Analysis of relaxant effects of trapidil in isolated dog coronary artery.
Effects of 7-diethylamino-5-methyl-s-triazolo [1,5-a]pyrimidine (trapidil, Rocornal) on dog coronary arteries were investigated in vitro. Trapidil produced dose-dependent relaxations of isolated arteries which were contracted with potassium or prostaglandins F2 alpha. These effects of trapidil were not affected by atropine and propranolol. 5-Hydroxytryptamine (5-HT) and phenylephrine dose-dependently increased the tension of isolated coronary arteries. Trapidil could inhibit these effects of 5-HT or phenylephrine. The results indicate that trapidil has not a muscarinic action and an adrenergic beta-receptor stimulating action, but it has a 5-HT receptor and an adrenergic alpha-receptor blocking action.
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D003331:Coronary Vessels / Q000187:drug effects*; D004285:Dogs; D004347:Drug Interactions; D005260:Female; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; 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*; D010646:Phentolamine / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology*; D014192:Trapidil / Q000494:pharmacology*
D011743:Pyrimidines; D014192:Trapidil; D007545:Isoproterenol; D000109:Acetylcholine; D008784:Methysergide; D010646:Phentolamine