Changes in N-acetylglutamate are involved in regulating urea synthesis in rats given a low gluten diet supplemented with L-lysine, L-methinone and L-threonine.
We have shown that urinary urea excretion decreased in rats fed a low gluten diet supplemented with dietary limiting amino acids. The purpose of present study was to determine whether the addition of dietary limiting amino acids to a low gluten diet affected the synthesis and degradation of N-acetylglutamate and regulated urea synthesis. Experiments were done on two groups of rats, given diets containing 10% gluten or 10% gluten+0.5% L-lysine, 0.2% L-threonine and 0.2% L-methionine for 10 d. The urinary excretion of urea, and the liver concentration of N-acetylglutamate, and the liver activity of N-acetylglutamate synthetase decreased with the addition of dietary L-lysine, L-threonine and L-methionine. N-Acetylglutamate concentration in the liver was closely correlated with the N-acetylglutamate synthetase activity in the liver and excretion of urea. The greater degradation of N-acetylglutamate was observed in the group fed the 10% gluten+L-lysine, L-threonine and L-methionine. The hepatic concentration of glutamate and plasma concentration of arginine were not related to the N-acetylglutamate concentration in the liver. These results suggest that the addition of limiting amino acids to the low gluten diet controls the synthesis and degradation of N-acetylglutamate in the liver and lowers urea synthesis.
Tujioka
Kazuyo
K
Faculty of Early Childhood Care and Education, Ohkagakuen University, Toyoake, Aichi, Japan.
Tuchiya
Tamami
T
Shi
Xianglan
X
Ohsumi
Miho
M
Hayase
Kazutoshi
K
Yokogoshi
Hidehiko
H
D000596:Amino Acids / Q000097:blood / Q000494:pharmacology*; D051046:Amino-Acid N-Acetyltransferase / Q000378:metabolism*; D000818:Animals; D001120:Arginine / Q000097:blood; D055050:Diet, Gluten-Free; D019587:Dietary Supplements; D005971:Glutamates / Q000378:metabolism*; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D014508:Urea / Q000378:metabolism* / Q000652:urine
D000596:Amino Acids; D005971:Glutamates; D014508:Urea; D001120:Arginine; D051046:Amino-Acid N-Acetyltransferase; C016195:N-acetylglutamic acid