title: Relaxant effect of dopamine on isolated rabbit pulmonary artery.
abstract: In rabbit pulmonary artery, dopamine (10(-11)-10(-5) M) produced a concentration-dependent relaxation of the arterial strips contracted with prostaglandin F2 alpha (PGF2 alpha) in the presence of prazosin (10(-6) M), yohimbine (10(-6) M), propranolol (10(-6) M), and methysergide (10(-6) M). SKF38393, an agonist for D1 or DA1 dopamine receptor, mimicked partially the concentration-response curve for dopamine, whereas LY171555 and apomorphine did not. The order of potency of dopamine antagonists on the inhibitory effect was: cis-flupenthixol greater than bulbo-capnine greater than metoclopramide greater than haloperidol. Sulpiride was inactive. Cis-flupenthixol did not block the relaxation induced by acetylcholine, adenosine, and papaverine. In the arterial strips of the rabbits pretreated with 6-hydroxydopamine, the concentration-response curve for dopamine was similar to that in non-treated rabbits. Thus it is concluded that a specific dopamine receptor is located on the postsynaptic muscle membrane of the rabbit pulmonary artery.
mesh_terms: D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D001552:Benzazepines / Q000494:pharmacology; D015237:Dinoprost; D004298:Dopamine / Q000494:pharmacology*; D018492:Dopamine Antagonists; D004305:Dose-Response Relationship, Drug; D004873:Ergolines / Q000494:pharmacology; D005260:Female; D008297:Male; D008784:Methysergide / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects*; D009126:Muscle Relaxation / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D011224:Prazosin / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011460:Prostaglandins F / Q000494:pharmacology; D011651:Pulmonary Artery / Q000187:drug effects*; D019257:Quinpirole; D011817:Rabbits; D014664:Vasodilation / Q000187:drug effects; D015016:Yohimbine / Q000494:pharmacology
chemical_list: D001552:Benzazepines; D018492:Dopamine Antagonists; D004873:Ergolines; D011460:Prostaglandins F; D019257:Quinpirole; D015016:Yohimbine; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D011433:Propranolol; D015237:Dinoprost; D001058:Apomorphine; D004298:Dopamine; D011224:Prazosin; D008784:Methysergide