INHIBITION BY THE TETRAMINE DISULPHIDE, BENEXTRAMINE, OF CARDIAC CHRONOTROPIC HISTAMINE H2‐RECEPTOR‐MEDIATED EFFECTS

Abstract
1 Benextramine (N,N'-bis[o-methoxybenzylamino)-n-hexyl]cystamine), which irreversibly blocks α-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 an additive blocking effect, benextramine appears to act directly on the chronotropic H2-receptor.