Luminal acid in water-immersion stress and the antiulcer effect of axetazolamide in the rat gastric mucosa.

The influence of water-immersion stress on gastric acid secretion, and the effect of acetazolamide (a potent carbonic anhydrase inhibitor) on acid secretion, and gastric mucosal lesion formation in rats under water-immersion stress were studied. Acid secretion in pylorus-ligated rats decreased under a 10_h stress period as compared with that of rats under normal conditions. Intraperitoneal administration of acetazolamide (100, 50, 25 mg/kg every 5 h for a total of two times) which significantly inhibited acid secretion in a dose-dependent fashion of stressed rats, prevented the development of gastric mucosal lesions produced by stress. Non antisecretory dose of acetazolamide (5 mg/kg, intraperitoneal administration every 5 h for a total of two times) did not prevent the formation of gastric mucosal lesions. Stress ulcer aggravation by acid administration (150 mM HCl, 0.5 ml/h) into the stomach during the stress was not prevented by treatment with antisecretory acetazolamide dose. We conclude that: (1) the exposure of rats to water-immersion stress for 10 h decreases gastric acid secretion, and (2) acetazolamide suppresses water-immersion stress-induced gastric lesions by inhibiting acid secretion.