Prostaglandins, Leukotrienes and Medicine, vol.18, no.1, pp.1-7, 1985 (Scopus)
The effects of (155)-15-methyl-prostaglandin E1, a synthetic analog of PGE1, other stable prostaglandins, histamine and noradrenaline were studied on the isolated spontaneously beating right atria from guinea-pig, rat and rabbit . When compared with other prostaglandins, histamine and noradrenaline, 15-methyl analog of PGE1 has the most potent positive chronotropic effect and the highest affinity as indicated by a significantly higher pD2 value as compared toother tested analogs in the isolated guinea-pig right atria . Neither the 15-methyl analog of PGE1 nor other stable prostaglandins induced any effect on the atria from rat and rabbit when relatively higher concentrations were used. 15-Methyl-PGE1 did not induce a positive inotropic effect . The maximum positive chronotropic response to 15-methyl-PGE1 was found to be about 60% of that of noradrenaline and histamine but almost equal to that of PGE1 . These results were taken as evidence that 15-methyl-PGE1 has an unexpected potent positive chronotropic effect on the isolated spontaneously beating guinea-pig right atrium . The possible mechanisms of the action of 15-methyl-PGE1 are discussed . © 1985.