Inhibition of Gastric Secretion of Acid in Dogs by Carbonic Anhydrase Inhibitor, 2-Acetylamino-1,3,4-Thiadiazole-5-Sulfonamide

Abstract

The secretion of HC1 by dogs with Heidenhain pouches in response to repeated subcut. injns. of histamine was markedly inhibited by the intraven. injn. of 2-acetylamino-l,3,4-thiadiazole-5-sulfonamide (Diamox, 6063, American Cyanamide Co.), an inhibitor of carbonic anhydrase. The concn. of acid, and the volume-rate of secretion was reduced 20-80 min. after admn. of the inhibitor, and recovery was present 24 hrs. later. 5-120 mg./kg. doses produced 70-97% inhibition of HC1, in 18 expts. and was not increased by larger doses. Doses of 5-60 mg./kg. were well-tolerated, apparently carbonic anhydrase of the parietal cell has an important role in the process of acid secretion.