The involvement of histamine receptor subtypes in gastric acid secretion and mucosal blood flow in the anaesthetized rabbit.

Publisher Website
Google Scholar
Abstract
The involvement of histamine receptor subtypes in the gastric acid secretory and mucosal blood flow responses of the pentobarbitone-anesthetized rabbit to histamine were investigated. Histamine produced a dose-related increase in gastric acid secretion and mucosal blood flow. Maximal effects were stimulated further by mepyramine and inhibited by metiamide. Mepyramine had no effect on methacholine- or impromidine-stimulated gastric acid secretion or mucosal blood flow. Impromidine also produced a dose-related increase in gastric acid secretion and mucosal blood flow. The maximal effect produced depended on the method of administration. The H1-receptor agonist 2-TEA [2-(2-aminoethyl)thiazole dihydrochloride] inhibited impromidine-stimulated blood flow but not gastric acid secretion. In addition to stimulating acid secretion by an action on H2-receptors, histamine evidently also exerts an inhibitory effect which is mediated by H1-receptors. This inhibitory effect evidently operates via a reduced blood flow resulting from vasoconstriction in the stomach.