Effects of 2-nicotinamidoethyl nitrate (SG-75, nicorandil) on indomethacin-induced contractions of isolated dog coronary arteries.
Effects of 2-nicotinamidoethyl nitrate (SG-75) on contractile responses of dog coronary arteries to indomethacin were investigated in vitro. Indomethacin (3 X 10(-8) and 3 X 10(-7) Gm/ml) produced contractions of isolated coronary arterial strips, which were reproduced by successive administration of the drug. SG-75 (10(-5) Gm/ml) administered 5 min prior to indomethacin, significantly depressed indomethacin-induced contractions of the strips. In coronary arterial strips under potassium-contracture, SG-75 10(-8)-10(-4) Gm/ml) produced concentration-dependent relaxations, which were not affected by prior administration of indomethacin (3 X 10(-6) Gm/ml). Tranylcypromine (10(-4) Gm/ml) did not influence the relaxant responses of the strips to SG-75 (10(-8)-10(-5) Gm/ml) but significantly depressed them to SG-75 (10(-4) Gm/ml). Results indicate that large doses of SG-75 will induce a relaxant effect on isolated dog coronary arteries through activation of intravascular biosynthesis or release of prostacyclin from vascular tissues.
D000818:Animals; D003331:Coronary Vessels / Q000187:drug effects*; D003864:Depression, Chemical; D004285:Dogs; D011464:Epoprostenol / Q000096:biosynthesis; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects*; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D009536:Niacinamide / Q000031:analogs & derivatives* / Q000494:pharmacology; D020108:Nicorandil; D014191:Tranylcypromine / Q000494:pharmacology
D009536:Niacinamide; D020108:Nicorandil; D014191:Tranylcypromine; D011464:Epoprostenol; D007213:Indomethacin