Antisecretory Effects of a Novel and Long-Lasting Histamine H2-Receptor Antagonist, YM-14471, in Rats and Dogs

[摘要] References(12)Cited-By(1)We investigated some properties of YM-14471 (2-2{-[2-(diaminomethyleneamino)thiazol-4-yl]methylthio}ethyl-5-[3-(diethylamino)propyl]-6-methyl-pyrimidine-4-one trihydrochloride), a new H2-receptor antagonist, in comparison with those of famotidine, cimetidine and omeprazole. In guinea pig atria, famotidine and cimetidine produced a competitive dose-dependent displacement of histamine-induced tachycardia. In contrast, low concentrations of YM-14471 showed competitive inhibition of tachycardia, whereas high concentrations were irreversible or slowly dissociable. In pylorus-ligated rats, intravenous YM-14471, famotidine and cimetidine dose-dependently inhibited basal gastric secretion with ED50 values of 0.04, 0.43 and 31.2 mg/kg, respectively. ED50 values for oral YM-14471, famotidine, cimetidine and omeprazole were 0.81, 0.42, 28.9 and 7.7 mg/kg when given at 1 hr before ligation, and 5.7, 26.7, 1639.5 and 18.6 mg/kg at 5 hr before ligation. In anesthetized dogs, intravenous YM-14471, famotidine, cimetidine and omeprazole also dose-dependently inhibited histamine (160 μg/kg·hr)-induced acid secretion with ED50 values of 13.7, 8.7, 333.3 and 65.3 μg/kg, respectively. In Heidenhain pouch dogs, YM-14471 inhibited histamine (40 μg/kg·hr)-induced acid secretion by both intravenous (0.02 mg/kg) and oral administration (0.3 mg/kg). Moreover, the inhibitory effect of YM-14471 was more prolonged than those of famotidine and cimetidine by either route, and it was as long as that of omeprazole dosed orally. These results suggest that YM-14471 is an irreversible or slowly dissociable H2-receptor antagonist, and has long antisecretory effect.

[学科分类] 药理学

[关键词] YM-14471;Histamine H2-receptor antagonist (novel);Gastric acid secretion;Famotidine;Cimetidine