【摘要】 <正> 不论外源性或内源性组织胺,胃泌素和乙酰胆碱均可通过壁细胞上相应的三种受体引起胃酸分泌,三者之间有一定关系,其中任何一种的存在都可显著地增强另二种泌酸更多还原

【Abstract】 Cimetidine, given both intravenously and orally, has been shown to be a potent inhibitor of histamine or pentagastrin stimulated gastric acid secretion. It is a specific competitive histamine H₂-receptor antagonist with little interaction with the catecholamine-receptors or histamine H₁-receptors. In this report, the role of cAMP in the cimetidine blocked gastric acid secretion has been investigated.In a total of seven gastric fistula dogs, observations indicating an involvement of cAMP in the inhibitory action of cimetidine were carried out. First, the administered histamine and pentagastrin not only elevated the levels of gastric acid in gastric juice but also markedly stimulated cAMP production. The increases caused by histamine were markedly prevented when H₂-receptor antagonist, cimetidine, was injected. The temporal relation between gastric acid and cAMP seemed parallel. However, cimetidine though still inhibitory to stimulated acid secretion, had no significant inhibitory effect on pentagastrin stimulated cAMP increase. The results seemed to support the hypothesis that the action of gastrin was mediated by the release of endogenous histamine from the gastric mucosa which then reacted with the receptor of the parietal cell. This action was shown to be prevented by cimetidine.更多还原