QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Garcia, P. A. Articles by Roderuck, C. E. Search for Related Content PubMed PubMed Citation Articles by Garcia, P. A. Articles by Roderuck, C. E.

Protein-Energy Relationship in Adult Rats

II. Qualitative and Quantitative Variations in Dietary Nitrogen and Effects on Deposition of Hepatic Fat and on Nitrogen Utilization¹

Home Economics Research Department, Iowa Agricultural and Home Economics Experiment Station, Ames, Iowa

Groups of female adult rats were fed ad libitum a diet providing 5% of the food energy as lactalbumin or the same diet supplemented with amino acids calculated to be most limiting after comparison of the ratio of amino acids to tryptophan with that of the daily amino acid requirements of the adult rat. After 20 days of unrestricted feeding, no significant differences in food intake were attributable to added arginine, methionine, phenylalanine and valine. Both groups were comparable in body weight, nitrogen retention and in weights and nitrogen concentrations of liver and carcass. However, hepatic fat was significantly lower with supplementation than without. Restriction of food energy intake for 30 days to two-thirds of amounts consumed voluntarily was associated with decreased hepatic weight and nitrogen; concentration of hepatic nitrogen increased. Total hepatic fat, carcass weight and total carcass nitrogen were reduced markedly. These effects of caloric restriction were not modified by variations in quality or quantity of nitrogen fed. Restricted groups had similar concentrations of hepatic fat. Increased nitrogen intake during restriction minimized losses in body weight and urinary nitrogen. Concentrations of carcass nitrogen were similar for supplemented and unsupplemented groups whether restricted or not.

² Food and Nutrition Department, Iowa State University.

Manuscript received 7 June 1963.