Open AccessAbsence of Blocking Effect of Burimamide and Metiamide on Positive Chronotropic and Inotropic Responses to Histamine in Isolated Dog Atrium
Author(s) -
Shigetoshi Chiba
Publication year - 1977
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.27.267
Subject(s) - metiamide , chronotropic , histamine , inotrope , medicine , chemistry , antagonist , diphenhydramine , endocrinology , pharmacology , histamine h2 receptor , receptor , heart rate , blood pressure
When histamine was injected into the sinus node artery of isolated dog atrium perfused with arterial blood led from a carotid artery of the heparinized support dog, positive chronotropic and inotropic effects were dose-relatedly induced at a dose range of 0.1 to 100 microgram. The threshold dose for ind1cing these positive effects was approximately 0.3 microgram. These positive responses to histamine were not blocked by tetrodotoxin, desmethylimipramine and alprenolol. These positive effects of histamine were also not significantly influenced by treatment with a histamine H2 receptor antagonist, tripelennamine or diphenhydramine, which enhanced the actions of norepinephrine. From these results, it is suggested that in the dog atrium, histamine causes positive chronotropic and inotropic effects via histamine H1 receptors.