The effect of acetazolamide on the endolymphatic sac DC potential

The effect of acetazolamide known as a potent carbonic anhydrase inhibitor of the endolymphatic sac DC potential (ESP) was examined in the guinea pig. Intravenous administration of acetazolamide produced a dose-dependent decrease in ESP amplitude at doses of less than 10 mg/kg. The effect of acetazolamide on ESP was saturated at doses exceeding 10 mg/kg. The maximum reduction of ESP induced by acetazolamide was approximately 50% of the original ESP amplitude. The results suggest that carbonic anhydrase is involved in the generation of ESP.