title: Heterogeneity of histamine H2-receptor mediated responses in the rabbit aorta.
abstract: Distribution and properties of histamine H2-receptor mediated responses in segments of rabbit aorta was studied with histamine and H2-receptor stimulating drugs, dimaprit and impromidine. All agonists produced concentration-dependent tonus decreased in precontracted vascular strips, which were antagonised by selective H2-receptor antagonists, cimetidine and oxmetidine. Activities of the agonists were segment-dependent, and increased caudally along the aorta. A nonspecific smooth muscle relaxant, papaverine had homogeneous activity along the vessel, suggesting receptor specific nature of the observed heterogeneity.
mesh_terms: D000818:Animals; D001011:Aorta / Q000502:physiology*; D002927:Cimetidine / Q000494:pharmacology; D017259:Dimaprit; D005260:Female; D006635:Histamine H2 Antagonists / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D017446:Impromidine; D066298:In Vitro Techniques; D008297:Male; D011817:Rabbits; D011970:Receptors, Histamine H2 / Q000187:drug effects / Q000502:physiology*; D013890:Thiourea / Q000494:pharmacology
chemical_list: D006635:Histamine H2 Antagonists; D007093:Imidazoles; D011970:Receptors, Histamine H2; D002927:Cimetidine; D017446:Impromidine; D013890:Thiourea; C027703:oxmetidine; D017259:Dimaprit