title: Tryptamine receptors in rat pulmonary artery.
abstract: Tryptamine and 5-hydroxytryptamine (5-HT) are equipotent in contracting spiral strips of rat isolated pulmonary artery, in doses between 5 and 20 mug. These 5-HT receptors are blocked by low concentrations (c. 10(-9) M) of both methysergide and morphine. In rat isolated lung perfused via the pulmonary circulation, 5-HT caused increases in perfusion pressure which were also antagonized by methysergide and by morphine. These vascular 5-HT receptors cannot therefore be classified as M or D receptors and, furthermore, are different from those 5-HT receptors mediating release of spasmogens from rat isolated lungs.
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D066298:In Vitro Techniques; D008168:Lung; D008297:Male; D008784:Methysergide / Q000494:pharmacology; D009020:Morphine / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D010477:Perfusion; D011651:Pulmonary Artery / Q000187:drug effects*; D051381:Rats; D011955:Receptors, Drug; D012701:Serotonin / Q000494:pharmacology; D014363:Tryptamines / Q000494:pharmacology
chemical_list: D011955:Receptors, Drug; D014363:Tryptamines; D012701:Serotonin; D009020:Morphine; D008784:Methysergide