Regulation of Ammonia Excretion in the Rat

Abstract

Experi-ments were performed in an effort to correlate rate of ammonia excretion, alterations in acid-base balance, urine pH, and renal glutaminase activity in the rat. Data support the conclusion that renal ammonia production is regulated primarily by factors related to body acid-base changes. Results are in contrast to those obtained in dog and man, in which urine pH is a primary factor in the control of both ammonia production and excretion. The activity of renal glutaminase is elevated in chronically acidotic rats in association with increased rates of urinary ammonia excretion. A rapid rise in ammonia excretion under conditions of acute acid loading occurs without an appreciable change in glutaminase activity. It is likely that other mechanisms are involved in the augmentation of ammonia excretion under these circumstances.