title: Histamine H1-receptor in heart: unique electrophoretic mobility and autoradiographic localization.
abstract: Histamine H1-receptors, visualized in the guinea pig heart by autoradiography using [125I]iodobolpyramine as a specific probe, are abundant in the nodal tissue and cardiac vessels but also occur heterogeneously in the myocardium. Following photoaffinity labeling with [125I]iodoazidophenpyramine and electrophoresis, the ligand binding domain of the heart H1-receptor was shown to be present on a major 68-kDa and a less abundant 54- to 58-kDa protein. The 68-kDa protein displayed a molecular size higher in heart than in all other tissues (56 kDa). This indicates the existence of at least two isoforms of the H1-receptor; the cardiac isoform, however, was pharmacologically indistinguishable from the common isoform studied in cerebellar membranes using available ligands. Its distinct electrophoretic properties suggest that the cardiac isoform may have a unique function.
authors.affiliation: Unité de Neurobiologie et Pharmacologie (U. 109), INSERM, Centre Paul Broca, Paris, France.
authors.forename: M
authors.initials: M
authors.lastname: Ruat
authors.forename: M L
authors.initials: ML
authors.lastname: Bouthenet
authors.forename: J C
authors.initials: JC
authors.lastname: Schwartz
authors.forename: C R
authors.initials: CR
authors.lastname: Ganellin
mesh_terms: D000345:Affinity Labels; D000818:Animals; D001345:Autoradiography; D002462:Cell Membrane / Q000032:analysis / Q000378:metabolism; D002531:Cerebellum / Q000378:metabolism; D002744:Chlorpheniramine / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D006168:Guinea Pigs; D006325:Heart Atria / Q000032:analysis / Q000378:metabolism; D007082:Ileum / Q000032:analysis / Q000378:metabolism; D007457:Iodine Radioisotopes; D008168:Lung / Q000032:analysis / Q000378:metabolism; D008297:Male; D008803:Mianserin / Q000494:pharmacology; D008970:Molecular Weight; D009206:Myocardium / Q000032:analysis / Q000378:metabolism*; D010777:Photochemistry; D011738:Pyrilamine / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D011969:Receptors, Histamine H1 / Q000378:metabolism*; D013388:Succinimides / Q000378:metabolism
chemical_list: D000345:Affinity Labels; D007457:Iodine Radioisotopes; D011969:Receptors, Histamine H1; D013388:Succinimides; C048171:iodobolpyramine; C055549:3-iodo-4-azidophenpyramine; D008803:Mianserin; D002744:Chlorpheniramine; D011738:Pyrilamine