Evidence for the histamine-mediated myotropic effect of angiotensin II in the rabbit aorta.
Histamine H1-receptor antagonist mepyramine and H2-receptor antagonist metiamide, respectively diminished and potentiated angiotensin II(A II)-induced myotropic responses in the rabbit aortic strips. The responses of the octapeptide were also inhibited in the presence of histidine decarboxylase inhibitor, 2-hydroxy-5-carbomethoxybenzoxyamine and restored when subcontractile quantities of histamine are added to the inhibitor-containing medium. Inhibition of histamine degradation by aminoguanidine potentiates A II's responses. These results are taken as evidences indicating A II-induced histamine synthesis in the test preparation.
D000804:Angiotensin II / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000818:Animals; D001011:Aorta / Q000187:drug effects; D005260:Female; D006146:Guanidines / Q000494:pharmacology; D006634:Histamine H1 Antagonists / Q000494:pharmacology; D006635:Histamine H2 Antagonists / Q000494:pharmacology; D006640:Histidine Decarboxylase / Q000037:antagonists & inhibitors; D008297:Male; D008785:Metiamide / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D011738:Pyrilamine / Q000494:pharmacology; D011817:Rabbits
D006146:Guanidines; D006634:Histamine H1 Antagonists; D006635:Histamine H2 Antagonists; D000804:Angiotensin II; D008785:Metiamide; D006640:Histidine Decarboxylase; D011738:Pyrilamine