title: Histamine H1 and H2 receptor activities in guinea-pig isolated arteries.
abstract: The actions of histamine, 2-methylhistamine (2 MeH) and 4-methylhistamine (4 MeH) were studied in isolated muscle preparations from pulmonary artery, aorta and terminal ileum of guinea-pigs. Relative to histamine, 2 MeH had a significantly higher activity in the arteries than in the ileum. In the arteries, 4 MeH inhibited 2 MeH--and histamine-induced contractions. Burimamide blocked the inhibitory effect of 4 MeH and potentiated histamine but not 2 MeH induced contractions in arteries. The results show that the arterial muscles studied contain both H1 and H2 receptors subserving contractile and dilator effects respectively.
mesh_terms: D000818:Animals; D001011:Aorta / Q000502:physiology; D002049:Burimamide / Q000494:pharmacology; D004347:Drug Interactions; D004357:Drug Synergism; D005260:Female; D006168:Guinea Pigs; D006632:Histamine / Q000031:analogs & derivatives / Q000494:pharmacology; D007082:Ileum / Q000502:physiology; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D011651:Pulmonary Artery / Q000502:physiology
chemical_list: D006632:Histamine; D002049:Burimamide