Abstract
Glutamine or ammonium acetate was infused at rates of 0.1, 0.05, 0.025 and 0.0125 mmole per kilogram of body weight per minute into the portal vein of chickens fed a 20% protein diet. When ammonium acetate was infused, blood ammonia concentration remained unchanged up to 0.025 mmole, and thereafter increased markedly. When glutamine was infused, however, blood ammonia concentration remained unchanged up to 0.05 mmole, and thereafter increased only slightly. Plasma glutamine concentration increased sharply with an increase of infusion rate of glutamine. When ammonium acetate was infused, the increase in plasma glutamine was very low. Both plasma and urinary uric acid increased with an increase of infusion rate of glutamine up to 0.1 mmole, and with ammonium acetate infusion increased up to the infusion rate of 0.05 mmole and thereafter tended to decrease slightly. Plasma uric acid concentration was higher in ammonium acetate infusion than in glutamine infusion when they were infused at the rate of 0.05 mmole or less, whereas urinary uric acid excretion was almost the same in both treatments at the infusion rates of 0.025 and 0.05 mmole. These results indicate that ammonia has more effect than glutamine in uric acid synthesis of chickens when they were infused at a relatively low rate.