Inhibition by the tetramine disulphide, benextramine, of cardiac chronotropic histamine H2-receptor-mediated effects.
1 Benextramine (N,N1-bis[o-methoxybenzylamino)-n-hexyl]cystamine), which irreversibly blocks alpha-adrenoceptors and does not inhibit the H1-receptor-mediated contractile effect of histamine on guinea-pig isolated ileum, also did not inhibit the H1-receptor-mediated inotropic effect of histamine on guinea-pig isolated atrium. 2 Benextramine irreversibly inhibited the H2-receptor-mediated chronotropic effect of histamine on guinea-pig isolated atrium. 3 Since its combination with the competitive H2-receptor blocking drug cimetidine had a additive blocking effect, benextramine appears to act directly on the chronotropic H2-receptor.
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D002927:Cimetidine / Q000494:pharmacology; D003538:Cystamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D006339:Heart Rate / Q000187:drug effects*; D006632:Histamine / Q000494:pharmacology; D006635:Histamine H2 Antagonists; D066298:In Vitro Techniques; D013997:Time Factors
D000317:Adrenergic alpha-Antagonists; D006635:Histamine H2 Antagonists; C029998:benextramine; D002927:Cimetidine; D006632:Histamine; D003538:Cystamine