Evidence for the existence of postsynaptic beta-1 and beta-2 adrenoceptors in isolated simian facial veins.
With the use of a steel cannula inserting method, the actions of the beta-adrenoceptor agonists, noradrenaline (NA, a mixed agonist), isoprenaline (a mixed agonist), dobutamine (a selective beta-1 agonist), salbutamol, and procaterol (selective beta-2 agonists), were investigated on isolated and perfused simian facial veins. Each beta-agonist usually induced a vasodilation in a dose-related manner in non-preconstricted vessel preparations. The rank order of potency was isoprenaline much greater than NA greater than dobutamine greater than salbutamol greater than procaterol. NA- and isoprenaline-induced vasodilations were inhibited by either metoprolol (a selective beta-1 adrenoceptor antagonist) or ICI 118,551 (a selective beta-2 antagonist). After beta-1 blockade, NA produced a vasoconstriction which was readily blocked by bunazosin (an alpha-1 antagonist). Dobutamine-induced vasodilations were strongly suppressed by metoprolol and slightly blocked by ICI 118,551. Salbutamol-induced vasodilations were blocked by metoprolol, while ICI 118,551 more markedly inhibited these dilations. From these results, it was concluded that there are abundant beta-adrenoceptors and predominantly beta-1 adrenoceptors in isolated simian facial veins.
Department of Pharmacology, Shinshu University School of Medicine, Matsumoto, Japan.
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Tsukada
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000420:Albuterol / Q000494:pharmacology; D000818:Animals; D004280:Dobutamine / Q000494:pharmacology; D004983:Ethanolamines / Q000494:pharmacology; D005145:Face / Q000098:blood supply; D005260:Female; D007545:Isoproterenol / Q000494:pharmacology; D008251:Macaca; D008297:Male; D008790:Metoprolol / Q000494:pharmacology; D009131:Muscle, Smooth, Vascular / Q000294:innervation*; D009638:Norepinephrine / Q000494:pharmacology; D017265:Procaterol; D011412:Propanolamines / Q000494:pharmacology; D011943:Receptors, Adrenergic, beta / Q000187:drug effects*; D013569:Synapses / Q000187:drug effects*; D009435:Synaptic Transmission / Q000187:drug effects*; D014664:Vasodilation / Q000187:drug effects*; D014680:Veins / Q000294:innervation
D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D004983:Ethanolamines; D011412:Propanolamines; D011943:Receptors, Adrenergic, beta; D004280:Dobutamine; C026777:ICI 118551; D008790:Metoprolol; D007545:Isoproterenol; D000420:Albuterol; D009638:Norepinephrine; D017265:Procaterol