Depression of Chloride Transport by Carbonic Anhydrase Inhibitors in the Absence of Carbonic Anhydrase

Abstract

CARBONIC anhydrase is present in the frog gastric mucosa and fish gill which actively transport chloride, and it has been observed that carbonic anhydrase inhibitors of the sulphonamide type decrease net chloride active transport in these tissues^1,2. Zadunaisky³ has reported that chloride is actively transported by the frog cornea, and 95–100 per cent of the observed short-circuit current is attributable to active transport of chloride. Our interest in the part played by carbonic anhydrase in the active transport of chloride by the isolated gastric mucosa led us to measure the content of carbonic anhydrase and the effect of a carbonic anhydrase inhibitor (methazolamide) on the potential difference of the frog cornea in vitro.