Reeves J J, Stables R
Agents Actions. 1987 Feb;20(1-2):22-8.
Four H2-receptor antagonists, famotidine, loxtidine, ranitidine and L-643,441 were tested against gastric secretory concentration-response curves to histamine, methacholine and dibutyryl cyclic AMP (dbcAMP) on the rat isolated gastric mucosa. All four drugs inhibited the secretory response to histamine, but the nature of this H2-receptor antagonism differed according to the drug. Ranitidine and famotidine were competitive, fully surmountable antagonists of histamine, but loxtidine and L-643,441 were unsurmountable antagonists. At high concentrations, the H2-receptor antagonists caused a small inhibition of the secretory response to methacholine but had no effect on the secretory response to dbcAMP. The rat isolated gastric mucosa is a useful preparation for characterisation of the antisecretory effects of H2-receptor antagonists.
对四种H2受体拮抗剂法莫替丁、洛替丁、雷尼替丁和L-643,441进行了测试，观察它们对大鼠离体胃黏膜上组胺、乙酰甲胆碱和二丁酰环磷腺苷（dbcAMP）的胃分泌浓度-反应曲线的影响。所有这四种药物均抑制对组胺的分泌反应，但这种H2受体拮抗作用的性质因药物而异。雷尼替丁和法莫替丁是组胺的竞争性、完全可克服的拮抗剂，但洛替丁和L-643,441是不可克服的拮抗剂。在高浓度时，H2受体拮抗剂对乙酰甲胆碱的分泌反应有轻微抑制作用，但对dbcAMP的分泌反应无影响。大鼠离体胃黏膜是表征H2受体拮抗剂抗分泌作用的有用标本。
