Prevention of bile reflux-induced acute gastric ulceration in the rat by cholestyramine.

The role of bile salts and refluxed duodenal content in the pathogenesis of acute gastric ulcers in the shocked rat were examined. The addition of cholestyramine to duodenal contents inhibits their ulcerogenic action in the stomach of rats challenged by an acid load, (100 mEq/l Hcl) and subsequently bled to a mean blood pressure of 20 mm Hg. Also, bile duct ligation 2 days before the reflux procedure and subsequent shock also inhibited ulcer formation. An ex vivo rat gastric chamber was used to further demonstrate that the "barrier" breaking action of bovine sodium taurocholate and sodium lauryl sulphate could be prevented by cholestyramine. Cholestyramine also inhibited the usual rapid depression of the transmucosal potential difference (PD) produced by both of these agents. It is concluded that cholestyramine protects the gastric mucosa from ulceration by blocking the barrier breaking action of bile salts in duodenal chyme.