rived hepatocytes with specific requirements for a collagen matrix or other suitable support. One of several unique properties of the WIF-B cells is ease of propagation and convenience relative to primary cell harvesting. For your reference, these cells form a pseudo-organized liver architecture containing bile canaliculi.

DENNIS BIER: I found this very intriguing because I think it is a new, expanded way to look at sodium metabolism. I am not sure you can do some of these things in other ways. For example, people have used specifically tritiated labeled glucose molecules for years to look at the appearance rate of tritiated water to measure various steps in glycolysis outside the cell.

One can look at the TCA [tricarboxylic acid] cycle activity by looking at the rearrangement of carbons and oxaloacetate, either radio-or isotopically labeled, and that can be done outside the cell as well.

Now, people have not looked at 10-s intervals because they have not felt that that was particularly important. Maybe it is, but there are other ways to approach this. I am not sure that it should not be combined in some way with what you are doing.

GUY MILLER: I think that the idea of combining several metabolic assessment modalities to simultaneously assess both cellular and tissue metabolic variables is a good one. As I understand from Harris Lieberman, one issue to be addressed by the CMNR during this session is to examine undertaking such activities. It would be my opinion that a concerted multidisciplinary effort needs to be undertaken in the area of acute metabolic derangements during circumstances of oxygen limitation, i.e., extreme exertion or illness. While we understand a great deal about particular metabolic transformations employing single enzyme experiments, we have just begun to decipher the processes governing the dynamics of metabolic control. New technologies and approaches will also be required that take advantage of our growing understanding of functional genomics. How these methodologies are fashioned together to enhance our understanding of relevant nutritional issues will be a challenging and vital task in forging the next set of advances.