azaserine and ammonium-acetate

Azaserine injected intravenously decreased uric acid in the blood and urine 1.6 and 2 times, respectively. It also resulted in 3 times larger increase in plasma glutamine concentration in chickens fed a 20% protein diet than in those fed a 5% protein diet, but it had no effect on liver glutamine synthetase activity in either dietary group. Thus the resultant concentration of plasma glutamine in the chickens fed the high protein diet was higher than in those fed the low protein diet, the reverse of the relationship observed before the injection. The infusion of ammonium acetate caused less of a rise in plasma glutamine concentration, but increased uric acid in the urine and blood, more with the high protein feeding than the low protein feeding. Pretreatment with azaserine further augmented the increase in plasma glutamine concentration caused by the infusion of ammonium acetate in the chickens fed the high protein diet but not in those fed the low protein diet, and concurrently removed the stimulatory effect of ammonia on uric acid in the blood and urine of both dietary groups. These data indicate that both glutamine in intact chickens and the increased glutamine in the ammonia-infused chickens are converted to uric acid more by high protein feeding than by low protein feeding, and this is a major reason for the low concentration of plasma glutamine in the chickens fed a high protein diet.

Topics: Acetates; Ammonia; Animals; Azaserine; Chickens; Dietary Proteins; Glutamate-Ammonia Ligase; Glutamine; Liver; Male; Uric Acid