The Role of H2Receptors in Gastric Mucosal Blood Flow

To determine the relation between H2 receptors and gastric mucosal blood flow, we measured the latter in rats by the electrolytically generated hydrogen gas clearance technique. The blood flow increased significantly after intravenous injection of 0.1 mg/kg of impromidine, a very potent and specific agonist of H2 receptors. On the other hand, gastric mucosal blood flow decreased significantly after intravenous administration of 5 or 20 mg/kg of cimetidine or 2 mg/kg of famotidine. However, 2 or 20 rng/kg of omeprazole, whose anti-secretory effect is as strong as that of H2 blockers such as cimetidine and famotidine, caused no significant change in the gastric rnucosal blood flow. This indicates that H2 receptors regulate gastric mucosal blood flow in rats.