Effect of dietary proteins and amino acid deficiencies on urinary excretion of nitrogen and the urea synthesizing system in rats
Hayase, K.; Yokogoshi, H.; Yoshida, A.
Journal of Nutrition 110(7): 1327-1337
1980
ISSN/ISBN: 0022-3166 PMID: 6770064 Document Number: 164507
A mechanism of regulation in urea biosynthesis in conditions of varying dietary protein quality was studied in rats adapted to 10% protein diets. A reverse correlation was found between activities of urea cycle enzymes and urinary excretion of urea. The concentrations of several nonessential amino acids in livers of rats given a 10% gluten diet significantly increased compared with those of rats on a 10% whole egg protein diet, without change in ornithine concentration. The contents of threonine, serine and ornithine in livers of rats on a methionine-free diet were higher than those of rats on a basal diet. The capacity of urea synthesis in vivo of rats on gluten or a methionine-free amino acid mixture was the same as that of rats on whole egg protein or basal amino acid mixture.