Dominant vasodilator action of norepinephrine in isolated, non-preconstricted simian facial veins.
Using the cannula inserting method, we investigated the vascular responses to norepinephrine (NE), phenylephrine and isoprenaline (Isp) in isolated, perfused simian facial veins. NE usually induced only a vasodilation in non-preconstricted veins. Phenylephrine consistently induced only a slight vasoconstriction, and Isp produced only a vasodilation. NE-induced vasodilations were reversed to vasoconstrictions after treatment with a relatively larger dose of propranolol. It is concluded that simian facial veins have a spontaneous intrinsic tone and dominant abundant beta-adrenoceptors but sparse alpha 1-adrenoceptors.
Chiba
S
S
Department of Pharmacology, Shinshu University School of Medicine, Matsumoto, Japan.
Tsukada
M
M
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008251:Macaca; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology*; D010656:Phenylephrine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D014665:Vasodilator Agents; D014680:Veins / Q000187:drug effects
D014665:Vasodilator Agents; D010656:Phenylephrine; D011433:Propranolol; D007545:Isoproterenol; D009638:Norepinephrine