Abstract

Sulfonamide carbonic anhydrase inhibitors not only inhibit carbonic anhydrase(s) but also the active transport of chloride by the gastric mucosa. The concentrations required for the latter effect are 100 or more times that required to block functions ascribed to the enzyme carbonic anhydrase. The slow rate of H⁺ ion secretion by the isolated mucosa is not inhibited by sulfonamide inhibitors. Agents that are the most potent inhibitors of carbonic anhydrase exert the greatest effect on chloride transport. Inactive analogs had no discernible effect on either system. For 15 agents, there is a striking parallel between their inhibition of chloride transport and the inhibition of carbonic anhydrase.