Ammonia metabolism during the suckling period in the rat

Abstract

1. 1. The time-courses of blood glutamine, glutamate, alanine, ammonia, urea and allantoin concentrations during the first 15 days of extrauterine life were studied. 2. 2. Glutamine and glutamate concentrations followed the same pattern and correlated positively, suggesting that both amino acids are utilized or released synchronously. 3. 3. Alanine concentrations decreased during the first 3 days, reaching levels close to those of adults which persisted up to the end of the observation period. 4. 4. A highly significant correlation was found between ammonia and urea concentrations, suggesting that during the suckling period urea synthesis may be limited by blood ammonia availability. 5. 5. The time-course of allantoin concentrations suggests that the synthesis of purines was enhanced during the first day, decreasing sharply during the 2nd to steeply increase to the end of the suckling period.