Effect of a new potent H2-blocker, 3-[[[2-(diaminomethylene)amino]-4-thiazolyl]methyl]thio]-N2-sulfamoyl propionamidine (YM-11170), on gastric secretion, ulcer formation and weight of male accessory sex organs in rats.

A new H2-blocker, 3-[[[2-[(diaminoethylene)amino]-4-thiazolyl]ethyl]thio]-N2-sulfamoyl propionamidine (YM 11170) inhibited gastric secretion of both acid and pepsin, when given intraduodenally to pylorus-ligated rats. The effectiveness of YM-11170 in the inhibition of acid output was 50 times as potent as that of cimetidine. The higher antisecretory activity of YM-11170 than that of 1-cyano-2-methyl-3-[2-[[(5-methylimidazol-4-yl)-methyl]thio]ethyl]guanidine (cimetidine) was also demonstrated by oral or i.v. administration. The development of gastric ulcer induced by either indometacin or acetylsalicylic acid in rats was markedly suppressed by YM-11170 with higher potency than by cimetidine. In castrated and androgenized rats, the decrease in the seminal vesicle and ventral prostate weights was not observed after treatment with YM-11170. These results suggest that YM-11170 is a potent antisecretory agent without antiandrogenic activity.