American Journal of Clinical Nutrition, Vol 4, 662-672, Copyright © 1956 by The American Society for Clinical Nutrition, Inc.

Optimal Nutrition Correlated With Nitrogen Retention

¹ From the Bureau of Biological Research and Department of Physiology and Biochemistry, Rutgers University, New Brunswick, N.J.

Experiments with rats and dogs indicate that the sulfur amino acids are particularly effective in reducing the catabolism of tissue proteins and promoting anabolic processes. This may reflect in part the increased requirement of these amino acids in these hairy species.

Overall nitrogen balance is a measure of the sum of gains and losses from the various body tissues, but may not indicate the shifts of protein nitrogen from one tissue to the other. An exaggerated example of a tissue in positive balance while other tissues are in negative balance is often seen in tumor-bearing animals.

The liver, being a very labile tissue, makes it possible to correlate the nutritive value of dietary proteins with their ability to form labile liver proteins. This may also be expressed as the measure of liver enzyme activity under the influence of dietary protein. Maximum elimination and minimum toxicity of the compound 2-aminofluorene developed when an excess of riboflavin was added to a high protein diet. Furthermore, increasing the amount of pantothenic acid in the diet resulted in an increased acetylation of 2-aminofluorene. Thus an adequate protein diet, especially one supplemented with vitamins, leads to the maximum development of enzyme systems in the liver.

The ethylenimino derivative, triethylene-phosphoramide (TEPA), will depress the growth of all body tissues.

With an adequate protein diet the growth of the carcass was so favored that the therapy could be continued until some regression of the tumor took place. Supplementation of the diet with methionine under conditions of food restriction protects the carcass both from the depleting effect of the tumor and the drug, thus offering a valuable combination of nutritional and chemotherapy.

This article has been cited by other articles:

				B. Humbert, L. Martin, H. Dumon, D. Darmaun, and P. Nguyen Dietary Protein Level Affects Protein Metabolism during the Postabsorptive State in Dogs J. Nutr., June 1, 2002; 132(6): 1676S - 1678. [Abstract] [Full Text] [PDF]