Depressant effect of trapidil on dog coronary arterial contraction induced by ergonovine.
Effects of trapidil on ergonovine-induced contractions of isolated dog coronary arteries were investigated in vitro. Ergonovine produced dose-dependent contractions of helical strips cut from the left circumflex branches of coronary arteries. Trapidil significantly depressed these-contractions. 5-HT also produced dose-dependent contractions of the strips, which were depressed by trapidil. In isolated rabbit femoral arterial preparations, norepinephrine dose-dependently contracted the strips. Phentolamine significantly depressed these contractions, and trapidil depressed them when relatively high doses were applied previously. Results indicate that trapidil has a depressant effect on coronary arterial contractions induced by ergonovine, partly through antagonism to 5-HT receptor and/or adrenergic alpha receptor.
D000818:Animals; D001158:Arteries / Q000187:drug effects; D003331:Coronary Vessels / Q000187:drug effects*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004874:Ergonovine / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D066298:In Vitro Techniques; D009638:Norepinephrine / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology*; D011817:Rabbits; D014192:Trapidil / Q000494:pharmacology*; D014661:Vasoconstriction / Q000187:drug effects*
D011743:Pyrimidines; D014192:Trapidil; D004874:Ergonovine; D009638:Norepinephrine