title: Modulatory effect of bradykinin on the release of noradrenaline from rat isolated atria.
abstract: 1. We investigated the modulation by bradykinin (BK) of electrically induced noradrenaline release in rat isolated atria preincubated with [3H]-noradrenaline. 2. BK (1-100 nM) enhanced significantly the stimulation-induced outflow of radioactivity in a concentration-dependent manner with a calculated EC50 of 0.58 nM. 3. Des-Arg9-BK (0.1-100 nM), a selective B1 receptor agonist, did not modify the stimulation-induced outflow of radioactivity. Hoe 140 (10 nM), a selective B2 receptor antagonist, but not [Leu8]-des-Arg9-BK (100 nM), a selective B1 receptor antagonist, blocked the facilitatory effect of BK. 4. The effect of BK was not affected by diclofenac (1 microM), a cyclo-oxygenase inhibitor. Bisindolylmaleimide (1 microM), a protein kinase C inhibitor, significantly reduced the facilitatory effect of BK (10 nM), angiotensin II (0.3 microM) and phorbol dibutyrate (0.1 and 1 microM) but not of fenoterol (1 microM). 5. The results suggest that BK enhances noradrenaline release via a prejunctional B2 kinin receptor in the rat atrium. The effect appears to involve protein kinase C as a second messenger.
authors.affiliation: Département de Physiologie, Faculté de Médecine, Université de Montréal, Québec, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Chulak
authors.forename: R
authors.initials: R
authors.lastname: Couture
authors.forename: S
authors.initials: S
authors.lastname: Foucart
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000704:Analysis of Variance; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001920:Bradykinin / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004008:Diclofenac / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004558:Electric Stimulation; D005280:Fenoterol / Q000494:pharmacology; D006325:Heart Atria / Q000187:drug effects* / Q000378:metabolism; D007211:Indoles / Q000494:pharmacology; D008297:Male; D008301:Maleimides / Q000494:pharmacology; D009638:Norepinephrine / Q000378:metabolism*; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000319:Adrenergic beta-Antagonists; D007211:Indoles; D008301:Maleimides; D000804:Angiotensin II; D004008:Diclofenac; C024626:bradykinin, des-Arg(9)-; D005280:Fenoterol; D015240:Phorbol 12,13-Dibutyrate; C051090:bradykinin, Leu(8)-des-Arg(9)-; C065679:icatibant; D011493:Protein Kinase C; C088060:bisindolylmaleimide; D001920:Bradykinin; D009638:Norepinephrine