Release of smooth muscle-contracting substances from isolated perfused lungs.
Infusion of tryptamine (1-4 mug/ml) through the pulmonary circulation of rat isolated lung perfused with Krebs solution caused release of a mixture of spasmogens contracting isolated smooth muscle preparations. One component of this mixture had biological activity comparable to E-type prostaglandins. Other components included a slow reacting substance comparable to SRS-A and a rabbit aorta-contracting substance comparable to RCS. Infusions of 5-hydroxytryptamine, acetylcholine and histamine (0.5-2 mug/ml) also caused release. Release induced by the tryptamines but not that by acetylcholine and histamine was prevented by methysergide whereas acetylcholine-induced release was prevented by hyoscine which did not affect tryptamine-induced release. The tryptamines and histamine released spasmogens from dog isolated lungs but only histamine was effective in guinea-pig lungs. We conclude that amine-induced release from isolated lungs is a fairly general phenomenon and that it may represent an endocrine function of lung.
D000109:Acetylcholine / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000502:physiology; D001920:Bradykinin / Q000494:pharmacology; D002395:Catecholamines / Q000494:pharmacology; D002415:Cats; D002645:Chickens; D004285:Dogs; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology; D007082:Ileum / Q000502:physiology; D066298:In Vitro Techniques; D008168:Lung / Q000378:metabolism*; D008784:Methysergide / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000378:metabolism*; D010477:Perfusion; D011312:Pressure; D011453:Prostaglandins / Q000032:analysis / Q000378:metabolism; D011817:Rabbits; D051381:Rats; D012601:Scopolamine / Q000494:pharmacology; D014363:Tryptamines / Q000494:pharmacology
D002395:Catecholamines; D011453:Prostaglandins; D014363:Tryptamines; D000804:Angiotensin II; D006632:Histamine; D012601:Scopolamine; D000109:Acetylcholine; D001920:Bradykinin; D008784:Methysergide