title: Characteristics of histamine H1-receptors in peripheral tissues labeled with [3H]mepyramine.
abstract: Specific binding of [3H]mepyramine to membranes of various peripheral tissues of different species has been demonstrated. Drug specificity indicates an association with histamine H1-receptors. Of all the tissues examined brain contains the highest numbers of binding sites, while substantial levels of specific [3H]mepyramine binding are also demonstrable in some species in heart, lung, adrenal and ileum. Negligible specific [3H]mepyramine binding is observed in the liver, stomach and uterus of several species. The lesser bronchoconstricting response of the rat than of other species to histamine is paralleled by a lower number of [3H]mepyramine binding sites in rat lung than in other species. However, similar numbers or [3H]mepyramine binding sites occur in ileal membranes of rat, guinea pig and rabbit, although contractile effects of histamine vary in these species. In the quinea-pig ileum, [3H]mepyramine binding is most concentrated in the longitudinal muscle itself where histamine exerts its predominant contractile effects. In the bovine adrenal gland, [3H]mepyramine binding is more abundant and has higher affinity for drugs in the medulla than in the cortex.
mesh_terms: D000311:Adrenal Glands / Q000378:metabolism; D000631:Aminopyridines / Q000378:metabolism*; D000818:Animals; D001011:Aorta / Q000378:metabolism; D006168:Guinea Pigs; D000882:Haplorhini; D007082:Ileum / Q000378:metabolism; D066298:In Vitro Techniques; D008168:Lung / Q000378:metabolism; D008252:Macaca fascicularis; D008297:Male; D051379:Mice; D009130:Muscle, Smooth / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D009928:Organ Specificity; D011738:Pyrilamine / Q000378:metabolism*; D011817:Rabbits; D051381:Rats; D011968:Receptors, Histamine / Q000378:metabolism*; D011969:Receptors, Histamine H1 / Q000187:drug effects / Q000378:metabolism*; D013045:Species Specificity
chemical_list: D000631:Aminopyridines; D011968:Receptors, Histamine; D011969:Receptors, Histamine H1; D011738:Pyrilamine