Amino acid induced orotic aciduria
Hatchwell, L.C.; Milner, J.A.
Journal of Nutrition 108(4): 578-584
1978
ISSN/ISBN: 0022-3166 PMID: 632945 Document Number: 130932
Male Sprague-Dawley rats were adapted for 4 days to a diet of 15% casein suspended in 2% agar gel. The rats were kept in 12 h of light and 12 h of dark and were made to eat during 2 h each day. After adaptation, the rats were given intraperitoneally 3 ml phosphate buffer or 0.5 mmol NH4Cl, (NH4)2CO3 or of any of 20 amino acids or 2 Sigma units of urease. Except for arginine and ornithine, all of the amino acids tested induced mild orotic aciduria in rats 2 h after feeding. The ammonium salts and urease also induced orotic aciduria. The ammoneogenic properties of the amino acids tested could not alone explain the induced excretion of orotic acid. Only serine, glutamine, NH4Cl, (NH4)2CO3 and urease increased orotic acid excretion in the rats starved for 24 h. Arginine or ornithine given at 0.5 mmol ameliorated the mild orotic aciduria induced by glycine or lysine. Arginine was more effective in preventing glycine-induced orotic aciduria than was ornithine. Amino acid-induced orotic aciduria was dependent on the physiological state of the rat, varying with the state of digestion and the supply of arginine.