Role of N-acetylglutamate turnover in urea synthesis of rats given proteins of different quality.
The purpose of this study was to find whether the synthesis and degradation of N-acetylglutamate would affect urea synthesis when the dietary protein quality was manipulated. Experiments were done on three groups of rats given diets containing 10 g gluten, 10 g casein or 10 g whole egg protein/100 g for 10 d. The urinary excretion of urea, the liver concentrations of N-acetylglutamate and free glutamate, the liver activity of N-acetylglutamate synthetase increased with the decline in quality of dietary protein. A reverse correlation was observed between the liver N-acetylglutamate degradation and liver Nacetylglutamate concentration. N-Acetylglutamate concentration in the liver was closely correlated with the concentration of glutamate and the N-acetylglutamate synthetase activity in the liver, and excretion of urea. These results suggest that the greater synthesis and the lower degradation rate of N-acetylglutamate in the liver of rats given the lower quality of protein increase the liver concentration of N-acetylglutamate and stimulate urea synthesis.
Tujioka
Kazuyo
K
Laboratory of Nutritional Biochemistry, School of Food and Nutritional Sciences, COE Program in 21st Century, The University of Shizuoka, Shizuoka 422-8526, Japan.
Fukaya
Yuka
Y
Sano
Atushi
A
Hayase
Kazutoshi
K
Yokogoshi
Hidehiko
H
D000123:Acetyltransferases / Q000378:metabolism; D051046:Amino-Acid N-Acetyltransferase; D000818:Animals; D002364:Caseins / Q000008:administration & dosage; D004044:Dietary Proteins / Q000008:administration & dosage*; D004527:Egg Proteins / Q000008:administration & dosage; D005971:Glutamates / Q000032:analysis / Q000378:metabolism*; D018698:Glutamic Acid / Q000032:analysis; D005983:Glutens / Q000008:administration & dosage; D007700:Kinetics; D008099:Liver / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D014508:Urea / Q000378:metabolism* / Q000652:urine
D002364:Caseins; D004044:Dietary Proteins; D004527:Egg Proteins; D005971:Glutamates; D018698:Glutamic Acid; D005983:Glutens; D014508:Urea; D000123:Acetyltransferases; D051046:Amino-Acid N-Acetyltransferase; C016195:N-acetylglutamic acid