Effect of propranolol on ricinoleic acid- and deoxycholic acid-induced changes of intestinal electrolyte movement and mucosal permeability. Evidence against the importance of altered permeability in the production of fluid and electrolyte accumulation.

Hydroxy fatty acids and bile acids produce both intestinal fluid and electrolyte accumulation and increases in inulin clearance, a parameter of mucosal permeability. The relationship of the changes in mucosal permeability to the production of fluid and electrolyte accumulation is uncertain. These experiments were designed to determine whether the alterations of mucosal permeability produced by ricinoleic acid and deoxycholic acid were related to production of hydroxy fatty acid- and bile acid-induced fluid and electrolyte accumulation in the rat colon. Propranolol (1 mg per 100 g of body weight) administered daily for 3 days inhibited ricinoleic acid- and deoxycholic acid-induced Na and water accumulation. In contrast, propranolol did not affect either the increase in inulin clearance or the decrease in electrical potential difference produced by ricinoleic acid and deoxycholic acid. Further, amphotericin B increased inulin clearance by the colon and also increased water and Na absorption. These studies suggest that changes in mucosal permeability are not primarily responsible for hydroxy fatty acid- and bile acid-induced fluid and Na accumulation.