Effect of impromidine (SK&F 92676) on the isolated papillary muscle of the guinea-pig.
Impromidine was found to have a positive inotropic effect on the isolated papillary muscle from the guinea-pig. The dose-response curve to impromidine was shifted to the right by cimetidine and ranitidine. Impromidine was 35 times more potent than histamine but with a maximal response of only 81% that obtained with histamine. This difference, which was statistically significant (P < 0.005), suggested that impromidine acts as a partial agonist at the histamine H2-receptors of the papillary muscle as has been observed in other tissues.
D000818:Animals; D006146:Guanidines / Q000494:pharmacology*; D006168:Guinea Pigs; D007093:Imidazoles / Q000494:pharmacology*; D017446:Impromidine; D066298:In Vitro Techniques; D009200:Myocardial Contraction / Q000187:drug effects*; D010210:Papillary Muscles / Q000187:drug effects; D011968:Receptors, Histamine / Q000187:drug effects*; D011970:Receptors, Histamine H2 / Q000187:drug effects*; D013268:Stimulation, Chemical
D006146:Guanidines; D007093:Imidazoles; D011968:Receptors, Histamine; D011970:Receptors, Histamine H2; D017446:Impromidine