Relation of Ammonia Excretion to Urine pH

Abstract

Inhibition of carbonic anhydrase activity with diamox in rats resulted in the formation of a relatively alkaline urine and an increased excretion of ammonia which compensated for the fall in titratable acid excretion. The increased ammonia excretion was associated with a rise in renal glutaminase activity from 788 [plus or minus] 59 [mu][image] NH3/100 mg dry kidney/hour in the control rats to 2246 [plus or minus] [mu][image] NH3/100 mg dry kidney/hour in rats receiving diamox. Since urine pH rose, the increased ammonia excretion was most likely the result of increased production rather than accelerated tubular transport. The increased glutaminase activity was not a result of K deficiency but may have been related to changes in intra-cellular acid-base equilibrium.