Orotic Aciduria in the Female Rat and Its Relation to Dietary Arginine

Abstract

Metabolic abnormalities in arginine deficient female rats are similar to those previously observed in males. Increased excretion of orotic acid and citric acid was observed in both immature and mature arginine deficient female rats. Although urea excretion was unchanged in the immature females, it was depressed in mature females fed the arginine deficient diet. Arginine deficiency depressed urinary ammonia indepen dently of age, weight and feed consumption. Nonpregnant rats showed significantly reduced quantities of citrate in their urine if their purified 12% casein diet was supplemented with 1.0% arginine. Urinary urea, citric acid, and orotic acid increased during gestation when a 12% casein basal diet was fed. Addition of 1.0% arginine abolished the increase in urinary excretion of citrate. Arginine supplementation also reduced orotic acid excretion during late gestation (days 16 to 18) and early lactation. Mean body weight gains exclusive of fetuses and placental tissue during gestation were 37 g for rats fed 1% arginine and 2 g for those fed the unsupplemented casein basal diet. Nonpregnant rats fed the casein diet showed considerable daily variation in urinary metabolites with arginine supplementation causing only a reduction in urinary citrate. Urine ob tained without respect to age, parity or nutritional history contained higher concentrations of orotic acid from pregnant women than from nonpregnant women and the concentrations increased with duration of pregnancy. J. Nutr. 108: 1281-1288, 1978.