title: Vascular dopamine receptors in the canine hindlimb.
abstract: 1 Increases in femoral blood flow were produced by intra-arterial injections of dopamine (5-50 mug) in some but not all anaesthetized dogs studied, following treatment with the alpha-adrenoceptor antagonist, phentolamine. 2 The dilator effect of dopamine was not due to inhibition of adrenergic vasomotor tone as it was not affected by pharmacological procedures which completely abolished the activity of vastomotor nerves. 3 Blockade of vascular beta-adrenoceptors using propanolol reduced the flow increases produced by dopamine much less than it did those produced by isoprenaline. 4 Responses to dopamine were significantly depressed by intra-arterial administration of ergometrine (0.5 mg). This dose of ergometrine did not reduce femoral dilator responses to acetylcholine, histamine, isopienaline, bradykinin, or 5-hydroxytryptamine. 5 It is concluded that the femoral vascular bed in the dog contains specific vasodilator receptors for dopamine. Ergometrine appears to be a selective antagonist of dopamine at these receptors.
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001920:Bradykinin / Q000494:pharmacology; D004285:Dogs; D004298:Dopamine / Q000494:pharmacology / Q000502:physiology*; D004874:Ergonovine / Q000494:pharmacology; D005260:Female; D005263:Femoral Artery; D005724:Ganglia / Q000502:physiology; D006614:Hindlimb / Q000098:blood supply*; D006632:Histamine / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D011941:Receptors, Adrenergic / Q000187:drug effects; D011955:Receptors, Drug / Q000187:drug effects*; D012039:Regional Blood Flow / Q000187:drug effects; D012701:Serotonin / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology; D014666:Vasomotor System / Q000187:drug effects
chemical_list: D011941:Receptors, Adrenergic; D011955:Receptors, Drug; D014665:Vasodilator Agents; D012701:Serotonin; D006632:Histamine; D007545:Isoproterenol; D000109:Acetylcholine; D001920:Bradykinin; D004298:Dopamine; D004874:Ergonovine