Comparison of Effects of Metiamide and Atropine on Gastric and Pancreatic Secretion and Peptic Ulcer Formation in Cat

Abstract

In conscious cats with chronic gastric and pancreatic fistulas, the actions of metiamide, a histamine H₂-receΡtor antagonist, was compared with those of atropine. Metiamide, given in a dose of 12 µmol/kg.h caused strong inhibition of gastric acid and pepsin secretion and prevented formation of peptic ulcers induced by histamine and pentagastrin without affecting pancreatic response to exogenous secretin or to duodenal acidification. Atropine given in a dose of 0.12 µmol/kg.h significantly decreased gastric acid and pepsin secretion and prevented duodenal ulcers induced by pentagastrin but not by histamine. Atropine also inhibited pancreatic response to exogenous secretin and duodenal acidification. These experiments provide evidence that metiamide is a more potent inhibitor of histamine-induced gastric secretion and peptic ulcer formation than atropine and does not affect pancreatic response to secretin inhibited by atropine.