Effect of acetazolamide on gastric mucosa in canine vivo-vitro preparations

¹ Gastrointestinal Physiology Research Laboratory and Division of Gastroenterology, Department of Medicine, The Mount Sinai Hospital, New York City

Segments of canine gastric fundus with intact blood supply were studied in acute experiments using the chamber preparation of Altamirano et al. Solutions of varying acidity were placed in the chamber in contact with the mucosal surface, and the effect of intravenous acetazolamide observed and compared with controls. Acetazolamide resulted in gross and microscopic damage to the surface mucosa in both secreting and nonsecreting preparations, provided the mucosal bathing solution had an acidity of 30 mEq/liter or greater. The apparent inhibition of acid secretion after acetazolamide was greater when mucosal bathing solutions of 160 mEq/liter of HCl were used than with solutions of lesser acidity. This relationship appears to result from the acceleration of H⁺ loss from the luminal fluid through the surface mucosa following acetazolamide. These effects of acetazolamide are not dependent on the presence of acid secretion per se, and occur in preparations in which acid secretion was not detected as well as in those actively secreting acid in response to histamine administration.

Key Words: gastric mucosal damage • inhibition of gastric acid secretion by acetazolamide • effects of acetazolamide on gastric • surface epithelium • carbonic anhydrase • loss of acid from gastric lumen • gastric mucous barrier

Submitted on October 19, 1964