Effects of Prolonged Administration of Diamox on Excretion of Acid and Carbonic Anhydrase and Glutaminase Activities in the Kidney

¹ From the Department of Internal Medicine, The University of Texas Southwestern Medical School, Dallas, Texas

Diamox inhibits renal carbonic anhydrase activity as effectively when given chronically as when given acutely. The persistently high urine ph, low titratable acid and high bicarbonate excretion in the urine of rats receiving Diamox chronically were the result of the alkaline load effects of sodium Diamox, rather than effects from the inhibition of carbonic anhydrase. The chronic administration of Diamox activated the renal glutaminase enzyme system, resulting in the excretion of normal or increased amounts of ammonia into an alkaline urine. The activation of glutaminase was potentiated by the restriction of dietary NaCl. An unexplained hypernatremia developed during the course of prolonged administration of Diamox.