can result in significant alterations in pancreatic exocrine and endocrine functions (Baly et al., 1985; Chang et al., 1990), impaired glucose transport and metabolism in adipose cells (Baly et al., 1990), an increase in tissue lipid peroxidation (Zidenberg-Cherr et al., 1983), abnormal lipoprotein metabolism (Davis et al., 1990; Kawano et al., 1987), decreased hepatic arginase activity (Brock et al., 1994), and marked inhibitions of osteoblast and osteoclast activities resulting in severe bone disease (Strause et al., 1987).

Signs of Manganese Toxicity The postnatal growth of rats is unaffected by dietary manganese intakes as high as 1,000 to 2,000 mg/kg diet, provided dietary iron is adequate. If dietary iron is low (820 mg/kg), dietary manganese concentrations in excess of 1,000 mg/kg can result in reduced weight gain and iron deficiency (Rehnberg et al., 1982). Diets in excess of 3,500 mg Mn/kg can result in severe growth retardation and mortality. Reproductive dysfunction resulting from long-term intake of excess manganese (>1,050 mg/kg) has been reported for both males and females (Laskey et al., 1982). Although the concentrations of dietary manganese needed for overt toxicity are quite high, weanling rats given water containing 55 µg Mn/mL for 3 weeks were reported to have reduced rates of brain RNA and protein synthesis (Magour et al., 1983). The mechanisms underlying the cellular toxicity of manganese have not been clearly identified but may involve manganese-initiated oxidative damage, disturbances in carbohydrate metabolism, and altered intracellular iron metabolism (Keen and Hurley, 1989).

Molybdenum

Molybdenum metabolism was reviewed by Mills and Davis (1989). Similar criteria used to establish selenium as an essential nutrient also can be used to establish the essentiality of molybdenum. Molybdenum is a cofactor for three known enzymes in the rat—xanthine oxidase/dehydrogenase (XDH), aldehyde oxidase (AO), and sulfite oxidase (SOX) (Rajagopalan, 1988). These enzymes catalyze redox reactions. When rats are fed diets with very low concentrations of molybdenum, activities of these enzymes in various tissues are depressed. However, it has not been demonstrated that this is detrimental to the animal. On the other hand, if rats are fed tungsten, an antagonist to molybdenum, the activities of molybdenum-dependent enzymes are scarcely measurable and signs of deficiency then become apparent. Genetic deficiencies of sulfite oxidase in humans have been shown to result in numerous pathologies (Mudd et al., 1967; Johnson et al., 1980; Abumrad et al., 1981).

Early studies used the effect of low dietary molybdenum on liver and intestinal XDH activities to establish the requirement for molybdenum. Studies by Higgings et al. (1956) concluded that 20 µg Mo/kg diet was sufficient to maintain normal growth and reproduction. Xanthine oxidase activity was impaired, however. Titration experiments showed that about 100 µg Mo/kg diet was required to maximize intestinal XDH activity. More recent studies showed that not all criteria affected by dietary molybdenum are maximized by the same concentrations of molybdenum. Wang et al. (1992) showed that 25 µg/kg diet satisfied growth requirements in female rats and that 50 µg/kg diet was the minimal concentration required to maintain maximum liver XDH and SOX activity as well as spleen and kidney molybdenum concentrations. It took 100 µg Mo/kg diet to maximize XDH activity in the intestine and 200 µg Mo/kg diet to maximize liver and brain concentrations. However, it may not be valid to use tissue concentra-

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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tion of a trace element as a criterion to establish requirements. In many instances, the element accumulates in the tissue above a certain concentration but does not have a physiological function. Based on these studies, the requirement for molybdenum is estimated to be about 150 µg/kg diet. There is a strong interaction among molybdenum, copper, and sulfur; thus the dietary requirement of molybdenum might depend on the amount of copper and sulfur in the diet.

Signs of Molybdenum Deficiency Outward signs of deficiency are difficult to produce when rats are fed purified diets with only molybdenum absent. Even when an antagonist of molybdenum, tungsten, was fed at a ratio of 2,000:1 (tungsten:molybdenum) there were no detrimental effects on weight gain, but the animals had very low activity concentrations of molybdenum-dependent enzymes in liver.

Signs of Molybdenum Toxicity The occurrence of signs of molybdenum toxicity when rats and other species are fed high concentrations depends on the amount of copper and sulfate in the diet. Gray and Daniel (1964) showed that as little as 10 mg Mo/kg diet caused weight loss in copper-deprived rats. This condition could be ameliorated with the addition of 3 mg Cu/kg diet. Miller et al. (1956) found that the reduction in growth rate of rats fed 100 mg Mo/kg diet could be prevented by sulfate supplementation. Molybdenum toxicity also causes elevated liver copper, decreased serum ceruloplasmin, and increased tissue concentrations of molybdenum. Most of these signs can be reversed by supplementing the diet with copper and/or sulfate.

Selenium

Selenium is found in living organisms as an integral part of selenoproteins (Sunde, 1990) in the form of selenomethionine or selenocystine. There are also selenium binding proteins. A number of important selenoenzymes have been discovered in mammalian systems—glutathione peroxidase (GSH-Px; Rotruck et al., 1973), selenoprotein P (75SeP; Burk and Gregory, 1982), phospholipid hydroperoxide GSH-Px (Ursini et al., 1985), and hepatic type I iodothyronine 5'-deiodinase (ITD-I; Berry et al., 1991). GSH-Px is found in most tissues and cells and catabolizes hydrogen peroxide and other free and membrane associated hydro- and phospholipid peroxides. ITD-I is found in liver, kidney, and thyroid and catalyzes the generation of 3,5,3'-triiodothyronine (T3), the metabolically active thyroid hormone, from T4, the main circulating thyroid hormone. Other functions for selenium are probable but have not been adequately defined (Beckett et al., 1989; Kim et al., 1991). Since the 1978 edition of Nutrient Requirements of Laboratory Animals (National Research Council, 1978), there have been many excellent reviews on selenium metabolism (Burk, 1983; National Research Council, 1983; Combs and Combs, 1984; Levander and Burk, 1990; Sunde, 1990).

Dietary sources of selenium can be of two forms—inorganic, represented by selenite or selenate, and organic, represented by selenomethionine or selenocystine. Because of the complex metabolic fate of these different forms, and because of the influence of other possible antioxidants in the diet, it is difficult to establish an exact dietary requirement for selenium. Selenium is more readily transported across the intestinal cells as selenate than as selenite. Selenium from selenomethionine is more readily transported than either selenate or selenite (Vendeland et al., 1992).

Various criteria have been used to assess the requirement for selenium. Schwarz and Foltz (1957) showed that 40 µg Se/kg diet was required to prevent nutritional liver necrosis in rats that were also deficient in vitamin E. Hafeman et al. (1974) found that 50 µg Se/kg diet permitted maximum growth in rats, but 100 µg/kg was required to maintain maximum tissue activity of GSH-Px. More recent studies (Arthur et al., 1990) showed that less than 5 µg Se/kg diet permitted growth not different from that found when 100 µg Se/kg diet was fed. However, liver and plasma GSH-Px activities decreased significantly after only 2 weeks on low-selenium diets. The vitamin E content of these diets, supplied as α-tocopheryl acetate, was 200 mg/kg.

Yang et al. (1989) used the concentration of selenoprotein P (SeP) (Yang et al., 1987) in plasma and GSH-Px activities in plasma and liver to assess selenium nutriture in rats. Weanling rats were fed diets supplemented with selenium as sodium selenate ranging from 10 to 2,000 µg/kg diet. The SeP concentrations in plasma reached a plateau between 100 and 500 µg Se/kg of diet but they continued to rise when 2,000 µg Se/kg was fed. GSH-Px activities in plasma and liver were not maximized until dietary selenium had reached 500 µg/kg diet.

Whanger and Butler (1988) fed rats selenium, from 20 to 4,000 µg/kg, as sodium selenite. GSH-Px activities for numerous tissues, except red blood cells, were maximized at 200 µg Se/kg diet. Pence (1991) fed rats diets with selenium concentrations of 20, 120, and 520 µg/kg; Pence found that selenium-dependent GSH-Px as well as total GSH-Px activities in liver and colon of rats fed 120 µg/kg were only about 50 percent of the activities in those fed 520 µg/kg. L'Abbé et al. (1991) found that liver GSH-Px activity was about 20 percent higher in rats fed 1,000 µg Se/kg for 25 weeks than in those fed 100 µg/kg, but the difference was not significant. This may suggest, however, that 100 µg/kg diet is close to the minimum needed for maximum activity of GSH-Px and that more than 100 µg/kg would be optimal. In this regard Eckhert et al. (1993)

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

found evidence that the microvasculature of rats may have a unique requirement for selenium. They fed male rats diets high in sucrose to induce an elevation in blood triglycerides and cholesterol—a feeding regimen used by Lockwood and Eckhert (1992) to cause insult to the microvascular system. To this diet 100 or 200 µg Se/kg was added. The results showed that dietary selenium concentration had no effect on GSH-Px activity in the erythrocytes; however, there was a marked effect on the microvasculature of the retinae. In two different experiments there were twofold increases in the number of acellular segments and in the number of vessels over the optic nerve head in rats fed 100 µg Se/kg diet compared to those fed 200 µg Se/kg diet. In addition, the inner retinal pericyte:endothelial cell ratio of the vessels was increased in rats fed the higher concentration of selenium. These authors interpreted these results to suggest that the higher concentration of dietary selenium protected the retinal microvasculature, particularly the pericyte cells, from sucrose-induced metabolic insult. These data suggest that a minimal dietary requirement for selenium is more than 100 µg/kg.

It has been suggested that GSH-Px activity might be the best criterion for establishing a dietary requirement for selenium. However, recent investigations by Sunde et al. (1992) and Evenson et al. (1992) showed that the concentrations of GSH-Px-mRNA and 75Se incorporation into selenoproteins may also be used. They fed selenium (as selenite) in concentrations ranging from 7 to 200 µg/kg diet in a titration scheme to determine the amount of dietary selenium required to maximize GSH-Px activity, GSH-Px mRNA concentration, and 75Se incorporation into liver selenoproteins of growing rats. In all three cases, 100 µg/kg was the minimal amount required. Vadhanavikit and Ganther (1993) used liver and thyroidal 5'-deiodinase (type I) activities as well as GSH-Px activities to determine selenium requirements for the rat. They fed rats diets containing 10, 50, 100, and 500 µg Se/kg for 20 weeks. Liver GSH-Px activity was significantly decreased in rats fed 10, 50, and 100 µg Se/kg than in those fed 500 µg Se/kg; however, liver 5'-deiodinase activity was significantly decreased (90 percent) only in rats fed 10 µg Se/kg. GSH-Px activity in the thyroid was decreased in rats fed 10 µg Se/kg but not in those fed other concentrations. Thyroidal 5'-deiodinase activity was not significantly affected even at the lowest concentration of dietary selenium.

Therefore, considering all the criteria mentioned for the establishment of the selenium requirement, it is suggested that 150 µg Se/kg diet is the minimal requirement for the growing rat. This concentration may also be used for maintenance.

Other investigators have provided evidence which suggests that the minimal selenium requirement in the form of selenite for pregnant and lactating rats might be higher than 150 µg/kg diet (Smith and Picciano, 1986, 1987). In one experiment, Smith and Picciano (1986) raised dams through pregnancy and lactation on four concentrations of dietary selenium: 25, 50, 100, and 200 µg/kg. At 15 days of gestation, erythrocyte selenium concentrations and GSH-Px activities of the dams were not different among the three highest concentrations of dietary selenium. At day 18 of lactation, erythrocyte GSH-Px activity was significantly higher in dams fed 200 µg Se/kg compared to those fed 100 µg Se/kg diet. At this period, selenium concentration and GSH-Px activity in the liver of nonpregnant controls was not different among the three highest concentrations of selenium. In the lactating females, however, liver selenium concentration and GSH-Px activity were different among all groups. The highest selenium concentrations and GSH-Px activities were in those lactating rats fed 200 µg Se/kg; however, this value was not as high as that from nonpregnant controls fed the same amount. GSH-Px activity in the liver of 18-day-old pups was 1.7 times greater when dams were fed 200 µg Se/kg diet than when they were fed 100 µg/kg diet.

Smith and Picciano (1987) also found that the form of dietary selenium could influence selenium bioavailability and dietary requirement. A concentration of 250 µg Se/kg diet as selenomethionine resulted in maximum GSH-Px activity in the tissues of both dams and pups. However, when selenium was supplied as sodium selenite, 500 µg Se/kg was necessary. Studies by Lane et al. (1991) showed that the livers of 14-day-old pups fed 150 µg Se/kg diet as selenomethionine had twice as much GSH-Px activity as livers from similar rats fed selenite. GSH-Px activity in the livers of dams was not different between the two sources. Whanger and Butler (1988) and Vendeland et al. (1992) also showed that selenium from selenomethionine was more available to rats than that from sodium selenite. Based on these criteria, it appears that when selenium is supplied as selenite, the minimal requirement during pregnancy and lactation is at least 400 µg Se/kg diet. If the dietary source of selenium is selenate or selenomethionine, the requirement could be less.

Signs of Selenium Deficiency Outward signs of selenium deficiency are difficult to produce in rats fed diets adequate in vitamin E. However, one report (McCoy and Weswig, 1969) demonstrated selenium deficiency signs in rats fed Torula yeast diets with adequate vitamin E. These signs included poor growth, sparse-hair coats, cataracts, and reproductive failure when the diets were fed for two generations. Caution should be exercised when interpreting these results, however. Male rats fed the Torula yeast diet with added selenium only gained about two-thirds as much as rats fed a commercial natural-ingredient diet during the first generation and less than one-half as much during the second. This indicates that the diet may have been lacking in other essential nutrients. Biochemical signs of selenium

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

deficiency include the reduction of selenium-dependent enzyme activities in various tissues and the reduction of T4 deiodination in liver.

Signs of Selenium Toxicity Studies by Harr et al. (1967) and Tinsley et al. (1967) showed that 4,000 to 16,000 µg Se/kg diet caused ascites, edema, and poor hair quality in rats fed purified diets for long periods. Many of the animals did not live beyond 100 days. Liver toxicity and hyperplastic hepatocytes were found in rats receiving selenium as selenite or selenate supplemented at 500 to 2,000 µg/kg diet for 30 months.

Zinc

Weanling and adult rats housed individually in wire-bottom stainless steel cages have a dietary zinc requirement on the order of 12 mg/kg when egg white or casein is used as the primary protein source (Williams and Mills, 1970; Pallauf and Kirchgessner, 1971; Wallwork et al., 1981). The requirement is higher (18 mg/kg) when soybean protein is used. The increased requirement for zinc with soybean protein-based diets is primarily attributed to the phytic acid content of these diets (Berger and Schneeman, 1988).

For optimal growth and survival of the neonate, the dietary requirement for zinc for the pregnant and lactating rat has been estimated to be on the order of 25 mg/kg, even when a high-quality protein such as egg white is used (Rogers et al., 1984). An increased requirement for dietary zinc during pregnancy is also supported by the observation of Fosmire et al. (1977) that, at term, fetal weight and fetal zinc concentrations were higher in litters from dams given water containing 25 mg Zn/L compared to dams given water containing 11 mg Zn/L. Given the above, the recommended concentration of dietary zinc for pregnant and lactating dams is 25 mg Zn/kg diet.

The dietary requirement for zinc can be significantly influenced by an animal's housing conditions. It should be noted that high concentrations of dietary cadmium, iron, phosphorus, and tin have been reported to increase the requirement for dietary zinc (Hambidge et al., 1986; Johnson and Greger, 1984; Sandstrom and Lönnerdal, 1989).

Signs of Zinc Deficiency The pathologic signs of zinc deficiency depend on the length and severity of the deficiency, the age and sex of the animal, and environmental surroundings. An inadequate intake of zinc can be reflected by marked reductions in plasma zinc concentrations within 24 hours and by mild-to-severe anorexia within 3 days (Hambidge et al., 1986). Prolonged consumption of a zinc-deficient diet can result in continued anorexia, growth retardation/failure, abnormalities in platelet aggregation and hemostasis, alopecia, thickening of the epidermis, increased rates of cell membrane lipid peroxidation, hyperirritability, significant impairment of multiple components of the immune system, and alterations in lipid, carbohydrate, and protein metabolism (Hambidge et al., 1986; Hammermueller et al., 1987; Emery et al., 1990; Keen and Gershwin, 1990; O'Dell and Emery, 1991; Avery and Bettger, 1992). Esophageal lesions can occur in weanling rats within 7 days of the introduction of a zinc-deficient diet (Diamond et al., 1971). For weanling males, the prolonged consumption of a diet containing less than 0.5 mg Zn/kg can result in arrested spermatogenesis, atrophy of the germinal epithelium, and impaired growth of accessory sex organs (Diamond et al., 1971; Hambidge et al., 1986). Zinc deficiency in females results in a disruption of the estrous cycle, a reduced frequency of mating, and a low implantation rate if mating occurs.

The consumption of a zinc-deficient diet after mating can result in severe embryonic and fetal pathologies including prenatal death; a high incidence of central nervous system, soft tissue, and skeletal system defects; and abnormal biochemical development of the lung and pancreas. Zinc-deficient dams are characterized by severe parturition difficulties and the offspring are characterized by lower-than-normal growth rates, a high incidence of early postnatal death, and behavioral abnormalities (Apgar, 1985; Bunce, 1989; Keen and Hurley, 1989).

Signs of Zinc Toxicity Zinc is often considered to be relatively nontoxic, however, dietary zinc concentrations in excess of 250 mg/kg can induce a copper deficiency if dietary copper is low or marginal (L'Abbé and Fischer, 1984; Keen et al., 1985); and zinc in excess of 5,000 mg/kg diet can result in reduced growth rates, anorexia, anemia, and death even when dietary copper is considered adequate (Hambidge et al., 1986). It should be noted that investigators often use control diets that contain 100 mg Zn/kg. Although this amount of zinc is not thought to represent a "toxic" risk to rats, it is high enough that it may prevent the detection of important nutrient and/or drug-zinc interactions. It may be more accurate to classify 100 mg Zn/kg diet as a zinc-supplemented diet.

NEPHROCALCINOSIS IN RATS FED PURIFIED DIETS

Nephrocalcinosis is histologically demonstrable in the rat as deposits of stainable calcium salts in the kidney, usually in the corticomedullary region. Urolith formation causes increased kidney calcium and phosphorus concentrations and eventually results in renal hypertrophy and heavier kidneys (Woodard and Jee, 1984). Sometimes kidney function is reduced (Ritskes-Hoitinga, 1992).

The etiology is complex. Females are more susceptible than males, and Sprague-Dawley and Wistar strains may be more susceptible than other strains (Ritskes-Hoitinga, 1992). Dietary factors are also important. Generally, rats

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

fed purified diets are more apt to develop nephrocalcinosis than rats fed commercially available stock diets (Ritskes-Hoitinga et al., 1991). As yet no common mechanism has been identified that explains all the dietary factors that have been related to the incidence of nephrocalcinosis. Thus a brief review of potential factors is warranted.

Phosphorus and Calcium

Rats (Sprague-Dawley, Wistar, RIVm:TOX, and Zucker; both males and females) fed purified diets with more than 5.0 g P/kg diet have, in a number of studies, been found to have elevated concentrations of calcium in their kidneys (Hitchman et al., 1979; Schaafsma and Visser, 1980; Woodard and Jee, 1984; Greger et al., 1987a; Ritskes-Hoitinga et al., 1989; Van Camp et al., 1990). Kidney calcification has also been noted in female rats (RIVm:TOX, Sprague-Dawley, and Wistar) fed 4.0 g P/kg diet (Shah et al., 1980; Mars et al., 1988; Schoenmakers et al., 1989; Henskens et al., 1991). For example, Schoenmakers et al. (1989) observed that 5-week-old female RIVm:TOX rats fed diets containing 4.3 g P/kg with 4.8 g Ca/kg and 0.4 Mg/kg accumulated 25-fold more calcium in their kidneys than rats fed 1.1, 1.9, or 2.8 g P/kg diet. Ritskes-Hoitinga et al. (1993) did long-term studies with three successive generations of rats fed casein-based purified diets containing 5.2 g Ca/kg, 0.6 g Mg/kg, and either 2.0 or 4.0 g P/kg diet. After 4 weeks of age, from 50 to 100 percent of the females fed the diet containing 4 g P/kg developed nephrocalcinosis, while only 2 of 54 rats fed 2.0 g P/kg had measurable nephrocalcinosis. Male rats were not affected.

The amount of calcium consumed and the ratio of dietary calcium to phosphorus are also important. Woodard and Jee (1984) found that ingestion of additional calcium (5.5 versus 3.5 g Ca/kg diet) by Sprague-Dawley rats fed moderately high concentrations of phosphorus (>5.5 g P/kg diet) increased the deposition of calcium in the kidneys. In contrast, Schaafsma and Visser (1980) observed that Zucker rats fed diets with low concentrations of calcium (2.0 g Ca/kg diet) were more sensitive to phosphorus-induced nephrocalcinosis than rats fed 6.0 g Ca/kg diet. Moreover, Hoek et al. (1988) observed that kidney calcium accumulation in RIVm:TOX rats dropped dramatically when dietary calcium was increased to 7.5 g Ca/kg diet. This may reflect the ratio of dietary calcium to phosphorus.

Investigators have noted that a dietary calcium:phosphorus molar ratio below 1.3 is associated with nephrocalcinosis in RIVm:TOX and Wistar strains of rats (Hitchman et al., 1979; Hoek et al., 1988). Ritskes-Hoitinga et al. (1991) compared the responses of Wistar rats to 10 commercial diets and found that the dietary ratios of calcium to phosphorus were inversely correlated to the degree of nephrocalcinosis, as determined by histological score. Reeves et al. (1993a) fed rats purified diets similar to the AIN-93G diet (Reeves et al., 1993b) but with varying amounts of calcium and phosphorus: 3.3, 5.9, and 6.7 g Ca/kg diet and 2.0, 3.0, and 4.0 g P/kg diet. The Ca:P molar ratio in all diets was 1.3. They found that the concentrations of calcium and phosphorus in the tibia of both male and female rats were similar to those in rats fed a commercial natural-ingredient diet that contained higher concentrations of calcium and phosphorus. In addition, there were no indications of nephrocalcinosis in female rats after they consumed these diets for 16 weeks.

Magnesium

Nephrocalcinosis is a sign of magnesium deficiency in laboratory rats. Several investigators have found that the addition of supplemental magnesium (above required or recommended amounts) reduced the accumulation of calcium in kidneys of rats (Sprague-Dawley and Wistar strains) fed higher concentrations of calcium and/or phosphorus (Goulding and Malthus, 1969; Shah et al., 1980; Ericsson et al., 1986; Shah et al., 1986). Although ingestion of generous amounts of phosphorus and/or calcium have been found to depress magnesium absorption (Greger et al., 1987b; Hoek et al., 1988) and sometimes serum magnesium concentrations (Ericsson et al., 1986) of rats (RIVm:TOX and Sprague-Dawley strains), kidney magnesium concentrations were not reduced. This suggests that the rats were not magnesium-deficient per se.

Protein

The ingestion of additional (25 or 30 percent versus 15 percent) protein was found to prevent phosphorus-induced nephrocalcinosis in rats in several studies (Hitchman et al., 1979; Van Camp et al., 1990). Similarly, Shah et al. (1986) observed that Sprague-Dawley rats fed purified diets containing recommended concentrations of phosphorus had less calcium deposited in their kidneys when the protein content of the diets was increased from 10 to 15 percent casein.

The substitution of lactalbumin for casein in semipurified diets, even if dietary phosphorus amounts are similar, also is associated with less accumulation of calcium in kidneys of Sprague-Dawley rats (Greger et al., 1987a,b). Zhang and Beynen (1992) found that an increased intake of protein, provided in the diet by soybean isolate or casein, reduced the incidence of calcinosis in female rats; however, protein from fish meal did not. They concluded that the antinephrocalcinogenic effect of the soybean protein was related to lower urinary phosphorus, and the effect of casein was the result of lower urine pH and elevated urinary magnesium.

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×
Other Dietary Factors

Bergstra et al. (1993) showed that dietary fructose, as opposed to glucose, stimulated nephrocalcinosis in female rats. This was related to fructose stimulating greater concentrations of urinary phosphorus and magnesium and lowering the pH.

Levine et al. (1974) also found that chloride depletion stimulated nephrocalcinosis in Charles River rats but only in the presence of increased dietary phosphate or sulfate. Kootstra et al. (1991) observed that supplementing purified diets that contained 6 mg P/kg with ammonium chloride, but not ammonium sulfate, reduced the accumulation of calcium in the kidneys of female Wistar rats. Supplementation of diets with fluoride has also been observed to decrease the accumulation of calcium in the kidneys of Sprague-Dawley rats in several studies (Shah et al., 1980; Ericsson et al., 1986; Shah et al., 1986; Cerklewski, 1987).

VITAMINS

In the conversion of many of the values to moles from international units or mass that appeared in the original literature, the values reported may not be an exact conversion. The molar values have been rounded to reflect the degree of precision present in the original published estimates. Conversion factors for molar, mass, and IU units of the vitamins are presented in Appendix Tables 3 and 4.

FAT-SOLUBLE VITAMINS

Vitamin A

Vitamin A is essential for many critical functions of the body such as vision, which requires 11-cis-retinaldehyde bound to the photoreceptor pigments. Many cellular differentiation processes are mediated by all-trans-retinoic acid and 9-cis-retinoic acid bound to their respective nuclear

TABLE 2-10 Equivalence of β-Carotene and Retinol at Different Concentrations

Dose of β-Carotene, µmol/kg BW

Relative Molar Biopotency, %

Moles β-Carotene Equivalent to 1 mole Retinol

µg β-Carotene Equivalent to 1 mole Retinol

<0.3

100.0

1.0

1.84

1

50.0

2.0

3.75

2

30.0

3.3

6.25

6

15.4

6.5

12.20

12

9.5

10.5

19.70

48

4.3

23.3

43.60

 

SOURCE: Adapted from Brubacher and Weiser (1985).

TABLE 2-11 Vitamin A Repletion of Vitamin A-Deficient Rats

Criteria for Repletion

Retinol Required, nmol/kg BW/day

Reference

Normal growth rate

14

K. C. Lewis et al., 1990; Moore, 1957

Maintenance of differentiation of vaginal epithelial cells

19–23

Guilbert et al., 1940

Maintenance of normal testes

20–40

Bieri et al., 1968

Maintenance of a positive vitamin A balance

100

Green, personal communication, 1992

''Natural" hepatic storagea

200

Moore, 1957

a Defined as liver reserves equal to those found in wild animals.

receptors, RAR and RXR (Zelent et al., 1989; Mangelsdorf et al., 1992). 14-Hydroxy-4,14-retro-retinol also has been shown to be involved in signal transduction in B lymphocytes (Buck et al., 1991).

Retinol, the retinyl esters, and β-carotene are the main dietary compounds present in diets with vitamin A activity. Several plant carotenoids are precursor forms of vitamin A, and β-carotene is the most active carotenoid. The concentration of dietary intake influences the biopotency of β-carotene (Brubacher and Weiser, 1985) as shown in Table 2-10. β-Carotene is transformed to retinol in the intestinal mucosa. The retinol, irrespective of its source, is esterified primarily with palmitate or stearate. The esters are transported to the parenchymal cells of the liver as components of the chylomicrons. The esters are either hydrolyzed and transported out of the liver to the target tissues in combination with a specific transport protein, retinol-binding protein, or they may be transferred to the stellate cells of the liver for storage. Vitamin A can be stored in the liver in large amounts.

Rats are born with very low liver stores of vitamin A. As a consequence the vitamin A requirement in weanling rats varies according to the criteria used, overt signs of deficiency (e.g., epithelial keratinization), hepatic storage, or retinol kinetics. Maximum blood concentrations (about 2 µmol/L) were reached when liver deposition was moderate (140 µmol/kg liver) in Holtzman rats (Muto et al., 1972). An elevation in the cerebrospinal fluid pressure occurred when the serum retinol concentration dropped below 0.35 µmol/L in Sprague-Dawley rats (Corey and Hayes, 1972). Some of the different criteria for vitamin A requirements for repletion of deficient animals are presented in Table 2-11.

Guilbert et al. (1940) demonstrated that the need for vitamin A was related to body weight rather than energy intake. This concept is consistent with the vitamin's activity

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

in maintaining integrity of the epithelia, which quantitatively directly correlate with body mass (Mitchell, 1950).

Takahashi et al. (1975) found that 56 nmol retinyl acetate/kg BW/day was sufficient to support gestation in Holzman rats with the delivery of pups of normal weight and with normal brain, liver, and kidney size. However, the mean number of live neonates was reduced to 4.8 compared to 9.5 for the controls, which received 1,400 nmol/kg BW/day. Sixty-three percent of the dams fed the marginal concentration of vitamin A delivered as compared to 100 percent of the dams fed the very high concentration. These low concentrations that supported gestation would not support optimal lactation, however. Davila et al. (1985) found that nursing Sprague-Dawley dams fed 2.1 µmol retinyl acetate/kg diet were healthy and their pups grew as well as the pups of dams fed 52 µmol/kg diet but had lower liver retinyl ester stores.

Vitamin A requirements are sensitive to other nutritional influences. Consumption of protein-deficient diets decreases the serum concentrations of vitamin A and its transport protein, retinol-binding protein (Peterson et al., 1974). Rates of depletion of liver and kidney reserves of vitamin A were linearly related to growth rate, which changed as dietary casein concentration varied from 0 to 18 percent (Rechcigl et al., 1962). In zinc-deficient rats, mobilization of vitamin A from the liver declined (Smith et al., 1973), but this effect was not confirmed by Apgar (1977). Vitamin E deprivation resulted in depletion of liver stores of vitamin A (Moore, 1957).

Age does not appear to have any significant effect on vitamin A requirement other than that related to differences in body weight. Suckling, young adult, and aged rats absorb retinol with about the same efficiency (Hollander and Morgan, 1979; Said et al., 1988).

Green and co-workers (1987) developed a computer model to describe the kinetics of vitamin A metabolism in male Sprague-Dawley rats and have studied the effects of vitamin A intake on vitamin A excretion. With diets containing 2.1 µmol/kg diet or less, the disposal was equal to the vitamin A intake. However, when the diets contained 2.4 µmol/kg diet the disposal rate was essentially the same as observed in the rats receiving 2.1 µmol/kg diet (Green and Green, 1991). The rats had a modest (»3.5 nmol/day) accumulation of vitamin A in the liver when they were fed 2.4 µmol/kg diet.

The estimated requirement for vitamin A, based on the kinetic studies of Green et al. (1987) and Green and Green (1991) and on the lactation study of Davila et al. (1985) is 2.4 µmol/kg diet (equivalent to 2,300 IU/kg) if retinol or retinyl esters are used. This requirement may be met by retinol at 0.7 mg/kg diet, retinyl acetate at 0.8 mg/kg diet, or retinyl palmitate at 1.3 mg/kg diet. At this low concentration β-carotene is used relatively efficiently, so the requirement would also be met by β-carotene at 12.4 µmol/kg diet (1.3 mg/kg diet). Because compounds with vitamin A activity are relatively unstable, the use of retinyl acetate or retinyl palmitate in gelatin coated beadlets is strongly recommended.

Several studies have shown that animals exposed to stress respond better at higher dietary concentrations of vitamin A than is recommended above. Gerber and Erdman (1982) reported that the strength of the scar tissue after a surgical incision was about twice as great in animals receiving 21 µmol retinyl acetate/kg diet or 13.4 µmol β-carotene/kg diet as it was in animals receiving 4.2 µmol retinyl acetate/kg diet. Demetriou et al. (1984) reported that rats fed a commercial diet containing 15 µmol retinol or retinyl esters per kg of diet and 12 µmol β-carotene/kg diet had only a 20 percent survival rate 72 hours after intra-abdominal sepsis. In contrast, when the diet was supplemented with an additional 525 µmol retinyl palmitate/kg, survival rose to 70 percent.

Signs of Vitamin A Deficiency The various procedures used to produce vitamin A-deficient rats have been reviewed in detail (Smith, 1990). The signs of vitamin A deficiency can be divided into six categories.

  1. Defect in vision. Because 11-cis-retinaldehyde is a necessary part of the visual pigments, a deficiency of vitamin A leads to a loss of vision through the lack of functional visual pigments (Wald, 1968).

  2. Bone defects. Vitamin A deficiency leads to improper bone cell differentiation, which causes retardation and disorganization of bone growth and failure of bone resorption during remodeling. The reduced size of the openings in the bones can cause a secondary compression of nerves (Underwood, 1984).

  3. Increase in cerebral spinal fluid pressure. The arachnoid villi, which release the fluid, become clogged with fibroblasts (Corey and Hayes, 1972).

  4. Reproductive failure. Cessation of spermatogenesis occurs in the male. In the female, severe and lethal deficiency causes cornification of the reproductive tract, which results in loss of reproductive function. With a more moderate deficiency, females will become pregnant but severe lethal fetal malformations and resorption are the most common result of the pregnancy (Wilson et al., 1953).

  5. Epithelial metaplasia and keratinization. All epithelia are sensitive to vitamin A deficiency to varying degrees. In early vitamin A deficiency, goblet cells and mucus formation decline in the intestine; squamous metaplasia followed by keratinization takes place in the trachea. Keratinization of the urogenital tract and the corneal epithelium combined with xerophthalmia and porphyrin deposits around the eyelids, and ultimate dissolution of the corneal stroma, takes place in severe vitamin A deficiency (Underwood, 1984).

  6. Growth failure. After 5 to 6 weeks of vitamin A defi-

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

ciency, the weight of a weanling rat plateaus for about a week and then drops rapidly until the animal dies. Under germ-free conditions, the rat can survive at the weight plateau stage for several months (Rogers et al., 1971).

Signs of Vitamin A Toxicity Acute retinol toxicity occurs with an intake of 180 µmol/kg BW/day, although the long-chain retinyl esters were not toxic at this concentration of intake (Leelaprute et al., 1973). All-trans-retinoic acid is much more toxic; signs were found at 47 µmol/kg BW/day (Kurtz et al., 1984). The signs typically associated with vitamin A toxicity are weight loss, fatty liver, hyperlipidemia, calcification of soft tissues, mobilization of bone calcium, bone fractures, increased urinary excretion of 3-methylhistidine, and hemorrhage. Vitamin A is also teratogenic, causing cleft palate in fetuses at a retinyl palmitate intake of 40 µmol/kg BW/day given on days 9 to 12 of gestation (Nanda et al., 1970). Retinoic acid was much more teratogenic when low-protein diets (2.5 to 10 percent) were fed compared to a 20 percent protein diet (Nolen, 1972). Hemorrhage was caused by an interference in vitamin K metabolism and could be corrected by increasing vitamin K intake (McCarthy et al., 1989). α-Tocopherol has been shown to greatly reduce the toxicity of vitamin A (Jenkins and Mitchell, 1975). In contrast to the retinoids, ciency, the weight of a weanling rat plateaus for about a week and then drops rapidly until the animal dies. Under germ-free conditions, the rat can survive at the weight plateau stage for several months (Rogers et al., 1971). β-carotene was not toxic at doses up to 1,800 µmol/kg BW/day (Heywood et al., 1985).

Vitamin D

Vitamin D is an important precursor of the hormone 1,25-dihydroxycholecalciferol. The hormonal action is mediated by the interaction with a specific nuclear receptor and the corresponding responsive elements in the promotor regions of the genes that code for several proteins, many of which are involved in calcium metabolism. Although 1,25-dihydroxycholecalciferol is best known for its role in the regulation of calcium and phosphorus homeostasis, it may have significant roles in many other processes, including the synthesis of red blood cells, the proliferation of B and T lymphocytes, and the secretion of insulin and prolactin (Reichel et al., 1989). Vitamin D is hydroxylated in two positions before it becomes active. First, cholecalciferol is converted to 25-hydroxycholecalciferol in the liver. In the kidney 25-hydroxycholecalciferol is hydroxylated to form the active 1,25-dihydroxycholecalciferol. The formation of 1,25-dihydroxycholecalciferol is a tightly regulated process. Serum calcium concentration regulates the activity of the kidney 1-α-hydroxylase enzyme via the parathyroid gland. Low concentrations of serum phosphate directly increase the synthesis of this kidney enzyme. High dietary concentrations of both cause a decrease in the formation of 1,25-dihydroxycholecalciferol.

Information about the vitamin D requirements of the rat is surprisingly limited. The actual requirements are difficult to determine because the rat can absorb sufficient calcium and phosphorus to prevent the overt signs of rickets if the dietary ratio of calcium and phosphorus is about equal and they are present in adequate amounts. Also, cholecalciferol can be synthesized in the skin of the rat if it is exposed to ultraviolet light of appropriate wavelength (280 to 320 nm).

Relatively small amounts of vitamin D are needed to produce most of the biological responses, and the amount needed is a function of calcium and phosphorus intakes. A single injection of 0.13 µmol of either ergocalciferol (vitamin D2) or cholecalciferol (vitamin D3) promoted maximum active calcium absorption within 48 hours in vitamin D-deficient adult male rats of the Sherman strain fed a diet containing 5 g Ca/kg and 5 g P/kg (Schachter et al., 1961). Vitamin D is clearly required for maximum growth even when calcium and phosphorus are at concentrations typically considered optimal (Coward et al., 1932). However, vitamin D-deficient rats had normal bone mineralization and grew at the same rate as rats supplemented with vitamin D when they were continuously infused with calcium and phosphorus (Underwood and DeLuca, 1984). Male Sprague-Dawley rats fed a vitamin D-deficient diet containing 4.7 g Ca/kg and 3 g P/kg had low reproductive rates, but weekly injections of 5.2 µmol cholecalciferol/rat was sufficient to return reproductive function of deficient rats to normal (Kwiecinski et al., 1989). However, when male rats were fed a vitamin D-deficient diet containing 12 g Ca/kg and 3 g P/kg the fertility rate greatly improved (Uhland et al., 1992). Vitamin D-deficient female rats became pregnant and produced pups; nonetheless, the number of dams giving live births was only one-half that of dams given an oral dose of 1.6 µmol vitamin D/day (Halloran and DeLuca, 1980). Vitamin D-deficient rats were less likely to become pregnant, had more spontaneous abortions, and had a greater risk of death during parturition. In general, suckling pups grow poorly when nursed by vitamin D-deficient dams; however, this was the result of reduced milk production. When the litter size was reduced to two pups, the growth rate was normal (Mathews et al., 1986). Increasing the dietary calcium (16 g/kg) and phosphorus (14 g/kg) concentrations increased milk production so that suckling and weaned pups of vitamin D-deficient rats had normal growth and bone mineral content (Clark et al., 1987).

The rate of active absorption of calcium in the duodenum in middle-aged (12 to 14 months) and elderly rats (18 to 24 months) fed optimal amounts of calcium and phosphorus for a long period was reduced to about 70 percent of the rate observed in young rats (2 to 3 months) (Armbrecht, 1990). In contrast, the older rats actually absorbed cholecalciferol more efficiently than young rats (Hollander and Tarnawski, 1984). The activity of the kidney 1-α-hydroxy-

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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lase enzyme, however, was reduced in the older rats (Ishida et al., 1987). The concentration of the enzyme can be increased by a 4-month exposure to a low-calcium and vitamin D-deficient diet (Armbrecht and Forte, 1985). In contrast, young respond rapidly to this stimulus. There is no evidence that increasing the intake of vitamin D will have a beneficial effect on the absorption of calcium or phosphorus in adult rats.

In the absence of additional data, the estimated requirement of 1,000 IU vitamin D/kg diet recommended in the 1978 edition of this volume (National Research Council, 1978) is retained. This is equivalent to 65 nmol cholecalciferol/kg diet (25 µg/kg). This concentration, although adequate, may not represent the biological minimum.

Signs of Vitamin D Deficiency Vitamin D deficiency induces rickets. This disease is classically brought about in rats by a diet lacking vitamin D, adequate in calcium, and low in phosphorus. However, a low-calcium diet deficient in vitamin D has a more severe effect on growth rate and results in irritability, tetany, and decreased bone calcification (Steenbock and Herting, 1955). Bones of rachitic rats show decreased or absent calcification with wide areas of uncalcified cartilage at the junction of diaphysis and epiphysis. Bone ash may be less than half normal. A full description of histological changes in bones of vitamin D-deficient rats is given by Jones (1971).

Signs of Vitamin D Toxicity The first sign of vitamin D toxicity is usually elevated serum calcium followed by calcification of the kidneys (Potvliege, 1962). Soon the arteries become calcified, and then the liver and heart become calcified. The animals usually die from heart failure secondary to the uremia that comes from kidney failure. The animals also have a decreased growth rate and show considerable resorption of bone. Massive arteriosclerotic lesions developed in 100 percent of male rats fed a diet containing 78,800 µmol ergocalciferol/kg, 39 mmol cholesterol/kg, and 12 mmol cholic acid/kg for 6 weeks. Rats receiving this diet but containing only 63,000 µmol ergocalciferol/kg did not develop lesions, and rats fed ergocalciferol without cholesterol did not develop lesions (Bajwa et al., 1971). Vitamin D is also teratogenic. Treatment of pregnant dams with 2,500 µmol ergocalciferol/day reduced the growth rate of the fetuses and retarded the ossification of the long bones (Ornoy et al., 1968). All the pups died shortly after birth. When the dose was lowered to 1,250 µmol ergocalciferol/day the placenta was much smaller but the pups were normal. Nonpregnant rats receiving this lower dose had very high serum calcium concentrations. At 250 µmol/day the nonpregnant animals appeared normal. Shelling and Asher (1932) demonstrated that the toxicity of vitamin D was related to the calcium and phosphorus content of the diet. Rats fed diets containing 4.4 g Ca/kg and 17.8 g P/kg had severe toxicity signs at relatively low vitamin D intakes. However, the animals were able to tolerate high concentrations of vitamin D when they were fed diets with an optimal ratio of calcium to phosphorus.

Vitamin E

"Vitamin E is nature's best fat-soluble antioxidant" (Scott, 1978). In fact the only clearly defined function of vitamin E is as an antioxidant. Most of the signs of vitamin E deficiency can be prevented by feeding the antioxidant N,N'-diphenyl-p-phenylene diamine (DPPD).

Several compounds have vitamin E activity. The most active naturally occurring compound is RRR-α-tocopherol (formerly called D-α-tocopherol). The synthetic all-rac-α-tocopherol is a mixture of eight stereoisomers, and the other seven are less active than RRR-α-tocopherol. One mole of RRR-α-tocopherol has a biopotency equivalent to 1.36 moles of all-rac-α-tocopherol (U.S. Pharmacopeia, 1985). Although it does not occur naturally, tocopheryl acetate is frequently used in animal diets. The ester is hydrolyzed in the intestine, and tocopherol is released for absorption. However, having the alcohol group linked to the acetate prevents the tocopherol from being destroyed in the diet before it is consumed by the animal. In this section the concentrations of all compounds having vitamin E activity are expressed as the equivalent concentration of RRR-α-tocopherol.

Polyunsaturated fatty acids are labile to autoxidation. Each fatty acid free-radical that is oxidized damages about three other polyunsaturated fatty acid molecules, thus producing a geometrically expanding chain reaction (Chow, 1979). Vitamin E can readily donate hydrogen atoms to the free-radicals to terminate the chain reaction. As a result the requirement for vitamin E is related to the dietary and tissue concentrations of the polyunsaturated fatty acids (Witting and Horwitt, 1964). Adequate dietary selenium will greatly reduce the requirement for vitamin E. The selenium-containing enzyme, glutathione peroxidase, will convert the peroxides that are intermediates in this breakdown process to stable alcohols, thus reducing the requirement for vitamin E (Hoekstra, 1975).

Several criteria have been used to evaluate vitamin E status of the rat including: survival, growth, prevention of nutritional muscular dystrophy, prevention of creatinuria, prevention of fetal resorption, prevention of testicular degeneration, reduction of pentane expiration, reduction of malondialdehyde production, and prevention of the spontaneous hemolysis of red blood cells after they are diluted with saline.

In selenium-deficient rats, Hakkarainen et al. (1986) found that about 5.2 mg α-tocopheryl acetate/kg diet (11 µmol/kg) was required for survival. Gabriel et al. (1980)

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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used plasma pyruvate kinase and glutamic oxaloacetic transaminase as indicators of myopathy of skeletal muscle. By feeding rats the antioxidant ethoxyquin (which is not stored) instead of vitamin E, they were able to rapidly produce vitamin E deficiency in rats from 12 to 68 weeks old by removing ethoxyquin from the diet. In all age groups the minimum vitamin E requirement to prevent myopathy of muscle was approximately 0.75 mg α-tocopheryl acetate/kg BW/day (1.6 µmol/kg BW/day). Jager and Houstsmuller (1970) found that preventing the spontaneous hemolysis of red blood cells required 13.2 mg RRR-α-tocopherol/kg diet (28 µmol/kg diet) when the diet contained 3.6 percent linoleic acid, but increasing the linoleic acid content to 13 percent increased the requirement to 18 mg/kg diet (38 µmol/kg). In a test of repletion of vitamin E-deficient rats, Bieri (1972) showed that hemolysis was prevented after feeding 20 mg RRR-α-tocopheryl acetate/kg diet (42 µmol/kg). The dietary lipid was a mixture of stripped corn oil and lard that provided 5.2 percent linoleic acid. At this percentage, α-tocopherol in the tissues reached a stable concentration within 8 weeks following the beginning of repletion. Buckingham (1985) studied the requirements of rats fed purified diets containing 20 percent lipid with polyunsaturated to saturated (P:S) ratios of 0.38, 0.82, and 2.30. Pentane expiration in the breath and production of malondialdehyde were reduced to normal levels when rats were fed a diet with 27 mg α-tocopherol/kg diet (62 µmol/kg). However, 44 percent spontaneous hemolysis was observed when the diet contained a 2.30 P:S ratio even with an α-tocopherol concentration of 67 mg/kg diet (156 µmol/kg).

Evans and Emerson (1943) investigated the rats' requirement for vitamin E during reproduction. As female rats aged, the requirement to maintain pregnancy became higher. To maintain pregnancy and optimal health in the suckling young, 0.57 mg α-tocopheryl acetate/rat/day (1.2 µmol/rat/day) was required. However, after the third pregnancy the suckling pups suffered slight muscular impairment at this concentration of intake. In young male rats 0.18 mg/rat/day (0.39 µmol/rat/day) was adequate to maintain reproduction; but at 9 months and older, the rats required 0.57 mg/rat/day (1.2 µmol/rat/day) to maintain fertility. Ames (1974) determined the amount of vitamin E necessary to maintain pregnancy in female rats. The dose to maintain 50 percent fetal viability increased about sevenfold from the first pregnancy (12 weeks) to the fourth pregnancy (60 weeks). This increase is more than can be explained by an increase in body weight. Gabriel et al. (1980) suggested that the increased requirement may be caused by accumulated toxic products from long-term exposure to very low intakes of antioxidants.

Autofluorescent pigment (lipofuscin) accumulates in the tissues of vitamin E-deficient animals and in old animals. Nonetheless the tissue distribution of the lipofuscin is different in vitamin E-deficient rats than in aging rats (Katz et al., 1984), thus the accumulation in aging rats does not appear to be the result of inadequate vitamin E intake. Although older rats may require more dietary vitamin E to maintain α-tocopherol concentrations in the cerebellum and brain stem (Meydani et al., 1986), the concentration needed has not been established. Hollander and Dadufalza (1989) have demonstrated that older rats absorb α-tocopherol more efficiently than younger rats.

Bendich et al. (1986) examined the vitamin E requirement of spontaneously hypertensive rats, which are more sensitive to vitamin E-deficient diets than the parent Wistar strain. Maintenance of normal growth required 7.5 mg all-rac-α-tocopheryl acetate/kg diet (16 µmol/kg diet); 15 mg/kg diet was required to prevent myopathy of muscle; and 50 mg/kg diet was required to prevent the spontaneous hemolysis of red blood cells. Optimal immune responses appeared to require slightly more than 50 mg/kg diet. The immune system response was the most sensitive indicator of vitamin E status.

The vitamin E requirement for most of the frequently used strains of rats is 18 mg RRR-α-tocopherol/kg diet (42 µmol/kg) when lipids comprise less than 10 percent of the diet. This corresponds to 27 IU/kg diet. When all-rac-α-tocopheryl acetate is used as the dietary source, this would be equivalent to 27 mg/kg diet (57 µmol/kg).

High intakes of either retinyl palmitate (42 µmol/kg diet) or β-carotene (89 µmol/kg diet) depressed plasma and liver concentrations of α-tocopherol to about one-half the normal concentrations (Blakely et al., 1990). It seems probable that high concentrations of vitamin A in the diet interfere with the absorption of vitamin E.

Signs of Vitamin E Deficiency Red blood cells from vitamin E-deficient rats show an increased hemolysis when diluted with saline or when treated with oxidizing agents (dialuric acid). Other signs are hyaline degeneration of skeletal muscle fibers with infiltration by histocytes, interfibrillar fat cells, and an increase in interstitial cells (Jager, 1972); accumulation of yellow pigment in smooth muscles; in the male, irreversible degeneration of the seminiferous epithelium of the testis, which occurs by age 40 to 50 days; in the female, induction of fetal abnormalities or intrauterine death and resorption; kyphoscoliosis (humped-back) (Machlin et al., 1977); rough coat; skin ulcers; neural lesions; and impaired learning ability (Sarter and Van Der Linde, 1987).

Signs of Vitamin E Toxicity In general vitamin E is relatively nontoxic. However, 2,000 mg RRR-α-tocopheryl acetate/kg BW (4,230 µmol/kg BW) prolonged the process of prothrombin production, and hemorrhagic diathesis developed in rats fed the AIN-76 diet (low vitamin K) (Abdo et al., 1986). The main metabolic product of vitamin E,

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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tocopheryl quinone, inhibits the normal metabolism of vitamin K. In addition, Martin and Hurley (1977) found eye abnormalities in pups from dams receiving 1,600 mg α-tocopheryl acetate/kg BW/day (3,500 µmol/kg BW/day). Yang and Desai (1977) found a decreased implantation index in inseminated females fed a diet containing 7,300 mg α-tocopheryl acetate/kg diet (15,500 µmol/kg).

Vitamin K

The only known function of vitamin K in mammalian systems is the posttranslational conversion of glutamic acid to γ-carboxyglutamic acid (Gla) (Stenflo, 1976). Gla is found only in a limited number of proteins including the blood clotting proteins, prothrombin and factors VII, IX, and X; the anticlotting proteins, protein C and protein S; blood protein Z; the bone proteins, osteocalcin and matrix Gla-containing protein (MGP); and a few other Gla-containing proteins in the kidney and intestine (Suttie, 1991).

Phylloquinone (vitamin K1) is the metabolically preferred source of vitamin K (Will and Suttie, 1992). Phylloquinone is also actively absorbed in the proximal portion of the small intestine (Hollander, 1973). The menaquinones (vitamin K2) are a family of compounds synthesized by bacteria. The bacteria in the large intestine produce substantial amounts of menaquinones. Because the rat is coprophagous, excrement provides a substantial source of vitamin K activity. Essentially no absorption of the larger menaquinones, such as menaquinone-9, occurs in the large intestine; but they are effectively absorbed if recycled to the small intestine by coprophagy (Ichihashi et al., 1992). The smaller menaquinone-4 is absorbed to a limited extent in the colon, but menaquinone-4 is a minor product of the intestinal bacteria. The synthetic derivative of vitamin K, menadione, lacks the isoprenoid side chain of the natural compounds with vitamin K activity, and it must be converted to menaquinone-4 in the liver to be functional (Dialameh et al., 1971). Menadione is about one-tenth as active as phylloquinone. Some of the water-soluble derivatives of menadione, such as the menadione sodium bisulfite complex, are much more readily absorbed and are about equally as active as phylloquinone (Griminger, 1966).

The most prominent function of vitamin K is its role in blood clotting. Failure of blood to coagulate occurs in some rats that have been fed a vitamin K-deficient diet for 2 to 3 weeks. However, in most rats overt clotting problems only develop after they have been fed antibiotics or when coprophagy is prevented.

Estimation of the vitamin K requirement of rats is complicated by several factors: (1) the contribution from coprophagy, (2) the difficulty in producing vitamin K-free diets, (3) the large differences in requirements between strains, and (4) the problem of selecting which criteria to use to determine normal status.

The typical contribution from coprophagy is probably on the order of 4 to 9 µmol/rat/day (Mameesh and Johnson, 1960; Wostmann et al., 1963). Rats fed diets with a high nutrient density and high digestibility are less coprophagous than rats fed low-digestibility diets (Giovannetti, 1982; Mathers et al., 1990). Housing rats in a very cold environment (Smith and Borchers, 1972) will almost eliminate coprophagy. The contribution from coprophagy is difficult to estimate and may necessitate the use of germ-free animals for experimental work.

The purified milk proteins, casein and lactalbumin, usually contain substantial vitamin K that is difficult to extract (Matschiner and Doisy, 1965). Therefore, soybean proteins are frequently used as the source of protein when vitamin K metabolism is studied. If the soybean proteins are extracted with ethanol, diets can be formulated containing as little as 9 µg phylloquinone/kg (0.02 µmol/kg) (Kindberg and Suttie, 1989).

Many different criteria have been used to evaluate vitamin K status. Wostmann et al. (1963) used survival of germ-free male Lobund rats as a criterion and estimated that the diet must contain 0.44 µmol phylloquinone/kg to maintain survival. At 0.33 µmol/kg diet most of the rats died from hemorrhages. However, the minimum amount necessary to keep rats from bleeding to death may not be the optimal vitamin K intake. Most frequently, some estimate of clotting time is used to predict the vitamin K requirement. Mameesh and Johnson (1960) reported that male Sprague-Dawley rats required phylloquinone at 0.25 µmol/kg diet to maintain normal prothrombin activity when coprophagy was prevented by tail cups. Matschiner and Doisy (1965) found that male rats of the St. Louis strain required 0.55 µmol/kg diet to maintain normal prothrombin activity when fed a 21 percent soybean protein diet that was not extracted and coprophagy was not prevented.

More sensitive criteria of vitamin K status were used by Kindberg and Suttie (1989) to determine the requirement of male Holtzman and Sprague-Dawley rats. The rats were fed an extracted soybean protein diet and coprophagy was not prevented. A diet containing 1.1 µmol phylloquinone/kg was not adequate to bring liver carboxylase enzyme activity or plasma prothrombin to the concentrations observed in rats fed a 3.3 µmol/kg diet. Based on extrapolations of this data the optimal concentration appears to be about 2.2 µmol/kg diet. Even at higher doses the rats maintained small liver stores of vitamin K that were essentially depleted within 5 days. Consequently, rats depend on a continuous dietary supply of vitamin K to maintain optimal status.

When fed diets with suboptimal vitamin K activity, female rats develop signs of vitamin K deficiency much more slowly than do males (Matschiner and Bell, 1973). The lower requirement seems to reflect differences in the effects of estrogen and testosterone on the production of

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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prothrombin (Matschiner and Willingham, 1974). In pregnancy the concentrations of prothrombin rise as a result of the increased estrogen concentrations. The requirement of female rats appears to be about three-fourths the requirement of males.

Mellette and Leone (1960) reported that rats 15 to 27 weeks old were about twice as likely to have a hemorrhagic death as rats 3 to 5 weeks old when fed irradiated beef diets low in vitamin K.

Warfarin-resistant rats have much higher vitamin K requirements than normal rats because they do not recycle vitamin K epoxide as efficiently as normal rats. Greaves and Ayres (1973) reported that the Wistar strain required 0.13 µmol phylloquinone/kg BW to maintain normal prothrombin activity, the Tolworth HS (Scottish) warfarin-resistant strain required 0.44 µmol/kg BW, and the Tolworth HW (Welsh) warfarin-resistant strain required 1.77 µmol/kg BW. The vitamin K was given by daily subcutaneous injections.

Roebuck et al. (1979) reported that male Wistar/Lewis rats developed hemorrhaging but had normal prothrombin activity when fed a modified AIN-76 diet for 8 to 20 weeks. The bleeding could be corrected by adding phylloquinone, 1.1 µmol/kg, to the diet. The AIN-76 diet (American Institute of Nutrition, 1977) was formulated to contain 0.18 µmol menadione sodium bisulfite/kg plus an undefined amount of vitamin K activity in the dietary casein and corn oil. Bieri (1979) confirmed that the amount of vitamin K activity in the AIN-76 diet was less than optimal for Fischer rats when the casein was replaced with other proteins; the American Institute of Nutrition recommended that the added menadione sodium bisulfite be increased to 1.8 µmol/kg diet (American Institute of Nutrition, 1980) and that the diet be designated AIN-76A.

For the most commonly used strains of rats (Fischer, Sprague-Dawley, and Wistar) a diet containing 1.00 mg phylloquinone/kg diet (2.22 µmol/kg) should satisfy the most sensitive criterion for vitamin K adequacy. Because the rat actively absorbs phylloquinone and gives preference to phylloquinone metabolically, phylloquinone is the recommended form to be used in diets. Menadione and its derivatives are not recommended.

High concentrations of dietary vitamin A and vitamin E have been shown to accelerate the onset of deficiency signs in rats fed vitamin K-deficient diets. As little as 5.2 µmol retinyl acetate/kg diet decreased the prothrombin activity in rats fed a diet low in vitamin K (Doisy, 1961). Supplementation of a low vitamin K diet with 12 µmol α-tocopherol orally twice a week increased hemorrhagic deaths (Mellette and Leone, 1960); hemorrhaging, however, could be corrected by phylloquinone supplementation. Vitamin E metabolites appear to interfere with the normal metabolism of vitamin K. The vitamin E metabolites tocopheryl hydroquinone and tocopheryl quinone are the most probable causes (Rao and Mason, 1975). Butylated hydroxytoluene (BHT, 1.2 percent of diet) has also been shown to induce hemorrhagic death when included in casein-based diets that were not supplemented with vitamin K. The simultaneous administration of 0.68 µmol phylloquinone/kg BW/day prevented the hemorrhages and maintained normal prothrombin concentrations (Takahashi and Hiraga, 1979).

Signs of Vitamin K Deficiency In vitamin K deficiency thrombin activity is depressed and liver carboxylase activity is greatly increased (Kindberg and Suttie, 1989). The first overt sign of vitamin K deficiency is usually a continuous oozing of blood from a minor injury such as a separated toenail or a small pin-prick on the tail. These injuries would not normally bleed longer than 30 seconds, but the vitamin K-deficient animal may continue to lose blood until death occurs. In an examination of specific-pathogen-free rats not supplemented with vitamin K, hemorrhages were found in the urogenital tract, the central nervous system, the chest cavity, the abdominal cavity, and under the skin (Fritz et al., 1968).

Signs of Vitamin K Toxicity Phylloquinone is essentially nontoxic when given orally. Rats given daily doses of 4,400 µmol phylloquinone/kg BW for 30 days did not show signs of toxicity, whereas 2,000 µmol menadione/kg BW was lethal (Molitor and Robinson, 1940). At 260 µmol/kg diet, menadione depressed the activity of several heme-containing enzymes in vitamin E-deficient rats (Hauswirth and Nair, 1975). This concentration is present in a popular commercial vitamin mix. At higher concentrations both menadione and menadione sodium bisulfite produce liver toxicity.

WATER-SOLUBLE VITAMINS

Vitamin B6

The vitamin B6 compounds (pyridoxine, pyridoxal, and pyridoxamine) function as coenzymes for amino acid decarboxylases, racemases, transaminases, and other enzymes in amino acid, glycogen, and fatty acid metabolism (Baker and Frank, 1968). The coenzymes are formed by phosphorylation of the aldehyde and amine; nearly 50 percent of pyridoxal phosphate in the body is stored as coenzyme for muscle glycogen phosphorylase (Anonymous, 1975; Chen and Marlatt, 1975). Pyridoxal phosphate is involved in releasing steroid-hormone-complexes tightly bound to receptors (Compton and Cidlowski, 1986; Bender et al., 1989).

Phosphatase-mediated hydrolysis is the first step in the intestinal absorption of pyridoxal-5'-phosphate. Gastric acid secretions are important for the hydrolysis as intestinal alkaline phosphatase is activated at low pH (3.4) (Middle-

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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ton 1986). Products of digestion—amino acids and oligopeptides—inhibit hydrolysis (Middleton, 1990). Cellulose, pectin, or lignin did not alter the in vitro jejunal absorption rates of pyridoxine, pyridoxal, or pyridoxamine (Nguyen et al., 1983). Weanling Sprague-Dawley rats fed diets containing 1.5 mg vitamin B6/kg diet or less had lower vitamin B6 concentrations in the intestinal mucosa than rats fed 3 to 100 mg/kg diet (Roth-Maier et al., 1982). Vitamin B6 aldehydes can reductively bind to food proteins as epsilonpyridoxyllysine complexes during processing and storage and, in this form, possess only 50 percent of the vitamin B6 activity (Gregory, 1980a,b). No differences were observed in urinary pyridoxic acid between germ-free and conventional rats, indicating that coprophagy does not alter requirements (Coburn et al., 1989).

Studies of the dietary requirement have been based on vitamin B6-dependent enzyme activities, body weight gain, tissue stores of pyridoxal phosphate, or reproductive performance. When male weanling rats were fed 1, 2, 4, or 8 mg vitamin B6/kg diet, growth was the same in all groups; but liver, serum, and red blood cell alanine-aminotransferase was maintained only at dietary concentrations of 4 mg/kg and above (Chen and Marlatt, 1975). Concentrations of 1.0 to 1.6 mg/kg diet were required to achieve maximum growth (Roth-Maier and Kirchgessner, 1981; Van den Berg et al., 1982; Mercer et al., 1984). Alterations in red blood cell transaminase activity indicated a vitamin B6 requirement of 6 to 7 mg/kg diet (Beaton and Cheney, 1965). Diets containing 7.0 mg pyridoxine-HCl/kg restored full activity of erythrocyte alanine aminotransferase and aspartate aminotransferase when fed to female Long-Evans rats that had been previously depleted of vitamin B6 (Skala et al., 1989).

Protein quality had no significant effect on urinary 4-pyridoxic acid, plasma pyridoxal phosphate or total hepatic vitamin B6 concentrations in rats fed 0.2 and 7.0 mg vitamin B6/kg diet (Fisher et al., 1984). Erythrocyte alanine aminotransaminase activity decreased with increasing dietary protein concentrations but was not altered when the quality of protein was changed (Dirige and Beaton, 1969).

Vitamin B6 is required by pregnant rats for normal development of their offspring. Vitamin B6-deficient offspring had retarded renal differentiation, abnormalities of cerebral lipids, and increased tissue and urinary concentrations of cystathionine (Kurtz et al., 1972; DiPaolo et al., 1974; Pang and Kirksey, 1974). Maternal weight gain and body and brain weight of offspring were normal when the diet contained 3 mg pyridoxine/kg and slightly, but not significantly, lower at 2 mg/kg/ 1 mg/kg was clearly inadequate. There was no significant difference between offspring of dams fed 3 mg/kg diet and those fed 6 mg/kg (Driskell et al., 1973). When female rats were reared on diets containing 1.2, 2.4, 4.8, 9.6, or 19.2 mg vitamin B6/kg diet, maternal and fetal weights were reduced in the group fed 1.2 mg/kg; erythrocyte alanine aminotransferase activity coefficients were maintained at 2.4 mg/kg and above; and tissue vitamin B6 saturation concentrations indicated that 9.6 mg/kg was required for growth and 4.8 mg/kg for maintenance. However, 19.2 mg/kg diet did not achieve saturation concentrations of maternal liver, fetal brain, or carcass during gestation (Kirksey et al., 1975). Rats fed 8 or 40 mg/kg during pregnancy had similar activities of hepatic aspartate aminotransferase, erythrocyte alanine aminotransferase, and gastrocnemius muscle glycogen phosphorylase (Shibuya et al., 1990).

Female rats fed diets that contained 1.2 to 19.6 mg vitamin B6/kg diet from weaning through breeding, gestation, and lactation bore offspring of normal weight at 2.4 mg/kg and above. Concentrations of vitamin B6, protein, and cerebrosides in brains were significantly decreased at 1.2 and 2.4 mg/kg; however, brain protein concentration continued to increase up to the highest dietary vitamin B6 concentration. Milk pyridoxine and erythrocyte transaminase were decreased when maternal diet was less than 4.8 mg/kg (Moon and Kirksey, 1973; Pang and Kirksey, 1974).

These studies indicate that vitamin B6 requirements are met by 4 to 7 mg/kg diet, although higher tissue concentrations of pyridoxal phosphate may be achieved by higher dietary concentrations. The estimated vitamin B6 requirement for maintenance, growth, and reproduction is set at 6 mg pyridoxine-HCl/kg diet.

Signs of Vitamin B6 Deficiency Rats fed diets deficient in vitamin B6 develop symmetrical scaling dermatitis on the tail, paws, face, and ears; microcytic anemia; hyperexcitability; and convulsions (Sherman, 1954). The amount of 3-hydroxykynurenine was increased in neonatal brain at 14 and 18 days of age but not in adult brain (Guilarte and Wagner, 1987). Amplitude of response to both acoustic and tactile stimuli was depressed by vitamin B6 depletion (Schaeffer, 1987) as well as differences in angle and width of the hind-leg gait (Schaeffer and Kretsch, 1987; Schaeffer et al., 1990). Depleted rats demonstrated a taste preference for NaCl and excreted reduced concentrations of sodium (Mei-Ying and Kare, 1979). They had deficits in active and passive avoidance learning (Stewart et al., 1975). The pyramidal cells of the cerebral cortex of rats fed deficient diets for 2 or 3 months showed partial to nearly complete dendritic loss and axonal swelling in the hippocampus (Root and Longenecker, 1983). Reduced brain concentrations of vitamin B6, dopamine, homovanillic acid, D-2 dopamine receptors, brain glutamic acid decarboxylase, gamma aminobutyric acid (GABA), and γ-aminobutyric acid transaminase have been measured in vitamin B6-deficient rats (Driksell and Chuang, 1974; Aycock and Kirksey, 1976; Rajeswari and Radha, 1984; Guilarte, 1989). Cerebroside and ganglioside content and fatty acids (18:2, 20:1, 20:4,

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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22:6, and 24:0) and n-6 fatty acids (18:2, 20:4, and 22:4) are decreased in brain as a result of vitamin B6 deficiency (Thomas and Kirksey, 1976a,b).

In deficiency, reproductive performance of both females and males was decreased; deficient production of insulin may occur (Huber et al., 1964). An 8-week deficiency resulted in decreases in hepatic alanine and aspartate aminotransferases, and the ability to use alanine for gluconeogenesis was impaired (Angel, 1980). The turnover of cytosolic, but not mitochondrial aspartate aminotransferase, was altered in vitamin B6 deficiency (Shibuya and Okada, 1986); and the total activities of both aspartate aminotransferase and alanine transferase were reduced (Ludwig and Kaplowitz, 1980). Pyridoxine deficiency reduced the intestinal uptake of glucose, glycine, alanine, and leucine as well as the activities of mucosal sucrase, lactase, alkaline phosphatase, leucine aminopeptidase, and membrane synthesis (Mahmood et al., 1985). In rats fed a high protein diet deficient in vitamin B6, urinary excretion of urea, free ammonia, and free amino acids were altered (Okada and Suzuki, 1974). Female rats fed vitamin B6-deficient diets excreted less taurine than pair-fed controls (Lewis et al., 1982; Lombardini, 1986). Vitamin B6-deficient rats had lower plasma homocystine in association with decreased and sporadic food intake (Smolin and Benevenga, 1984). Creatine in skeletal muscle and liver was higher and creatinine excretion lower in deficient rats (Loo et al., 1986). Vitamin B6 deficiency produced a decrease in glucose-6-phosphate dehydrogenase activity in the periosteum and in the developing callus (Dodds et al., 1986) and a decrease in collagen cross-link formation (Fujii et al., 1979). Liver parenchymal ultrastructural changes after 7 weeks on a vitamin B6-deficient diet included hyperplasia in the nucleoli and smooth endoplasmic reticulum and hypoplasia in the Golgi, rough endoplasmic reticulum, and mitochondria with reduced numbers of orthoperoxisomes (Riede et al., 1980). Vitamin B6-deficient male rats had larger and a greater number of urinary calcium oxalate stones than females or castrated males (Gershoff, 1970). Changes in fatty acid oxidation and incorporation of the fatty acids into triglycerides, phospholipids, and cholesterol fractions have been observed (Dussault and Lepage, 1979).

Signs of Vitamin B6 Toxicity Excess vitamin B6 has been shown to have detrimental effects. Twelve-week-old rats fed 6 weeks on diets containing 1,400 mg vitamin B6/kg had elevated red blood cell alanine aminotransferase activity and pyridoxal-5'-phosphate concentrations, but muscle pyridoxal-5'-phosphate concentrations were lower. Tissue pyridoxal concentrations were higher and muscle glycogen phosphorylase A activity was increased by the consumption of excessive dietary vitamin B6 (Schaeffer et al., 1989). Rats injected intraperitoneally with 200 mg/kg BW developed gait ataxia with impaired oxidative metabolism in peripheral nerve tissue and an axonal degeneration of the sensory system fibers (Windebank et al., 1985).

Vitamin B12

In mammals, vitamin B12 is required as a coenzyme for the transmethylation of homocystine to methionine, in utilizing 5-methyl-tetrahydrofolic acid, and in the conversion of methylmalonyl-CoA to succinyl-CoA (Weissbach and Taylor, 1970). The concentration of vitamin B12 needed in the diet of the rat may vary with dietary content of choline, methionine, and folic acid. A number of conditions have been reported that impair vitamin B12 absorption. Rats fed a diet with raw kidney bean (Phaseolus vulgaris) as 4 percent of dietary protein or 0.5 percent phytohemagglutinin developed vitamin B12 malabsorption after only 3 days, and the condition was not correctable by giving intrinsic factor (Banwell et al., 1980). Highly fermentable fibers such as pectin, guar gum, and xylan fed as 5 percent of the diet increased urinary methylmalonic acid and depressed the oxidation of propionate to CO2 (Cullen and Oace, 1989a). The half-life of vitamin B12 was 58 days for rats fed fiber-free diets and 38 days for rats fed a 5 percent pectin diet (Cullen and Oace, 1989b). Vitamin B12 deficiency has been induced by diets containing unheated soybean flour, but amino acid deficiencies occur also and unheated soybean flour contains other toxins; therefore, it has been suggested that its use for the study of vitamin B12 deficiency is not justified (Edelstein and Guggenheim, 1971; Williams and Spray, 1973). Giardiasis also has been reported to impair vitamin B12 absorption (Deka et al., 1981). The oxidation of acetaldehyde, generated from the metabolism of ethanol, by xanthine oxidase inhibited the ability of vitamin B12 to bind to intrinsic factor (Shaw et al., 1990). Decreased vitamin B12 concentrations have been reported in rats fed liquid diets with ethanol but not natural-ingredient diets with ethanol (Frank and Baker, 1980). Hypothyroidism slowed the rate of depletion of hepatic vitamin B12 (Stokstad and Nair, 1988). Vitamin B12 deficiency developed rapidly in rats exposed to nitrous oxide (Horne and Briggs, 1980; Muir and Chanarin, 1984).

The minimum requirement for vitamin B12 has not been established; however, a dietary concentration of 10 µg vitamin B12/kg seems to be inadequate based on urinary excretion of methylmalonic acid (Thenen, 1989). A concentration of 50 µg vitamin B12/kg diet supported normal growth and reproduction (Woodard and Newberne, 1966). In the absence of more complete information, the requirement is currently set at 50 µg vitamin B12/kg diet.

Signs of Vitamin B12 Deficiency Induction of isolated vitamin B12 deficiency in the rat, as well as in other experimental animals, is achieved with difficulty and generally does not reproduce the signs of human vitamin B12 deficiency—

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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megaloblastic blood cells and neurological lesions. Deficiency can be induced in rats fed vegetable rather than animal protein (which contains vitamin B12). Female rats fed a diet that contained soybean protein supplemented with methionine and choline, but not vitamin B12, grew normally or at a slightly decreased rate and bred and littered normally. The average weights of their offspring were decreased, and 10 percent of the litters were hydrocephalic. Hepatic content of vitamin B12 was markedly decreased in both mothers and offspring. Deletion of choline from the diet increased the incidence of congenital abnormalities in the neonates. Supplementation of the diet with 50 µg vitamin B12/kg supported normal growth in the mothers and prevented development of hydrocephalic offspring (Woodard and Newberne, 1966). When litters born to vitamin B12-deficient females were fed diets deficient in vitamin B12, growth was retarded by day 30 and the animals remained small throughout the 150 day experiment. Methionine (0.5 percent DL) reduced the growth retardation (Doi et al., 1989). Germ-free females fed soybean protein aborted, bore short-lived pups, or cannibalized their pups. The germ-free condition apparently enhanced vitamin B 12 deficiency (Valencia and Sacquet, 1968). Vitamin B12-deficient rats accumulated more odd-chained fatty acids in phosphatidylcholine of cerebrum and liver, more 18:2 acids in liver phosphatidylethanolamine, and arachidonate [20:4(n-6)] and 22:5 in liver phosphatidylcholine, but smaller amounts of 20:4(n-6) and 22:6(n-6) in cerebral phosphatidylcholine (Peifer and Lewis, 1979).

Biotin

Biotin is required by four carboxylase enzymes in mammalian systems: acetyl CoA carboxylase (fatty acid synthesis), pyruvate carboxylase (Gluconeogenesis), 3-methylcrotonyl CoA carboxylase (leucine catabolism), and propionyl CoA carboxylase (methionine, threonine, and valine catabolism).

Under normal conditions rats do not require biotin in the diet. Adequate biotin is provided by the intestinal microorganisms through coprophagy. Biotin deficiency can be produced in rats fed a biotin-free diet by (1) preventing coprophagy (Barnes et al., 1959b); (2) using germ-free animals (Luckey et al., 1955); (3) feeding sulfa drugs (Daft et al., 1942); or feeding raw egg white, which contains the biotin-binding protein avidin (Nielsen and Elvehjem, 1941).

Klevay (1976) fed 20 percent raw egg white diets to rats and determined that 2 mg d-biotin/kg diet (8.2 µmol/kg) was required to obtain optimal growth for 60 days. Several other investigators have given various amounts of biotin to animals to cure or prevent signs of deficiency, but these experiments do not permit conclusions to be made about requirements because the amounts given were insufficient to correct fully the deficiency, the animals did not grow at a rate equivalent to controls, controls were not used, or the biotin administration was erratic.

The AIN-76 diet (American Institute of Nutrition, 1977) and AIN-93G and AIN-93M diets (Reeves et al., 1993b) were formulated to contain 0.2 mg d-biotin/kg (0.82 µmol/kg). This concentration appears to be adequate when casein is the dietary protein; however, if spray-dried raw egg white is used as the dietary protein, the concentration of biotin should be increased to 2.0 mg/kg diet.

Signs of Biotin Deficiency Biotin deficiency causes rats to develop a progressive exfoliative dermatitis, "spectacle eye," achromotrichia (in black rats), and general alopecia. With severe deficiency many animals develop a spastic gait or assume a "kangaroo-like" posture. Immune responses were also depressed in biotin-deficient rats (Rabin, 1983).

Signs of Biotin Toxicity Biotin is relatively nontoxic. Paul et al. (1973) reported that 50 mg biotin/kg BW (205 µmol/kg BW) divided between morning and evening subcutaneous injections produced irregularities in the estrous cycle and a massive infiltration of leukocytes in the vagina. Mittelholzer (1976) did not observe problems in the reproduction of females given this dose.

Choline

Choline is a component of lecithin, of sphingomyelin, and of the neurotransmitter acetylcholine. Choline also has an important role in one-carbon metabolism.

Diets are usually formulated with either choline chloride or choline bitartrate. Although all choline compounds tend to be hygroscopic, choline bitartrate is substantially less hygroscopic than choline chloride, and does not add more chloride, so use of choline bitartrate is preferable for most practical diets.

Choline is required by the rat, but the requirement is a function of the methionine and lipid content of the diet. Diets containing about 14 percent casein require more choline than diets containing either more or less casein (Aoyama et al., 1971). Diets that contain 0.8 percent methionine or more do not require choline (Griffith, 1941; Newberne et al., 1969; Aoyama et al., 1971). Rats fed diets containing suboptimal amounts of methionine have been reported to require 0.6 to 2.0 g choline chloride/kg diet (4 to 14 mmol/kg) (Griffith and Wade, 1939; Griffith, 1941; Engel, 1942; Mulford and Griffith, 1942; Hale and Schaefer, 1951).

Using a diet that contained 38 percent sucrose, 20 percent lipid, and 36 percent protein (0.34 percent methionine), Chahl and Kratzing (1966) found that male Wistar rats housed at 21° C required 500 mg choline (free base)

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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per kg diet (4.8 mmol/kg) to prevent lipid accumulation in the liver. However, when the rats were housed at 33° C the requirement was increased to 1,000 mg choline (free base) per kg diet (9.6 mmol/kg). In contrast, housing the rats at 2° C reduced the requirement to 250 mg choline (free base) per kg diet (2.4 mmol/kg).

Based on the studies of Chahl and Kratzing (1966), Mulford and Griffith (1942), and Griffith and Wade (1939), the requirement for choline is set at 750 mg/kg diet (7.2 mmol/kg diet). This is equivalent to 1.8 g choline bitartrate/kg diet. However, if diets with 5 to 15 percent and 20 to 40 percent fat are to be used, if the diets are deficient in folate or vitamin B12, or if the rats are to be housed in a high environmental temperature, then the amount of choline may need to be increased.

Signs of Choline Deficiency Choline deficiency appears much more rapidly in male than in female rats (Patek et al., 1969). Droplets of triglycerides and abnormalities of the intracellular membranes appear in the livers of weanling male rate within 24 hours after they have ingested a choline-deficient diet. Long-term deficiency leads first to fatty liver, in which triglycerides may compose as much as 50 percent of the total wet weight of the liver and the liver cells are markedly distended with fat vacuoles, and then to cirrhosis, in which there is proliferation of fibrovascular tissue, vascular shunting, and hepatic failure (Zaki et al., 1963; Rogers and MacDonald, 1965). Sucrose was found to cause twice as great an increase in liver triglycerides as dextrin in choline-deficient diets (Chalvardjian and Stephens, 1970).

Choline deficiency has marked effects on both the kidney and the cardiovascular system in young rats. If male rats are fed a choline-deficient diet at weaning, 50 to 90 percent die within 10 days to 2 weeks of hemorrhagic renal necrosis. They may develop myocardial necrosis and atheromatous changes in arteries (Salmon and Newberne, 1962; Monserrat et al., 1974). Supplementation with about one-half the requirement will protect against renal damage and prevent cirrhosis of the liver, but it will not prevent the infiltration of the liver with triglyceride.

Signs of Choline Toxicity Sahu et al. (1986) reported that 100 mg choline chloride/kg BW/day (700 µmol/kg BW/day) depressed the rate of growth and caused pathological changes in the lungs and lymph nodes. The safety margin between the daily requirement (16 to 42 mg/kg BW or 115 to 300 µmol/kg BW) and the toxic concentration is relatively narrow with choline, so caution should be used in increasing the concentrations. The LD50 of choline chloride has been reported to range from 0.28 to 0.75 g/kg BW/day (2,000 to 5,400 µmol/kg BW/day) depending on the concentration of the injected solution (Hodge, 1944; Ho et al., 1979; Sahu et al., 1986). Bell and Slotkin (1985) reported that a diet containing 5.0 percent soybean lecithin caused alterations in sensorimotor development and brain cell maturation.

Folates

Folates are composed of pteridines linked to p-aminobenzoic acid conjugated to one or more glutamic acid residues (Blakley and Benkovic, 1984; Blakley and Whitehead, 1986). Folates in most tissues exist primarily in the pentaglutamyl form. The principal function of folates is to transfer one-carbon units such as in thymidylate synthesis, purine synthesis, serine synthesis from glycine, and methionine synthesis from homocystine (Shane and Stokstad, 1985; Appling, 1991). Measurement of red blood cell, serum, and tissue folate content of the various folate forms as well as measurement of the urinary histidine metabolite, formiminoglutamic acid, is used to assess folate nutritional status (Shane and Stokstad, 1985; Clifford et al., 1989; Ward and Nixon, 1990; Varela-Moreiras and Selhub, 1992). Furthermore, folate biosynthesis by intestinal bacteria may meet much of the folate requirement (Rong et al., 1991). Diets inadequate in choline, methionine, and cobalamin may induce deficiency through the various interactions of these compounds (Thenen and Stokstad, 1973). Dietary concentrations between 0.5 and 10 mg/kg diet (1.1 and 23 µmol/kg) have been used. Studies by Clifford et al. (1989) have demonstrated that 2 mg folic acid/kg diet (4.5 µmol/kg) was no more effective than 1 mg/kg (2.3 µmol/kg) in young Sprague-Dawley rats that had been depleted of folic acid for 52 days. Thus, 1 mg/kg diet (about 2.3 µmol/kg) is recommended.

Signs of Folate Deficiency Induction of deficiency requires prolonged periods of feeding, usually with an amino acid-based diet and/or with an antibiotic to inhibit intestinal bacteria (Clifford et al., 1989; Ward and Nixon, 1990). Decreased growth rate, leukopenia, anemia, and formiminoglutamate excretion are reported.

Niacin

The only known roles of niacin are as components of the coenzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP), which function as electron carriers dehydrogenases in intermediary metabolism.

Both NAD and NADP can be synthesized from tryptophan in the liver of the rat, so pure niacin deficiency does not occur. Harris and Kodicek (1950) found that 24 moles of tryptophan were equivalent to 1 mole of niacin. Hundley (1947) found that rats fed a diet containing 15 percent casein required niacin for optimal growth, but rats fed a 20 percent casein diet did not require additional niacin.

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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Several investigators have reported that niacin-free diets containing fructose and low concentrations of tryptophan resulted in niacin deficiency. The amount of niacin required to restore normal growth was 15 mg/kg diet (120 µmol/kg) (Krehl et al., 1946; Henderson et al., 1947; Hundley, 1949). The requirement for niacin is much lower with diets containing glucose or starch than with high-sucrose or -fructose diets (Hundley, 1949). A high-fat (40 percent peanut oil) diet was found to decrease the urinary excretion of niacin metabolites, apparently because of an inhibition in the conversion of tryptophan to niacin (Shastri et al., 1968). Fleming and Barrows (1982) found that aging did not influence the absorption of nicotinic acid.

The AIN-93G diet (Reeves et al., 1993b) was formulated to contain 30 mg nicotinic acid/kg (244 µmol/kg). This provides an adequate amount for any experimental condition.

Signs of Niacin Deficiency Niacin deficiency causes reduced growth rate, rough coat, alopecia, and tissue concentrations of NAD and NADP are lowered. The concentrations of myelin in brain tissue are reduced as a result of a reduced synthesis of cerebrosides (Nakashima and Suzue, 1982, 1984).

Signs of Niacin Toxicity As the main excretory metabolites of nicotinic acid and nicotinamide are methylated, administration of high concentrations of niacin depletes the methyl pools of the body. Handler and Dann (1942) found that 10 g nicotinic acid/kg (80,000 µmol/kg) in a 10 percent casein diet caused an increase in fatty acids in the liver similar to a choline deficiency but without weight loss. A concentration of 2.5 g nicotinamide/kg diet (20,000 µmol/kg) caused the fatty liver and 10 g/kg diet (80,000 µmol/kg) decreased the rate of weight gain. The fatty livers could be prevented by including 1.5 g choline chloride/kg diet (11 mmol/kg), but choline alone would not support growth. Adding 0.6 percent methionine to the diet would correct the fatty liver and support growth. Growth could also be supported by 1.5 g choline chloride/kg and 0.6 percent homocystine in the diet. Jaus et al. (1977) noted that the injection of 0.50 g nicotinamide/kg BW (4,000 µmol/kg BW) twice daily caused enlarged liver cells and increased glycogen deposits. The effect was more pronounced in female rats. The injection of 0.6 g nicotinamide/kg BW (4,900 µmol/kg BW) per day resulted in reduced weight gain, and as little as 0.05 g/kg BW/day (400 µmol/kg BW/day) induced fatty livers (Kang-Lee et al., 1983; Sun et al., 1986). The LD50 for nicotinic acid is 4.3 to 4.9 g/kg BW (35,000 to 40,000 µmol/kg BW), but 0.85 g/kg BW/day (6,900 µmol/kg BW/day) was tolerated for 40 days with no abnormal histology. Nicotinamide is more toxic, and the LD50 is 1.7 to 3.0 g/kg BW (14,000 to 25,000 µmol/kg BW) (Unna, 1939; Brazda and Coulson, 1946).

Pantothenic Acid

Pantothenic acid functions as a constituent of coenzyme A and as a component of the acyl carrier protein in fatty acid synthesis. Pure pantothenic acid is an unstable viscous oil. Because pantothenic acid is difficult to handle, calcium pantothenate is normally used in diets. Only the d-pantothenic acid isomer has biological activity. The l-isomer does not have pantothenic acid activity and is actually a pantothenic acid inhibitor when its concentration is 100-fold greater than the d-isomer (Kimura et al., 1980). Some commercial preparations are equal molar mixtures of the d- and l-isomers and are only one-half as active as d-pantothenate. In this document the concentrations are expressed as the moles of d-pantothenic acid. One mole of calcium pantothenate is equivalent to 2 moles of d-pantothenic acid, and sodium pantothenate or hemicalcium pantothenate is only equivalent to 1 mole.

Unna (1940) found that 80 µg d-pantothenate/rat/day (0.36 µmol/rat/day) was necessary to maintain optimal growth. Henderson et al. (1942) found that only 40 µg/day (0.17 µmol/day) was needed to prevent the graying of black or hooded rats, that 80 µg/rat/day (0.36 µmol/rat/day) was required for optimal growth, and that about 100 µg/rat/day (0.42 µmol/rat/day) was necessary before pantothenate was excreted in the urine. Barboriak et al. (1957a) found 4 mg calcium pantothenate/kg diet (17 µmol pantothenic acid/kg diet) was needed to obtain optimal growth confirming the earlier values. This concentration would maintain pregnancy, but would not support lactation (Barboriak et al., 1957b). Nelson and Evans (1961) obtained normal growth of the suckling pups from dams receiving 10 mg calcium d-pantothenate/kg diet (42 µmol pantothenic acid/kg).

The AIN-76 (American Institute of Nutrition, 1977) and AIN-93G (Reeves et al., 1993b) diets were formulated to contain 15 mg calcium d-pantothenate/kg diet (63 µmol pantothenic acid/kg). The diets appear to contain an adequate safety margin because no problems related to pantothenic acid have been reported.

The antibiotics aureomycin, streptomycin, penicillin (Lih and Baumann, 1951; Sauberlich, 1952), and hygromycin (Barboriak and Krehl, 1957) delayed the appearance of the signs of pantothenic acid deficiency. In the later stages of the deficiency the signs develop in spite of the antibiotics. The effect seems to be related to changes in the intestinal microflora as the antibiotics did not delay the onset of deficiency when they were injected.

Signs of Pantothenic Acid Deficiency Pantothenic acid deficiency induces achromotrichia, exfoliative dermatitis, oral hyperkeratosis, necrosis, and ulceration of the gastrointestinal tract. Focal or generalized hemorrhagic necrosis of the adrenals may occur, and death results after 4 to 6

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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weeks of deficiency (Ralli and Dumm, 1953). Deficient rats had impaired antibody synthesis, decreased serum globulins, and decreased antibody forming cells in response to antigen. Restoration of antibody synthesis was achieved by parenteral administration of calcium pantothenate beginning 9 days before antigen injection (Lederer et al., 1975).

Signs of Pantothenic Acid Toxicity Pantothenic acid is relatively nontoxic. When excess amounts are consumed most of the excess is excreted in the urine. Daily administration of 185 mg (840 µmol) of pantothenate for 6 months did not produce any pathological changes in the rats (Unna and Greslin, 1941). The LD50 for rats was 3 g/kg BW/day (13,700 µmol/kg BW/day).

Riboflavin

Riboflavin is the precursor of the flavin coenzymes and is stored in the liver primarily as flavin adenine dinucleotide (FAD) (Rivlin, 1970). The coenzymes function with many oxidation-reduction enzymes, e.g., cytochrome c reductase, xanthine oxidase, and diaphorase. They are required, as is vitamin B6, for the conversion of tryptophan to nicotinic acid. Riboflavin is required for normal metabolism of vitamin B6 and folate coenzymes (Baker and Frank, 1968; Rivlin, 1970; Tamburro et al., 1971). The requirement is influenced by the dietary content of carbohydrate. Starch increases intestinal synthesis of the vitamin and decreases the required amount in the diet; sucrose does the reverse. Rats fed high-fiber diets had lower red blood cell riboflavin concentrations (Brady et al., 1983).

Adult rats fed diets providing 31 kcal ME/day (130 kJ ME/day) and 0 or 12 mg riboflavin/kg diet were compared to groups provided energy supplements containing sucrose:starch:corn oil (10:3:1 by weight). Glutathione reductase activity coefficients in liver, gastrocnemius, and soleus muscles, and erythrocytes were increased by riboflavin deficiency but were unaffected by the supplemental energy intake. The concentration of riboflavin in muscle decreased in the energy-restricted rats (Turkki et al., 1989). In another study, rats were fed 0.6 or 1.8 g casein/day and 30 mg riboflavin and then progressively restricted to 30 percent of energy intake 6.2 kcal ME/day (26 kJ ME/day); muscle riboflavin concentrations decreased during energy deprivation, did not return to normal with riboflavin supplementation at 100 mg/day, and were unaffected by the amount of protein intake (Turkki and Degruccio, 1983). The effect of protein on the riboflavin requirement was shown to be related to the rate of growth and not to the protein intake per se (Turkki and Holtzapple, 1982; Turkki et al., 1986).

Maximum hepatic storage of flavins was found in rats fed 40 mg/day (equivalent to 2.7 mg/kg diet) and the maximum weight gain at 30 mg/day (equivalent to 2 mg/kg diet) (Bessey et al., 1958). A dietary content of 0.9 or 1.2 mg/kg produced hepatic storage in rats equivalent to that produced by 15.6 or 23.0 mg/kg (Gaudin-Harding et al., 1971). A dietary concentration of 3 mg/kg saturated the pools of riboflavin, flavin mononucletotide (FMN), and FAD in the retina (Batey and Eckhert, 1992). The effect of exercise has been studied in relation to riboflavin status in the rat. It did not increase the requirement in growing rats but did increase the concentration of flavins in the gastrocnemius and soleus muscles (Hunter and Turkki, 1987). Studies to determine the minimal requirement for riboflavin suggested that it may be as low as 3.2 mg/rat/day, the equivalent of 0.2 mg/kg diet; but the dietary concentration recommended was 17 mg/rat/day or about 1.2 mg/kg diet (Anonymous, 1972). The dietary requirement based on growth response and hepatic stores is 2 to 3 mg riboflavin/kg diet. The requirement can be expressed on a caloric basis as 0.6 to 0.8 mg riboflavin/1,000 kcal ME.

Offspring of dams fed a diet containing 1 mg riboflavin/kg after weaning had decreased body weight, brain weight, and brain DNA content compared to offspring of rats fed a diet containing 8 mg/kg. Correction of these defects in the riboflavin-deficient young was achieved by feeding their dams 2.7 mg/kg diet during lactation but not by supplementation of the diet of the offspring after weaning (Fordyce and Driskell, 1975). In another study rats were fed diets containing 0.40, 0.52, 0.65, or 15.4 mg riboflavin/kg diet 4 weeks before mating, throughout pregnancy, and up to day 15 of lactation (Duerden and Bates, 1985). Fetal resorption occurred in rats receiving 0.4 mg/kg, but those receiving 0.52 mg/kg had successful litters. Dams and their offspring receiving 0.52 or 0.65 mg/kg had higher erythrocyte glutathione reductase activity coefficients and their liver riboflavin concentrations were lower than those fed 15 mg/kg. The concentration of milk riboflavin in the rats fed 0.52 or 0.65 mg/kg was about one-eighth that of rats fed 15 mg/kg diet. The offspring of lactating dams fed diets containing 2, 4, 6, 8, 12, or 16 mg riboflavin/kg had blood glutathione reductase activity coefficients of 1.45, 1.12, 1.12, and 1.12, respectively, at 17 days postpartum. At day 34 the activity coefficients for those fed 4 and 8 mg/kg diet were 1.09 and 1.10 (Leclerc and Miller, 1987). In pregnant rats 4 mg/kg diet produced growth and hepatic riboflavin stores equivalent to 100 mg/kg diet (Schumacher et al., 1965). The intestinal transport of riboflavin is decreased during the period between 14 days to 3 months old and remained constant up to 26 months (Said et al., 1985; Said and Hollander, 1985). The requirement for normal reproduction is 3 to 4 mg/kg diet.

Signs of Riboflavin Deficiency The classical signs of riboflavin deficiency are dermatitis, alopecia, weakness, and decreased growth. Corneal vascularization and ulceration, cataract formation, anemia, and myelin degeneration may

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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occur (Horwitt, 1954). The activity coefficient of lenticular glutathione reductase was increased and gamma crystallin lowered by deficiency (Bhat, 1982, 1987). Riboflavin-deficient rats may have fatty liver, abnormal hepatocyte mitochondria, and metabolic abnormalities of hepatocytes. The complex metabolic effects of riboflavin deficiency have been reviewed and summarized as (1) a decrease in flavoproteins involved in cellular oxidations; (2) increased protein turnover and an increased pool of free amino acids, which result in increased amounts of enzymes associated with amino acid metabolism, particularly enzymes of gluconeogenesis; and (3) a large decrease in mitochondrial respiration and adenosine triphosphate (ATP) synthesis (Garthoff et al., 1973). Reproductive performance is decreased in both males and females; offspring of deficient females may have congenital anomalies. On day 18 of gestation the iron-mobilizing activity in placental mitochondria was reduced. Maternal iron stores were higher and fetal tissue iron was unaffected presumably because of reduced fetal mass that limited maternal iron depletion and maternofetal iron transfer (Powers, 1987).

Riboflavin deficiency leads to a reduction in the storage of liver and spleen iron, transferring saturation, hemoglobin concentrations, plasma iron, iron absorption, and liver ferritin-Fe (Adelekan and Thurnham, 1986a; Yu and Cho, 1989; Shanghai, 1991). When deficiencies of riboflavin and iron were induced, riboflavin had a sparing effect on iron status because of the reduction in growth rate induced by the vitamin deficiency (Adelekan and Thurnham, 1986b). In rats fed purified diets deficient in riboflavin, both red blood cell and hepatic glutathione reductase was significantly decreased (Bamji and Sharada, 1972). Red blood cells of deficient rats have decreased fluidity and increased membrane bound acetylcholinesterase, increased glutathione peroxidase activity, and higher concentrations of peroxidation products (Levin et al., 1990). Increases in the amount of lipid peroxides were observed in serum and liver after a 5-week deficiency (Taniguchi, 1980). Rats fed riboflavin-deficient diets had decreased activities of hepatic flavokinase and FAD synthetase but not FMN phosphatase and FAD pyrophosphatase (Lee and McCormick, 1983). Rats deficient in riboflavin had depressed hepatic folate stores despite adequate or even increased intake of folate (Tamburro et al., 1971). Riboflavin-deficient rats prevented from coprophagy had lower hepatic methylene-tetrahydrofolate reductase activity but not lower dihydrofolate reductase activity (Bates and Fuller, 1986). Deficient rats had lower activities of the mitochondrial FAD-dependent straight-chain acyl-CoA dehydrogenases and the branched-chain acyl-CoA dehydrogenases (Veitch et al., 1988), NADPH-cytochrome c reductase (Taniguchi, 1980; Wang et al., 1985), ethoxycoumarin-0-deethylase and aryl hydrocarbon hydroxylase (Hietanen et al., 1980), and aflatoxin B1 activation and DNA adduct formation (Prabhu et al., 1989). Plasma and tissue carnitine concentrations were reduced by deficiency (Khan-Siddiqui and Bamji, 1987). Riboflavin-deficient rats failed to increase their food intake when fed energy-diluted diets even when given insulin. However, cold exposure stimulated their intake (Matsuo and Suzuoki, 1982).

The activity coefficient of glutathione reductase in red blood cells, liver, and skin correlate with chronic marginal riboflavin deficiency (0, 0.5, 1.0, and 1.5 mg/kg diet). Hepatic and renal FAD is conserved at the expense of riboflavin and FMN. ATP:riboflavin 5-phosphotransferase was decreased in proportion to the concentration of dietary riboflavin, but ATP:FMN adenylyltransferase (FAD pyrophosphorylase) was increased in severely deficient rats. A reduction in succinate:(acceptor) oxidoreductase (succinate dehydrogenase) and NADH:(acceptor) oxidoreductase (NADH dehydrogenase) was tissue dependent (Prentice and Bates, 1981).

Signs of Riboflavin Toxicity Excessive concentrations of dietary riboflavin have been shown to decrease survivability of newborn rat pups. Mortality during the first week of life was increased 19 percent in a strain of Long-Evans rats by increasing the concentration from 6 to 12 mg/kg (Eckhert, 1987), and the percent of newborn Sprague-Dawley rats surviving to weaning was reduced 7 percent by increasing riboflavin from 8 to 80 mg/kg (Shirley, 1982). Chronic intakes of 12 mg/kg have been shown to cause photoreceptor damage (Eckhert et al., 1989, 1991).

Thiamin

Thiamin is the precursor of thiamin pyrophosphate, which is the storage form and the coenzyme for oxidative decarboxylation and other oxidative reactions. The requirement for thiamin in the diet of the rat depends in part on the quantity and source of dietary energy and is increased by increasing carbohydrate. It has been reported to decrease when dietary fat was increased (Scott and Griffith, 1957), but not in all cases (Murdock et al., 1974). Xylitol had a sparing effect on thiamin resulting from an increase in intestinal facultative bacteria that have the ability to synthesize the vitamin (Rofe et al., 1982). Diabetic rats may have an increased requirement for the vitamin as a result of the alterations in glucose turnover (Berant et al., 1988).

Male weanling rats fed a diet containing either 1.25 or 12.5 mg thiamin/kg diet did not differ in their feed efficiency ratio, but rats fed the higher concentration of thiamin grew faster (Mackerer et al., 1973). There was no significant difference in growth of rats fed either 5 or 50 mg thiamin/kg diet (Itokawa and Fujiwara, 1973). Growth curves of young male rats fed diets containing 0, 0.3, 0.6, 1.5, 6.0, 30.0, and 100.0 mg/kg were used to calculate the

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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amount of thiamin required for maximum growth (Mercer et al., 1986). The theoretical maximum growth rate was 7.0 g/day, and a concentration of 3.68 mg/kg was sufficient to achieve 99 percent (6.93 g/day) of this rate. A concentration of 3.3 mg/kg supported retention of carcass thiamin in nonpregnant and pregnant female rats fed an 18.2 percent protein diet and 3.75 kcal ME/kg diet (15.7 kJ ME/kg) (Roth-Maier et al., 1990). The requirement for growth is 4 mg thiamin-HCl/kg diet.

In pregnant rats the concentration of plasma thiamin remained constant throughout the first 18 days of gestation, while erythrocyte thiamin reached a maximum at day 11 and then declined (Chen et al., 1984). Urinary excretion of thiamin in pregnant rats fed diets containing 2, 4, 6, or 8 mg/kg were stable up to day 16 of gestation and then decreased until parturition (Leclerc, 1991). Pregnant rats fed diets containing 0, 0.8, 1.7, 3.3, 6.7, 13.3, 20, 26.7, 100, 1,000, and 10,000 mg/kg were evaluated for organ thiamin retention (Roth-Maier et al., 1990). The amount of thiamin retained by the liver, muscle, brain, and whole carcass increased with each increase in dietary thiamin. Pregnant rats were fed diets that contained either 4 or 100 mg thiamin/kg. The hepatic stores of thiamin were higher at weaning in the offspring of dams fed the higher concentration, but growth was not affected (Schumacher et al., 1965). The requirement for pregnancy and lactation is 4 mg thiamin-HCl/kg diet.

Signs of Thiamin Deficiency Thiamin deficiency can be induced readily and produces anorexia and weight loss with an increase in food spillage (Tagliaferro and Levitsky, 1982) and in coprophagy (Fajardo and Hornicke, 1989). Thiamin-deficient rats avoid eating sucrose (Yudkin, 1979) and are slower to respond to tasks where food pellets are used for reinforcement (Hashimoto, 1981). Evaluations of behavior demonstrated that rats maintained on thiamin-deficient diets showed muricide aggression (Onodera et al., 1981; Onodera, 1987). After 7 days of deficiency there is a decrease in white and red blood cells and a drop in hemoglobin. After 30 days this is reversed and reticulocytes and plasma erythropoietin are increased, but red blood cell 2,3-diphosphoglycerate, membrane cholesterol, and phospholipids decrease (Hobara and Yasuhara, 1981). After 4 weeks there is a decrease in liver thiamin and an elevation in plasma branched-chain amino acids, α-ketoacids, and α-hydroxyacids (Shigematsu et al., 1989). Deficiency during pregnancy resulted in intrauterine growth retardation (Roecklein et al., 1985) and decreased activity of the thiamin-dependent enzymes pyruvate dehydrogenase, α-ketoglutarate dehydrogenase, and transketolase (Fournier and Butterworth, 1990) and gangliosides (Vaswani, 1985) in newborn rat brains. Acetylcholine was reduced in weanling rats of thiamin-deficient mothers (Kulkarni and Gaitonde, 1983).

In the adult, deficiency results in abnormalities of the central and peripheral nervous systems and the heart. Chronic thiamin deprivation leads to selective neuropathological damage in the brain. Rats become ataxic and a decrease in pyruvate dehydrogenase occurs in the midbrain and lateral vestibular nucleus (Butterworth et al., 1985). Conduction velocity in peripheral nerves was reduced, but axonal transport was increased (McLane et al., 1987). Treatment with pyrithiamine, a thiamine phosphokinase inhibitor, in combination with deficiency, resulted in a decrease in brain amino acids and monoamines (Langlais et al., 1988) and in the activities of glutamic acid decarboxylase and GABA-transaminase (Thompson and McGeer, 1985). Thiamin deficiency produced an increase in cardiac weight, a decrease in cardiac and renal ATP and pyruvate carboxylase, but no cardiac ultrastructural abnormalities (Schenker et al., 1969; McCandless et al., 1970). Cytochrome P-450 concentration and drug metabolizing ability are increased (Wade et al., 1983; Yoo et al., 1990). Thiamin deficiency resulted in an increase in liver nicotinamide methyltransferase and in the excretion of N-1-methylnicotinamide (Shibata, 1986).

Thiamin status has been reported to be influenced by folate deficiency. Folate-deficient rats had decreased absorption of low doses of thiamin, but large doses were absorbed normally (Howard et al., 1974). In an earlier study (Thomson et al., 1972), folate-deficient rats fed 22 mg/kg diet had a significant depletion of thiamin in blood and liver but not in brain. In a more recent study (Walzem and Clifford, 1988b), however, no differences were observed in either thiamin absorption or excretion as a result of folate deficiency.

The enzymatic activity of transketolase in blood and tissues of thiamin-deficient animals correlates with thiamin status, and it may or may not be restored in vitro by the addition of thiamin pyrophosphate (TPP). This may depend on the duration of the deficiency and the resultant instability of the apoenzyme (Brin, 1966; Pearson, 1967; Warnock, 1970; Bamji and Sharada, 1972; Walzem and Clifford, 1988a).

POTENTIALLY BENEFICIAL DIETARY CONSTITUENTS

Requirements have not been determined for the nutrients discussed in this section; however, they are ubiquitous and in abundant supply in natural-ingredient diets and are often missing, or their quantities greatly reduced, in purified diets. Although purified diets support growth and reproduction, numerous investigators have noted that animals exposed to stress, whether carcinogens, age, or diet imbalances, survive longer when fed diets composed of natural-ingredients (Longnecker et al., 1981). This suggests

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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that dietary substances not recognized as essential may have beneficial effects.

FIBER

Although dietary fiber has not been shown to be required by the rat, its inclusion in diets may be potentially beneficial. The effects elicited by fiber depend on the properties of the fiber source (i.e., viscosity, solubility, fermentability). Feeding rats fiber increases their fecal bulk and decreases gastrointestinal transit time; decreases in transit time are more pronounced with insoluble fibers (Fleming and Lee, 1983). Increases in the weight of the cecum and colon are observed when fiber is included in rat diets. Inclusion of cellulose (insoluble fiber) in the diet led to greater enlargement of the colon; glucomannan (soluble fiber) led to greater enlargement of the cecum (Konishi et al., 1984).

Increases in cecal wall weight occur in rats fed lactulose, a disaccharide fermented in the cecum, suggesting that microbial fermentation plays an important role in stimulating this hypertrophy (Remesy and Demigne, 1989). The viscosity of fiber sources also may be an important factor influencing cecal hypertrophy (Ikegami et al., 1990). The energy value of fiber for rats depends on fermentation in the hindgut. Microbial fermentation of fiber results in volatile fatty acid production, predominantly of acetate, propionate, and butyrate, which are absorbed and can be used as energy sources by the rat. The digestible energy values of cellulose, a relatively unfermentable fiber, and guar, a highly fermentable fiber, were 0 and 2.4 kcal/g (10 kJ/g), respectively, for the rat. Consumption of guar-containing diets, however, increased heat production by rats such that, despite additional energy supply from guar, there was no additional gain of body energy (i.e., NE = 0; Davies et al., 1991). It is unknown if this thermogenic effect of guar applies to other fermentable fibers.

Additions of insoluble, undegradable sources of fiber such as cellulose, oat hulls, wheat bran, and corn bran to rat diets at concentrations up to 20 percent do not affect growth. Because these nonfermentable fiber sources dilute the nutrient density of the diet, feed intake increases and gain:feed decreases as these fiber sources are added to the diet (Schneeman and Gallaher, 1980; Fleming and Lee, 1983; Lopez-Guisa et al., 1988; Nishina et al., 1991). At high concentrations, viscous polysaccharides such as pectin, guar, and carboxymethylcellulose may decrease weight gain. When added at high concentrations, feed intake may decrease, especially during initial adaptation (Davies et al., 1991). The effects of pectin in particular are difficult to assess because its properties can vary greatly among sources depending on molecular weight and degree of esterification. The more viscous pectins (high molecular weight and degree of esterification) tend to cause greater decreases in feed intake than less viscous pectins (Atallah and Melnik, 1982). Delorme and Gordon (1983) observed a 30 percent decrease in growth of rats when 4.8 percent pectin was added to diets and a 50 percent mortality when 28.6 percent pectin was added. Fleming and Lee (1983) observed a 35 percent decrease in weight gain when 10 percent pectin was added to the diet, but Nishina et al. (1991), Thomsen et al. (1983), and Track et al. (1982) found no differences in growth when 5 to 8 percent pectin was added to purified fiber-free diets. Guar added to diets at 5 percent of dry matter had no effect on body weight (Ikegami et al., 1990), but 8 percent guar depressed gain (Cannon et al., 1980; Track et al., 1982).

Nitrogen metabolism can be altered by dietary additions of fermentable fiber sources. Fecal nitrogen excretion increases and urinary nitrogen excretion decreases as a result of microbial fermentation and growth in the hindgut. Remesy and Demigne (1989) demonstrated that absorption of ammonia from the hindgut increased when fermentable fiber sources (pectin and guar) were added to the diet, but transfer of urea to the gut was stimulated to a greater extent such that net fecal excretion of nitrogen was increased. The addition of fermentable fiber sources to diets deficient in arginine may improve growth by decreasing the need for arginine for hepatic urea synthesis (Ulman and Fisher, 1983).

Many fiber sources have been used in rat diets including soybean fiber (Levrat et al., 1991), carrageenan, xanthan, alginates (Ikegami et al., 1990), and gum arabic (Tulung et al., 1987). The effects of these fibers can generally be predicted based on their physical properties and fermentabilities. Some carbohydrates that cannot be properly called fiber also elicit some responses similar to those observed for true fibers. Lactulose (disaccharide), raffinose (trisaccharide), and fructooligosaccharides are not absorbed in the small intestine but are rapidly fermented in the hindgut (Fleming and Lee, 1983; Remesy and Demigne, 1989; Tokunaga et al., 1989). Some starches, particularly raw potato, escape small intestinal digestion, are fermented in the cecum, and exert effects similar to true fibers (Calvert et al., 1989).

MINERALS

Many of the mineral elements—including chromium, arsenic, boron, nickel, vanadium, silicon, tin, fluorine, lead, and cadmium—are present in very low concentrations in tissues and body fluids. Some of these elements may be essential for metabolic functions. As with other nutrients, the mineral elements are considered nutritionally essential if a dietary deficiency consistently results in a suboptimal response of an essential physiological function, and if the suboptimal response is preventable or reversible by providing physiological amounts of the mineral by dietary or

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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parenteral means (Nielsen, 1984; Underwood and Mertz, 1987).

Perhaps this is a simplistic definition of essentiality when nutrients that have similar physiological functions are considered together. For example, in the antioxidant class of nutrients, selenium and vitamin E may interact so that gross signs of selenium deficiency, such as body weight reduction and reproductive failure, may not be evident in the presence of adequate vitamin E (Combs and Combs, 1984). Similar interactions may occur among other minor nutrients when the deficiency of one may not be expressed in the presence of an abundance of another (Nielsen, 1985).

Many of the essential mineral elements known to be required in the diet in very low concentrations are components of enzymes or metabolic cofactors. Although chromium, arsenic, boron, nickel, vanadium, silicon, tin, lithium, fluorine, lead, and cadmium produce some physiological responses when included in the diets of mammals, they have not been found to associate with enzymes or cofactors. Chromium and vanadium, for example, seem to enhance glucose metabolism, but the mechanism is unknown and the physiological significance of their effects has not been demonstrated; thus, their essentiality remains a question.

Requirements cannot be assessed at this time for any of the mineral elements listed above, but they are widespread in natural-ingredient diets. On the other hand, in purified and chemically defined diets they are often at very low concentrations or cannot be detected. Consequently, a selection of the minor elements are sometimes included in purified diets (Reeves et al., 1993b; Table 2-5).

If these minor elements have any positive effect on the metabolic responses of animals, it could be the result of an indirect effect caused by microbial populations in the gut. For example, the amounts of organic nutrients and/or unknown growth factors produced by microbes may be changed, or changes in microbial populations may affect the utilization of nutrients (Shurson et al., 1990; Rong et al., 1991; Andrieux et al., 1992; Yoshida et al., 1993).

Chromium

Because supplemental trivalent chromium has been reported to have an enhancing effect on insulin and glucose metabolism, it has been suggested that chromium is essential for the rat and that chromium's function is to aid in the utilization of glucose. The work of Schwarz and Mertz (1959), Schroeder et al. (1963), Schroeder (1966), Roginski and Mertz (1967), Mertz et al. (1965), Mertz and Roginski (1969), and Roginski and Mertz (1969), using highly restrictive environmental conditions, often are cited as evidence for the essentiality of chromium for the rat. Whether this constitutes a beneficial physiological function is uncertain. Specificity is questioned because other heavy metals may initiate similar effects (Fagin et al., 1987; Pederson et al., 1989).

Other studies have failed to show positive effects of chromium on glucose tolerance or glucose utilization by tissues of rats (Woolliscroft and Barbosa, 1977; Flatt et al., 1989; Holdsworth and Neville, 1990). Woolliscroft and Barbosa (1977) fed 6-week-old Sprague-Dawley rats 30 percent torula yeast diets containing low-chromium concentrations (30 to 100 µg/kg, estimated) or diets that contained 5,000 µg Cr/kg. After 6 weeks, there was no significant difference in intravenous glucose tolerance between the two groups. Flatt et al. (1989) found no significant difference in food intake, body weight gain, glycosylated hemoglobin, plasma glucose, plasma insulin, glucose tolerance, or insulin sensitivity between two groups of weanling Wistar rats fed either 30 or 1,000 µg Cr/kg diet for 32 days. Differences in chromium concentrations in tissues between the two groups was variable—from no change in skeletal muscle to a 44 percent reduction in the pancreas.

Holdsworth and Neville (1990) found no effect of dietary chromium supplementation on glucose metabolism in rats. They fed weanling Wistar rats Torula yeast diets similar to those designed by Schwarz (1951) but supplemented with L-cystine, L-methionine, and L-histidine. These supplemented diets supported more rapid growth than the original diet and contained 100 (low-chromium diet) or 1,000 µg Cr/kg (high-chromium diet). A control group was fed a commercial natural-ingredient diet. After 5 weeks, the rats fed the Torula yeast diets gained 30 percent less weight than did the control rats, regardless of whether chromium was present. Those fed chromium-supplemented yeast diets did not grow at a significantly higher rate than those without supplemental chromium. The incorporation of glucose carbon into liver glycogen in the rats fed the low-chromium diet was only one-fifth that of the control rats, but was not different from that of rats given the chromium-supplemented yeast diet. Yeast was grown in media with or without chromium. Extracts from this yeast enhanced glucose incorporation into glycogen of hepatocytes isolated from rats fed low- or high-chromium diets regardless of whether chromium was present in the extract.

Others have reported lower sperm counts in rats fed low-chromium diets (<100 µg/kg) for 8 months than in rats fed high-chromium diets (2,000 µg/kg) (Anderson and Polansky, 1981). Effects of chromium supplementation on weight gain in rats are achieved only with restrictive environmental conditions (Schroeder et al., 1963). Under similar conditions, supplementation of the diet with other heavy metals such as cadmium and lead also enhance initial weight gain, suggesting a nonspecific pharmacological response rather than a nutritional response (Schroeder et al., 1963).

Although the earlier studies seemed to indicate that

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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dietary chromium supplements enhanced glucose metabolism, the more recent studies did not. It could be argued that the duration of the experiments and environmental conditions in the later studies were not sufficient to allow chromium stores to be depleted and deficiency signs to be expressed. Signs of chromium deprivation might have been more evident if longer feeding periods or multiple-generation studies had been used.

Trivalent chromium salts, chromic oxide, and metallic chromium have low orders of toxicity; however, because of their oxidizing properties, chromium trioxide, chromates, and bichromates are potent poisons. A detailed discussion of tolerance concentrations for chromium in animals can be found in Mineral Tolerance of Domestic Animals (National Research Council, 1980).

Lithium

Pickett and O'Dell (1992) fed rats a low-lithium diet (5 µg/kg) through five successive generations and found that the weaning weights of the offspring were significantly lower than weaning weights from dams fed diets with 500 µg Li/kg. Other experiments showed that litter size and birth weights were decreased by feeding rats low-lithium diets through three generations. They also showed an interaction between lithium and sodium in that low-lithium effects were exaggerated in rats fed high-sodium diets. Earlier studies by this laboratory (Patt et al., 1978; Pickett, 1983) showed that second- and third-generation females fed low-lithium diets were less fertile than controls. These studies suggest that diets containing less than 10 µg Li/kg fed to rats through multiple generations could impair reproductive performance.

Signs of Lithium Toxicity Lithium in high doses can be toxic to the kidney. The minimal toxic concentration of dietary lithium is unknown, but rats fed 280 mg Li/kg diet from 0 to 65 weeks of age developed renal failure (Nyengaard et al., 1994). Nephrotoxicity occurred in rats given 14 mg Li/kg BW/day subcutaneously for 8 days (Qureshi et al., 1992). Rat embryos grown in rat serum with a lithium concentration of 0.6 mmol/L showed signs of toxicity. Until more is learned about the minimal toxic concentration of dietary lithium, it is recommended that the dietary concentration not exceed 1 mg/kg diet (Hansen et al., 1990).

Nickel

Nickel biochemistry plays a prominent role in the metabolism of anaerobic bacteria, plants, and tunicates. Many plant species contain the enzyme urease, which is nickel dependent (Cammack, 1988). Although investigators have shown some cause to believe that nickel is essential for animals, the results among experiments are not consistent. Lederer and Lourau (1948) first suggested that nickel was involved in hematopoiesis because it activated an enzyme required for this process. This began a series of nutritional experiments designed to show a relationship between dietary nickel and iron metabolism. Initial studies showed that nickel-deficient rats showed deficiency signs that could be alleviated by ingesting an adequate dietary concentration of iron (Schneggg and Kirchgessner, 1975a,b, 1976a,b, 1978). Subsequent studies by other investigators (Nielsen et al., 1979; Nielsen, 1980a,b, 1984) demonstrated that the apparent nickel-iron interaction in rats depended on the form of iron fed; however, these investigators could not show a consistent effect of nickel deprivation. They suggested that previously observed effects of nickel on iron metabolism were pharmacological rather than physiological because the amount of nickel supplementation was so high.

Studies with nickel have been carried through multiple generations. Nielsen et al. (1975) fed rats low-nickel diets (2 to 15 µg Ni/kg diet) for three generations and reported that this had no effect on growth of the offspring, but thriftiness and coat condition were worse in the nickel-deprived rats than in similar rats fed diets containing added nickel (3,000 µg/kg). They also found lower hematocrits in the deprived rats than in controls. These results strongly suggest that nickel is essential for the well-being of the rat, but the experiments have not been repeated or confirmed in other laboratories. Other studies have shown that higher concentrations of dietary nickel (20 µg Ni/kg diet) increased weight gain in F1 and F2 generation neonatal rats (Nielsen et al., 1979). However, growth rate in rats from weanling to 10 weeks old was not affected by this amount of nickel in the diet (Nielsen et al., 1984).

Studies to determine the possible interaction between nickel and other nutrients have not established with certainty that nickel is essential for growth or any known biochemical process in animal tissues (Nielsen et al., 1989). Given the question about pharmacological versus physiological actions (Nielsen et al., 1984), the lack of marked pathological effects with low dietary intakes of nickel, and the lack of defined biochemical functions in animals, it is not certain that nickel is essential.

Signs of Nickel Toxicity The amount of dietary nickel required to cause a toxic response in rats is relatively high. Numerous studies have demonstrated that rats have no adverse effects when fed 100 to 1,000 mg Ni/kg diet (Phatak and Patwardhan, 1950; Ambrose et al., 1976) or only lose weight (at 1,000 mg/kg diet; Whanger, 1973). Schnegg and Kirchgessner (1976b) found that rats fed 1,000 mg Ni/kg diet developed many abnormal physiological responses such as increased hematocrit, hemoglobin, and serum protein.

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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Silicon

Earlier work in two separate laboratories suggested that silicon was an essential nutrient for animals. Carlisle (1972) and Schwarz and Milne (1972) described the effects of silicon supplementation on growth of rats and chicks. Schwarz and Milne observed that the addition of silicon to diets at 500 mg/kg led to increased growth rates in rats fed added silicon as opposed those fed diets not supplemented with silicon. These data may be somewhat misleading because the maximal growth rate of the controls was only 25 to 50 percent of the rate expected for the strain of rat used. This suggests that the diets were generally deficient in some other nutrient(s). Carlisle (1972) showed similar results in chicks fed 100 mg Si/kg diet, but the maximal weight gain of the control chicks was relatively small, only 25 percent of the normal rate for chicks of this age. As in the experiments with rats, the diets seemed to be generally inadequate to support rapid growth.

Although these studies have been cited as establishing silicon essentiality, they have not been verified by subsequent studies. Elliot and Edwards (1991) found that weight gains were depressed in chicks fed 250 mg Si/kg diet compared to those fed diets with no added silicon. No significant effects on growth or any other measures were found in the animals fed the higher silicon concentration compared to those not receiving silicon in their diet. In this experiment the chicks grew at a rate expected for the age and strain.

A number of experiments have shown effects of dietary silicon supplementation on various physiological measures in rats, but none has been able to confirm that the effects are nutritional (Carlisle, 1970; Emerick and Kayongo-Male, 1990a,b; Carlisle et al., 1991).

Signs of Silicon Toxicity Large doses of silicon in the form of tetraethylorthosilicate (2 percent: »2,600 mg Si/kg diet) cause urolithiasis in the rat. Death occurred in some rats as a result of urethral obstruction. The lesion was enhanced as the dietary calcium concentration was increased (Schreier and Emerick, 1986).

Sulfur

Sulfur is required as an integral part of sulfur-containing amino acids and vitamins. Michells and Smith (1965) showed that dietary sulfate was readily incorporated into cartilage of Wistar rats and spared methionine for other purposes. Bernhart and Tomarelli (1966) reported a positive effect on growth of Sprague-Dawley rats with added sulfate in the diet. When fed an 8.8 percent lactalbumin diet with a mineral mix that met the requirements of the rat (National Research Council, 1962), growth was improved by inclusion of 1,000 mg sulfate/kg diet. No increased growth response was observed when sulfate was included in diets with adequate protein.

Jacob and Forbes (1969) found that weanling Sprague-Dawley rats grew slightly better when fed 15 percent casein diets supplemented with methionine and 350 mg S/kg than with a similar diet supplemented with methionine and 40 mg S/kg as sulfate. Smith (1973) reported that 200 mg inorganic sulfate/kg diet was optimal for adult Long-Evans rats because this amount of inorganic sulfate reduced expiration of 14CO2 from a test dose of 1-14C-methionine. On the basis of these limited data, 300 mg S/kg diet as inorganic sulfate may be beneficial.

Vanadium

In the early 1970s there were several reports from different laboratories that led to the conclusion that vanadium was an essential trace mineral for the rat (Schwarz and Milne, 1971; Strasia, 1971; Hopkins and Mohr, 1974); however, this conclusion has not been supported by all studies (Williams, 1973). Later studies suggest that the results of the previous work demonstrated pharmacological rather than nutritional actions of vanadium (Nielsen, 1984; Nechay et al., 1986; Nielsen and Uthus, 1990).

Reports of the pharmacologic effects of vanadium are numerous. One of the most studied effects is on insulin action. Vanadium is an insulinomimetic agent in vitro and may be in vivo as well. Given in the drinking water, vanadium was shown to lower blood glucose and reduce the activity of phosphotyrosyl-protein phosphatase in the liver of mice (Meyerovitch et al., 1991). The concentration of vanadium given was many times higher than that found in a normal rodent diet, however. Others have shown that pervanadate mimics insulin action by activating the insulin receptor kinase (Fantus et al., 1989). Seaborn et al. (1992) found serum glucose significantly lower in male guinea pigs fed 500 µg V/kg diet compared to those fed less than 10 µg/kg. However, plasma cortisol in the vanadium-fed guinea pigs was elevated more than 100 percent over that of guinea pigs not fed vanadium, suggesting that vanadium in the diet might have stressed the animals. Other measurements were enhanced by vanadium in the diet, but because there were no criteria for normalcy in these studies, the results suggest that vanadium may have caused a toxic reaction rather than demonstrating nutritive value.

Because vanadium is known to be required by some haloperoxidases in lower life forms (Yu and Whittaker, 1989), it has been suggested that peroxidases involved in iodine metabolism in animals may be vanadium-dependent. Some studies have attempted to show an interaction between iodine and vanadium, but the findings were inconclusive and more definitive experiments have not been forthcoming (Uthus and Nielsen, 1990). Because of the lack of definitive and repeatable experiments on the nutritive

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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response to vanadium, its essentiality for the rat or other mammals is uncertain.

Signs of Vanadium Toxicity The toxicity of vanadium is probably manifested through its effect on tissue enzyme activity. Vanadium has been shown to inhibit numerous enzymes that hydrolyze phosphate esters, including ribonuclease (Lindquist et al., 1973), acid and alkaline phosphatases (Lopez et al., 1976), and phosphotyrosyl-protein phosphatase (Swarup et al., 1982). Sodium, K-ATPase also is inactivated by vanadium (Nieder et al., 1979). Vanadium activates other enzymes such as adenylate cyclase (Grupp et al., 1979) and enhances the phosphorylation of the tyrosyl moiety on proteins. The latter is apparently involved in the overstimulation of membrane receptors, as seen when vanadium stimulates insulin action (Fantus et al., 1989). Rau et al. (1987) found that vanadate stimulated NADH oxidation in microsomes with an increased production of hydrogen peroxide and possible superoxide. Earlier work showed that as little as 25 mg V/kg diet caused visible signs of toxicity such as reduced growth and food utilization in the rat (Franke and Moxon, 1937; Hansard, 1975).

VITAMINS

Ascorbic Acid

Rats do not require a dietary source of ascorbic acid. Enzymatic synthesis of this vitamin can occur via glucuronolactone or gulonolactone in the liver. However, ascorbic acid is a potentially beneficial dietary constituent.

Rats fed ascorbic acid store the vitamin as ascorbic acid and ascorbic acid 2-sulfate (Pillai et al., 1990). Ascorbic acid sulfotransferase was increased, whereas ascorbic acid-2-sulfate sulfohydrolase was reduced in activity in ascorbic acid-supplemented rats. When ascorbic acid was withdrawn from the diet, tissue ascorbic acid, ascorbic acid 2-sulfate, and the activity of ascorbic acid sulfotransferase were reduced and ascorbic acid-2-sulfate sulfohydrolase was increased (Pillai et al., 1990).

Ascorbic acid may be potentially beneficial in thiamin and vitamin B12 deficiencies. Five percent ascorbic acid in the diet supported normal weight gain in thiamin-deficient rats and increased the fecal content of thiamin (Scott and Griffith, 1957; Murdock et al., 1974). The inclusion of 100 mg ascorbic acid/kg in a vitamin B12-deficient diet raised liver vitamin B12 concentrations in rats (Thenen, 1989).

Several interactions of ascorbic acid with minerals have been identified in rats. Magnesium deficiency reduced ascorbic acid concentration in liver and kidney, as well as the enzymatic synthesis of the vitamin from glucuronolactone or gulonolactone in liver (Hsu et al., 1983). Supplementation of the diet with high iron (5 mg/rat/day) decreased tissue, blood, and urinary concentrations of ascorbic acid (Majumder et al., 1975). However, dietary ascorbic acid increased the absorption of nonheme iron in rats but to a lesser extent than in humans (Reddy and Cook, 1991). Ascorbic acid fed at 1 percent of the diet decreased tissue copper and, in the presence of high iron (191 mg/kg), caused severe anemia and reductions in ceruloplasmin in copper-deficient rats (Johnson and Murphy, 1988). A 1 percent ascorbic acid diet decreased the efficiency of intestinal copper absorption. When copper was given intraperitoneally, however, the rate of copper excretion was decreased (Van den Berg et al., 1989). Lead exposure reduced brain ascorbic acid concentrations (Seshadri et al., 1982). Ascorbic acid given orally was as effective on a molar basis as was parenterally administered EDTA in removing lead from the central nervous system (Goyer and Cherian, 1979). In rats fed lead (500 mg/kg diet) the addition of ascorbic acid as 1 percent of the diet and of 400 mg Fe/kg diet decreased the accumulation of lead in the tissues and prevented growth depression, anemia, and food intake decreases (Suzuki and Yoshida, 1979).

Ascorbic acid may help protect against peroxidation and spare vitamin E. It has been shown to decrease expired pentane, used as a marker for lipid peroxidation (Dillard et al., 1984). Ascorbic acid supplementation reduced the elevation of liver thiobarbituric acid values and reversed decreases in hepatic pyruvate kinase, aspartate aminotransferase, plasma creatine phosphokinase, and vitamin E in vitamin E-deficient rats (Chen and Thacker, 1987). However, high concentrations of ascorbic acid (1.5 g/kg diet) increased in vitro erythrocyte hemolysis and liver lipid peroxidation while lowering reduced glutathione in plasma and erythrocytes (Chen, 1981).

A rat mutant (ODS) unable to synthesize ascorbic acid because of a lack of L-gluconolactone oxidase has been identified (Mizushima et al., 1984). Poor growth, muscle and leg joint hemorrhage, decreased cytochrome P-450, elevated serum and adrenal corticosterone, and lowered urinary excretion of hydroxyproline were prevented in the ODS rat by feeding them 300 mg ascorbic acid/kg diet (Horio et al., 1985). Concentrations of 1,000 to 3,000 mg ascorbic acid/kg diet were required to achieve maximum activities of several microsomal drug-metabolizing enzymes in the liver of these rats when exposed to polychlorinated biphenyls (PCBs) (Horio et al., 1986). A dietary concentration of 250 mg/kg increased survival time to at least 36 weeks following exposure to N-butyl-N-(4-hydroxybutyl)-nitrosamine to induce bladder cancer, while unsupplemented rats died within 4 weeks (Mori et al., 1988). Unsupplemented ODS rats developed an increase in ovarian aromatase activity (Tsuji et al., 1989). LDL cholesterol was higher in unsupplemented ODS rats (Horio et al., 1991).

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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Myo-inositol

Myo-inositol is not required by rats in conventional laboratory conditions, but Burton and Wells (1976) reported a requirement in lactating rats fed antibacterial drugs. Lactating rats fed phthalylsulfathiazole, to decrease myo-inositol contribution from the microflora, developed fatty livers with increased concentrations of cholesterol esters and triglycerides, but plasma lipoprotein lipid concentrations were depressed. These alterations in the lactating dam were corrected by supplementing the diet with 0.5 percent myo-inositol (Wells and Burton, 1978). The free myo-inositol content of milk is 80 mg/100 g in rat's milk and 4 mg/100 g in cow's milk. Myo-inositol concentration in milk was influenced by dietary intake (Byun and Jenness, 1982).

Galactose, when fed in high concentrations, results in an accumulation of polyol products, galactitol and sorbitol, which alter osmoregulation and deplete myo-inositol. The accumulation of polyols and depletion of myo-inositol can be prevented by feeding myo-inositol or aldose reductase inhibitors (Bondy et al., 1990). In diabetic rats the accumulation of sorbitol and depletion of myo-inositol in peripheral nerves reduces axonal transport of choline acetyltransferase, choline-containing lipids, and motor nerve conduction velocity. Maintaining the concentration of myo-inositol in tissue, either through ingesting myo-inositol or by the inhibition of aldose reductase, can prevent these changes (Greene et al., 1982; Tomlinson et al., 1986). Na+-K+-ATPase in diabetic rats was increased in nerve but not kidney tissue by ingesting dietary myo-inositol (Finegold and Strychor, 1988). A phospholipid-derived protein kinase C agonist that is myo-inositol dependent may be involved (J. Kim et al., 1991).

A comparison of rats fed diets containing 0 or 5 g myo-inositol/kg diet demonstrated that after 3 to 4 days, supplementation decreased the activities of liver fatty acid synthetase and acetyl-CoA followed by a return to unsupplemented concentrations (Beach and Flick, 1982). Liver triglyceride accumulation in rats fed diets devoid of myo-inositol only occurred in young rats and decreased with age (Andersen and Holub, 1980). Rats fed a liquid formula diet with myo-inositol supplementation (114 or 250 mg/100 g) did not exhibit any differences in weight gain, liver fat, or myelination of the brain; but supplemented rats had higher tissue free and lipid-bound myo-inositol concentrations (Burton et al., 1976).

REFERENCES

Aaes-Jorgensen, E., E. E. Leppik, H. W. Hayes, and R. T. Holman. 1958. Essential fatty acid deficiency II. In adult rats. J. Nutr. 66:245–259.

Abdo, K. M., G. Rao, C. A. Montgomery, M. Dinowitz, and K. Kanagalingam. 1986. Thirteen-week toxicity study of d-α-tocopheryl acetate (vitamin E) in Fischer 344 rats. Chem. Toxicol. 24:1043–1050.

Abrams, G. M., and P. R. Larsen. 1973. Triiodothyronine and thyroxine in the serum and thyroid glands of iodine-deficient rats. J. Clin. Invest. 52:2522–2531.

Abumrad, N. N., A. J. Schneider, D. Steel, and L. S. Rogers. 1981. Amino acid intolerance during prolonged total parenteral nutrition reversed by molybdate therapy. Am. J. Clin. Nutr. 34:2551–2559.

Adelekan, D. A., and D. I. Thurnham. 1986a. The influence of riboflavin deficiency on absorption and liver storage of iron in the growing rat. Br. J. Nutr. 56:171–179.

Adelekan, D. A., and D. I. Thurnham. 1986b. Effects of combined riboflavin and iron deficiency on the hematological status and tissue iron concentrations of the rat. J. Nutr. 116:1257–1265.

Adkins, J. S., J. M. Wertz, and E. L. Hone. 1966. Influence of nonessential L-amino acids on growth of rats fed high levels of essential L-amino acids. Proc. Soc. Exp. Biol. Med. 122:519–523.

Ahlström, A., and M. Jantti. 1969. Effects of various dietary iron levels on rat reproduction and fetal chemical composition. Ann. Acad. Sci. Fenn. A IV. Biologica 152:1–14.

Ahmad, G., and M. A. Rahman. 1975. Effects of undernutrition and protein malnutrition on brain chemistry of rats. J. Nutr. 105:1090–1103.

Ahrens, R. A. 1967. Influence of dietary nitrogen level on heat production in rats of two ages fed casein and amino-acid diets. J. Dairy Sci. 50:237–239.

Akrabawi, S. S., and J. P. Salji. 1973. Influence of meal-feeding on some of the effects of dietary carbohydrate deficiency in rats. Br. J. Nutr. 30:37–43.

Alexander, H. D., and H. E. Sauberlich. 1957. The influence of lipotropic factors on the prevention of nutritional edema in rats. J. Nutr. 61:329–341.

Allen, K. G. D., K. J. Lampi, P. J. Bostwick, and M. M. Mathias. 1991. Increased thromboxane production in recalcified challenged whole blood from copper-deficient rats. Nutr. Res. 11:61–70.

Almquist, H. J. 1949. Amino acid balance at supernormal dietary levels of protein. Proc. Soc. Exp. Biol. Med. 72:179–184.

Ambrose, P., P. S. Larson, J. F. Borzelleca, and G. R. Hennigar, Jr. 1976. Long-term toxicologic assessment of nickel in rats and dogs. J. Food Sci. Technol. 13:181–186.

American Institute of Nutrition. 1977. Report of the American Institute of Nutrition ad hoc committee on standards for nutritional studies. J. Nutr. 107:1340–1348.

American Institute of Nutrition. 1980. Second report of the ad hoc committee on standards for nutritional studies. J. Nutr. 110:1726.

Ames, S. R. 1974. Age, parity, and vitamin A supplementation and the vitamin E requirement of female rats. Am. J. Clin. Nutr. 27:1017–1025.

Ammerman, C. B., L. R. Arrington, A. C. Warnick, J. L. Edwards, R. L. Shirley, and G. K. Davis. 1964. Reproduction and lactation in rats fed excessive iodine. J. Nutr. 84:108–112.

Andersen, D. B., and B. J. Holub. 1980. Myo-inositol-responsive liver lipid accumulation in the rat. J. Nutr. 110:488–495.

Anderson, B. M., and H. E. Parker. 1955. The effects of dietary manganese and thiamine levels on growth rate and manganese concentration in tissues of rats. J. Nutr. 57:55–59.

Anderson, R. A., and M. M. Polansky. 1981. Dietary chromium deficiency effect on sperm count and fertility in rats. Biol. Trace Elem. Res. 3:1–5.

Andrieux, C., E. D. Pacheco, B. Bouchet, D. Gallant, and O. Szylit. 1992. Contribution of the digestive tract microflora to amylomaize starch degradation in the rat. Br. J. Nutr. 67:489–499.

Angel, J. F. 1980. Gluconeogenesis in meal-fed, vitamin B6 deficient rats. J. Nutr. 110:262–269.

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

Anonymous. 1972. The fate of riboflavin in the mammal. Nutr. Rev. 30:75.

Anonymous. 1975. Regulation of liver metabolism of pyridoxal phosphate. Nutr. Rev. 33:214.

Aoyama, Y., H. Yasui, and K. Ashida. 1971. Effect of dietary protein and amino acids in a choline-deficient diet on lipid accumulation in rat liver. J. Nutr. 101:730–746.

Apgar, J. 1977. Mobilization of vitamin A by the zinc-deficient female rat. Nutr. Rep. Int. 15:553–559.

Apgar, J. 1985. Zinc and reproduction. Annu. Rev. Nutr. 5:43–68.

Apgar, J. L., C. A. Shively, and S. M. Tarka, Jr. 1987. Digestibility of cocoa butter and corn oil and their influence on fatty acid distribution in rats. J. Nutr. 117:660–665.

Appling, D. R. 1991. Compartmentation of folate-mediated one-carbon metabolism in eukaryotes. FASEB J. 5:2645–2651.

Armbrecht, H. J. 1990. Effect of age on calcium and phosphate absorption. Role of 1,25-dihydroxyvitamin D. Miner. Electrolyte Metab. 16:159–166.

Armbrecht, H. J., and L. R. Forte. 1985. Adaptation of middle aged rats to long-term restriction of dietary vitamin D and calcium. Arch. Biochem. Biophys. 242:464–469.

Armbrecht, H. J., and R. H. Wasserman. 1976. Enhancement of Ca++ uptake by lactose in the rat small intestine. J. Nutr. 106:1265–1271.

Arthur, J. R., F. Nicol, A. R. Hutchinson, and G. J. Beckett. 1990. The effects of selenium depletion and replation on the metabolism of thyroid hormones in the rat. J. Inorg. Biochem. 39:101–108.

Arthur, J. R., F. Nicol, E. Grant, and G. F. Beckett. 1991. The effects of selenium deficiency and hepatic type-I iodothyronine deiodinase and protein disulfide-isomerase assessed by activity measurements and affinity labelling. Biochem. J. 274:297–300.

Atallah, M. T., and T. A. Melnik. 1982. Effect of pectin structure on protein utilization by growing rats. J. Nutr. 112:2027–2032.

Avery, R. A., and W. J. Bettger. 1992. Zinc deficiency alters the protein composition of the membrane skeleton but not the extractability or oligomeric form of spectrin in rat erythrocyte membranes. J. Nutr. 122:428–434.

Aycock, J. E., and A. Kirksey. 1976. Influence of different levels of dietary pyridoxine on certain parameters of developing and mature brains in rats. J. Nutr. 106:680–688.


Babu, U., and M. L. Failla. 1990a. Copper status and function of neutrophils are reversibly depressed in marginally and severely copper-deficient rats. J. Nutr. 120:1700–1709.

Babu, U., and M. L. Failla. 1990b. Respiratory burst and candidacidal activity of peritoneal macrophages are impaired in copper-deficient rats. J. Nutr. 120:1692–1699.

Bajwa, G. S., L. M. Morrison, and B. H. Ershoff. 1971. Induction of aortic and coronary athero-arteriosclerosis in rats fed a hypervitaminosis D, cholesterol-containing diet. Proc. Soc. Exp. Biol. Med. 138:975–982.

Baker, D. A. 1986. Problems and pitfalls in animal experiments designed to establish dietary requirements for essential nutrients. J. Nutr. 116:2339–2349.

Baker, D. H., D. E. Becker, A. H. Jensen, and B. G. Harmon. 1967. Response of the weanling rat to alpha- or beta-lactose with or without an excess of dietary phosphorus. J. Dairy Sci. 50:1314–1318.

Baker, H., and O. Frank. 1968. Clinical vitaminology: Methods and interpretation. New York: Interscience, Wiley.

Baldwin, J. K., and P. Griminger. 1985. Nitrogen balance studies in aging rats. Exp. Gerontol. 20:29–34.

Baldwin, R. L., and A. C. Bywater. 1984. Nutritional energetics of animals. Annu. Rev. Nutr. 4:101–114.

Baly, D. L., D. L. Curry, C. L. Keen, and L. S. Hurley. 1985. Dynamics of insulin and glucagon release in rats: Influence of dietary manganese. Endocrinol. Soc. 116:1734–1740.

Baly, D. L., C. L. Keen, and L. S. Hurley. 1986. Effects of manganese deficiency on pyruvate carboxylase and phosphoenol-pyruvate carboxykinase activity and carbohydrate homeostasis in adult rats. Biol. Trace Elem. Res. 11:201–212.

Baly, D. L., J. S. Schneiderman, and A. L. Garcia-Welsh. 1990. Effect of manganese deficiency on insulin binding glucose transport and metabolism in rat adipocytes. J. Nutr. 120:1075–1079.

Bamji, M. S., and D. Sharada. 1972. Hepatic glutathione reductase and riboflavin concentrations in experimental deficiency of thiamin and riboflavin in rats. J. Nutr. 102:443.

Banwell, J., J. Deese, B. Miller, and D. Bolt. 1980. Inhibition of Vitamin B12 absorption by a dietary lectin: Effect of phytohemagglutinins in the rat. Am. J. Clin. Nutr. 33:930 (abstr.).

Barboriak, J. J., and W. A. Krehl. 1957. Effect of ascorbic acid in pantothenic acid deficiency. J. Nutr. 63:601–609.

Barboriak, J. J., W. A. Krehl, and G. R. Cowgill. 1957a. Pantothenic acid requirement of the growing and adult rat. J. Nutr. 61:13–21.

Barboriak, J. J., W. A. Krehl, G. R. Cowgill, and A. D. Whedon. 1957b. Effect of partial pantothenic acid deficiency on reproductive performance of the rat. J. Nutr. 63:591–599.

Barki, V. H., H. Nath, E. B. Hart, and C. A. Elvehjem. 1947. Production of essential fatty acid deficiency symptoms in the mature rat. Proc. Soc. Exp. Biol. Med. 66:474–478.

Barnes, R. H., M. J. Bates, and J. E. Maack. 1946. The growth and maintenance utilization of dietary protein. J. Nutr. 32:535–548.

Barnes, R. H., S. Tuthill, E. Kwong, and G. Fiala. 1959a. Effects of the prevention of coprophagy in the rat. V. Essential fatty acid deficiency. J. Nutr. 68:121–130.

Barnes, R. H., E. Kwong, and G. Fiala. 1959b. Effects of the prevention of coprophagy in the rat. IV. Biotin. J. Nutr. 67:599–610.

Bartholmey, S. J., and A. R. Sherman. 1986. Impaired ketogenesis in iron-deficient rat pups. J. Nutr. 116:2180–2189.

Bates, C. J., and N. J. Fuller. 1986. The effect of riboflavin deficiency on methylenetetrahydrofolate reductase (NADPH) (EC 1.5.1.20) and folate metabolism in the rat. Br. J. Nutr. 55:455–464; erratum 56:683.

Batey, D. B., and C. D. Eckhert. 1992. Flavin levels in the rat retina. Exp. Eye Res. 54:605–609.

Bavetta, L. A., and E. J. McClure. 1957. Protein factors and experimental rat caries . J. Nutr. 63:107–117.

Beach, D. C., and P. K. Flick. 1982. Early effect of myo-inositol deficiency on fatty acid synthetic enzymes of rat liver. Biochim. Biophys. Acta 711:452–459.

Beaton, G. H., and M. C. Cheney. 1965. Vitamin B6 requirement of the male albino rat. J. Nutr. 87:125–132.

Becker, D. E., A. H. Jensen, S. W. Terrill, I. D. Smith, and H. W. Norton. 1957. The isoleucine requirements of weanling swine fed two protein levels. J. Anim. Sci. 16:26–34.

Beckett, G. J., D. A. MacDougall, F. Nicol, and J. R. Arthur. 1989. Inhibition of type I and type II iodothyronine deiodinase activity in rat liver, kidney and brain produced by selenium deficiency. Biochem. J. 259:887–892.

Bell, J. M., and T. A. Slotkin. 1985. Perinatal dietary supplementation with a commercial soy lecithin preparation: Effects on behavior and brain biochemistry in the developing rat. Dev. Psychobiol. 18:383–394.

Bender, D. A., K. Gartery-Sam, and A. Singh. 1989. Effects of vitamin B6 deficiency and repletion on the uptake of steroid hormones into uterus slices and isolated liver cells of rats. Br. J. Nutr. 61:619–628.

Bendich, A., E. Gabriel, and L. J. Machlin. 1986. Dietary vitamin E requirement for optimum immune responses in the rat. J. Nutr. 116:675–681.

Benditt, E. P., R. L. Woolridge, C. H. Steffe, and L. E. Frazier. 1950. The minimum requirements of the indispensable amino acids

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

for maintenance of the well-nourished male albino rat. J. Nutr. 40:335–350.

Benevenga, N. J., and R. D. Steele. 1984. Adverse effects of excessive consumption of amino acids. Annu. Rev. Nutr. 4:157–181.

Benevenga, N. J., M. J. Gahl, T. D. Crenshawa and M. D. Finke. 1994. Protein and amino acid requirements for maintenance and amino acid requirements for growth of laboratory rats. J. Nutr. 124:451–453.

Berant, M., D. Berkovitz, H. Mandel, O. Zinder, and D. Mordohovich. 1988. Thiamin status of the offspring of diabetic rats. Pediat. Res. 23:574–575.

Berg, B. N. 1965. Dietary restriction and reproduction in the rat. J. Nutr. 87:344–348.

Berger, J., and B. O. Schneeman. 1988. Intestinal zinc and carboxypeptidase A and B activity in response to consumption of test meals containing various proteins by rats. J. Nutr. 118:723–728.

Bergstra, A. E., A. G. Lemmens, and A. C. Beynen. 1993. Dietary fructose vs. glucose stimulates nephrocalcinogenesis in female rats. J. Nutr. 123:1320–1327.

Bernhart, F. W., and R. M. Tomarelli. 1966. A salt mixture supplying the National Research Council estimates of the mineral requirements of rats. J. Nutr. 89:495–500.

Bernhart, F. W., S. Savini, and R. M. Tomarelli. 1969. Calcium and phosphorus requirements for maximal growth and mineralization of the rat. J. Nutr. 98:443–448.

Bernick, S., and R. B. Alfin-Slater. 1963. Pulmonary infiltration of lipid in essential fatty-acid deficiency. Arch. Pathol. 75:13–20.

Bernsohn, J., and F. J. Spitz. 1974. Linoleic and linolenic acid dependency of some brain membrane-bound enzymes after lipid deprivation in rats. Biochem. Biophys. Res. Commun. 57:293–298.

Berry, M. J., L. Banu, and P. R. Larsen. 1991. Type I iodothyronine deiodinase is a selenocysteine-containing enzyme. Nature 349:438–440.

Bessey, O. A., O. H. Lowry, E. B. Davis, and J. L. Dorn. 1958. The riboflavin economy of the rat. J. Nutr. 64:185–202.

Bhat, K. S. 1982. Alterations in lenticular proteins of rats on riboflavin deficient diet. Curr. Eye Res. 83:829–834.

Bhat, K. S. 1987. Changes in lens and erythrocyte glutathione reductase in response to endogenous flavin adenine dinucleotide and liver riboflavin content of rat on riboflavin deficient diet. Nutr. Res. 7:1203–1208.

Bieri, J. G. 1972. Kinetics of tissue α-tocopherol depletion and repletion. Ann. N.Y. Acad. Sci. 203:181–191.

Bieri, J. G. 1979. Letter to the Editor. J. Nutr. 109:925–926.

Bieri, J. G., K. E. Mason, and E. L. Prival. 1968. Testis requirement for vitamin A in the rat and the effect of essential fatty acid. Int. Z. Vit. Forschung 38:312–319.

Bivin, W. S., M. P. Crawford, and N. R. Brewer. 1979. Morphophysiology. Pp. 73–103 in The Laboratory Rat, Vol. 1, H. J. Baker, J. R. Lindsey, and S. H. Wisbroth, eds. New York: Academic Press.

Black, A., K. H. Maddy, and R. W. Swift. 1950. The influence of low levels of protein on heat production. J. Nutr. 42:415–422.

Blakely, S. R., E. Grundel, M. Y. Jenkins, and G. V. Mitchell. 1990. Alterations in β-carotene and vitamin E status in rats fed β-carotene and excess vitamin A. Nutr. Res. 10:1035–1044.

Blakley, R. L., and Benkovic, S. J., eds. 1984. Folates and Pterins, Vol. 1: Chemistry and Biochemistry of Folates. New York: Wiley.

Blakley, R. L., and V. M. Whitehead, eds. 1986. Folates and Pterins, Vol. 3: Nutritional, Pharmacological and Physiological Aspects. New York: Wiley.

Boelter, M. D. D., and D. M. Greenberg. 1941. Severe calcium deficiency in growing rats. I. Symptoms and pathology. J. Nutr. 21:61–74.

Boelter, M. D. D., and D. M. Greenberg. 1943. Effect of severe calcium deficiency on pregnancy and lactation in the rat. J. Nutr. 26:105–121.

Bondy, C., B. D. Cowley, Jr., S. L. Lightman, and P. F. Kador. 1990. Feedback inhibition of aldose reductase gene expression in rat renal medulla. Galactitol accumulation enzyme reduces mRNA levels and depletes cellular inositor content. J. Clin. Invest. 86:1103–1108.

Booth, A. N., R. H. Wilson, and F. DeEds. 1953. Effects of prolonged ingestion of xylose on rats. J. Nutr. 49:347–355.

Borel, M. J., S. H. Smith, D. E. Brigham, and J. L. Beard. 1991. The impact of varying degrees of iron nutriture on several functional consequences of iron deficiency in rats. J. Nutr. 121:729–736.

Bottino, N. R., G. A. Vandenburg, and R. Reiser. 1967. Resistance of certain long-chain polyunsaturated fatty acids of marine oils to pancreatic lipase hydrolysis. Lipids 2:489–493.

Bourre, J., M. Francois, A. Youyoo, O. Dumont, M. Piciotti, G. Pascal, and G. Durand. 1989. The effects of dietary α-linolenic acid on the composition of nerve membranes, enzymatic activity, amplitude of electrophysiological parameters, resistance to poisons, and performance of learning tasks in rats. J. Nutr. 119:1880–1892.

Bourre, J. M., M. Piciotti, O. Dumont, G. Pascal, and G. Durand. 1990. Dietary linoleic acid and polyunsaturated fatty acids in rat brain and other organs: Minimal requirements of linoleic acid. Lipids 25:465–472.

Boyden, R., V. R. Potter, and C. A. Elvehjem. 1938. Effect of feeding high levels of copper to albino rats. J. Nutr. 15:397–402.

Brady, P. S., C. M. Knoeber, and L. J. Brady. 1983. High fiber breads and breakfast cereals effect on rat growth and selected vitamin bioavailability. Nutr. Rep. Int. 28:295–304.

Brazda, F. G., and R. A. Coulson. 1946. Toxicity of nicotinic acid and some of its derivatives. Proc. Soc. Exp. Biol. Med. 62:19–20.

Bressani, R., and E. T. Mertz. 1958. Relationship of protein level to the minimum lysine requirement of the rat. J. Nutr. 65:481–491.

Breuer, L. H., W. G. Pond, R. G. Warner, and J. K. Loosli. 1963. A comparison of several amino acid and casein diets for the growing rat. J. Nutr. 80:243–250.

Breuer, L. H., W. G. Pond, R. G. Warner, and J. K. Loosli. 1964. The role of dispensable amino acids in the nutrition of the rat. J. Nutr. 82:499–506.

Breuer, L. H., R. G. Warner, D. A. Benton, and J. K. Loosli. 1966. Dietary requirement for asparagine and its metabolism in rats. J. Nutr. 88:143–150.

Bricker, M. L., and H. H. Mitchell. 1947. The protein requirements of the adult rat in terms of the protein contained in egg, milk and soy flour. J. Nutr. 34:491–505.

Brin, M. 1966. Transketolase: Clinical aspects. Methods Enzymol. 9:508–514.

Brinegar, M. J., H. H. Williams, F. H. Ferris, J. K. Loosli, and L. A. Marnard. 1950. The lysine requirement for the growth of swine. J. Nutr. 42:129–138.

Brink, E. J., P. R. Dekker, E. C. H. van Beresteijn, and A. C. Beynen. 1991. Inhibitory effects of dietary soybean protein vs. casein on magnesium absorption in rats. J. Nutr. 121:1374–1381.

Brink, E. J., A. C. Beynen, P. R. Dekker, E. C. H. Van Beresteijn, and R. van der Meer. 1992. Interaction of calcium and phosphate decreases ileal magnesium solubility and apparent magnesium absorption in rats. J. Nutr. 122:580–586.

Britton, R. S., R. O'Neill, and B. R. Bacon. 1991. Chronic dietary iron overload in rats results in impaired calcium sequestration by hepatic mitochondria and microsomes. Gastroenterology 101:806–811.

Brock, A. A., S. A. Chapman, E. A. Ulman, and G. Wu. 1994. Dietary manganese deficiency decreases rat hepatic arginase activity. J. Nutr. 124:340–344.

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

Brockerhoff, H., R. J. Hoyle, and P. C. Huang. 1966. Positional distribution of fatty acids in the fats of a polar bear and a seal. Can. J. Biochem. 44:1519–1525.

Brody, S. 1945. Bioenergetics and Growth, with Special Reference to the Efficiency Complex in Domestic Animals. New York: Reinhold.

Brody, S., J. Riggs, K. Kaufman, and V. Herring. 1938. Growth and development with special reference to domestic animals. 45. Energy-metabolism levels during gestation, lactation and post-lactation rest. Mo. Agr. Exp. Stn. Res. Bull. 281.

Brommage, R. 1989. Measurement of calcium and phosphorus fluxes during lactation in the rat. J. Nutr. 119:428–438.

Brommage, R., and H. F. DeLuca. 1984. Self-selection of a high calcium diet by vitamin D-deficient lactating rats increases food consumption and milk production. J. Nutr. 114:1377–1385.

Brubacher, G. B., and H. Weiser. 1985. The vitamin A activity of β-carotene . Int. J. Vitam. Nutr. Res. 55:5–15.

Buchowski, M. S., and D. D. Miller, 1991. Lactose, calcium source and age affect calcium bioavailability in rats. J. Nutr. 121:1746–1754.

Buck, J., F. Derguini, E. Levi, K. Nakanishi, and U. Hammerling. 1991. Intracellular signaling by 14-hydroxy-4,14-retro-retinol. Science 254:1654–1656.

Buckingham, K. W. 1985. Effect of dietary polyunsaturated/saturated fatty acid ratio and dietary vitamin E on lipid peroxidation in the rat. J. Nutr. 115:1425–1435.

Bunce, G. E. 1989. Zinc in endocrine function. Pp. 249–258 in Human Biology, C. F. Mills, ed. New York: Springer-Verlag.

Bunce, G. E., H. E. Sauberlich, P. G. Reeves, and T. S. Oba. 1965. Dietary phosphorus and magnesium deficiency in the rat. J. Nutr. 86:406–414.

Burk, R. F., and P. E. Gregory. 1982. Characteristics of 75Se-P, a selenoprotein found in rat liver and plasma, and comparison of it with selenoglutathione peroxidase . Arch. Biochem. Biophys. 213:73–80.

Burk, R. F. 1983. Biological activity of selenium. Annu. Rev. Nutr. 3:53–70.

Burns, M. J., S. M. Hauge, and F. W. Quackenbush. 1951. Utilization of vitamin A and carotene by the rat. I. Effects of tocopherol, tween, and dietary fat. Arch. Biochem. 30:341–346.

Burton, L. E., and W. W. Wells. 1976. Myo-inositol metabolism during lactation and development in the rat: The prevention of lactation-induced fatty liver by Myo-inositol. J. Nutr. 106:1617–1628.

Burton, L. E., R. E. Ray, J. R. Bradford, J. P. Orr, J. A. Nickerson, and W. W. Wells. 1976. Myo-inositol metabolism in the neonatal and developing rat fed a myo-inositol-free diet. J. Nutr. 106:1610–1616.

Butterworth, R. F., J. F. Giguere, and A. M. Besnard. 1985. Activities of thiamin-dependent enzymes in the two experimental models of thiamin-deficiency encephalopathy. 1. The pyruvate dehydrogenase complex. Neurochem. Res. 10:1417–1428.

Byun, S. M., and R. Jenness. 1982. Estimation of free myo-inositol in milks of various species and its source in milk of rats (Rattus norvegicus). J. Dairy Sci. 65:531–536.


Calhoun, J. B. 1963. The ecology and sociology of the Norway rat. Baltimore: U.S. Public Health Service.

Calvert, R. J., M. Otsuka, and S. Satchithanandam. 1989. Consumption of raw potato starch alters intestinal function and colonic cell proliferation in the rat. J. Nutr. 119:1610–1616.

Cammack, R. 1988. Nickel in metalloproteins. Adv. Inorg. Chem. 32:297–333.

Cannon, M., A. Flenniken, and N. S. Track. 1980. Demonstration of acute and chronic effects of dietary fibre upon carbohydrate metabolism. Life Sci. 27:1397–1401.

Cannon, P. R. 1948. Some Pathologic Consequences of Protein and Amino Acid Deficiencies. Springfield, Ill.: Charles C Thomas.

Cardot, P., J. Chambaz, G. Thomas, Y. Rayssiguier, and G. Bereziat. 1987. Essential fatty acid deficiency during pregnancy in the rat: Influence of dietary carbohydrates. J. Nutr. 117:1504-1513.

Carey, M. C., D. M. Small, and C. M. Bliss. 1983. Lipid digestion and absorption. Annu. Rev. Physiol. 45:651–678.

Carlisle, E. M. 1970. Silicon: A possible factor in bone calcification. Science 167:279–280.

Carlisle, E. M. 1972. Silicon: An essential element for the chick. Science 178:619–621.

Carlisle, E. M., M. J. Curran, and T. Duong. 1991. The effect of interrelationships between silicon, aluminum, and the thyroid on zinc content in brain. Pp. 12.16–12.17 in Trace Elements in Man and Animals, B. Momcilovic, ed. Zagreb, Yugoslavia: Institute for Medical Research and Occupational Health, University of Zagreb.

Carmel, N., A. M. Konijn, N. A. Kaufmann, and K. Guggenheim. 1975. Effects of carbohydrate-free diets on the insulin-carbohydrate relationships in rats. J. Nutr. 105:1141–1149.

Caster, W. O., and P. Ahn. 1963. Electrocardiographic notching in rats deficient in essential fatty acids. Science 139:1213.

Cerklewski, F. 1987. Influence of dietary magnesium on fluoride bioavailability in the rat. J. Nutr. 117:496–500.

Cerklewski, F. L. 1979. Determination of a copper requirement to support gestation and lactation for the female albino rat. J. Nutr. 109:1529–1533.

Cha, C.-J. M., and H. T. Randall. 1982. Effects of substitution of glucose-oligosaccharides by sucrose in a defined formula diet on intestinal disaccharidases, hepatic lipogenic enzymes and carbohydrate metabolism in young rats. Metabolism 31:57–66.

Chahl, J. S., and C. C. Kratzing. 1966. Environmental temperature and choline requirements in rats. II. Choline and methionine requirements for lipotropic activity. J. Lipid Res. 7:22–26.

Chalvardjian, A., and S. Stephens. 1970. Lipotropic effect of dextrin versus sucrose in choline-deficient rats. J. Nutr. 100:397–403.

Champigny, O. 1963. Respiratory exchange and nitrogen balance in the pregnant rat: Energy cost of anabolic processes of gestation. C. R. Acad. Sci. Paris 256:4755.

Chang, S., P. M. Brannon, and M. Korc. 1990. Effects of dietary manganese deficiency on rat pancreatic amylase mRNA levels . J. Nutr. 120:1228–1234.

Chen, I. S., S. Subramanian, M. M. Cassidy, A. J. Sheppard, and G. V. Vahouny. 1985. Intestinal absorption and lipoprotein transport of (ω-3) eicosapentanoic acid. J. Nutr. 115:219–225.

Chen, I. S., L. Truc, S. Subramanian, M. M. Cassidy, A. J. Sheppard, and G. V. Vahouny. 1987a. Comparison of the clearances of serum chylomicron triglycerides enriched with eicosapentanoic acid or oleic acid. Lipids 22:318–321.

Chen, I. S., S. Hotta, I. Ikeda, M. M. Cassidy, A. J. Sheppard, and G. V. Vahouny. 1987b. Digestion, absorption and effects on cholesterol absorption of Menhaden oil, fish oil concentrate and corn oil by rats. J. Nutr. 117:1676–1680.

Chen, I. S., S. Subramanian, G. V. Vahouny, M. M. Cassidy, I. Ikeda, and D. Kritchevsky. 1989. A comparison of the digestion and absorption of cocoa butter and palm kernel oil and their effects on cholesterol absorption in rats. J. Nutr. 119:1569–1573.

Chen, L. H. 1981. An increase in vitamin E requirement induced by high supplementation of vitamin C in rats. Am. J. Clin. Nutr. 34:1036–1041.

Chen, L. H., and A. L. Marlatt. 1975. Effects of dietary vitamin B6 levels and exercise on glutamic-pyruvic transaminase activity in rat tissues. J. Nutr. 105:401.

Chen, L. H., and R. R. Thacker. 1987. Effect of ascorbic acid and

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

vitamin E on biochemical changes associated with vitamin E deficiency in rats. Int. J. Vitam. Nutr. Res. 57:385–390.

Chen, L. T., C. H. Bowen, and M. F. Chen. 1984. Vitamin B1 and B12 blood levels in rats during pregnancy. Nutr. Rep. Int. 30:433–437.

Chow, C. K. 1979. Nutritional influence on cellular antioxidant defense systems. Am. J. Clin. Nutr. 32:1066–1081.

Clandinin, M. T., S. Cheema, C. J. Field, M. L. Garg, J. Venkatraman, and T. R. Clandinin. 1991. Dietary fat: Exogenous determination of membrane structure and cell function. FASEB J. 5:2761–2769.

Clark, I., and L. F. Belanger. 1967. Effects on alteration of dietary magnesium on calcium, phosphate and skeletal metabolism. Calcif. Tissue Res. 1:204–218.

Clark, S. A., A. Boass, and S. U. Toverud. 1987. Effects of high dietary contents of calcium and phosphorus on mineral metabolism and growth of vitamin D-deficient suckling and weaned rats. Bone Mineral 2:257–270.

Clifford, A. J., D. S. Wilson, and N. D. Bills. 1989. Repletion of folate-depleted rats with an amino acid-based diet supplemented with folic acid. J. Nutr. 119:1956–1961.

Coburn, S. P., J. D. Mahuren, B. S. Wostmann, D. L. Snyder, and D. W. Townsend. 1989. Role of intestinal microflora in the metabolism of vitamin B6 and 4'-deoxypyridoxine examined using germ-free guinea pigs and rats. J. Nutr. 119:181–188.

Cohen, N. L., C. L. Keen, and B. Lönnerdal. 1985. Effects of varying iron on the expression of copper deficiency in the growing rat: Anemia and ferroxidase I and II, tissue trace elements, ascorbic acid, and xanthine dehydrogenase. J. Nutr. 115:633–649.

Cole, A. S., and W. Robson. 1951. Tryptophan deficiency and requirements in the adult rat. Br. J. Nutr. 5:306–320.

Combs, G. F., Jr., and S. B. Combs. 1984. The nutritional biochemistry of selenium. Annu. Rev. Nutr. 4:257–280.

Compton, M. M., and J. A. Cidlowski. 1986. Vitamin B6 and glucocorticoid action. Endocrine Rev. 7:140–148.

Conrad, H. E., W. R. Watts, J. M. Iacino, H. F. Kraybill, and T. E. Friedmann. 1958. Digestibility of uniformly labeled carbon-14 soybean cellulose in the rat. Science 127:1293.

Corey, J. E., and K. C. Hayes. 1972. Cerebrospinal fluid pressure, growth, and hematology in relation to retinol status of the rat in acute vitamin A deficiency. J. Nutr. 102:1585–1593.

Coward, K. H., K. M. Key, and B. G. E. Morgan. 1932. The quantitative determination of vitamin D by means of its growth-promoting property. Biochem. J. 26:1585–1592.

Crawford, M. A., N. M. Casperd, and A. J. Sinclair. 1976. The long chain metabolites of linoleic and linolenic acids in liver and brain in herbivores and carnivores. Comp. Biochem. Physiol. 54B:395–401.

Crockett, M. E., and H. J. Deuel, Jr. 1947. A comparison of the coefficient of digestibility and rate of absorption of several natural and artificial fats as influenced by melting point. J. Nutr. 33:187–194.

Crosby, L. O., and T. R. Cline. 1973. Effect of asparagine on growth and protein synthesis in weanling rats. J. Anim. Sci. 37:713–717.

Cullen, R. W., and S. M. Oace. 1989a. Fermentable dietary fibers elevate urinary methylmalonate and decrease propionate oxidation in rats deprived of vitamin B12. J. Nutr. 119:1115–1120.

Cullen, R. W., and S. M. Oace. 1989b. Neomycin has no persistent sparing effect on vitamin B12 status in pectin-fed rats. J. Nutr. 119:1399–1403.

Cuthbertson, E. M., and D. M. Greenberg. 1945. Chemical and pathological changes in dietary chloride deficiency in the rat. J. Biol. Chem. 160:83–94.

Czarnecki, G. L., M. S. Edmonds, O. A. Izquierdo, and D. H. Baker. 1984. Effect of 3-nitro-4'-hydroxyphenylarsenic acid on copper utilization by the pig, rat, and chick. J. Anim. Sci. 59:997–1002.


Daft, F. S., L. L. Ashburn, and W. H. Sebrell. 1942. Biotin deficiency and other changes in rats given sulfanilylguanidine or succinyl sulfathiazole in purified diets. Science 96:321–322.

Davies, I. R., J. C. Brown, and G. Livesey. 1991. Energy values and energy balance in rats fed on supplements of guar gum or cellulose. Br. J. Nutr. 65:415–433.

Davila, M. E., L. Norris, M. P. Cleary, and A. C. Ross. 1985. Vitamin A during lactation: Relationship of maternal diet to milk vitamin A content and to the vitamin A status of lactating rats and their pups. J. Nutr. 115:1033–1041.

Davis, C. D., D. M. Ney, and J. L. Greger. 1990. Manganese, iron and lipid interactions in rats. J. Nutr. 120:507–513.

Davis, G. K., and W. Mertz. 1987. Copper. Pp. 301–364 in Trace Elements in Human and Animal Nutrition, W. Mertz, ed. Orlando, Fla.: Academic Press.

Day, H. G., and E. V. McCollum. 1939. Mineral metabolism, growth and symptomatology of rats and a diet extremely deficient in phosphorus. J. Biol. Chem. 130:269–283.

Day, H. G., and W. Pigman. 1957. Carbohydrates in nutrition. Pp. 779–806 in The Carbohydrates, W. Pigman, ed. New York: Academic Press.

Deb, S., R. J. Martin, and T. V. Hershberger. 1976. Maintenance requirement and energetic efficiency of lean and obese Zucker rats. J. Nutr. 106:191–197.

Deka, N. C., A. K. Sehgal, and P. N. Chhuttani. 1981. Absorption and transport of radioactive cobalt-57 labeled vitamin B12 in experimental giardiasis in rats. Indian J. Med. Res. 74:675–679.

Delorme, C. B., and C. I. Gordon. 1983. The effect of pectin on the utilization of marginal levels of dietary protein by weanling rats. J. Nutr. 113:2432–2441.

Demetriou, A. A., I. Franco, S. Bark, G. Rettura, E. Seifter, and S. M. Levenson. 1984. Effects of vitamin A and beta carotene on intra-abdominal sepsis. Arch. Surg. 119:161–165.

Deuel, H. J., Jr. 1950. Non-caloric functions of fat in the diet. J. Am. Diet. Assoc. 26:255–259.

Deuel, H. J., Jr. 1955. Fat as a required nutrient of the diet. Fed. Proc. 14:639–649.

Deuel, H. J., E. R. Meserve, E. Straub, C. Hendrick, and B. T. Scheer. 1947. The effect of fat level of the diet on general nutrition. I. Growth, reproduction, and physical capacity of rats receiving diets containing various levels of cottonseed oil or margarine fat ad libitum. J. Nutr. 33:569–582.

Deuel, H. J., Jr., C. R. Martin, and R. B. Alfin-Slater. 1954. The effect of fat level of the diet on general nutrition. XII. The requirement of essential fatty acids for pregnancy and lactation. J. Nutr. 54:193–199.

Dialameh, G. H., W. V. Taggart, J. T. Matschiner, and R. E. Olson. 1971. Isolation and characterization of menaquinone-4 as a product of menadione metabolism in chicks and rats. Int. J. Vitam. Nutr. Res. 41:391–400.

Diamond, I., H. Swenerton, and L. S. Hurley. 1971. Testicular and esophageal lesions in zinc-deficient rats and their reversibility. J. Nutr. 101:77–84.

Dibak, O., M. Krajcovicova-Kudlackova, E. Grancicova, and M. Jankovicova. 1986. Body composition and physiological casein and wheat gluten protein requirements of 180-day-old rats. Physiol. Bohemoslov. 35:71–80.

Dillard, C. J., J. E. Downey, and A. L. Tappel. 1984. Effect of antioxidants on lipid peroxidation in iron-loaded rats. Lipids 19:127–133.

DiPaolo, R. V., V. S. Caviness, Jr., and J. N. Kanfer. 1974. Delayed maturation of the renal cortex in the vitamin B6-deficient newborn rat. Pediat. Res. 8:546.

Dirige, O. V., and J. R. Beaton. 1969. Factors affecting vitamin B6

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

requirement in the rat as determined by erythrocyte transaminase activity. J. Nutr. 97:109–116.

Dodds, R. A., A. Catterall, L. Bitensky, and J. Chayen. 1986. Abnormalities in fracture healing induced by vitamin B6 deficiency in rats. Bone 7:489–495.

Doi, T., T. Kawata, N. Tadano, T. Iijima, and A. Maekawa. 1989. Effect of vitamin B12 deficiency on the activity of hepatic cystathionine beta-synthase in rats. J. Nutr. Sci. Vitaminol. 35:101–110.

Doisy, E. A., Jr. 1961. Nutritional hypoprothrombinemia and metabolism of vitamin K. Fed. Proc. 20:989–994.

Draper, H. H., T.-L. Sie, and J. G. Bergan. 1972. Osteoporosis in aging rats induced by high phosphorus diets. J. Nutr. 102:1133–1142.

Drescher, A. N., N. B. Talbot, P. A. Meara, M. Terry, and J. D. Crawford. 1958. A study of the effects of excessive potassium intake upon body potassium stores. J. Clin. Invest. 37:1316–1322.

Driskell, J. A., and S.-L. L. Chuang. 1974. Relation between glutamate decarboxylase activities in brains and the vitamin B6 requirement of male rats. J. Nutr. 104:1657–1661.

Driskell, J. A., L. A. Strickland, C. H. Poon, and D. P. Foshee. 1973. The vitamin B6 requirement of the male rat as determined by behavioral patterns, brain pyridoxal phosphate and nucleic acid compositin and erythrocyte alanine aminotransferase activity. J. Nutr. 103:670–680.

Dubick, M. A., G. S. M. Yu, and A. P. N. Majumdar. 1989. Morphological and biochemical changes in the pancreas of the copper-deficient female rat. J. Nutr. 119:1165–1172.

Duerden, J. M., and C. J. Bates. 1985. Effect of riboflavin deficiency on reproductive performance and on biochemical indices of riboflavin status in the rat. Br. J. Nutr. 53:97–105.

Dupont, J. 1990. Lipids. Pp. 56–66 in Present Knowledge in Nutrition, M. L. Brown, ed. Washington, D.C.: International Life Sciences Institute.

Dussault, P. E., and M. Lepage. 1979. In vitro studies of fatty acid metabolism in vitamin B6 deficient rats. J. Nutr. 109:138–141.


Eckhert, C. D. 1987. Differential effects of riboflavin and RRR-tocopheryl acetate on the survival of newborn RCS rats with inheritable retinal degeneration. J. Nutr. 117:208–211.

Eckhert, C. D., M. H. Hsu, and D. W. Batey. 1989. Effect of dietary riboflavin on retinal density and flavin concentrations in normal and dystrophic RCS rats: Inherited and environmentally induced retinal degenerations. Prog. Clin. Biol. Res. 314:331–341.

Eckhert, C. D., M. H. Hsu, and N. Pang. 1991. Photoreceptor damage following exposure to excess riboflavin. Experientia 49:1084–1087.

Eckhert, C. D., M. K. Lockwood, and B. Shen. 1993. Influence of selenium on the microvasculature of the retina. Microvas. Res. 45:74–78.

Edelstein, S., and K. Guggenheim. 1971. Effects of sulfur-amino acids and choline on vitamin B12-deficient rats. Nutr. Metab. 13:339–343.

Elliot, M. A., and H. M. Edwards, Jr. 1991. Effect of dietary silicon on growth and skeletal development in chickens. J. Nutr. 121:201–207.

Emerick, R. J., and H. Kayongo-Male. 1990a. Interactive effects of dietary silicon, copper and zinc in the rat. J. Nutr. Biochem. 1:35–40.

Emerick, R. J., and H. Kayongo-Male. 1990b. Silicon facilitation of copper utilization in the rat. J. Nutr. Biochem. 1:487–492.

Emery, M. P., J. D. Browning, and B. L. O'Dell. 1990. Impaired hemostasis and platelet function in rats fed low zinc diets based on egg white protein. J. Nutr. 120:1062–1067.

Engel, R. W. 1942. The relation of B vitamins and dietary fat to the lipotropic action of choline. J. Nutr. 24:175–185.

Enslen, M., H. Milon, and A. Malnoe. 1991. Effect of low intake of n-3 fatty acids during development on brain phospholipid fatty acid composition and exploratory behavior in rats. Lipids 26:203–208.

Ericsson, Y., H. Luoma, and O. Ekberg. 1986. Effects of calcium, fluoride and magnesium supplementations on tissue mineralization in calcium- and magnesium-deficient rats. J. Nutr. 116:1018–1027.

Ertel, N. H., S. Akgun, F. W. Kemp, and J. C. Mittler. 1983. The metabolic fate of exogenous sorbitol in the rat. J. Nutr. 113:566–573.

Evans, H. M., and G. A. Emerson. 1943. The prophylactic requirement of the rat for alpha-tocopherol. J. Nutr. 26:555–568.

Evenson, J. K., K. M. Thompson, S. L. Weiss, and R. A. Sunde. 1992. Dietary selenium regulation of 75Se—Implications for the selenium requirement. FASEB J. 6:(Part 1)A1398.


Fagin, J. A., K. Ikejiri, and S. R. Levin. 1987. Insulinotropic effects of vanadate. Diabetes 36:1248–1252.

Failla, M. L., U. Babu, and K. E. Seidel. 1988. Use of immunoresponsiveness to demonstrate that the dietary requirement for copper in young rats is greater with dietary fructose than dietary starch. J. Nutr. 118:487–496.

Fajardo, G., and H. Hornicke. 1989. Problems in estimating the extent of coprophagy in the rat. Br. J. Nutr. 62:551–561.

Fantus, G. I., S. Kadota, G. Deragon, B. Foster, and B. I. Posner. 1989. Pervanadate [peroxide(s) of vanadate] mimics insulin action in rat adipocytes via activation of the insulin receptor tyrosine kinase. Biochemistry 28:8864–8871.

Feldmann, J. D. 1960. Iodine deficiency in newborn rats. Am. J. Physiol. 199:1081–1083.

Fergusson, M. A., and K. G. Koski. 1990. Comparison of effects of dietary glucose versus fructose during pregnancy on fetal growth and development in rats. J. Nutr. 120:1312–1319.

Fields, M., J. Holbrook, D. Scholfield, A. Rose, J. C. Smith, and S. Reiser. 1986. Development of copper deficiency in rats fed fructose or starch: Weekly measurements of copper indices in blood. Proc. Soc. Exp. Biol. Med. 181:120–124.

Finegold, D. N., and S. Strychor. 1988. Renal ouabain inhibitable Na+-K+-ATPase activity and myo-inositol supplementation in experimental diabetes mellitus. Metabolism 37:557–561.

Finke, M. D., G. R. DeFoliart, and N. J. Benevenga. 1987a. Use of a four-parameter logistic model to evaluate the protein quality of mixtures of mormon cricket meal and corn gluten meal. J. Nutr. 117:1740–1750.

Finke, M. D., G. R. DeFoliart, and N. J. Benevenga. 1987b. Use of simultaneous curve fitting and a four-parameter logistic model to evaluate the nutritional quality of protein sources at growth rates of rats from maintenance to maximum gain. J. Nutr. 117:1681–1688.

Finke, M. D., G. R. DeFoliart, and N. J. Benevenga. 1989. Use of a four-parameter logistic model to evaluate the quality of the protein from three insect species when fed to rats. J. Nutr. 119:864–871.

Fisher, J. H., R. A. Willis, and B. E. Haskell. 1984. Effect of protein quality on vitamin B6 status in the rat. J. Nutr. 114:786–791.

Flatt, P. R., L. Juntti-Berggren, P. O. Berggren, B. J. Gould, and S. K. Swanston-Flatt. 1989. Effects of dietary inorganic trivalent chromium (Cr3+) on the development of glucose homeostasis in rats. Diabetes Metab. 15:93–97.

Fleming, B. B., and C. H. Barrows, Jr. 1982. The influence of aging on intestinal absorption of vitamin B12 and niacin in rats. Exp. Gerontol. 17:121–126.

Fleming, S. E., and B. Lee. 1983. Growth performance and intestinal transit time of rats fed purified and natural dietary fibers. J. Nutr. 113:592–601.

Follis, R. H. 1958. Deficiency disease. Springfield, Ill.: Charles C Thomas.

Forbes, E. B., R. W. Swift, R. R. Elliott, and W. H. James. 1946a. Relation of fat to economy of food utilization. I. By the growing albino rat. J. Nutr. 31:203–212.

Forbes, E. B., R. W. Swift, R. R. Elliott, and W. H. James. 1946b.

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

Relation of fat to economy of food utilization. II. By the mature albino rat. J. Nutr. 31:213–227.

Forbes, R. M. 1966. Effects of magnesium, potassium and sodium nutriture on the mineral composition of selected tissues of the albino rat. J. Nutr. 88:403–410.

Forbes, R. M., and L. Vaughan. 1954. Nitrogen balance of young albino rats force-fed methionine or histidine deficient diets. J. Nutr. 52:25–37.

Forbes, R. M., L. Vaughan, and H. W. Norton. 1955. Studies on the utilization of dietary isoleucine by the growing albino rat. I. Isoleucine requirements determined with amino acid mixtures. J. Nutr. 57:593–598.

Forbes, R. M., and T. Rao. 1959. The effect of age on the net requirements for nitrogen, lysine and tryptophan by the well-fed rat. Arch. Biochem. Biophys. 82:348–354.

Fordyce, M. K., and J. A. Driskell. 1975. Effects of riboflavin repletion during different developmental phases on behavioral patterns, brain nucleic acid and protein contents, and erythrocyte glutathione reductase activity of male rats. J. Nutr. 105:1150–1156.

Fosmire, A. J., S. Greeley, and H. H. Sandstead. 1977. Maternal and fetal response to various suboptimal levels of zinc intake during gestation in the rat. J. Nutr. 107:1543–1550.

Fournier, H., and R. F. Butterworth. 1990. Effects of thiamin deficiency on thiamin-dependent enzymes in regions of the brain of pregnant rats and their offspring. Metab. Brain Dis. 5:77–84.

Frank, O., and H. Baker. 1980. Vitamin profile in rats fed stock or liquid ethanolic diets. Am. J. Clin. Nutr. 33:221–226.

Franke, K. W., and A. L. Moxon. 1937. The toxicity of orally ingested arsenic, selenium, tellurium, vanadium and molybdenum. J. Pharmacol. Exp. Ther. 61:89–102.

French, C. E., R. H. Ingram, J. A. Uram, G. P. Barron, and R. W. Swift. 1953. The influence of dietary fat and carbohydrate on growth and longevity in rats. J. Nutr. 51:329–339.

Fritz, T. E., D. V. Tolle, and R. J. Flynn. 1968. Hemorrhagic diathesis in laboratory rodents. Proc. Soc. Exp. Biol. Med. 128:228–234.

Fujii, K., T. Kajiwara, and H. Kurosu. 1979. Effect of vitamin B6 deficiency on the crosslink formation of collagen. FEBS Lett. 97:193–195.

Furuse, M., Y. Tamura, S. Matsuda, T. Shimizu, and J. Okumura. 1989. Lower fat deposition and energy utilization of growing rats fed diets containing sorbose. Comp. Biochem. Physiol. 94A:813–817.


Gabriel, E., L. J. Machlin, R. Filipski, and J. Nelson. 1980. Influence of age on the vitamin E requirement for resolution of necrotizing myopathy. J. Nutr. 110:1372–1379.

Gahl, M. J., M. D. Finke, T. D. Crenshaw, and N. J. Benevenga. 1991. Use of a four-parameter logistic equation to evaluate the response of growing rats to ten levels of each indispensable amino acid. J. Nutr. 121:1720–1729.

Gander, J. E., and M. O. Schultze. 1955. Concerning the alleged occurrence of an ''animal protein factor" required for the survival of young rats. I. Studies with unpurified rations. J. Nutr. 55:543–557.

Ganguli, M. C., J. D. Smith, and L. E. Hanson. 1969a. Sodium metabolism and its requirement during reproduction in female rats. J. Nutr. 99:225–234.

Ganguli, M. C., J. D. Smith, and L. E. Hanson. 1969b. Sodium metabolism and requirements in lactating rats. J. Nutr. 99:395–400.

Garthoff, L. H., S. K. Garthoff, R. B. Tobin, and M. A. Mehlman. 1973. The effect of riboflavin deficiency on key gluconeogenic enzyme activities in rat liver. Proc. Soc. Exp. Biol. Med. 143:693–697.

Gaudin-Harding, F., S. Griglio, B. Bois-Joyeuz, P. de Gasquet, and R. Karlin. 1971. Réserves en vitamines du group B chez des rats Westar soumis a des régimes témoins ou hyperlipidiques à deux niveaux vitaminiques. J. Int. Vitaminol. Nutr. 42:21–32.

Gerber, L. E., and J. W. Erdman. 1982. Effect of dietary retinyl acetate, β-carotene and retinoic acid on wound healing in rats. J. Nutr. 112:1555–1564.

Gershoff, S. N. 1970. Production of urinary calculi in vitamin B6-deficient male, female, and castrated male rats. J. Nutr. 100:117–122.

Giovanetti, P. M. 1982. Effect of coprophagy on nutrition. Nutr. Res. 2:335–349.

Goettsch, M. 1949. Minimal protein requirement of the rat for reproduction and lactation. Arch. Biochem. 21:289–300.

Goldberg, A. 1971. Carbohydrate metabolism in rats fed carbohydrate-free diets. J. Nutr. 101:693–698.

Goulding, A., and R. S. Malthus. 1969. Effect of dietary magnesium on the development of nephrocalcinosis in rats. J. Nutr. 97:353–358.

Goyer, R. A., and M. G. Cherian. 1979. Ascorbic acid and EDTA treatment of lead toxicity in rats . Life Sci. 24:433–438.

Grau, C. R. 1948. Effect of protein level on the lysine requirement of the chick. J. Nutr. 36:99–108.

Gray, G. M., R. J. White, and J. R. Majer. 1978. 1–(3'-0-acyl)-β-glucosylN- dihydroxypentatriacontadienoylsph igosine, a major component of the glucosyl ceramides of pig and human epidermis. Biochim. Biophys. Acta 528:127–137.

Gray, L. F., and L. J. Daniel. 1964. Effect of the copper status of the rat on the copper-molybdenum-sulfate interaction. J. Nutr. 84:3137.

Greaves, J. H., and P. Ayres. 1973. Warfarin resistance and vitamin K requirement in the rat. Lab. Anim. 7:141–148.

Green, M. H., and J. B. Green. 1991. Influence of vitamin A intake on retinol (ROH) balance, utilization and dynamics. FASEB J. 5:A718.

Green, M. H., J. B. Green, and K. C. Lewis. 1987. Variation in retinol utilization rate with vitamin A status in the rat. J. Nutr. 117:694–703.

Greenberg, D. M., and E. M. Cuthbertson. 1942. Dietary chloride deficiency and alkalosis in the rat. J. Biol. Chem. 145:179–187.

Greenberg, S. M., C. E. Calbert, E. E. Savage, and H. J. Deuel, Jr. 1950. The effect of fat level of the diet on general nutrition. J. Nutr. 41:473–486.

Greene, D. A., R. A. Lewis, S. A. Lattimer, and M. J. Brown. 1982. Selective effects of myo-inositol administration on sciatic and tibial motor nerve conduction parameters in the streptozocin-diabetic rat. Diabetes 31:573–578.

Greger, J. L. 1982. Effect of phosphorus-containing compounds on iron and zinc utilization. Pp. 107–120 in Nutritional Bioavailability of Iron, ACS Symposia Series 203, C. Kies, ed. Washington, D.C.: American Chemical Society.

Greger, J. L. 1989. Effect of dietary protein and minerals on calcium and zinc utilization. Crit. Rev. Food Sci. Nutr. 28:249–271.

Greger, J. L., C. E. Krzykowski, R. R. Khazen, and C. L. Krashoc. 1987a. Mineral utilization by rats fed various commercially available calcium supplements or milk. J. Nutr. 117:717–724.

Greger, J. L, C. L. Krashoc, and C. E. Krzykowski. 1987b. Calcium, sodium and chloride interactions in rats. Nutr. Res. 7:401–412.

Gregory, J. F., III. 1980a. Effects of epsilon-pyridoxyllysine bound to dietary protein on the vitamin B6 status of rats. J. Nutr. 110:995–1005.

Gregory, J. F., III. 1980b. Effects of epsilon pyridoxyl lysine and related compounds on liver and brain pyridoxal kinase EC 2.7.1.35 and liver pyridoxamine pyridoxine 5'-phosphate oxidase EC 1.4.3.5. J. Biol. Chem. 255:2355–2359.

Grenby, T. H., and A. Phillips. 1989. Dental and metabolic effects of lactitol in the diet of laboratory rats. Br. J. Nutr. 61:17–24.

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

Griffith, W. H. 1941. Choline metabolism. V. The effect of supplementary choline, methionine, and cystine and of casein, lactalbumin, fibrin, edestin and gelatin in hemorrhagic degeneration in young rats. J. Nutr. 21:291–306.

Griffith, W. H., and N. J. Wade. 1939. Choline metabolism. I. The occurrence and prevention of hemorrhagic degeneration in young rats on a low choline diet. J. Biol. Chem. 131:567–577.

Grigor, M. R., M. J. Sneyd, A. Geursen, and U. R. Gain. 1984. Effects of litter size at mid-lactation on lactation in rats. J. Endocrinol. 101:69–73.

Griminger, P. 1966. Biological activity of the various vitamin K forms. Vitamin. Horm. 24:605–618.

Gross, J. 1962. Iodine and bromine. In Mineral Metabolism, C. L. Comar and F. Bronner, eds. New York: Academic Press.

Gross, K. L., W. J. Hartman, A. Ronnenberg, and R. L. Prior. 1991. Arginine-deficient diets alter the plasma and tissue amino acids in young and aged rats. J. Nutr. 121:1591–1599.

Grunert, R. R., J. H. Meyer, and P. H. Phillips. 1950. The sodium and potassium requirements of the rat for growth. J. Nutr. 42:609–618.

Grupp, G., I. Grupp, C. L. Johnson, E. T. Wallick, and A. Schwartz. 1979. Effect of vanadate on cardiac contraction and adenylate cyclase. Biochem. Biophys. Res. Commun. 88:440–447.

Guggenheim, M., and R. Jurgens. 1944. Das schachtelhalm schwanzsymptom bei saugenden jungratten die beziehungen der ungesättigten fettsäuren zu den vitaminen des B-komplexes. Helv. Physiol. Pharmacol. Acta 2:417–433.

Guilarte, T. R. 1989. Effect of vitamin B6 nutrition on the levels of dopamine, dopamine metabolites, dopa decarboxylase activity, tyrosine, and GABA in the developing rat corpus striatum. Neurochem. Res. 14:571–578.

Guilarte, T. R., and H. N. Wagner, Jr. 1987. Increased concentrations of 3–hydroxykynurenine in vitamin B6 deficient neonatal rat brain. J. Neurochem. 49:1918–1926.

Guilbert, H. R., C. E. Howell, and G. H. Hart. 1940. Minimum vitamin A and carotene requirements of mammalian species. J. Nutr. 19:91–103.

Guthneck, B. T., B. A. Bennett, and B. S. Schweigert. 1953. Utilization of amino acids from foods by the rat. II. Lysine. J. Nutr. 49:289–294.


Hafeman, D. G., R. A. Sunde, and W. G. Hoekstra. 1974. Effect of dietary selenium on erythrocyte and liver glutathione peroxidase in the rat. J. Nutr. 104:580–587.

Hakkarainen, J., J. Tyopponen, and L. Jonsson. 1986. Vitamin E requirement of the growing rat during selenium deficiency with special reference to selenium-dependent and selenium-independent glutathione peroxidase. J. Vet. Med. 33:247–258.

Hale, O. M., and A. E. Schaefer. 1951. Choline requirement of rats as influenced by age, strain, vitamin B12 and folacin. Proc. Soc. Exp. Biol. Med. 77:633–636.

Halloran, B. P., and H. F. DeLuca. 1980. Effect of vitamin D deficiency on fertility and reproductive capacity in the female rat. J. Nutr. 110:1573–1580.

Hallquist, N. A., L. K. McNeil, J. F. Lockwood, and A. R. Sherman. 1992. Maternal-iron-deficiency effects on peritoneal macrophage and peritoneal natural-killer-cell cytotoxicity in rat pups. Am. J. Clin. Nutr. 55:741–746.

Halverson, A. W., J. H. Shaw, and E. B. Hart. 1945. Goiter studies in the rat. J. Nutr. 30:59–65.

Hambidge, K. M., C. E. Casey, and N. F. Krebs. 1986. Zinc. Pp. 1–137 in Trace Elements in Human and Animal Nutrition, W. Mertz, ed. Orlando, Fla.: Academic Press.

Hamilton, T. S. 1939. The growth, activity, and composition of rats fed diets balanced and unbalanced with respect to protein. J. Nutr. 17:565–582.

Hammermueller, J. D., T. M. Bray, and W. J. Bettger. 1987. Effect of zinc and copper deficiency on microsomal NADPH-dependent active oxygen generation in rat lung and liver. J. Nutr. 117:894–901.

Handler, P., and W. J. Dann. 1942. The inhibition of rat growth by nicotinamide. J. Biol. Chem. 146:357–368.

Hansard, S. L., II. 1975. Toxicity and physiological movement of vanadium in the sheep and rat. Ph.D. dissertation. University of Florida, Gainesville, Fla.

Hansen, D. K., R. C. Walker, T. F. Grafton. 1990. Effect of lithium carbonate on mouse and rat embryos in vitro. Teratology 41:155–160.

Hansen, H. S., and B. Hensen. 1985. Essential function of linoleic acid esterified in acylglucosylceramide and acylceramide in maintaining the epidermal water permeability barrier. Evidence from feeding studies with oleate, linoleate, arachidonate, columbinate, and α-linolenate . Biochim. Biophys. Acta 834:357–363.

Hardwick, L. L., R. A. Clemens, and M. R. Jones. 1987. Effects of calcium phosphate supplementation on calcium, phosphorus, and magnesium metabolism in the Wistar rat. Nutr. Res. 7:787–796.

Hardwick, L. L., M. R. Jones, N. Bratubar, and K. B. N. Lee. 1991. Magnesium absorption: Mechanisms and the influence of vitamin D, calcium, and phosphate. J. Nutr. 121:13–23.

Harper, A. E., and C. A. Elvehjem. 1957. Dietary carbohydrates. A review of the effects of different carbohydrates on vitamin and amino acid requirements. J. Agr. Food Chem. 5:754–758.

Harper, A. E., and H. E. Spivey. 1958. Relationship between food intake and osmotic effect of dietary carbohydrate. Am. J. Physiol. 193:483–487.

Harper, A. E., N. J. Benevenga, and R. M. Wohlhueter. 1970. Effects of ingestion of disproportionate amounts of amino acids. Physiol. Rev. 50:428–458.

Harr, J. R., J. F. Bone, I. J. Tinsley, P. H. Weswig, and R. S. Yamamoto. 1967. Selenium toxicity in rats. II. Histopathology. Pp. 153–178 in Symposium: Selenium in Biomedicine, O. H. Muth, ed. Westport, Conn.: AVI Publishing.

Harris, H. A., A. Neuberger, and F. Sanger. 1943. Lysine deficiency in young rats. Biochem. J. 37:508–513.

Harris, L. J., and E. Kodicek. 1950. Quantitative studies and dose-response curves in nicotinamide deficiency in rats. Br. J. Nutr. 4:xiii-xiv.

Hartroft, P. M., and E. Sowa. 1964. Effect of potassium on juxtaglomerular cells and adrenal zona glomerulosa of rats. J. Nutr. 82:439–442.

Hartsook, E. W., and H. H. Mitchell. 1956. The effect of age on the protein and methionine requirements of the rat. J. Nutr. 60:173–195.

Hartsook, E. W., T. V. Hershberger, and J. C. M. Nee. 1973. Effects of dietary protein content and ratio of fat to carbohydrate calories on energy metabolism and body composition of growing rats. J. Nutr. 103:167–178.

Hashimoto, K. 1981. Effects of repeated administration of pyrithiamin and oxythiamin on timing behavior in rats. Nippon Yakurigaku Zasshi 78:521–528.

Hauswirth, G. W., and P. P. Nair. 1975. Effects of different vitamin E deficient basal diets on hepatic catalase and microsomal cytochromes P-450 and B5 in rats. Am. J. Clin. Nutr. 28:1087–1094.

Haywood, S. 1979. The effect of the sex of weaned rats on the accumulation of dietary copper in their livers. J. Comp. Pathol. 89:481–487.

Haywood, S. 1985. Copper toxicosis and tolerance in the rat. I. Changes in copper content of the liver and kidney. J. Pathol. 145:149–158.

Heger, J., and Z. Frydrych. 1985. Efficiency of utilization of essential

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

amino acids in growing rats at different levels of intake. Br. J. Nutr. 54:499–508.

Hegsted, D. M., and Y. Chang. 1965. Protein utilization in growing rats. I. Relative growth index as a bioassay procedure. J. Nutr. 85:159–168.

Henderson, L. M., J. M. McIntire, H. A. Waisman, and C. A. Elvehjem. 1942. Pantothenic acid in the nutrition of the rat. J. Nutr. 23:47–58.

Henderson, L. M., T. Deodhar, W. A. Krehl, and C. A. Elvehjem. 1947. Factors affecting the growth of rats receiving niacin-tryptophan-deficient diets. J. Biol. Chem. 170:261–268.

Henskens, Y. M. C., J. Ritskes-Hoitinga, J. N. J. J. Mathot, I. Van Camp, and A. C. Beynen. 1991. The influence of dietary lactose on phosphorus-induced nephrocalcinosis in female rats. Int. J. Vit. Nutr. Res. 61:77–86.

Hepburn, F. N., and W. B. Bradley. 1964. The glutamic acid and arginine requirement for high growth rate of rats fed amino acid diets. J. Nutr. 84:305–312.

Heppel, L. A., and C. A. A. Schmidt. 1949. Studies on the potassium metabolism of the rat during pregnancy, lactation and growth. Univ. Calif. Publ. Physiol. 8:189–195.

Herzberg, G. R., and M. Rogerson. 1988a. Hepatic fatty acid synthesis and triglyceride secretion in rats fed fructose- or glucose-based diets containing corn oil, tallow or marine oil. J. Nutr. 118:1061–1067.

Herzberg, G. R., and M. Rogerson. 1988b. Interaction of dietary carbohydrate and fat in the regulation of hepatic and extrahepatic lipogenesis in the rat. Br. I. Nutr. 59:233–241.

Heywood, R., A. K. Palmer, R. L. Gregson, and H. Hummler. 1985. The toxicity of beta-carotene. Toxicology 36:91–100.

Hietanen, E., U. Koivusaari, M. Laitinen, and A. Norling. 1980. Hepatic drug metabolism during ethanol ingestion in riboflavin deficient rats. Toxicology 16:103–111.

Higgings, E. S., D. Richert, and W. W. Westerfeld. 1956. Molybdenum deficiency and tungstate inhibition studies. J. Nutr. 59:539–559.

Hill, E. G., S. B. Johnson, and R. T. Holman. 1979. Intensification of essential fatty acid deficiency in the rat by dietary trans-fatty acids. J. Nutr. 109:1759–1765.

Hirano, T., J. Mamo, M. Poapst, and G. Steiner. 1988. Very-low-density lipoprotein triglyceride kinetics in acute and chronic carbohydrate-fed rats. Am. J. Physiol. 255:E236–E240.

Hitchman, A. J., S. A. Hasany, A. Hitchman, J. E. Harrison, and C. Tam. 1979. Phosphate-induced renal calcification in the rat. Can. J. Physiol. Pharmacol. 57:92–97.

Ho, I. K., H. H. Loh, and E. L. Way. 1979. Toxic interaction between choline and morphine. Toxicol. Appl. Pharmacol. 51:203–208.

Hoagland, R., and G. G. Snider. 1943. Digestibility of some animal and vegetable fats. J. Nutr. 25:295–302.

Hoagland, R., N. R. Ellis, O. G. Hankins, and G. G. Snider. 1948. Supplemental value of certain amino acids for beef protein. J. Nutr. 35:167–176.

Hobara, R., and H. Yasuhara. 1981. Erythrocytosis in thiamine deficient rats. Jpn. J. Pharmacol. 31:985–993.

Hodge, H. C. 1944. Acute toxicity of choline hydrochloride administered intraperitoneally to rats. Proc. Soc. Exp. Biol. Med. 57:26–28.

Hoek, A. C., A. G. Lemmens, J. W. M. A. Mullink, and A. C. Beynen. 1988. Influence of dietary calcium: phosphorus ratio on mineral excretion and nephrocalcinosis in female rats. J. Nutr. 118:1210–1216.

Hoekstra, W. G. 1975. Biochemical function of selenium and its relation to vitamin E. Fed. Proc. 34:2083–2089.

Holdsworth, E. S., and E. Neville. 1990. Effects of extracts of high-and low-chromium brewer's yeast on metabolism of glucose by hepatocytes from rats fed on high- or low-Cr diets. Br. J. Nutr. 63:623–630.

Hollander, D. 1973. Vitamin K1 absorption by everted intestinal sacs of the rat. Am. J. Physiol. 225:360–364.

Hollander, D., and D. Morgan. 1979. Aging: Its influence on vitamin A intestinal absorption in vivo by the rat. Exp. Geront. 14:301–305.

Hollander, D., and V. Dadufalza. 1989. Lymphatic and portal absorption of vitamin E in aging rats. Digest. Dis. Sci. 34:768–772.

Hollander, D., and H. Tarnawski. 1984. Influence of aging on vitamin D absorption and unstirred water layer dimensions in the rat. J. Lab. Clin. Med. 103:462–468.

Holman, R. T. 1960. The ratio of trienoic:tetraenoic acids in tissue lipids as a measure of essential fatty acid requirement. J. Nutr. 70:405–410.

Holman, R. T. 1968. Essential fatty acid deficiency. Prog. Chem. Fats Other Lipids 9:275–348.

Holman, R. T. 1970. Biological activities of and requirements for polyunsaturated acids. Prog. Chem. Fats Other Lipids 9:607–682.

Holman, R. T., and J. J. Peiffer. 1960. Acceleration of essential fatty acid deficiency by dietary cholesterol. J. Nutr. 70:411–417.

Holtkamp, D. E., and R. M. Hill. 1950. The effect on growth of the level of managanese in the diet of rats, with some observations on the manganese-thiamine relationship. J. Nutr. 41:307–316.

Hopkins, L. L., Jr., and H. E. Mohr. 1974. Vanadium as an essential nutrient. Fed. Proc. 33:1773–1775.

Horio, F., K. Ozaki, A. Yoshida, S. Makino, and Y. Hayashi. 1985. Requirement for ascorbic acid in a rat mutant unable to synthesize ascorbic acid. J. Nutr. 115:1630–1640.

Horio, F., K. Ozaki, M. Kohmura, A. Yoshida, S. Makino, and Y. Hayashi. 1986. Ascorbic acid requirement for the induction of microsomal drug-metabolizing enzymes in a rat mutant unable to synthesize ascorbic acid. J. Nutr. 116:2278–2289.

Horio, F., N. Takahashi, S. Makino, Y. Hayashi, and A. Yoshida. 1991. Ascorbic acid deficiency elevates serum level of LDL-cholesterol in a rat mutant unable to synthesize ascorbic acid. J. Nutr. Sci. Vitaminol. 37:63–71.

Horne, D. W., and W. T. Briggs. 1980. Effect of dietary and nitrous oxide-induced vitamin B12 deficiency on uptake of 5-methyltetrahy-drofolate by isolated rat hepatocytes. J. Nutr. 110:223–230.

Horwitt, M. K. 1954. Riboflavin. Pp. 380–391 in The Vitamins, Vol. III, W. H. Sebrell, Jr., and R. S. Harris, eds. New York: Academic Press.

Houghlum, K., M. Filip, J. L. Witztum, and M. Chojkier. 1990. Malondialdehyde and 4-hydroxynoneanal protein adducts in plasma and liver of rats with iron overload. J. Clin. Invest. 86:1191–1198.

Howard, L., C. Wagner, and S. Schenker. 1974. Malabsorption of thiamin in folate-deficient rats. J. Nutr. 104:1024–1032.

Hsu, J. M., J. C. Smith, Jr., A. A. Yunice, and G. Kepford. 1983. Impairment of ascorbic acid synthesis in liver extracts of magnesium-deficient rats. J. Nutr. 113:2041–2047.

Hsueh, A. M., C. E. Agustin, and B. F. Chow. 1967. Growth of young rats after differential manipulation of maternal diets. J. Nutr. 91:195–200.

Huber, A. M., S. N. Gershoff, and D. M. Hegsted. 1964. Carbohydrate and fat metabolism and response to insulin in vitamin B6-deficient rats. J. Nutr. 82:371.

Hundley, J. M. 1947. Production of niacin deficiency in rats. J. Nutr. 34:253–262.

Hundley, J. M. 1949. Influence of fructose and other carbohydrates on the niacin requirement of the rat. J. Biol. Chem. 181:1–9.

Hunter, K. E., and P. R. Turkki. 1987. Effect of exercise on riboflavin status of rats. J. Nutr. 117:298–304.

Hurley, L. S., and L. T. Bell. 1974. Genetic influence on response to dietary manganese deficiency. J. Nutr. 104:133–137.

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

Hurley, L. S., and C. L. Keen. 1987. Manganese. Pp. 185–223 in Trace Elements in Human and Animal Nutrition, W. Mertz, ed. Orlando, Fla.: Academic Press.

Hurley, L. S., G. Cosens, and L. L. Therialut. 1976a. Teratogenic effects of magnesium deficiency in rats. J. Nutr. 106:1254–1260.

Hurley, L. S., G. Cosens, and L. L. Therialut. 1976b. Magnesium, calcium, and zinc levels of maternal and fetal tissues in magnesium-deficient rats. J. Nutr. 106:1261–1264.


Ichihashi, T., Y. Takagishi, K. Uchida, and H. Yamada. 1992. Colonic absorption of menaquinone-4 and menaquinone-9 in rats. J. Nutr. 122:506–512.

Ikegami, S., F. Tsuchihashi, H. Harada, N. Tsuchihashi, E. Nishide, and S. Innami. 1990. Effect of viscous indigestible polysaccharides on pancreatic-biliary secretion and digestive organs in rats. J. Nutr. 120:353–360.

Ishida, M., B. Bulos, S. Takamoto, and B. Sacktor. 1987. Hydroxylation of 25-hydroxyvitamin D3 by renal mitochondria from rats of different ages. Endocrinology 121:443–448.

Itokawa, Y., and M. Fujiwara. 1973. Lead and vitamin effect on heme synthesis. Arch. Environ. Health 27:31–35.


Jacob, M., and R. M. Forbes. 1969. Effects of magnesium deficiency, dietary sulfate and thryoxine treatment on kidney calcification and tissue protein-bound carbohydrate in the rat . J. Nutr. 99:51–57.

Jager, F. C. 1972. Long-term dose-response effects of vitamin E in rats. Significance of the in vitro haemolysis test. Nutr. Metab. 14:1–7.

Jager, F. C., and U. M. T. Houtsmuller. 1970. Effect of dietary linoleic acid on vitamin E requirement and fatty acid composition of erythrocyte lipids in rats. Nutr. Metab. 12:3–12.

Jaus, H., G. Sturm, B. Grassle, W. Romen, and G. Siebert. 1977. Metabolic effects and liver damage after prolonged administration of high doses of nicotinamide to rats. Nutr. Metab. 21(Suppl. 1):38–41.

Jenkins, M. Y., and G. V. Mitchell. 1975. Influence of excess vitamin E on vitamin A toxicity in rats. J. Nutr. 105:1600–1606.

Johnson, J. L., W. R. Waud, K. V. Rajagopalan, M. Duran, F. A. Beemer, and S. K. Wadman. 1980. Inborn errors of molybdenum metabolism: Combined deficiencies of sulfite oxidase and xanthine dehydrogenase in a patient lacking the molybdenum cofactor. Proc. Natl. Acad. Sci. USA 77:3715–3719.

Johnson, M., and J. L. Greger. 1984. Absorption, distribution and endogenous excretion of zinc by rats fed various dietary levels of inorganic tin and zinc. J. Nutr. 114:1843–1852.

Johnson, M. A., and C. L. Murphy. 1988. Adverse effects of high dietary iron and ascorbic acid on copper status in copper-deficient and copper-adequate rats. Am. J. Clin. Nutr. 47:96–101.

Johnson, P. E., and E. D. Korynta. 1992. Effects of copper, iron and ascorbic acid on manganese availability to rats. Proc. Soc. Exp. Biol. Med. 199:470–480.

Johnson, W. T., and S. N. Dufault. 1989. Altered cytoskeletal organization and secretory response of thrombin-activated platelets from copper-deficient rats. J. Nutr. 119:1404–1410.

Johnson, W. T., S. N. Dufault, and A. C. Thomas. 1993. Platelet cytochrome c oxidase activity is an indicator of copper status in rats. Nutr. Res. 13:1153–1162.

Johnston, P. V. 1985. Dietary fat, eicosanoids, and immunity. Adv. Lipid Res. 21:103–141.

Jones, J. H. 1971. Vitamin D: Requirement of animals. Pp. 285–289 in The Vitamins, Vol. III, W. H. Sebrell, Jr., and R. S. Harris, eds. New York: Academic Press.


Kahlenberg, O. J., A. Black, and E. B. Forbes. 1937. The utilization of energy producing nutriment and protein as affected by sodium deficiency. J. Nutr. 13:97–108.

Kametaka, M., J. Inaba, and R. Ishikawa. 1974. Estimation of the daily milk intake of the suckling rat using the turnover rate of potassium. J. Nutr. Sci. Vitamin. 20:421–429.

Kane, G. G., F. E. Lovelace, and C. M. McCay. 1949. Dietary fat and calcium wastage in old age. J. Gerontol. 4:185–192.

Kang, S. S., R. G. Price, J. Yudkin, N. A. Worcester, and K. R. Bruckdorfer. 1979. The influence of dietary carbohydrate and fat on kidney calcification and the urinary excretion of N-acetyl-β-glucosaminidase (EC 3.2.1.30). Br. J. Nutr. 41:65–71.

Kang-Lee, Y. A., R. W. McKee, S. M. Wright, M. E. Swendseid, D. J. Jenden, and R. S. Jope. 1983. Metabolic effects of nicotinamide administration in rats. J. Nutr. 113:215–221.

Katz, M. L., W. G. Robison, Jr., R. K. Herrmann, A. B. Groome, and J. G. Bieri. 1984. Lipofuscin accumulation resulting from senescence and vitamin E deficiency: Spectral properties and tissue distribution. Mech. Ageing Dev. 25:149–159.

Kaup, S. N., A. R. Behling, L. Choquette, and J. L. Greger. 1990. Calcium and magnesium utilization in rats: Effect of dietary butterfat and calcium and of age. J. Nutr. 120:226–273.

Kaup, S. M., A. R. Behling, and J. L. Greger. 1991a. Sodium, potassium and chloride utilization by rats given various inorganic anions. Br. J. Nutr. 66:523–532.

Kaup, S. M., J. L. Greger, and K. Lee. 1991b. Nutritional evaluation with an animal model of cottage cheese fortified with calcium and guar gum. J. Food. Sci. 56:692–695.

Kaup, S. M., J. L. Greger, M. S. K. Marcus, and N. M. Lewis. 1991c. Blood pressure, fluid compartments and utilization of chloride in rats fed various chloride diets . J. Nutr. 121:330–337.

Kawano, J., D. N., Ney, C. L. Keen, and B. O. Schneeman. 1987. Altered high density lipoprotein composition in manganese-deficient Sprague-Dawley and Wistar rats. J. Nutr. 117:902–906.

Keen, C. L., and L. S. Hurley. 1989. Zinc and reproduction: Effects of deficiency on fetal and postnatal development. Pp. 183–220 in Zinc in Human Biology, C. F. Mills, ed. New York: Springer-Verlag.

Keen, C. L., and M. E. Gershwin. 1990. Zinc deficiency and immune function. Annu. Rev. Nutr. 10:415–431.

Keen, C. L., B. Lönnerdal, and L. S. Hurley. 1982. Teratogenic effects of copper deficiency and excess. Pp. 109–122 in Inflammatory Diseases and Copper, J. R. J. Sorenson, ed. New Jersey: Humana Press.

Keen, C. L., N. H. Reinstein, J. Goudey-Lefevre, M. Lefevre, B. Lönnerdal, B. O. Schneeman, and L. S. Hurley. 1985. Effect of dietary copper and zinc levels on tissue copper, zinc, and iron in male rats . Biol. Trace Elem. Res. 8:123–136.

Kellerman, J. H. 1934. A well-balanced ration for stock rats. Onderstepoort J. Vet. Sci. Anim. Ind. 2:649–654.

Keymer, A., D. W. T. Crompton, and A. Singhvi. 1983. Mannose and the "crowding effect" of hymenolepis in rats. Int. J. Parasitol. 13:561–570.

Khan, M. A., and B. Munira. 1978. Biological utilization of protein as influenced by dietary carbohydrates. Acta Agr. Scand. 28:282–284.

Khan-Siddiqui, L., and M. S. Bamji. 1987. Effect of riboflavin or pyridoxine deficiency on tissue carnitine levels in rats. Nutr. Res. 7:445–448.

Kielanowski, J. 1965. Estimates of the Energy Costs of Protein Deposition in Growing Animals: Animal Production (EAPP) Pub. No. 11. London: Butterworths.

Kielanowski, J. 1976. Energy cost of protein deposition. Pp. 207–217 in Protein Metabolism and Nutrition, Animal Production (EAPP) Pub. No. 16, D. J. A. Cole, K. N. Boorman, P. J. Buttery, D. Lewis, R. J. Neale, and H. Swan, eds. London: Butterworths.

Kim, H. Y., M. F. Picciano, M. A. Wallig, and J. A. Milner. 1991. The role of selenium nutrition in the development of neonatal rat lung. Pediat. Res. 29:440–445.

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

Kim, J., H. Kyriazi, and D. A. Green. 1991. Normalization of Na+-K +-ATPase activity in isolated membrane fraction from sciatic nerves of streptozocin-induced diabetic rats by dietary myo-inositol supplementation in vivo or protein kinase C agonist in vitro. Diabetes 40:558–567.

Kimura, S., Y. Furukawa, J. Wakasugi, Y. Ishihara, and A. Nakayama. 1980. Antagonism of L(-)pantothenic acid on lipid metabolism in animals. J. Nutr. Sci. Vitaminol. 26:113–117.

Kindberg, C. G., and J. W. Suttie. 1989. Effect of various intakes of phylloquinone on signs of vitamin K deficiency and serum and liver phylloquinone concentrations in the rat. J. Nutr. 119:175–180.

Kinsella, J. E., D. H. Hwang, P. Yu, J. Mai, and J. Shimp. 1979. Prostaglandins and their precursors in tissues from rats fed on trans,trans -linoleate. Biochem. J. 184:701–704.

Kirksey, A., and R. L. Pike. 1962. Some effects of high and low-sodium intakes during pregnancy in the rat. I. Food consumption, weight gain, reproductive performance, electrolyte balances, plasma total protein and protein fractions in normal pregnancy. J. Nutr. 77:33–42.

Kirksey A., R. L. Pang, and W.-J. Lin. 1975. Effects of different levels of pyridoxine fed during pregnancy superimposed upon growth in the rat. J. Nutr. 105:607–615.

Kleiber, M. 1975. The Fire of Life: An Introduction to Animal Energetics. New York: Krieger.

Kleiber, M., A. H. Smith, and T. N. Chernikoff. 1956. Metabolic rate of female rats as a function of age and body size. Am. J. Physiol. 186:9–12.

Kleiber, M., and H. H. Cole. 1945. Body size and energy metabolism during pregnancy of normal and precocious rats. Fed. Proc. 4:40 (abstr.).

Klevay, L. M. 1976. The biotin requirement of rats fed 20% egg white. J. Nutr. 106:1643–1646.

Klevay, L. M., and J. T. Saari. 1993. Comparative responses of rats to different copper intakes and modes of supplementation. Proc. Soc. Exp. Biol. Med. 203:214–220.

Kligler, D., and W. A. Krehl. 1952. Lysine deficiency in rats. II. Studies with amino acid diets. J. Nutr. 46:61–74.

Knapka, J. J. 1983. Nutrition. Pp. 51–67 in The Mouse in Biomedical Research, Vol. 3, H. L. Foster, J. D. Small, J. G. Fox, eds. New York: Academic Press.

Knapka, J. J., K. P. Smith, and F. J. Judge. 1974. Effect of open and closed formula rations on the performance of three strains of laboratory mice. Lab. Anim. Sci. 24:480–487.

Ko, K. W., F. X. Fellers, and J. M. Craig. 1962. Observations on magnesium deficiency in the rat. Lab. Invest. 11:294–305.

Kochanowski, B. A., and A. R. Sherman. 1983. Iron status of suckling rats as influenced by maternal diet during gestation and lactation. Br. J. Nutr. 49:51–57.

Kochanowski, B. A., and A. R. Sherman. 1984. Phagocytosis and lysozyme activity in granulocytes from iron-deficient rat dams and pups. Nutr. Res. 4:511–520.

Kochanowski, B. A., and A. R. Sherman. 1985. Decreased antibody formation in iron-deficient rat pups—effect of iron repletion. Am. J. Clin. Nutr. 41:278–284.

Koh, E. T. 1990. Comparison of copper status in rats when dietary fructose is replaced by either cornstarch or glucose. Proc. Soc. Exp. Biol. Med. 194:108–113.

Koh, E. T., S. Reiser, and M. Fields. 1989. Dietary fructose as compared to glucose and starch increases the calcium content of kidney of magnesium-deficient rats. J. Nutr. 119:1173–1178.

Koller, L. D., S. A. Mulhern, N. C. Frankel, M. G. Steven, and J. R. Williams. 1987. Immune dysfunction in rats fed a diet deficient in copper. Am. J. Clin. Nutr. 45:997–1006.

Kollmorgen, G. M., M. M. King, S. D. Kosanke, and C. Do. 1983. Influence of dietary fat and indomethacin on the growth of transplantable mammary tumors in rats. Cancer Res. 43:4714–4719.

Konijn, A. M., D. N. C. Muogbo, and K. Guggenheim. 1970. Metabolic effects of carbohydrate-free diets. Isr. J. Med. Sci. 6:498–505.

Konishi, F., T. Oku, and N. Hosoya. 1984. Hypertrophic effect of unavailable carbohydrate on cecum and colon in rats. J. Nutr. Sci. Vitaminol. 30:373–379.

Koong, L. J., C. L. Ferrell, and J. A. Neinaber. 1985. Assessment of interrelationships among levels of intake and production, organ size and fasting heat production in growing animals. J. Nutr. 115:1383–1390.

Kootstra, Y., J. Ritskes-Hoitinga, A. G. Lemmens, and A. C. Beynen. 1991. Diet-induced calciuria and nephrocalcinosis in female rats. Int. J. Vitam. Nutr. Res. 61:100–101.

Kornberg, A., and K. M. Endicott. 1946. Potassium deficiency in the rat. Am. J. Physiol. 145:291–298.

Koski, K. G., and F. W. Hill. 1986. Effect of low carbohydrate diets during pregnancy on parturition and postnatal survival of the newborn rat pup. J. Nutr. 116:1938–1948.

Koski, K. G., and F. W. Hill. 1990. Evidence for a critical period during late gestation when maternal dietary carbohydrate is essential for survival of newborn rats. J. Nutr. 120:1016–1027.

Koski, K. G., F. W. Hill, and L. S. Hurley. 1986. Effect of low carbohydrate diets during pregnancy on embryogenesis and fetal growth and development in rats. J. Nutr. 116:1922–1937.

Koski, K. G., F. W. Hill, and B. Lönnerdal. 1990. Altered lactational performance in rats fed low carbohydrate diets and its effect on growth of neonatal rat pups. J. Nutr. 120:1028–1036.

Kotchen, T. A., R. G. Luke, C. E. Ott, J. H. Galla, and S. Whitescarver. 1983. Effect of chloride on renin and blood pressure responses to sodium chloride. Ann. Intern. Med. 98:817–822.

Kramar, J., and V. L. Levine. 1953. Influence of fats and fatty acids on the capillaries. J. Nutr. 50:149–160.

Kramer, T. R., W. T. Johnson, and M. Briske-Anderson. 1988. Influence of iron and the sex of rats on hematological, biochemical and immunological changes during copper deficiency. J. Nutr. 118:214–221.

Krehl, W. A., P. S. Sarma, L. J. Teply, and C. A. Elvehjem. 1946. Factors affecting the dietary niacin and tryptophane requirement of the growing rat. J. Nutr. 31:85–106.

Kulkarni, A. B., and B. B. Gaitonde. 1983. Effects of early thiamin deficiency and subsequent rehabilitation on the cholinergic system in developing rat brain. J. Nutr. Sci. Vitaminol. 29:217–225.

Kummerow, F. A., H. P. Pan, and H. Hickman. 1952. The effect of dietary fat on the reproductive performance and the mixed fatty acid composition of fat-deficient rats. J. Nutr. 46:489–498.

Kumta, U. S., and A. E. Harper. 1962. Amino acid balance and imbalance. Effect of amino acid imbalance on blood amino acid pattern. Proc. Soc. Exp. Biol. Med. 110:512–517.

Kunkel, H. O., and P. B. Pearson. 1948. The quantitative requirements of the rat for magnesium. Arch. Biochem. 18:461–465.

Kurtz, D. J., H. Levy, and J. N. Kanfer. 1972. Cerebral lipids and amino acids in the vitamin B6-deficient suckling rat. J. Nutr. 102:291.

Kurtz, P. J., D. C. Enunerling, and D. J. Donofrio. 1984. Subchronic toxicity of all-trans-retinoic acid and retinylidene dimedone in Sprague-Dawley rats. Toxicology 30:115–124.

Kwiecinski, G. G., G. I. Petrie, and H. F. DeLuca. 1989. Vitamin D is necessary for reproductive functions of the male rat. J. Nutr. 119:741–744.


L'Abbe, M. R., and P. W. F. Fischer. 1984. The effects of high dietary zinc and copper deficiency on the activity of copper-requiring metalloenzymes in the growing rat. J. Nutr. 114:813–822.

L'Abbe, M. R., P. W. F. Fischer, D. D. Trick, J. S. Campbell, and

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

E. R. Chavez. 1991. Dietary Se and tumor glutathione peroxidase and superoxide dismutase activity. J. Nutr. Biochem. 2:430–436.

Lamptey, M. S., and B. L. Walker. 1976. A possible essential role for dietary linolenic acid in the development of the young rat. J. Nutr. 106:86–93.

Lane, H. W., R. Strength, J. Johnson, and M. White. 1991. Effect of chemical form of selenium on tissue glutathione peroxidase activity in developing rats. J. Nutr. 121:80–86.

Langlais, P. J., R. G. Mair, C. D. Anderson, and W. J. McEntee. 1988. Long-lasting changes in regional brain amino acids and monoamines in recovered pyrithiamine treated rats. Neurochem. Res. 13:1199–1206.

Laskey, J. W., G. L. Rehnberg, J. F. Hein, and S. D. Carter. 1982. Effects of chronic manganese exposure on selected reproductive parameters in rats. J. Toxicol. Environ. Health 9:677–687.

Leclerc, J. 1991. Study of vitamin B1 nutrition in the pregnant rat and its litter as a function of dietary thiamin supply. Int. J. Vitam. Nutr. Res. 48:333–340.

Leclerc, J., and M. L. Miller. 1987. Relationship between riboflavin intake and excretion in female rats after weaning of the litter. Int. J. Vitam. Nutr. Res. 57:45–51.

Lederer, E., and M. Lourau. 1948. Action antagoniste de certains cations devalents sur un enzyme secrété par la muquerise gastrique et jouant un rôle dans l'hematopoiese. Biochim. Biophys. Acta 2:278–285.

Lederer, W. H., M. Kumar, and A. E. Axelrod. 1975. Effects of pantothenic acid deficiency on cellular antibody synthesis in rats. J. Nutr. 105:17–25.

Lee, J. H., M. Fukumoto, H. Nishida, I. Ikeda, and M. Sugano. 1989. The interrelated effects of n-6/n-3 and polyunsaturated/saturated ratios of dietary fats on the regulation of lipid metabolism in rats. J. Nutr. 119:1893–1899.

Lee, S. S., and D. B. McCormick. 1983. Effect of riboflavin status on hepatic activities of flavin-metabolizing enzymes in rats. J. Nutr. 113:2274–2279.

Leelaprute, V., V. Boonpucknavig, N. Shamarapravati, and W. Weerapradist. 1973. Hypervitaminosis A in rats. Arch. Pathol. 96:5–9.

Levander, O. A., and R. F. Burk. 1990. Selenium. Pp. 268–273 in Present Knowledge in Nutrition, M. L. Brown, ed. Washington, D.C.: International Life Sciences Institute, Nutrition Foundation.

Levin, G., U. Cogan, Y. Levy, and S. Mokady. 1990. Riboflavin deficiency and the function and fluidity of rat erythrocyte membranes. J. Nutr. 120:857–861.

Levine, D. Z., D. Roy, G. Tolnai, L. Nash, and B. G. Shah. 1974. Chloride depletion and nephrocalcinosis. Am. J. Physiol. 227:878–883.

Levine, H., R. E. Remington, and H. von Kilnitz. 1933. Studies on the relation of diet to goiter. II. The iodine requirement of the rat. J. Nutr. 6:347–354.

Levrat, M.-A., S. R. Behr, C. Remesy, and C. Demigne. 1991. Effects of soybean fiber on cecal digestion in rats previously adapted to a fiber-free diet. J. Nutr. 121:672–678.

Lewis, C. J., B. Shannon, and B. Kleeman. 1982. Taurine and cystathionine excretion in female rats as influenced by dietary vitamin B6 and estradiol administration. Nutr. Rep. Int. 25:269–276.

Lewis, C. G., M. Fields, and T. Beal. 1990. Effect of changing the type of dietary carbohydrate or copper level of copper-deficient, fructose-fed rats on tissue sorbitol concentrations. J. Nutr. Biochem. 1:160–166.

Lewis, K. C., M. H. Green, J. B. Green, and L. A. Zech. 1990. Retinol metabolism in rats with low vitamin A status: A compartmental model. J. Lipid Res. 31:1535–1548.

Lih, H., and C. A. Baumann. 1951. Effects of certain antibiotics on the growth of rats fed diets limiting in thiamine, riboflavin, or pantothenic acid. J. Nutr. 45:143–152.

Likins, R. C., L. A. Bavetta, and A. S. Posner. 1957. Calcification in lysine deficiency. Arch. Biochem. Biophys. 70:401–412.

Lin, W., and A. Kirksey. 1976. Effects of different levels of dietary iron on pregnancy superimposed upon growth in the rat. J. Nutr. 106:543–554.

Lindquist, R. N., J. L. Lynn, Jr., and G. E. Lienhard. 1973. Possible transition state analogs for ribonuclease. The complexes of urdine with oxovanadium (IV) and vanadium (V) ion . J. Am. Chem. Soc. 95:8762–8768.

Lindsey, J. R. 1979. Historical foundations. In The Laboratory Rat, Vol. 1, H. J. Baker, J. R. Lindsey, and S. H. Wisbroth, eds. New York: Academic Press.

Linscher, W. G., and A. J. Vergroeson. 1988. Lipids. Pp. 72–107 in Modern Nutrition in Health and Disease, M. E. Shils and V. R. Young, eds. Washington, D.C.: Lea & Febiger.

Lockwood, M. K., and C. D. Eckhert. 1992. Sucrose induced lipid, glucose and insulin elevations, microvascular injury and Se. Am. J. Physiol. 262:R144–R149.

Loeb, H. G., and G. O. Burr. 1947. A study of sex differences in the composition of rats, with emphasis on the lipid component. J. Nutr. 33:541–551.

Lojkin, M. L. 1967. Effect of levels of nitrogen intake on tryptophan metabolism and requirement for pregnancy of the rat. J. Nutr. 91:89–98.

Lombardini, J. B. 1986. Taurine levels in blood and urine of vitamin B6 deficient and estrogen-treated rats . Biochem. Med. Metab. Biol. 35:125–131.

Longnecker, D. S., B. D. Roebuck, J. D. Yager, Jr., H. S. Lilja, and B. Siegmund. 1981. Pancreatic carcinoma in azaserine-treated rats; induction, classification and dietary modulation of incidence. Cancer 47:1561–1572.

Longnecker, J. B., and N. L. Hause. 1959. Relationship between plasma amino acids and composition of the ingested protein. Arch. Biochem. Biophys. 84:46–59.

Loo, G., P. J. Goodman, K. A. Hill, and J. T. Smith. 1986. Creatine metabolism in the pyridoxine-deficient rat. J. Nutr. 116:2403–2408.

Loosli, J. K., J. F. Lingenfelter, J. W. Thomas, and L. A. Maynard. 1944. The role of dietary fat and linoleic acid in the lactation of the rat. J. Nutr. 28:81–88.

Lopez, V., T. Stevens, and R. N. Lindquist. 1976. Vandium ion inhibition of alkaline phosphatase-catalyzed phosphate ester hydrolysis. Arch. Biochem. Biophys. 175:31–38.

Lopez-Guisa, J. M., M. C. Harned, R. Dubielzig, S. C. Rao, and J. A. Marlett. 1988. Processed oat hulls as potential dietary fiber sources in rats. J. Nutr. 118:953–962.

Lowry, R. R., and I. J. Tinsley. 1966. Oleic and linoleic acid interaction in polyunsaturated fatty acid metabolism in the rat. J. Nutr. 88:26–32.

Luckey, T. D., T. J. Mende, and J. Pleasants. 1954. The physical and chemical characterization of rat's milk. J. Nutr. 54:345–359.

Luckey, T. D., J. R. Pleasants, M. Wagner, H. A. Gordon, and J. A. Reyniers. 1955. Some observations on vitamin metabolism in germ-free rats. J. Nutr. 57:169–182.

Ludwig, S., and N. Kaplowitz. 1980. Effect of pyridoxine deficiency on serum and liver transaminases in experimental liver injury in the rat. Gastroenterology 79:545–549.

Lushbough, C. H., T. Porter, and B. S. Schweigert. 1957. Utilization of amino acids from foods by the rat. J. Nutr. 62:513–526.


Machlin, L. J., R. Filipski, J. Nelson, L. R. Horn, and M. Brin. 1977. Effects of a prolonged vitamin E deficiency in the rat. J. Nutr. 107:1200–1208.

Mackerer, C. R., M. A. Mehlman, and R. B. Tobin. 1973. Effects of chronic acetylsalicylate administration on several nutrition and biochemical parameters in rats fed diets of varied thiamin content. Biochem. Med. 8:51–60.

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

Magour, S., H. Maser, and I. Steffen. 1983. Effect of daily oral intake of manganese on free polysomal protein synthesis of rat brain. Acta Pharmacol. Toxicol. 53:88–91.

Mahmood, S., H. M. Dani, and A. Mahmood. 1985. Effect of dietary pyridoxine deficiency on intestinal functions in rats. Nutr. Res. 5:299–304.

Majumder, A. K., K. B. Nandi, N. Subramanian, and I. B. Chatterjee. 1975. Nutrient interrelation of ascorbic acid and iron in rats and guinea pigs fed cereal diets. J. Nutr. 105:240–244.

Mameesh, M. S., and B. C. Johnson. 1960. Dietary vitamin K requirement of the rat. Proc. Soc. Exp. Biol. Med. 103:378–380.

Mangelsdorf, D. J., U. Borgmeyer, R. A. Heyman, J. Y. Zhou, E. S. Ong, A. E. Oro, A. Kakizuka, and R. M. Evans. 1992. Characterization of three RXR genes that mediate the action of 9-cis retinoic acid. Genes Dev. 6:329–344.

Mars, Y. W. H. M., A. G. Lemmens, and A. C. Beynen. 1988. Dietary phosphorus and nephrocalcinosis in female rats. Nutr. Rep. Int. 38:249–258.

Martin, M. M., and L. S. Hurley. 1977. Effect of large amounts of vitamin E during pregnancy and lactation. Am. J. Clin. Nutr. 30:1629–1637.

Martindale, L., and F. W. Heaton. 1964. Magnesium deficiency in the adult rat. Biochem. J. 92:119–126.

Mathers, J. C., F. Fernandez, M. J. Hill, P. T. McCarthy, M. J. Shearer, and A. Oxley. 1990. Dietary modification of potential vitamin K supply from enteric bacterial menaquinones in rats. Br. J. Nutr. 63:639–652.

Mathews, C. H. E., R. Brommage, and H. F. DeLuca. 1986. Role of vitamin D in neonatal skeletal developments in rats. Am. J. Physiol. 250:E725–E730.

Matschiner, J. T., and A. K. Willingham. 1974. Influence of sex hormones on vitamin K deficiency and epoxidation of vitamin K in the rat. J. Nutr. 104:660–665.

Matschiner, J. T., and R. G. Bell. 1973. Effect of sex and sex hormones on plasma prothrombin and vitamin K deficiency. Proc. Soc. Exp. Biol. Med. 144:316–320.

Matschiner, J. T., and E. A. Doisy, Jr. 1965. Effect of dietary protein on the development of vitamin K deficiency in the rat. J. Nutr. 86:93–99.

Matsuo, T., and Z. Suzuoki. 1982. Feeding responses of riboflavindeficient rats to energy dilution, cold exposure and gluoprivation. J. Nutr. 112:1052–1056.

Mattson, F. H. 1959. The absorbability of stearic acid when fed as a simple or mixed triglyceride. J. Nutr. 69:338–342.

Mayer, J., N. B. Marshall, J. J. Vitale, J. H. Christensen, M. B. Mashay, Mashekhi, and F. J. Store. 1954. Exercise, food intake and body weight in normal rats and genetically obese adult mice. Am. J. Physiol. 177:544–548.

McAleese, D. M., and R. M. Forbes. 1961. The requirement and tissue distribution of magnesium in the rat as influenced by environmental temperature and dietary calcium. J. Nutr. 73:94–106.

McCall, M. G., G. E. Newman, J. R. P. Obrien, L. S. Valberg, and L. J. Witts. 1962a. Studies in iron metabolism. 1. The experimental production of iron metabolism. Br. J. Nutr. 16:297–304.

McCall, M. G., G. E. Newman, J. R. P. Obrien, and L. J. Witts. 1962b. Studies in iron metabolism. 2. The effects of experimental iron deficiency in the growing rat. Br. J. Nutr. 16:305–323.

McCandless, D. W., C. Hanson, K. V. Speeg, Jr., and S. Schenker. 1970. Cardiac metabolism in thiamin deficiency in rats. J. Nutr. 100:991–1002.

McCarthy, D. J., C. Lindamood III, C. M. Gundberg, and D. L. Hill. 1989. Retinoid-induced hemorrhaging and bone toxicity in rats fed diets deficient in vitamin K. Toxicol. Appl. Pharmacol. 97:300–310.

McCoy, K. E. M., and P. H. Weswig. 1969. Some selenium responses in the rat not related to vitamin E. J. Nutr. 98:383–389.

McCraken, K. J. 1975. Effect of feeding pattern on the energy metabolism of rats given low-protein diets. Br. J. Nutr. 33:277–289.

McLane, J. A., T. Khan, and I. R. Held. 1987. Increased axonal transport in peripheral nerves of thiamin-deficient rats. Exp. Neurol. 95:482–491.

Mead, J. F. 1984. The noneicosanoid functions of the essential fatty acids. J. Lipid Res. 25:1517–1521.

Medeiros, D. M., Z. Liao, and R. L. Hamlin. 1992. Electrocardiographic activity and cardiac function in copper-restricted rats. Proc. Soc. Exp. Biol. Med. 200:78–84.

Mei-Ying, C. M., and M. R. Kare. 1979. Effect of vitamin B6 deficiency on preference for several taste solutions in the rat. J. Nutr. 109:339–344.

Meister, A. 1957. Biochemistry of the Amino Acids. New York: Academic Press.

Mellette, S. J., and L. A. Leone. 1960. Influence of age, sex, strain of rat and fat-soluble vitamins on hemorrhagic syndromes in rats fed irradiated beef. Fed. Proc. 19:1045–1049.

Menaker, L., and J. M. Navia. 1973. Appetite regulation in the rat under various physiological conditions: The role of dietary protein and calories. J. Nutr. 103:347–352.

Mercer, L. P., J. M. Gustafson, P. T. Higbee, C. E. Geno, M. R. Schweisthal, and T. B. Cole. 1984. Control of physiological response in the rat by nutrient concentration. J. Nutr. 114:144–152.

Mercer, L. P., S. J. Dodds, and J. M. Gustafson. 1986. The determination of nutritional requirements: A modeling approach. Nutr. Rep. Int. 34:337–350.

Mercer, L. P., H. E. May, and S. J. Dodds. 1989. The determination of nutritional requirements in rats: Mathematical modeling of sigmoidal, inhibited nutrient-response curves. J. Nutr. 119:1465–1471.

Mertz, W., and E. E. Roginski. 1969. Effect of chromium (III) supplementation on growth and survival under stress in rats fed low-protein diets. J. Nutr. 97:531–536.

Mertz, W., E. E. Roginski, and H. A. Schroeder. 1965. Some aspects of glucose metabolism of chromium deficient rats raised in the strictly controlled environment. J. Nutr. 86:107–112.

Meydani, M., J. B. Macauley, and J. B. Blumberg. 1986. Influence of dietary vitamin E, selenium and age on regional distribution of α-tocopherol in the rat brain. Lipids 21:786–791.

Meyer, J. H. 1956. Influence of dietary fiber on metabolic and endogenous nitrogen excretion. J. Nutr. 58:407–413.

Meyer, J. H. 1958. Interactions of dietary fiber and protein on food intake and body composition of growing rats. Am. J. Physiol. 193:488–494.

Meyerovitch, J., P. Rothenberg, Y. Shechter, S. Bonner-Weir, and C. R. Kahn. 1991. Vanadate normalizes hyperglycemia in two mouse models of non-insulin-dependent diabetes mellitus. J. Clin. Invest. 87:1286–1294.

Michaelis, O. E., IV, R. E. Martin, L. B. Gardner, and K. C. Ellwood. 1981. Effect of simple and complex carbohydrate on lipogenic parameters of spontaneously hypertensive rats. Nutr. Rep. Int. 24:313–321.

Michells, F. G., and J. T. Smith. 1965. A comparison of the utilization of organic and inorganic sulfur by the rat. J. Nutr. 87:217–220.

Middleton, H. M. 1986. Intestinal hydrolysis of pyridoxal 5'-phosphate in vivo in the rat: Effect of ethanol. Am. J. Clin. Nutr. 43:374–381.

Middleton, H. M. 1990. Intestinal hydrolysis of pyridoxal 5'-phosphate in vitro and in vivo in the rat: Effect of amino acids and oligopeptides. Dig. Dis. Sci. 35:113–120.

Miller, H. G. 1926. Sodium deficiency in a corn ration. J. Biol. Chem. 70:759–762.

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

Miller, R. F., N. O. Price, and R. W. Engel. 1956. Added dietary inorganic sulfate and its effect upon rats fed molybdenum. J. Nutr. 60:539–545.

Miller, S. C., M. A. Miller, and T. H. Omura. 1988. Dietary lactose improves endochondral growth and bone development and mineralization in rats fed a vitamin D-deficient diet. J. Nutr. 118:72–77.

Mills, C. F., and G. K Davis. 1989. Molybdenum. Pp. 429–463 in Trace Elements in Human and Animal Nutrition, Vol. 1, W. Mertz, ed. San Diego: Academic Press.

Milner, J. A., A. E. Wakeling, and W. J. Visek. 1974. Effect of arginine deficiency on growth and intermediary metabolism in rats. J. Nutr. 104:1681–1689.

Mitchell, H. H. 1950. Nutrient requirements as related to body size and body function. Scientia 85:165–175.

Mitchell, H. H., and J. R. Beadles. 1952. The determination of the protein requirement of the rat for maximum growth under conditions of restricted consumption of food. J. Nutr. 47:133–145.

Mittelholzer, E. 1976. Absence of influence of high doses of biotin on reproductive performance in female rats. Int. J. Vitam. Nutr. Res. 46:33–39.

Mizushima, Y., T. Harauchi, T. Yoshizaki, and S. Makino. 1984. A rat mutant unable to synthesize vitamin C. Experientia 40:359–361.

Molitor, H., and H. J. Robinson. 1940. Oral and parenteral toxicity of vitamin K1, phthiocol, and 2-methyl-1,4-naphthoquinone. Proc. Soc. Exp. Biol. Med. 43:125–128.

Monserrat, A. J., E. A. Porta, A. K. Ghoshal, and S. B. Hartman. 1974. Sequential renal lipid changes in weanling rats fed a choline-deficient diet. J. Nutr. 104:1496–1502.

Moon, W.-H., and A. Kirksey. 1973. Cellular growth during prenatal and early postnatal periods in progeny of pyridoxine-deficient rats. J. Nutr. 103:123–133.

Moore, R. J., P. G. Reeves, and T. L. Veum. 1984. Influence of dietary phosphorus and sulphaguanidine levels on P utilization in rats. Br. J. Nutr. 51:453–465.

Moore, T. 1957. Vitamin A. New York: Elsevier.

Morhauer, H., and R. T. Holman. 1963. The effect of dose level of essential fatty acids upon fatty acid composition of the rat liver. J. Lipid Res. 4:151–159.

Mori, S., Y. Takeuchi, M. Toyama, S. Makino, T. Harauchi, Y. Kurata, and S. Fukushima. 1988. Assessment of L-ascorbic acid requirement for prolonged survival in ODS rats and their susceptibility to urinary bladder carcinogenesis by N-butyl-N-(4–hydroxybutyl)-nitrosamine. Cancer Lett. 38:275–282.

Morrison, S. D. 1956. The total energy and water metabolism during pregnancy in the rat. J. Physiol. 134:650–664.

Morrison, S. D. 1968. The constancy of the energy expended by rats on spontaneous activity, and the distribution of activity between feeding and non-feeding. J. Physiol. 197:305–323.

Mudd, S. H., F. Irrverre, and L. Laster. 1967. Sulfite oxidase deficiency in man: Demonstration of the enzymatic defect. Science 156:1599–1602.

Muir, M., and I. Chanarin. 1984. Conversion of endogenous cobalamins into microbiologically-inactive cobalamin analogues in rats exposed to nitrous oxide. Br. J. Haematol. 58:517–523.

Mulford, D. J., and W. H. Griffith. 1942. Choline metabolism. VIII. The relation of cystine and of methionine to the requirement of choline in young rats. J. Nutr. 23:91–100.

Murdock, D. S., M. L. Donaldson, and C. J. Gubler. 1974. Studies on the mechanism of the "thiamin-sparing" effect on ascorbic acid in rats. Am. J. Clin. Nutr. 27:696–699.

Muto, Y., J. E. Smith, P. O. Milch, and D. S. Goodman. 1972. Regulation of retinol-binding protein metabolism by vitamin A status in the rat. J. Biol. Chem. 247:2542–2550.


Nakashima, Y., and R. Suzue. 1982. Effect of nicotinic acid on myelin lipids in the brain of developing rats. J. Nutr. Sci. Vitaminol. 28:491–500.

Nakashima, Y., and R. Suzue. 1984. Influence of nicotinic acid on cerebroside synthesis in the brain of developing rats. J. Nutr. Sci. Vitaminol. 30:525–534.

Naismith, D. J., D. P. Richardson, and A. E. Pritchard. 1982. The utilization of protein and energy during lactation in the rat, with particular regard to the use of fat accumulated during pregnancy. Br. J. Nutr. 48:433–441.

Nanda, R., F. P. G. M. Van Der Linden, and H. W. B. Jansen. 1970. Production of cleft palate with dexamethasone and hypervitaminosis A in rat embryos. Experientia 26:1111–1112.

Narayan, K. A., and J. J. McMullen. 1980. Accelerated induction of fatty livers in rats fed fat-free diets containing sucrose or glycerol. Nutr. Rep. Int. 21:689–697.

National Institutes of Health. 1982. NIH Rodents, 1980 Catalogue: Strains and Stocks of Laboratory Rodents Provided by the NIH Genetic Resource. NIH Publication 83-606. Bethesda, Md.: U.S. Public Health Service.

National Research Council. 1962. Nutrient Requirements of Domestic Animals, Number 10. Pub. 990. Washington, D.C.: National Academy of Sciences.

National Research Council. 1972. Nutrient Requirements of Laboratory Animals, Second Edition. Washington, D.C.: National Academy Press.

National Research Council. 1978. Nutrient requirements of the laboratory rat. Pp. 7–37 in Nutrient Requirements of Laboratory Animals, Third Revised Ed. Washington, D.C.: National Academy Press.

National Research Council. 1980. Chromium. Pp. 142–153 in Mineral Tolerance of Domestic Animals. Washington, D.C.: National Academy Press.

National Research Council. 1983. Selenium in Nutrition. Washington, D.C.: National Academy Press.

National Research Council. 1988. Nutrient Requirements of Swine, Ninth Revised Ed. Washington, D.C.: National Academy Press.

National Research Council. 1994. Nutrient Requirements of Poultry, Ninth Revised Ed. Washington, D.C.: National Academy Press.

Nechay, B. R., L. B. Nanninga, P. S. E. Nechay, R. L. Post, J. J. Grantham, I. G. Macara, L. F. Kubena, T. D. Phillips, and F. H. Nielsen. 1986. Role of vanadium in biology. Fed. Proc. 45:123–132.

Nelson, G. J., and R. G. Ackman. 1988. Absorption and transport of fat in mammals with emphasis on n-3 polyunsaturated fatty acids. Lipids 23:1005–1014.

Nelson, M. M., and H. M. Evans. 1953. Relation of dietary protein levels to reproduction in the rat. J. Nutr. 51:71–84.

Nelson, M. M., and H. M. Evans. 1958. Sulfur amino acid requirement for lactation in the rat. Proc. Soc. Exp. Biol. Med. 99:723–725.

Nelson, M. M., and H. M. Evans. 1961. Dietary requirements for lactation in rats and other laboratory animals. Pp. 137–191 in Milk: The Mammary Gland and Its Secretion, Vol. II, S. K. Kon and A. T. Cowie, eds. New York: Academic Press.

Newberne, P. M. 1964. Cardiorenal lesions of potassium depletion or steroid therapy in the rat. Am. J. Vet. Res. 25:1256–1266.

Newberne, P. M., A. E. Rogers, C. Bailey, and V. R. Young. 1969. The induction of liver cirrhosis in rats by purified amino acid diets. Cancer Res. 29:230–235.

Newburg, D. S., and L. C. Fillios. 1979. A requirement for dietary asparagine in pregnant rats. J. Nutr. 109:2190–2197.

Newburg, D. S., D. L. Frankel, and L. C. Fillios. 1975. An asparagine requirement in young rats fed the dietary combinations of aspartic acid, glutamine, and glutamic acid. J. Nutr. 105:356–363.

Nguyen, L. B., J. F. Gregory III, and J. J. Cerda. 1983. Effect of

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

dietary fiber on absorption of B-6 vitamins in a rat jejunal perfusion study. Proc. Soc. Exp. Biol. Med. 173:568–573.

Nieder, G. L., C. N. Corder, and P. A. Culp. 1979. The effect of vanadate on human kidney potassium dependent phosphatase. Arch. Pharmacol. 307:191–198.

Nielsen, E., and C. A. Elvehjem. 1941. Cure of spectacle eye condition in rats with biotin concentrate. Proc. Soc. Exp. Biol. Med. 48:349–352.

Nielsen, F. H. 1980a. Effect of form of iron on the interaction between nickel and iron in rats: Growth and blood parameters. J. Nutr. 110:965–973.

Nielsen, F. H. 1980b. Evidence of the essentiality of arsenic, nickel, and vanadium and their possible nutritional significance. Pp. 157–172 in Advances in Nutritional Research, Vol. 3, H. H. Draper, ed. New York: Plenum Press.

Nielsen, F. H. 1984. Ultra-trace elements in nutrition. Annu. Rev. Nutr. 4:21–41.

Nielsen, F. H. 1985. The importance of diet composition in ultra-trace element research. J. Nutr. 115:1239–1247.

Nielsen, F. H., and E. O. Uthus. 1990. The essentiality and metabolism of vanadium. Pp. 51-62 in Vanadium in Biological Systems, N. D. Chasteen, ed. The Netherlands: Klumer Academic.

Nielsen, F. H., D. R. Myron, S. H. Givand, T. J. Zimmerman, and D. A. Ollerich. 1975. Nickel deficiency in rats. J. Nutr. 105:1620–1630.

Nielsen, F. H., T. J. Zimmerman, M. E. Collings, and D. R. Myron. 1979. Nickel deprivation in rats: Nickel-iron interactions. J. Nutr. 109:1623–1632.

Nielsen, F. H., T. R. Shuler, T. G. McLeod, and T. J. Zimmerman. 1984. Nickel influences iron metabolism through physiologic, pharmacologic and toxicologic mechanisms in the rat. J. Nutr. 114:1280–1288.

Nielsen, F. H., T. J. Zimmerman, T. R. Shuler, B. Brossart, and E. O. Uthus. 1989. Evidence for a cooperative metabolic relationship between nickel and vitamin B12 in rats. J. Trace Elem. Exp. Med. 2:21–29.

Nishina, P. M., B. O. Schneeman, and R. A. Freedland. 1991. Effects of dietary fibers on nonfasting plasma lipoprotein levels in rats. J. Nutr. 121:431–442.

Nolen, G. A. 1972. The effects of various levels of dietary protein on retinoic acid-induced teratogenicity in rats. Teratology 5:143–152.

Nowak, R. M. 1991. Walker's Mammals of the World, 5th Ed. Baltimore, Md.: Johns Hopkins University Press.

Nyengaard, J. R., T. F. Bendtsen, S. Christensen, and P. D. Ottosen. 1994. The number and size of glomeruli in long-term lithium-induced nephropathy in rats. APMIS 102:59–66.


O'Connor, D. L., M. F. Picciano, T. Tamura and B. Shane. 1990. Impaired milk folate secretion is not corrected by supplemental folate during iron deficiency in rats. J. Nutr. 120:499–506.

O'Dell, B. L., and M. Emery. 1991. Compromised zinc status in rats adversely affects calcium metabolism in platelets. J. Nutr. 121:1763–1768.

O'Dell, B. L., E. R. Morris, and W. O. Regan. 1960. Magnesium requirement of guinea pigs and rats: Effect of calcium and phosphorus and symptoms of magnesium deficiency. J. Nutr. 70:103–110.

Oftedal, O. T. 1984. Milk composition, milk yield, and energy output at peak lactation: A comparative review. Symp. Zool. Soc. London 51:33–85.

Okada, M., and K. Suzuki. 1974. Amino acid metabolism in rats fed a high protein diet with pyridoxine. J. Nutr. 104:287–293.

Okuyama, H., M. Saitoh, Y. Naito, T. Hori, A. Hashimoto, A. Moriuchi, and N. Yamamoto. 1987. Re-evaluation of the essentiality of alpha-linolenic acid in rats. Pp. 296–300 in Polyunsaturated Fatty Acids and Eicosanoids, W. E. M. Lands, ed. Champaign, Ill.: American Oil Chemists Society.

Onodera, K. 1987. Effects of decarboxylase inhibitors on muricidal suppression by L-dopa in thiamine deficient rats. Arch. Int. Pharmacodyn. Ther. 285:263–276.

Onodera, K., Y. Ogura, and K. Kisara. 1981. Characteristics of muricide induced by thiamine deficiency and its suppression by antidepressants or intraventricular serotonin. Physiol. Behav. 27:847–853.

Orent-Keiles, E., A. Robinson, and E. V. McCollum. 1937. The effects of sodium deprivation on the animal organism. Am. J. Physiol. 119:651–661.

Ornoy, A., J. Menczel, and L. Nebel. 1968. Alterations in the mineral composition and metabolism of rat fetuses and their placentas induced by maternal hypervitaminosis D2. Isr. J. Med. Sci. 4:827–831.


Pallauf, J., and M. Kirchgessner. 1971. Zum Zinkbedarf wachsender Ratten. Int. J. Vitam. Nutr. Res. 41:543–553.

Pang, R. L., and A. Kirksey. 1974. Early postnatal changes in brain composition in progeny of rats fed different levels of dietary pyridoxine . J. Nutr. 104:111–117.

Parker, H. E., F. N. Andrews, S. M. Hauge, and F. W. Quackenbush. 1951. Studies on the iodine requirement of white rats during growth, pregnancy and lactation. J. Nutr. 44:501–511.

Patek, A. J., E. Erenoglu, N. M. O'Brian, and R. L. Hirsch. 1969. Sex hormones and susceptibility of the rat to dietary cirrhosis. Arch. Pathol. 87:52–56.

Patt, E. L., E. E. Pickett, and B. L. O'Dell. 1978. Effect of dietary lithium levels on tissue lithium concentration, growth rate, and reproduction in the rat. Bioinorg. Chem. 9:299–310.

Paul, P. K., P. N. Duttagupta, and H. C. Agarwal. 1973. Effects of an acute dose of biotin on the reproductive organs of the female rat. Curr. Sci. 42:206–208.

Pazos-Moura, C. C., E. G. Moura, M. L. Dorris, S. Rehnmark, L. Melendez, J. E. Silva, and A. Taurog. 1991. Effect of iodine deficiency on thyroxine 5'-deiodinase activity in various rat tissues. Am. J. Physiol. 260:E175–E182.

Pearson, P. B. 1948. High levels of dietary potassium and magnesium and growth of rats. Am. J. Physiol. 153:432–435.

Pearson, W. N. 1967. Blood and urinary vitamin levels as potential indices of body stores. Am. J. Clin. Nutr. 20:514–525.

Pederson, R. A., S. Ramanadham, A. M. J. Buchan, and J. H. McNeill. 1989. Long-term effects of vanadyl treatment on streptozocin-induced diabetes in rats. Diabetes 38:1390–1395.

Peifer, J. J., and R. D. Lewis. 1979. Effects of vitamin B12 deprivation on phospholipid fatty acid patterns in liver and brain of rats fed high and low levels of linoleate in low methionine diets. J. Nutr. 109:2160–2172.

Pence, B. C. 1991. Dietary selenium and antioxidant status: Toxic effects of 1,2-dimethylhydrazine in rats. J. Nutr. 121:138–144.

Perisse, J., and E. Salmon-Legagneur. 1960. Influence of plane of nutrition during pregnancy and lactation on milk production in the rat. Arch. Sci. Physiol. 14:105.

Peters, J. C., and A. E. Harper. 1985. Adaptation of rats to diets containing different levels of protein: Effects on food intake, plasma and brain amino acid concentrations and brain neurotransmitter metabolism. J. Nutr. 115:382–398.

Peterson, A. D., and B. R. Baumgardt. 1971a. Food and energy intake of rats fed diets varying in energy concentration and density. J. Nutr. 101:1057–1067.

Peterson, A. D., and B. R. Baumgardt. 1971b. Influence of level of energy demand on the ability of rats to compensate for diet dilution. J. Nutr. 101:1069–1074.

Peterson, C. A., J. A. C. Eurell, and J. W. Erdman, Jr. 1992. Bone composition and histology of young growing rats fed diets of varied calcium bioavailability: Spinach, nonfat dry milk, or calcium carbonate added to casein. J. Nutr. 122:137–144.

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

Peterson, P. A., S. F. Nilsson, L. Ostberg, L. Rask, and A. Vahlquist. 1974. Aspects of the metabolism of retinol-binding protein and retinol. Vitam. Horm. 32:181–214.

Pfaller, W., W. M. Fischer, N. Streider, H. Wurnig, and P. Deetjen. 1974. Morphologic changes of cortical nephron cells in potassiumadapted rats. Lab. Invest. 31:678–684.

Phatak, S. S., and V. N. Patwardhan. 1950. Toxicity of nickel. J. Sci. Ind. Res. 9B:70–75.

Phillips, R. D. 1981. Linear and nonlinear models for measuring protein nutritional quality. J. Nutr. 111:1058–1066.

Picciano, M. F. 1970. Chloride nutriture of the growing rat. M.S. thesis. Pennsylvania State University, University Park, Pa.

Pickett, E. E. 1983. Evidence for the essentiality of lithium in the rat. Pp. 66–70 in Fourth Trace Element Symposium: Lithium, M. Anke, W. Baumann, H. Bräunlich, and Chr. Brückner, eds. Jena, Germany: Friedrich Schiller Universität.

Pickett, E. E., and B. L. O'Dell. 1992. Evidence for the dietary essentiality of lithium in the rat. Biol. Trace Elem. Res. 334(3):299–319.

Pillai, G. R., M. Indira, and P. L. Vijayammal. 1990. Ascorbic acid 2-sulfate storage form of ascorbic acid in rats. Curr. Sci. 59:800–804.

Poiley, S. M. 1972. Growth tables for 66 strains and stocks of laboratory animals. Lab. Anim. Sci. 22:759–779.

Potvliege, P. R. 1962. Hypervitaminosis D2 in gravid rats. Arch. Pathol. 73:371–382.

Powers, H. J. 1987. A study of maternofetal iron transfer in the riboflavin-deficient rat. J. Nutr. 117:852–856.

Prabhu, A. L., V. S. Aboobaker, and R. K. Bhattacharya. 1989. In vivo effect of dietary factors on the molecular action of aflatoxin B1: Role of riboflavin on the catalytic activity of liver fractions. Cancer Lett. 48:89–94.

Prentice, A. M., and C. J. Bates. 1981. A biochemical evaluation of the erythrocyte glutathione reductase (EC 1.6.4.2) test for riboflavin status. 2. Dose-response relationships in chronic marginal deficiency. Br. J. Nutr. 45:53–65.

Pudelkewicz, C., J. Seuffert, and R. T. Holman. 1968. Requirements of the female rat for linoleic and linolenic acids. J. Nutr. 94:138–146.

Pullar, J. D., and A. J. F. Webster. 1974. Heat loss and energy retention during growth in congenitally obese and lean rats . Br. J. Nutr. 31:377–392.

Pullar, J. D., and A. J. F. Webster. 1977. The energy cost of fat and protein deposition in the rat. Br. J. Nutr. 37:355–363.


Qureshi, S. A., H. S. Buttar, and I. J. McGilveray. 1992. Lithium-induced nephrotoxicity in rats following subcutaneous multiple injections and infusion using miniosmotic pumps. Fund. Appl. Toxicol. 18:616–620.


Rabin, B. S. 1983. Inhibition of experimentally induced autoimmunity in rats by biotin deficiency. J. Nutr. 113:2316–2322.

Rahm, J. J., and R. T. Holman. 1964. The relationship of single dietary polyunsaturated fatty acids to fatty acid composition of lipids from subcellular particles of liver. J. Lipid Res. 5:169–176.

Rajagopalan, K. V. 1988. Molybdenum: An essential trace element in human nutrition. Annu. Rev. Nutr. 8:401–427.

Rajeswari, T. S., and E. Radha. 1984. Age-related effects of nutritional vitamin B6-dependent enzymes of glutamate, gamma-aminobutyrate and glutamine systems in the rat brain. Exp. Gerontol. 19:87–93.

Ralli, E. P., and M. E. Dumm. 1953. Relation of pantothenic acid to adrenal cortical function. Vitam. Horm. 11:133–154.

Ranhotra, G. S., and B. C. Johnson. 1965. Effects of feeding different amino acids on growth rate and nitrogen retention of weanling rats. Proc. Soc. Exp. Biol. Med. 118:1197–1201.

Rao, G. H., and K. E. Mason. 1975. Antisterility and antivitamin K activity of d-α-tocopheryl hydroquinone in the vitamin E-deficient female rat. J. Nutr. 105:495–498.

Rau, M., M. S. Patole, S. Vijaya, C. K. R. Kurup, and T. Ramasarma. 1987. Vanadate-stimulated NADH oxidation in microsomes. Mol. Cell. Biochem. 75:151–159.

Rechcigl, M., Jr., S. Berger, J. K. Loosli, and H. H. Williams. 1962. Dietary protein and utilization of vitamin A. J. Nutr. 76:435–440.

Reddy, M. B., and J. D. Cook. 1991. Assessment of dietary determinants of nonheme-iron absorption in humans and rats. Am. J. Clin. Nutr. 54:723–728.

Reeves, P. G. 1989. AIN-76 diet: Should we change the formulation? J. Nutr. 119:1081–1082.

Reeves, P. G., and R. M. Forbes. 1972. Prevention by thyroxine of nephrocalcinosis in early magnesium deficiency in the rat. Am. J. Physiol. 222:220–224.

Reeves, P. G., K. L. Rossow, and J. Lindlauf. 1993a. Development and testing of the AIN-93 purified diets for rodents: Results on growth, kidney calcification and bone mineralization in rats and mice. J. Nutr. 123:1923–1931.

Reeves, P. G., F. H. Nielsen, and G. C. Fahey, Jr. 1993b. AIN-93 purified diets for laboratory rodents: Final report of the American Institute of Nutrition Ad Hoc Writing Committee on the reformulation of the AIN-76A rodent diet. J. Nutr. 123:1939–1951.

Reeves, P. G., K. L. Rossow, and L. Johnson. 1994. Maintenance nutrient requirements for copper in adult male mice fed AIN-93 rodent diet. Nutr. Res. 14:1219–1226.

Rehnberg, G. L., J. F. Hein, S. D. Carter, R. S. Linko, and J. W. Laskey. 1982. Chronic ingestion of Mn304 by rats: Tissue accumulation and distribution of manganese in two generations. J. Toxicol. Environ. Health 9:175–188.

Reichel, H., H. P. Koeffler, and A. W. Norman. 1989. The role of the vitamin D endocrine system in health and disease. N. Engl. J. Med. 320:980–991.

Remesy, C., and C. Demigne. 1989. Specific effects of fermentable carbohydrates on blood urea flux and ammonia absorption in rat cecum. J. Nutr. 119:560–565.

Remington, R. E., and J. W. Remington. 1938. The effect of enhanced iodine intake on growth and on the thyroid glands of normal goitrous rats. J. Nutr. 15:539–545.

Richardson, L. R., J. Godwin, S. Wilkes, and M. Cannon. 1964. Reproductive performance of rats receiving various levels of dietary protein and fat. J. Nutr. 82:257–262.

Riede, U. N., W. Sandritter, A. Pietzsch, and R. Rohrbach. 1980. Reaction patterns of cell organelles in vitamin B6 deficiency: Ultrastructural-morphometric analysis of the liver parenchymal cell. Pathol. Res. Prac. 170:376–387.

Ritskes-Hoitinga, J. 1992. Diet and Nephrocalcinoisis in the Laboratory Rat. Ph.D. dissertation. State University, Wageningen, The Netherlands.

Ritskes-Hoitinga, J., A. G. Lemmens, L. H. J. C. Danse, and A. C. Beynen. 1989. Phosphorus-induced nephrocalcinosis and kidney function in female rats. J. Nutr. 119:1423–1431.

Ritskes-Hoitinga, J., J. N. J. J. Mathot, L. H. J. C. Danse, and C. C. Beynen. 1991. Commercial rodent diets and nephrocalcinosis in weanling female rats. Lab. Anim. 25:126–132.

Ritskes-Hoitinga, J., J. N. J. J. Mathot, A. G. Lemmens, L. H. J. C. Danse, G. W. Meijer, G. Van Tintelen, and A. C. Beynen. 1993. Long-term phosphorus restriction prevents corticomedullary nephrocalcinosis and sustains reproductive performance but delays bone mineralization in rats. J. Nutr. 123:754–763.

Rivlin, R. S. 1970. Riboflavin metabolism. N. Engl. J. Med. 283:463–472.

Robbins, J. D., R. R. Oltjen, C. A. Cabell, and E. H. Dolnick. 1965. Influence of varying levels of dietary minerals on the development

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

of urolithiosis, hair growth and weight gains in rats. J. Nutr. 85:355–361.

Roebuck, B. D., S. A. Wilpone, D. S. Fifield, and J. D. Yager, Jr. 1979. Letter to the Editor. J. Nutr. 109:924–925.

Roecklein, B., S. W. Levin, M. Comly, and A. B. Mukherjee. 1985. Intrauterine growth retardation induced by thiamin deficiency and pyrithiamine during pregnancy in the rat. Am. J. Obstet. Gynecol. 151:455–460.

Rofe, A. M., R. Krishnan, R. Bais, J. B. Edwards, and R. A. Conyers. 1982. A mechanism for the thiamin-sparing action of dietary xylitol in the rat. Aust. J. Exp. Biol. Med. Sci. 60:101–111.

Rogers, A. E., and R. A. MacDonald. 1965. Hepatic vasculature and cell proliferation in experimental cirrhosis. Lab. Invest. 14:1710–1724.

Rogers, J. M., C. L. Keen, N. Reinstein, and L. S. Hurley. 1984. Maternal zinc nutriture during pregnancy and lactation in the rat: Survivability and growth of offspring. Fed. Proc. 43:1052 (abstr.).

Rogers, Q. R., and A. E. Harper. 1965. Amino acid diets and maximum growth in the rat. J. Nutr. 87:267–273.

Rogers, W. E., Jr., J. G. Bieri, and E. G. McDaniel. 1971. Vitamin A deficiency in the germ-free state. Fed. Proc. 30:1773–1778.

Roginski, E. E., and W. Mertz. 1967. An eye lesion in rats fed low-chromium diets. J. Nutr. 93:249–251.

Roginski, E. E., and W. Mertz. 1969. Effects of chromium (III) supplementation on glucose and amino acid metabolism in rats fed a low-protein diet. J. Nutr. 97:525–530.

Rolls, B. J., and E. A. Rowe. 1982. Pregnancy and lactation in the obese rat: Effects on maternal and pup weights. Physiol. Behav. 28:393–400.

Rong, N., J. Selhub, B. R. Goldin, and I. H. Rosenberg. 1991. Bacterially synthesized folate in rat large intestine is incorporated into host tissue folyl polyglutamates. J. Nutr. 121:1955–1959.

Root, E. J., and J. B. Longnecker. 1983. Brain cell alterations suggesting premature aging induced by dietary deficiency of vitamin B6 and/or copper . Am. J. Clin. Nutr. 37:540–552.

Rose, W. C., M. J. Oesterling, and M. Womack. 1948. Comparative growth on diets containing ten and nineteen amino acids, with further observation upon the role of glutamic and aspartic acid. J. Biol. Chem. 176:753–762.

Rosenberg, H. F., and R. Culik. 1955. Lysine requirement of the growing rat as a function of the productive energy level of the diet. J. Anim. Sci. 14:1221 (abstr.).

Roth-Maier, D. A., and M. Kirchgessner. 1981. Homeostasis and requirement of vitamin B6 growing rats. Z. Tierphysiol. Tierernaehr. Futtermittelkde 46:247–254.

Roth-Maier, D. A., P. M. Zinner, and M. Kirchgessner. 1982. Effect of varying dietary vitamin B6 supply on intestinal absorption of vitamin B6. Int. J. Vitam. Nutr. Res. 52:272–279.

Roth-Maier, D. A., M. Kirchgessner, and S. Rajtek. 1990. Retention and utilization of thiamin by gravid and non gravid rats with varying dietary thiamin supply. Int. J. Vitam. Nutr. Res. 60:343–350.

Rotruck, J. T., A. L. Pope, H. E. Ganther, and W. G. Hoekstra. 1973. Selenium: Biochemical role as a component of glutathione peroxidase. Science 179:588–590.


Saari, J. T. 1992. Dietary copper deficiency and endothelium-dependent relaxation of rat aorta. Proc. Soc. Exp. Biol. Med. 200:19–24.

Sahu, A. P., A. K. Saxena, K. P. Singh, and R. Shanker. 1986. Effect of chronic choline administration in rats. Indian J. Exp. Biol. 24:91–96.

Said, A. K., and D. M. Hegsted. 1970. Response of adult rats to low dietary levels of essential amino acids. J. Nutr. 100:1363–1375.

Said, H. M., and D. Hollander. 1985. Does aging affect the intestinal transport of riboflavin? Life Sci. 36:69–73.

Said, H. M., F. K. Ghishan, H. L. Greene, and D. Hollander. 1985. Development maturation of riboflavin intestinal transport in the rat. Pediat. Res. 19:1175–1178.

Said, H. M., D. Ong, and R. Redha. 1988. Intestinal uptake of retinol in suckling rats: Characteristics and ontogeny. Pediat. Res. 24:481–485.

Sainz, R. D., C. C. Calvert, and R. L. Baldwin. 1986. Relationships among dietary protein feed intake and changes in body composition of lactating rats. J. Nutr. 116:1529–1539.

Salmon, W. D., and P. M. Newberne. 1962. Cardiovascular disease in choline-deficient rats. Arch. Pathol. 73:190–208.

Sampson, D. A., and G. R. Janson. 1984. Protein and energy nutrition during lactation. Annu. Rev. Nutr. 4:43–67.

Sandstrom, B., and B. Lönnerdal. 1989. Promoters and antagonists of zinc absorption. Pp. 57–78 in Zinc in Human Biology, C. F. Mills, ed. New York: Springer-Verlag.

Sarter, M., and A. Van Der Linde. 1987. Vitamin E deprivation in rats: Some behavioral and histochemical observations. Neurobiol. Aging 8:297–307.

Sato, Y., K. Ando, E. Ogata, and T. Fujita. 1991. High-potassium diet attenuates salt-induced acceleration of hypertension in SHR. Am. J. Physiol. 260:R21–R26.

Sauberlich, H. E. 1952. Effect of aureomycin and penicillin upon the vitamin requirements of the rat. J. Nutr. 46:99–108.

Schaafsma, G., and R. Visser. 1980. Nutritional interrelationships between calcium, phosphorus and lactose in rats. J. Nutr. 110:1101–1111.

Schachter, D., D. V. Kimberg, and H. Schenker. 1961. Active transport of calcium by intestine: Action and bio-assay of vitamin D. Am. J. Physiol. 200:1263–1271.

Schaeffer, M., and M. J. Kretsch. 1987. Quantitative assessment of motor and sensory function in vitamin B6 deficient rats. Nutr. Res. 7:851–864.

Schaeffer, M. C. 1987. Attenuation of acoustic and tactile startle responses of vitamin B6 deficient rats. Physiol. Behav. 40:473–478.

Schaeffer, M. C., D. A. Sampson, J. H. Skala, D. W. Gietzen, and R. E. Grier. 1989. Evaluation of vitamin B6 status and function of rats fed excess pyridoxine . J. Nutr. 119:1392–1398.

Schaeffer, M. C., E. F. Cochary, and J. A. Sadowski. 1990. Subtle abnormalities of gait detected early in vitamin B6 deficiency in aged and weanling rats with hind leg gait analysis. J. Am. Coll. Nutr. 9:120–127.

Schemmel, R., O. Mickelsen, and K. Motowi. 1972. Conversion of dietary to body energy in rats as affected by strain, sex and ration. J. Nutr. 102:1187–1197.

Schenker, S., R. M. Qualls, R. Butcher, and D. W. McCandless. 1969. Regional renal adenosine triphophate metabolism in thiamine deficiency. J. Nutr. 99:168–176.

Schneeman, B. O., and D. Gallaher. 1980. Changes in small intestinal digestive enzyme activity and bile acids with dietary cellulose in rats. J. Nutr. 110:584–590.

Schnegg, A., and M. Kirchgessner. 1975a. Zur Essentialität von Nickel für das tierische Wachstum. Z. Tierphysiol. Tierernaehr. Futtermittelkde 36:63–74.

Schnegg, A., and M. Kirchgessner. 1975b. Veränderungen des Hämoglobingehaltes, der Erythrozytenzahl und des Hämatokrits bei Nickelmangel. Nutr. Metabol. 19:268–278.

Schnegg, A., and M. Kirchgessner. 1976a. Zur Absorption und Verfügbarkeit von Eisen bei Nickel-Mangel. Int. Z. Vitaminforsch. 46:96–99.

Schnegg, A., and M. Kirchgessner. 1976b. Zur Toxizität von Alimentär Verabreichtem Nickel. Landwirtsch. Forsch. 29:177–185.

Schnegg, A., and M. Kirchgessner. 1978. Ni deficiency and its effect on metabolism. Pp. 236–243 in Trace Element Metabolism in Man

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

and Animals—3, M. Kirchgessner, ed. Freising-Weihenstephan, Germany: University of Munich.

Schoenmakers, A. C. M., J. Ritskes-Hoitinga, A. G. Lemmens, and A. C. Beynen. 1989. Influence of dietary phosphorus restriction on calcium and phosphorus metabolism in rats. Int. J. Vitam. Nutr. Res. 59:200–206.

Schrader, C. A., C. Prickett, and W. D. Salmon. 1937. Symptomatology and pathology of potassium and magnesium deficiencies in the rat. J. Nutr. 14:85–109.

Schreier, C. J., and R. J. Emerick. 1986. Diet calcium carbonate, phosphorus and acidifying and alkalizing salts as factors influencing silica urolithiasis in rats fed tetraethylorthosilicate. J. Nutr. 116:823–830.

Schroeder, H. A. 1966. Chromium deficiency in rats: A syndrome simulating diabetes mellitus with retarded growth. J. Nutr. 88:439–445.

Schroeder, H. A., W. H. Vinton, Jr., and J. J. Balassa. 1963. Effects of chromium, cadmium and lead on the growth and survival of rats. J. Nutr. 80:48–54.

Schulz, A. R. 1991. Interpretation of nutrient-response relationships in rats. J. Nutr. 121:1834–1843.

Schumacher, M. F., M. A. Williams, and R. L. Lyman. 1965. Effect of high intakes of thiamine, riboflavin, and pyridoxine on reproduction in rats and vitamin requirements of the offspring. J. Nutr. 86:343–349.

Schwarz, K. 1951. Production of dietary necrotic liver degeneration using American Torula yeast. Proc. Soc. Exp. Biol. Med. 77:818–823.

Schwarz, K., and C. M. Foltz. 1957. Selenium as an integral part of factor 3 against dietary necrotic liver degeneration. J. Am. Chem. Soc. 79:3292–3293.

Schwarz, K., and W. Mertz. 1959. Chromium (III) and the glucose tolerance factor. Arch. Biochim. Biophys. 85:292–295.

Schwarz, K., and D. B. Milne. 1971. Growth effects of vanadium in the rat. Science 174:426–428.

Schwarz, K., and D. B. Milne. 1972. Growth-promoting effects of silicon in rats. Science 238:333–334.

Schweigert, B. S., and B. T. Guthneck. 1953. Utilization of amino acids from foods by the rat. I. Methods of testing for lysine. J. Nutr. 49:277–287.

Schweigert, B. S., and B. T. Guthneck. 1954. Utilization of amino acids from foods by the rat. II. Methionine. J. Nutr. 54:333–343.

Scott, E. M., and I. V. Griffith. 1957. A comparative study of thiamine-sparing agents in the rat. J. Nutr. 61:421–436.

Scott, M. L. 1978. Vitamin E. Pp. 133–210 in Handbook of Lipid Research, Vol. 2, The Fat-Soluble Vitamins, H. F. DeLuca, ed. New York: Plenum Press.

Seaborn, C. D., E. D. Mitchell, and B. J. Stoecker. 1992. Vanadium and ascorbate effects on hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase, cholesterol, and tissue minerals in guinea pigs fed low-chromium diets. Magnes. Trace Elem. 10:327–338.

Sealey, J. E., I. Clark, M. B. Bull, and J. H. Laragh. 1970. Potassium balance and the control of renin secretion. J. Clin. Invest. 49:2119–2127.

Seshadri, S., L. Das, and A. Patil. 1982. Effect of varying the level of lead on ascorbic acid status in rats fed low and high protein diets. Arogya 8:34–39.

Shah, B. G., and B. Belonje. 1991. Different dietary calcium levels required to prevent nephrocalcinosis in male and female rats. Nutr. Res. 11:385–390.

Shah, B. G., B. Belonje, and E. A. Nera. 1980. Reduction of nephrocalcinosis in female rats by additional magnesium and by fluoride. Nutr. Rep. Int. 22:957–963.

Shah, B. G., K. D. Trick, and B. Belonje. 1986. Factors affecting nephrocalcinosis in male and female rats fed AIN-76 salt mixture. Nutr. Res. 6:559–570.

Shane, B., and E. L. R. Stokstad. 1985. Vitamin B12-folate relationships. Annu. Rev. Nutr. 5:115–141.

Shanghai, Y. D. X. 1991. Effects of riboflavin deficiency on iron nutritional status in rats. Shanghai Yike Dazue Xuebao 18:9–13.

Shastri, N. V., S. G. Nayudu, and M. C. Nath. 1968. Effect of high-fat and high-fat-high protein diets on biosynthesis of niacin from tryptophan in rats. J. Vitaminol. 14:198–202.

Shaw, S., V. Herbert, N. Colman, and E. Jayatilleke. 1990. Effect of ethanol-generated free radicals on gastric intrinsic factor and glutathione. Alcohol 7:153–157.

Sheehan, P. M., B. A. Clevidence, L. K. Reynolds, F. W. Thye, and S. J. Ritchey. 1981. Carcass nitrogen as a predictor of protein requirement for mature female rats. J. Nutr. 111:1224–1230.

Shelling, D. H., and D. E. Asher. 1932. Calcium and phosphorus studies. IV. The relation of calcium and phosphorus of the diet to the toxicity of viosterol. Bull. Johns Hopkins 50:318–343.

Shepard, T. H., B. Mackler, and C. A. Finch. 1980. Reproductive studies in the iron-deficient rat. Teratology 22:329–334.

Sherman, H. 1954. Pyridoxine and related compounds. Pp. 265–276 in The Vitamins, Vol. III, W. H. Sebrell, Jr., and R. S. Harris, eds. New York: Academic Press.

Shibata, K. 1986. Nutritional factors affecting the activity of liver nicotinamide methyltransferase and urinary excretion of N-1-methylnicotinamide in rats. Agr. Biol. Chem. 50:1489–1494.

Shibuya, M., and M. Okada. 1986. Effect of pyridoxine-deficiency on the turnover of aspartate aminotransferase isozymes in rat liver. J. Biochem. 99:939–944.

Shibuya, M., F. Hisaoka, and M. Okada. 1990. Effects of pregnancy on vitamin B6-dependent enzymes and B6 content in tissues of rats fed diets containing two levels of pyridoxine-hydrochloride. Nippon Eiyo Shokuryo Gakkaishi 43:189–195.

Shigematsu, Y., Y. Kikawa, M. Sudo, and Y. Itokawa. 1989. Branched-chain α-ketoacids and related acids in thiamin-deprived rats. J. Nutr. Sci. Vitaminol. 35:163–70.

Shirley, B. 1982. Detrimental effects of increased riboflavin intake by pregnant and lactating rats. IRCS Med. Sci. 10:632–633.

Shurson, G. C., P. K. Ku, G. L. Waxler, M. T. Yokoysma, and E. R. Miller. 1990. Physiological relationships between microbiological status and dietary copper levels in the pig. J. Anim. Sci. 68:1061–1071.

Sibbald, I. R., R. T. Berg, and J. P. Bowland. 1956. Digestible energy in relation to food intake and nitrogen retention in the weanling rat. J. Nutr. 59:385–392.

Sibbald, I. R., J. P. Bowland, A. R. Robblee, and R. T. Berg. 1957. Apparent digestible energy and nitrogen in the food of the weanling rat: Influence of food consumption, nitrogen retention and carcass composition . J. Nutr. 61:71–85.

Sinclair, H. M. 1952. Essential fatty acids and their relation to pyridoxine. Biochem. Soc. Symp. 9:80–99.

Skala, J. H., M. C. Schaeffer, D. A. Sampson, and D. Gretz. 1989. Effects of various levels of pyridoxine on erythrocyte aminotransferase activities in the rat. Nutr. Res. 9:195–204.

Small, D. M. 1991. The effects of glyceride structure on absorption and metabolism. Annu. Rev. Nutr. 11:413–434.

Smith, A. M., and M. F Picciano. 1986. Evidence for increased selenium requirement for the rat during pregnancy and lactation. J. Nutr. 116:1068–1079.

Smith, A. M., and M. F. Picciano. 1987. Relative bioavailability of seleno-compounds in the lactating rat. J. Nutr. 117:725–731.

Smith, B. S. W., and A. C. Field. 1963. Effect of age on magnesium deficiency in rats. Br. J. Nutr. 17:591–600.

Smith, E. B., and B. C. Johnson. 1967. Studies of amino acid requirements of adult rats. Br. J. Nutr. 21:17–27.

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

Smith, J. C., Jr., E. G. McDaniel, F. F. Fan, and J. A. Halsted. 1973. Zinc: A trace element essential in vitamin A metabolism. Science 181:954–955.

Smith, J. E. 1990. Preparation of vitamin A-deficient rats and mice. Methods Enzymol. 190:229–236.

Smith, J. T. 1973. An optimal level of inorganic sulfate for the diet of a rat. J. Nutr. 103:1008–1011.

Smith, J. E., and R. Borchers. 1972. Environmental temperature and the utilization of β-carotene by the rat. J. Nutr. 102:1017–1024.

Smolin, L.A., and N.J. Benevenga. 1984. Factors affecting the accumulation of homocyst(e)ine in rats deficient in vitamin B6. J. Nutr. 114:103–111.

Sowers, J. E., W. L. Stockland, and R. J. Meade. 1972. L-Methionine and L-cystine requirements of the growing rat. J. Anim. Sci. 35:782–788.

Spoerl, R., and M. Kirchgessner. 1975a. Changes in the copper status and the ceruloplasmin activity of mother and suckling rats in response to the copper supplied at graded levels. Z. Tierphysiol. Tierernaehr. Futtermittelke 35:113–127.

Spoerl, R., and M. Kirchgessner. 1975b. Effect of copper deficiency during rearing and gravidity on reproduction. Z. Tierphysiol. Tierernaehr. Futtermittelkd 35:321–328.

Sprecher, H. 1991. Metabolism of dietary fatty acids. Pp. 12–20 in Health Effects of Dietary Fatty Acids, G. J. Nelson, ed. Champaign, Ill.: American Oil Chemists Society.

Steenbock, H., and D. C. Herting. 1955. Vitamin D and growth. J. Nutr. 57:449–468.

Stenflo, J. 1976. Vitamin K-dependent carboxylation of blood coagulation proteins. Trends Biochem. Sci. 1:256–258.

Stewart, C. N., D. B. Coursin, and H. N. Bhagavan. 1975. Avoidance behavior in vitamin B6-deficient rats. J. Nutr. 105:1363–1370.

Stockland, W. L., Y. F. Lai, R. J. Meade, J. E. Sowers, and G. Oeskmer. 1971. L-Phenylalanine and L-tyrosine requirements of the growing rat. J. Nutr. 101:177–184.

Stockland, W. L., R. J. Meade, D. F. Wass, and J. E. Sowers. 1973. Influence of levels of methionine and cystine on the total sulfur amino acid requirement of the growing rat. J. Anim. Sci. 36:526–530.

Stokstad, E. L., and C. P. Nair. 1988. Effect of hypothyroidism on methylmalonate excretion and hepatic vitamin B12 levels in rats. J. Nutr. 118:1495–1501.

Strasia, C. A. 1971. Vanadium essentiality and toxicity in the laboratory rat. Ph.D. dissertation. Purdue University, Lafayette, Indiana.

Strause, L., P. Saltman, and J. Glowacki. 1987. The effect of deficiencies of manganese and copper on osteoinduction and on resorption of bone particles in rats. Cal. Tiss. Int. 41:145–150.

Stucki, W. P., and A. E. Harper. 1962. Effects of altering the ratio of indispensable to dispensable amino acids in diets for rats. J. Nutr. 78:278–287.

Sun, S., R. McKee, J. S. Fisler, and M. E. Swendseid. 1986. Muscle creatine content in rats given repeated large doses of nicotinamide: Effects of dietary methionine, choline, carnitine, and other supplements. J. Nutr. 116:2409–2414.

Sunde, R. A. 1990. Molecular biology of selenoproteins. Annu. Rev. Nutr. 10:451–474.

Sunde, R. A., S. L. Weiss, K. M. Thompson, and J. K. Evenson. 1992. Dietary selenium regulation of glutathione peroxidase mRNA—Implications for the selenium requirement. FASEB J. 6(Part 1):A1365.

Suttie, J. W. 1991. Vitamin K. Pp. 145–194 in Handbook of Vitamins, 2nd Ed., L. J. Machlin, ed. New York: Marcel Dekker.

Suzuki, T., and A. Yoshida. 1979. Effectiveness of dietary iron and ascorbic acid in the prevention and cure of moderately long-term toxicity in rats. J. Nutr. 109:1974–1978.

Swarup, G., S. Cohen, and D. L. Garbers. 1982. Inhibition of membrane phosphotyrosyl-protein phosphatase activity by vanadate. Biochem. Biophys. Res. Commun. 107:1104–1109.

Swift, R. W., and A. Black. 1949. Fats in relation to caloric efficiency. J. Am. Oil Chem. Soc. 26:171–176.

Swift, R. W., and R. M. Forbes. 1939. The heat production of the fasting rat in relation to the environmental temperature. J. Nutr. 18:307–318.


Tagliaferro, A. R., and D. A. Levitsky. 1982. Spillage behavior and thiamin deficiency in the rat. Physiol. Behav. 28:933–937.

Takahashi, O., and K. Hiraga. 1979. Preventive effects of phylloquinone on hemorrhagic death induced by butylated hydroxytoluene in male rats. J. Nutr. 109:453–457.

Takahashi, Y. I., J. E. Smith, M. Winick, and D. S. Goodman. 1975. Vitamin A deficiency and fetal growth and development in the rat. J. Nutr. 105:1299–1310.

Tamburro, C., O. Frank, A. D. Thomson, M. F. Sorrell, and H. Baker. 1971. Interactions of folate, nicotinate, and riboflavin deficiencies in rats. Nutr. Rep. Int. 4:185–189.

Taniguchi, M. 1980. Effects of riboflavin deficiency on lipid peroxidation of rat liver microsomes. J. Nutr. Sci. 26:401–413.

Taylor, S., and E. Poulson. 1956. Long-term iodine deficiency in the rat. J. Endocrinol. 13:439–444.

Taylor, S. A., R. E. Shrader, K. G. Koski, and F. J. Zeman. 1983. Maternal and embryonic response to a ''carbohydrate-free" diet fed to rats. J. Nutr. 113:253–267.

Taylor, T. G. 1980. Availability of phosphorus in animal feeds. Pp. 23–33 in Recent Advances in Animal Nutrition-1979, W. Haresign and D. Lewis, eds. Boston: Butterworths.

Thenen, S. W. 1989. Megadose effects of vitamin C on vitamin B12 status in the rat. J. Nutr. 119:1107–1114.

Thenen, S. W., and E. L. R. Stokstad. 1973. Effect of methionine on specific folate coenzyme pools in vitamin B12 deficient and supplemented rats. J. Nutr. 103:363–370.

Thomas, M. R., and A. Kirksey. 1976a. Postnatal patterns of rain lipids in progeny of vitamin B6-deficient rats before and after pyridoxine supplementation. J. Nutr. 106:1404–1414.

Thomas, M. R., and A. Kirksey. 1976b. Postnatal patterns of fatty acids in brain of progeny from vitamin B6-deficient rats before and after pyridoxine supplementation. J. Nutr. 106:1415–1420.

Thompson, S. G., and E. G. McGeer. 1985. GABA-transaminase and glutamic acid decarboxylase changes in the brain of rats treated with pyrithiamine. Neurochem. Res. 10:1653–1660.

Thomsen, L. L., C. Tasman-Jones, and C. Maher. 1983. Effects of dietary fat and gel-forming substances on rat jejunal disaccharidase levels. Digestion 26:124–130.

Thomson, A. D., O. Frank, B. De Angelis, and H. Baker. 1972. Thiamin depletion induced by dietary folate deficiency in rats. Nutr. Rep. Int. 6:107–110.

Tinoco, J. 1982. Dietary requirements and functions of α-linolenic acid in animals. Prog. Lipid Res. 21:1–45.

Tinoco, J., M. A. Williams, I. Hincenbergs, and R. L. Lyman. 1971. Evidence for nonessentiality of linolenic acid in the diet of the rat. J. Nutr. 101:937–946.

Tinsley, I. J., J. R. Harr, J. G. Bone, P. H. Weswig, and R. S. Yamamoto. 1967. Selenium toxicity in rats. I. Growth and longevity. Pp. 141–152 in Symposium: Selenium in Biomedicine, O. H. Muth, ed. Westport, Conn.: AVI Publishing.

Tobian, L. 1991. Salt and hypertension: Lessons from animal models that relate to human hypertension. Hypertension 17:152–158.

Tobin, B. W., and J. L. Beard. 1990. Interactions of iron deficiency and exercise training relative to tissue norepinephrine turnover, triiodothyronine production and metabolic rate in rats. J. Nutr. 120:900–908.

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

Tokunaga, T., T. Oku, and N. Hosoya. 1989. Utilization and excretion of a new sweetener, fructooligosaccharide (neosugar), in rats. J. Nutr. 119:553–559.

Tomlinson, D. R., G. B. Willars, and J. P. Robinson. 1986. Prevention of defects of axonal transport in experimental diabetes by aldose reductase inhibitors. Drugs 32(Suppl. 2):15–18.

Track, N. S., M. M. Cannon, A. Flenniken, S. Katamay, and E. F. A. Woods. 1982. Improved carbohydrate tolerance in fibre-fed rats: Studies of the chronic effect. Can. J. Physiol. Pharmacol. 60:769–776.

Trugnan, G., G. Thomas-Benhamou, P. Cardot, Y. Rayssiguier, and G. Bereziat. 1985. Short-term essential fatty acid deficiency in rats: Influence of dietary carbohydrates. Lipids 20:862–868.

Tsuji, M., Y. Ito, H. Fukuda, N. Terada, and H. Mori. 1989. Aromatase activity and progesterone metabolism in ovaries of scorbutic mutant rats unable to synthesize ascorbic acid. Int. J. Vitam. Nutr. Res. 59:353–359.

Tufts, E. V., and D. M. Greenberg. 1938. The biochemistry of magnesium deficiency. II. The minimum magnesium requirement for growth, gestation, and lactation, and the effect of the dietary calcium level thereon. J. Biol. Chem. 122:715–726.

Tulung, B., C. Remesy, and C. Demigne. 1987. Specific effects of guar gum or gum arabic on adaptation of cecal digestion to high fiber diets in the rat. J. Nutr. 117:1556–1561.

Turkki, P. R., and G. D. Degruccio. 1983. Riboflavin status of rats fed two levels of protein during energy deprivation and subsequent repletion. J. Nutr. 113:282–292.

Turkki, P. R., and P. G. Holtzapple. 1982. Growth and riboflavin status of rats fed different levels of protein and riboflavin. J. Nutr. 112:1940–1952.

Turkki, P. R., J. Buratto, M. Corteville, and M. P. Driscoll. 1986. Effect of riboflavin status on nitrogen retention during energy restriction and repletion in the rat. Nutr. Res. 6:993–1008.

Turkki, P. R., L. Ingerman, S. B. Kurlandsky, C. Yang, and R. S. Chung. 1989. Effect of energy restriction on riboflavin retention in normal and deficient tissues of the rat. Nutrition 5:331–337.

Turner, N. D., G. T. Schelling, P. G. Harms, L. W. Greene, and F. M. Byers. 1987. A comparison of the protein requirements for growth and reproduction in the rat. Nutr. Rep. Int. 36:73–88.


U.S. Pharmacopeia. 1985. U.S. Pharmacopeia, 21st Rev. XXI:1118–1119.

Uhland, A. M., G. G. Kwiecinski, and H. F. DeLuca. 1992. Normalization of serum calcium restores fertility in vitamin D-deficient male rats. J. Nutr. 122:1338–1344.

Ulman, E. A., and H. Fisher. 1983. Arginine utilization of young rats fed diets with simple versus complex carbohydrates. J. Nutr. 113:131–137.

Underwood, B. A. 1984. Vitamin A in animal and human nutrition. Pp. 281–391 in The Retinoids, Vol. 1, M. B. Spron, A. B. Roberts, and D. S. Goodman, eds. New York: Academic Press.

Underwood, E. J., and W. Mertz. 1987. Introduction. Pp. 1–19 in Trace Elements in Human and Animal Nutrition, 5th Ed., Vol. 1, W. Mertz, ed. San Diego: Academic Press.

Underwood, J. L., and H. F. DeLuca. 1984. Vitamin D is not directly necessary for bone growth and mineralization. Am. J. Physiol. 246:E493–E498.

Unna, K. 1939. Studies on the toxicity and pharmacology of nicotinic acid. J. Pharmacol. Exp. Therap. 65:95–103.

Unna, K. 1940. Pantothenic acid requirement of the rat. J. Nutr. 20:565–576.

Unna, K., and J. G. Greslin. 1941. Studies on the toxicity and pharmacology of pantothenic acid. J. Pharmacol. Exp. Therap. 73:85–90.

Ursini, F., M. Maiorino, and C. Gregolin. 1985. The selenoenzyme phospholipid hydroperoxide glutathione peroxidase. Biochim. Biophys. Acta 839:62–70.

Uthus, E. O., and F. H. Nielsen. 1990. Effect of vanadium, iodine and their interaction on growth blood variables, liver trace elements and thyroid status indices in rats. Magnes. Trace Elem. 9:219–226.


Vadhanavikit, S., and H. E. Ganther. 1993. Selenium requirements of rats for normal hepatic and thyroidal 5'-deiodinase (Type I) activities. J. Nutr. 123:1124–1128.

Vahouny, G. V. 1982. Dietary fibers and intestinal absorption of lipids. Pp. 203–227 in Dietary Fiber in Health and Disease, G. V. Vahouny, and D. Kritchevsky, eds. New York: Plenum Press.

Valencia, R., and E. Sacquet. 1968. La carence en vitamine B12 chez l'animal amicrobien (Anomalies tératog nes et signes hémagtologiques). Ann. Nutr. Aliment. 22:71–76.

Van Camp, I., J. Ritskes-Hoitinga, A. G. Lemmens, and A. C. Beynen. 1990. Diet-induced nephrocalcinosis and urinary excretion of albumin in female rats. Lab. Anim. 24:137–141.

Van den Berg, H., J. J. P. Bogaards, and E. J. Sinkeldam. 1982. Effect of different levels of vitamin B6 in the diets of rats on the content of pyridoxamine-5'-phosphate and pyridoxal-5'-phosphate in the liver. Int. J. Vitam. Nutr. Res. 52:407–416.

Van den Berg, G. J., J. P. Van Wouwe, and A. C. Beynen. 1989. Ascorbic acid supplementation and copper status in rats. Biol. Trace Elem. Res. 23:165–172.

van Es, A. J. H. 1972. Maintenance. Pp. 1–55 in Handbuch der Tierernaehrung, Vol. 2, W. Lenkeit, and K. Breirem, eds. Hamburg/Berlin: Paul Parey.

Varela-Moreiras, G., and Selhub, J. 1992. Long-term folate deficiency alters folate content and distribution differentially in rat tissues. J. Nutr. 122:986–991.

Vaswani, K. K. 1985. Effect of neonatal thiamin and vitamin A deficiency on rat brain gangliosides. Life Sci. 37:1107–1115.

Veitch, K., J. P. Draye, F. Van Hoof, and H. S. Sherratt. 1988. Effects of riboflavin deficiency and colfibrate treatment on the five acylCoA dehydrogenases in rat liver mitochondria. Biochem. J. 254:477–481.

Vendeland, S. C., J. A. Butler, and P. D. Whanger. 1992. Intestinal absorption of selenite, selenate, and selenomethionine in the rat. J. Nutr. Biochem. 3:359–365.

Voris, L., and E. J. Thacker. 1942. The effects of the substitution of bicarbonate for chloride in the diet of rats on growth, energy and protein metabolism. J. Nutr. 23:365–374.

Vorontsov, N. N. 1979. Evolution of the alimentary system in myomorph rodents (translated from Russian) . New Delhi: Indian National Scientific Documentation Centre.


Wade, A. E., J. S. Evans, D. Holmes, and M. T. Baker. 1983. Influence of dietary thiamin on phenobarbital induction of rat hepatic enzymes responsible for metabolizing drugs and carcinogens. Drug-Nutr. Interact. 2:117–130.

Wald, G. 1968. Molecular basis of visual excitation. Science 162:230–239.

Walker, J. J., and W. N. Garrett. 1971. Shifts in the energy metabolism of male rats during their adaptation to prolonged undernutrition and their subsequent realimentation. Pp. 193–197 in Energy Metabolism of Farm Animals, Proceedings of the Fifth Symposium of the European Association for Animal Production, Pub. 13. London: Butterworths.

Wallwork, J. C., G. J. Fosmire, and H. H. Sandstead. 1981. Effect of zinc deficiency on appetite and plasma amino acid concentrations in the rat. Br. J. Nutr. 45:127–136.

Walzem, R. L., and A. J. Clifford. 1988a. Determination of blood transketolase—An improved procedure with optimized conditions. J. Micronutr. Anal. 4:17–32.

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

Walzem, R. L., and A. J. Clifford. 1988b. Thiamin absorption is not compromised in folate-deficient rats. J. Nutr. 118:1343–1348.

Wang, F., L. Wang, E. H. Khairallah, and R. Schwartz. 1971. Magnesium depletion during gestation and lactation in rats. J. Nutr. 101:1201–1210.

Wang, T., K. W. Miller, Y. Y. Tu, and C. S. Yang. 1985. Effects of riboflavin deficiency on metabolism of nitrosamines by rat liver microsomes. J. Natl. Cancer Inst. 74:1291–1297.

Wang, X., D. Oberleas, M. T. Yang, and S. P. Yang. 1992. Molybdenum requirement of female rats. J. Nutr. 122:1036–1041.

Ward, G. J., and Nixon, P. F. 1990. Modulation of pterylpolyglutamate concentration and length in response to altered folate nutrition in a comprehensive range of rat tissues. J. Nutr. 120:476–484.

Warnock, L. G. 1970. A new approach to erythrocyte transketolase measurement. J. Nutr. 100:1057–1062.

Weaver, C., B. R. Martin, J. S. Ebner, and C. A. Krueger. 1987. Oxalic acid decreases calcium absorption in rats. J. Nutr. 117:1903–1906.

Webster, A. J. F., G. E. Lobley, P. J. Reedsan, and J. D. Pullar. 1980. Protein mass, protein synthesis and heat loss in the Zucker rat. Pp. 125–128 in Energy Metabolism of Farm Animals, Proceedings of the Eighth Symposium of the European Association for Animal Production, Pub. 26, L. E. Mount, ed. London: Butterworths.

Weissbach, H., and R. T. Taylor. 1970. Roles of vitamin B12 and folic acid methionine synthesis. Vitam. Horm. 28:415–440.

Wells, W. W., and L. E. Burton. 1978. Requirement for dietary myo-inositol in the lactating rat. Pp. 471–485 in Cyclitols Phosphoinositides, W. W. Wells, F. Eisenberg, Jr., eds. New York: Academic Press.

Wertz, P. W., W. Abraham, E. Cho, and D. T. Downing. 1986. Linoleate-rich O-acylsphingolipids of mammalian epidermis: Structures and effects of essential fatty acid deficiency. Prog. Lipid Res. 25:383–389.

Wesson, L. G., and G. O. Burr. 1931. The metabolic rate and respiratory quotients of rats on a fat-deficient diet. J. Biol. Chem. 91:525–539.

Whanger, P. D. 1973. Effects of dietary nickel on enzyme activities and mineral content in rats. Toxicol. Appl. Pharmacol. 25:323–331.

Whanger, P. D., and J. A. Butler. 1988. Effects of various dietary levels of selenium as selenite or selenomethionine on tissue selenium levels and glutathione peroxidase activity in rats. J. Nutr. 118:846–852.

Whitescarver, S. A., B. J. Holtzclaw, J. H. Downs, C. E. Ott, J. R. Sowers, and T. A. Kotchen. 1986. Effect of dietary chloride on salt-sensitive and renin-dependent hypertension. Hypertension 8:56–61.

Will, B. H., and J. W. Suttie. 1992. Comparative metabolism of phylloquinone and menaquinone-9 in rat liver. J. Nutr. 122:953–958.

Williams, D. L. 1983. Biological value of vanadium for rats, chickens, and sheep. Ph.D. dissertation. Purdue University, Lafayette, Indiana.

Williams, R. B., and C. F. Mills. 1970. The experimental production of zinc deficiency in the rat . Br. J. Nutr. 24:989–1003.

Williams, D. L., and G. H. Spray. 1973. The effects of diets containing raw soya-bean flour on the vitamin B12 status of rats. Br. J. Nutr. 29:57–63.

Willis, W. T., K. Gohil, G. A. Brooks, and P. R. Dallman. 1990. Iron deficiency: Improved exercise performance within 15 hours of iron treatment in rats. J. Nutr. 120:909–916.

Wilson, J. G., C. B. Roth, and J. Warkany. 1953. An analysis of the syndrome of malformations induced by maternal vitamin A deficiency: Effects of restoration of vitamin A at various times during gestation. Am. J. Anat. 92:189–217.

Windebank, A. J., P. A. Low, and M. D. Blexrud. 1985. Pyridoxine neuropathy in rats: Specific degeneration of sensory axons. Neurology 35:1617–1622.

Witting, L. A., and M. K. Horwitt. 1964. Effect of degree of fatty acid unsaturation in tocopherol deficiency-induced creatinuria. J. Nutr. 82:19–33.

Woodard, J. C., and P. M. Newberne. 1966. Relation of vitamin B12 and 1-carbon metabolism to hydrocephalus in the rat . J. Nutr. 88:375–381.

Woodard, J. C., and W. S. S. Jee. 1984. Effects of dietary calcium, phosphorus and magnesium on intranephronic calculosis in rats. J. Nutr. 114:2331–2338.

Woolliscroft, J., and J. Barbosa. 1977. Analysis of chromium-induced carbohydrate intolerance in the rat. J. Nutr. 107:1702–1706.

Worcester, N. A., K. R. Bruckdorfer, T. Hallinan, A. J. Wilkins, and J. A. Mann. 1979. The influence of diet and diabetes on stearoyl Coenzyme A desaturase (EC 1.14.99.5) activity and fatty acid composition in rat tissues. Br. J. Nutr. 41:239–252.

Wostmann, B. S., P. L. Knight, L. L. Keeley, and D. F. Kan. 1963. Metabolism and function of thiamine and naphthoquinones in germ-free and conventional rats. Fed. Proc. 22:120–124.

Wretlind, K. A. J., and W. C. Rose. 1950. Methionine requirement for growth and utilization of its optical isomers. J. Biol. Chem. 187:697–703.

Wu, W. H., M. Meydani, S. N. Meydani, P. M. Burklund, J. B. Blumberg, and H. N. Munro. 1990. Effect of dietary iron overload on lipid peroxidation, prostaglandin synthesis and lymphocyte proliferation in young and old rats. J. Nutr. 120:280–289.


Yamamoto, N., M. Saitoh, A. Moriuchi, M. Nomura, and H. Okuyama. 1987. Effect of dietary α-linolenate/linoleate balance on brain lipid compositions and learning ability of rats. J. Lipid Res. 28:144–151.

Yamamoto, N., A. Hashimoto, Y. Takemoto, H. Okuyama, M. Nomura, R. Kitajima, T. Togashi, and Y. Tamai. 1988. Effect of dietary α-linolenate/linoleate balance on lipid composition and learning ability of rats. II. Discrimination process, extinction process, and glycolipid compositions. J. Lipid Res. 29:1013–1021.

Yamanaka, W. K., G. W. Clemans, and M. L. Hutchinson. 1980. Essential fatty acid deficiency in humans. Prog. Lipid Res. 19:187–215.

Yang, J.-G., J. Morrison-Plummer, and R. F. Burk. 1987. Purification and quantitation of a rat plasma selenoprotein distinct from glutathione peroxidase using monoclonal antibodies . J. Biol. Chem. 262:13372–13375.

Yang, J.-G., K. E. Hill, and R. F. Burk. 1989. Dietary selenium intake controls rat plasma selenoprotein P concentration. J. Nutr. 119:1010–1012.

Yang, M. G., K. Manoharan, and A. K. Young. 1969. Influence and degradation of dietary cellulose in cecum of rats. J. Nutr. 97:260–264.

Yang, N. Y. J., and I. D. Desai. 1977. Reproductive consequences of mega vitamin E supplements in female rats. Experientia 33:1460–1461.

Yokogoshi, H., K. Hayase, and A. Yoshida. 1980. Effect of carbohydrates and starvation on nitrogen sparing action of methionine and threonine in rats. Agr. Biol. Chem. 44:2503–2506.

Yoo, J. S., H. S. Park, S. M. Ning, M. J. Lee, and C. S. Yang. 1990. Effects of thiamine deficiency on hepatic cytochromes P-450 and drug-metabolizing enzyme activities. Biochem. Pharmacol. 39:519–525.

Yoshida, A., and K. Ashida. 1969. Pattern of essential amino acid requirement for growing rats fed on a low amino acid diet. Agr. Biol. Chem. 33:43–49.

Yoshida, A., A. E. Harper, and C. A. Elvehjem. 1957. Effects of protein per calorie ratio and dietary levels of fat on calorie and protein utilization. J. Nutr. 63:555–560.

Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
×

Yoshida, A., A. E. Harper, and C. A. Elvehjem. 1958. Effect of dietary level of fat and type of carbohydrate on growth and food intake. J. Nutr. 66:217–228.

Yoshida, T., T. Oowada, A. Ozaki, and T. Mizutani. 1993. Role of gastrointestinal microflora in the mineral absorption of young adult mice. Biosci. Biotech. Biochem. 57:1775–1776.

Yu, H., and J. W. Whittaker. 1989. Vanadate activation of bromoperoxidase from Corallian officinalis. Biochem. Biophys. Res. Commun. 160:87–92.

Yu, J. Y., and Y. O. Cho. 1989. The effect of vitamin B2 and (or) vitamin B6 deficiency on hematologic profile in rats. Korean J. Nutr. 22:167–174.

Yudkin, J. 1979. The avoidance of sucrose by thiamin-deficient rats. Int. J. Vitam. Nutr. Res. 49:127–135.


Zaki, F. G., C. Bandt, and F. W. Hoffbauer. 1963. Fatty cirrhosis in the rat. III. Liver lipid and collagen content in various stages. Arch. Pathol. 75:648–653.

Zelent, A., A. Krust, M. Petkovich, P. Kastner, and P. Chambon. 1989. Cloning of murine α and β retinoic acid receptors and a novel receptor γ predominantly expressed in skin. Nature 339:714–717.

Zeman, F. J., and E. C. Stanbrough. 1969. Effect of maternal protein deficiency on cellular development in the fetal rat. J. Nutr. 99:274–282.

Zhang, X., and A. C. Beynen. 1992. Increasing intake of soybean protein or casein, but not cod meal, reduces nephrocalcinosis in female rats. J. Nutr. 122:2218–2225.

Zidenberg-Cherr, S., C. L. Keen, B. Lönnerdal, and L. S. Hurley. 1983. Superoxide dismutase activity and lipid peroxidation: Developmental correlations affected by manganese deficiency. J. Nutr. 113:2498–2504.

Ziesenitz, S. C., G. Siebert, D. Schwengers, and R. Lemmes. 1989. Nutritional assessment in humans and rats of leucrose [D-glucopyranosyl-α(1-5)-D-fructopyranose] as a sugar substitute. J. Nutr. 119:971–978.

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Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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Suggested Citation:"2 Nutrient Requirements of the Laboratory Rat." National Research Council. 1995. Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995. Washington, DC: The National Academies Press. doi: 10.17226/4758.
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Nutrient Requirements of Laboratory Animals,: Fourth Revised Edition, 1995 Get This Book
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In the years since the third edition of this indispensable reference was published, a great deal has been learned about the nutritional requirements of common laboratory species: rat, mouse, guinea pig, hamster, gerbil, and vole.

The Fourth Revised Edition presents the current expert understanding of the lipid, carbohydrate, protein, mineral, vitamin, and other nutritional needs of these animals. The extensive use of tables provides easy access to a wealth of comprehensive data and resource information. The volume also provides an expanded background discussion of general dietary considerations.

In addition to a more user-friendly organization, new features in this edition include:

  1. A significantly expanded section on dietary requirements for rats, reporting substantial new findings.
  2. A new section on nutrients that are not required but that may produce beneficial results.

New information on growth and reproductive performance among the most commonly used strains of rats and mice and on several hamster species.

  1. An expanded discussion of diet formulation and preparation--including sample diets of both purified and natural ingredients.
  2. New information on mineral deficiency and toxicity, including warning signs.

This authoritative resource will be important to researchers, laboratory technicians, and manufacturers of laboratory animal feed.

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