Effect of mifentidine on histamine-stimulated human atrium "in vitro": comparison with ranitidine and cimetidine.
The new H2-antagonist mifentidine was tested on human atrium, in comparison with cimetidine and ranitidine, for its activity against histamine-induced inotropic effect. Mifentidine was found to be 10 times more potent than ranitidine and 100 times more potent than cimetidine. The kinetics of the three compounds are typical of a competitive antagonism and the pA2 value was of 8.60, 6.35, 5.94 for mifentidine, ranitidine and cimetidine, respectively. Our data confirm previous findings in another isolated heart preparation, namely the guinea-pig papillary muscle.
Poli
E
E
Medici
D
D
Contini
G A
GA
Bertaccini
G
G
D002927:Cimetidine / Q000494:pharmacology*; D006325:Heart Atria / Q000187:drug effects; D006632:Histamine / Q000494:pharmacology; D006635:Histamine H2 Antagonists / Q000494:pharmacology*; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology*; D066298:In Vitro Techniques; D009200:Myocardial Contraction / Q000187:drug effects*; D011899:Ranitidine / Q000494:pharmacology*
D006635:Histamine H2 Antagonists; D007093:Imidazoles; C039796:mifentidine; D002927:Cimetidine; D006632:Histamine; D011899:Ranitidine