[The mechanism of action of histamine on the myocardium and the smooth vascular muscles].
Histamine-H1-receptors are only present in the left atrium of guinea-pig hearts, whereas the ventricular myocardium contains histamine-H2-receptors exclusively. Although the stimulation of both receptor types causes positive intropic effects, only the H2-receptor response is closely associated with increases of cyclic AMP. H1- as well as H2-receptors are present in the rabbit mesenteric artery. Cyclic AMP serves as a messenger for H2-receptor mediated relaxation only and not for H1-receptor mediated contraction. Thus, the different effects on the cyclic AMP-system must also be considered in H1- and H2-receptor differentiation.
D000818:Animals; D001808:Blood Vessels; D002049:Burimamide / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects*; D006325:Heart Atria / Q000187:drug effects; D006632:Histamine / Q000494:pharmacology*; D008638:Mesenteric Arteries / Q000187:drug effects; D008785:Metiamide / Q000494:pharmacology; D009130:Muscle, Smooth / Q000187:drug effects*; D010208:Papaverine / Q000494:pharmacology; D010210:Papillary Muscles / Q000187:drug effects; D011817:Rabbits; D011969:Receptors, Histamine H1; D011970:Receptors, Histamine H2
D011969:Receptors, Histamine H1; D011970:Receptors, Histamine H2; D008785:Metiamide; D006632:Histamine; D010208:Papaverine; D000242:Cyclic AMP; D002049:Burimamide
Zum Wirkungsmechanismus von Histamin auf Myokard und glatte Gefässmuskulatur.