title: Involvement of bradykinin B1 and B2 receptors in relaxation of mouse isolated trachea.
abstract: 1. The aim of the present study was to investigate the effects of bradykinin and [des-Arg9]-bradykinin and their relaxant mechanisms in the mouse isolated trachea. 2. In the resting tracheal preparations with intact epithelium, bradykinin and [des-Arg9]-bradykinin (each drug, 0.01-10 microM) induced neither contraction nor relaxation. In contrast, bradykinin (0.01-10 microM) induced concentration-dependent relaxation when the tracheal preparations were precontracted with methacholine (1 microM). The relaxation induced by bradykinin was inhibited by the B2 receptor antagonist, D-Arg0-[Hyp3,Thi5,D-Tic7,Oic8]-bradykinin (Hoe 140, 0.01-1 microM) in a concentration-dependent manner whereas the B1 receptor antagonist, [des-Arg9,Leu8]-bradykinin (0.01-1 microM), had no inhibitory effect on bradykinin-induced relaxation. [des-Arg9]-bradykinin (0.01-10 microM) also caused concentration-dependent relaxation after precontraction with methacholine. The relaxation induced by [des-Arg9-bradykinin was concentration-dependently inhibited by the B1 receptor antagonist, [des-Arg9,Leu8]-bradykinin (0.01-1 microM), whereas the B2 receptor antagonist, Hoe 140 (0.01-1 microM) was without effect. 3. In the presence of the cyclo-oxygenase inhibitor, indomethacin (0.01-1 microM), the relaxations induced by bradykinin and [des-Arg9]-bradykinin were inhibited concentration-dependently. 4. Two nitric oxide (NO) biosynthesis inhibitors NG-nitro-L-arginine methyl ester (L-NAME, 100 microM) and NG-nitro-L-arginine (L-NOARG, 100 microM) had no inhibitory effects on the relaxations induced by bradykinin and [des-Arg9]-bradykinin. Neither did the selective inhibitor of the soluble guanylate cyclase, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 10 microM) inhibit the relaxations induced by bradykinin and [des-Arg9]-bradykinin. 5. Prostaglandin E2 (PGE2, 0.01-33 microM) caused concentration-dependent relaxation of the tracheal preparations precontracted with methacholine. Indomethacin (1 microM) and ODQ (10 microM) exerted no inhibitory effects on the relaxation induced by PGE2. 6. The NO-donor, sodium nitroprusside (SNP; 0.01-100 microM) also caused concentration-dependent relaxation of the tracheal preparations precontracted with methacholine. ODQ (0.1-1 microM) concentration-dependently inhibited the relaxation induced by SNP. 7. These data demonstrate that bradykinin and [des-Arg9]-bradykinin relax the mouse trachea precontracted with methacholine by the activation of bradykinin B2-receptors and B1-receptors, respectively. The stimulation of bradykinin receptors induces activation of the cyclo-oxygenase pathway, leading to the production of relaxing prostaglandins. The NO pathway is not involved in the bradykinin-induced relaxation. The relaxation caused by NO-donors in the mouse trachea is likely to be mediated via activation of soluble guanylate cyclase.
authors.affiliation: Institute of Biomedicine, Department of Pharmacology and Toxicology, University of Helsinki, Finland.
authors.forename: L
authors.initials: L
authors.lastname: Li
authors.forename: K
authors.initials: K
authors.lastname: Vaali
authors.forename: I
authors.initials: I
authors.lastname: Paakkari
authors.forename: H
authors.initials: H
authors.lastname: Vapaatalo
mesh_terms: D000818:Animals; D001920:Bradykinin / Q000031:analogs & derivatives / Q000494:pharmacology; D065168:Bradykinin Receptor Antagonists; D015232:Dinoprostone / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009126:Muscle Relaxation / Q000187:drug effects / Q000502:physiology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D019335:Nitroarginine / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D010069:Oxadiazoles / Q000494:pharmacology; D011451:Prostaglandin-Endoperoxide Synthases / Q000187:drug effects; D011810:Quinoxalines / Q000494:pharmacology; D043783:Receptor, Bradykinin B1; D043782:Receptor, Bradykinin B2; D018002:Receptors, Bradykinin / Q000502:physiology*; D014132:Trachea / Q000187:drug effects / Q000502:physiology*
chemical_list: C095284:1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one; D065168:Bradykinin Receptor Antagonists; D004791:Enzyme Inhibitors; D010069:Oxadiazoles; D011810:Quinoxalines; D043783:Receptor, Bradykinin B1; D043782:Receptor, Bradykinin B2; D018002:Receptors, Bradykinin; D009599:Nitroprusside; D019335:Nitroarginine; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D011451:Prostaglandin-Endoperoxide Synthases; D006162:Guanylate Cyclase; D015232:Dinoprostone; D001920:Bradykinin; D019331:NG-Nitroarginine Methyl Ester; D007213:Indomethacin