title: Lack of adrenomedullin on antigen-induced bronchoconstriction in guinea pigs in vivo.
abstract: Antigen challenge can provoke acute bronchoconstriction, recognized as immediate asthmatic response (IAR), but the evolving events in this reaction are not well defined. Recently, a novel peptide, designated adrenomedullin, was isolated from human pheochromocytoma, and has been shown to have potent systemic and pulmonary vasodilator activity.The purpose of this study was to elucidate the influence of adrenomedullin in the development of IAR. Passively sensitized guinea pigs were anesthetized and treated with diphenhydramine hydrochloride, and then artificially ventilated. Ovalbumin was inhaled after an intravenous administration of adrenomedullin. Other studies were performed in naive guinea pigs to investigate the airway responses to inhaled methacholine or histamine after an intravenous administration of adrenomedullin. Antigen challenge caused bronchoconstriction in sensitized guinea pigs. Adrenomedullin did not inhibit the antigen-induced bronchoconstriction in sensitized guinea pigs or the dose-dependent responses to inhaled methacholine or histamine in naive animals in spite of its vasodilating effect. We conclude that an intravenous administration of adrenomedullin does not influence antigen-induced bronchoconstriction or bronchial responsiveness to inhaled methacholine or histamine in vivo.
authors.affiliation: Pulmonary Medicine, Cellular Transplantation Biology, Kanazawa, Graduate University School of Medicine, Japan. ishiura-@p2322.nsk.ne.jp
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Ishiura
authors.forename: Masaki
authors.initials: M
authors.lastname: Fujimura
authors.forename: Kouichi
authors.initials: K
authors.lastname: Nobata
authors.forename: Shigeharu
authors.initials: S
authors.lastname: Myou
authors.forename: Tokunao
authors.initials: T
authors.lastname: Amemiya
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Kurashima
mesh_terms: D053607:Adrenomedullin; D000818:Animals; D000941:Antigens / Q000276:immunology / Q000494:pharmacology*; D016084:Bronchoconstriction / Q000187:drug effects*; D016085:Bronchoconstrictor Agents / Q000494:pharmacology; D001993:Bronchodilator Agents / Q000494:pharmacology*; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology; D006967:Hypersensitivity / Q000503:physiopathology; D008297:Male; D016210:Methacholine Chloride / Q000494:pharmacology; D010323:Passive Cutaneous Anaphylaxis; D010455:Peptides / Q000494:pharmacology*; D012121:Respiration, Artificial
chemical_list: D000941:Antigens; D016085:Bronchoconstrictor Agents; D001993:Bronchodilator Agents; D010455:Peptides; D016210:Methacholine Chloride; D053607:Adrenomedullin; D006632:Histamine