Effects of a new antianginal agent, nicorandil, on normoxic and anoxic contractions in isolated miniature pig coronary arteries exposed to 5-hydroxytryptamine and norepinephrine: comparison with nitroglycerin and diltiazem.
Nicorandil, nitroglycerin and diltiazem effects on normoxic and anoxic contractile responses to 5-hydroxytryptamine (5-HT) and norepinephrine (NE) were compared in isolated miniature pig coronary artery strips. Anoxia augmented contractile responses of the strips to 5-HT and NE. Nicorandil and nitroglycerin inhibited the normoxic contractile responses to 5-HT and NE and the further contraction induced by subsequently imposed anoxia. Diltiazem inhibited only the responses to 5-HT and to subsequently imposed anoxia. Whereas nicorandil and nitroglycerin produced relaxation of both potassium- and lanthanum-induced contractions, diltiazem was an effective relaxant of the potassium-induced contraction. The present experiments demonstrate that anoxia can augment the contractions of isolated large coronary arteries to 5-HT and NE. Nicorandil as well as nitroglycerin attenuate normoxic and anoxic contractions to 5-HT and NE. This is probably accomplished by inhibition of intracellular Ca2+ mobilization.
D000818:Animals; D001552:Benzazepines / Q000494:pharmacology*; D003331:Coronary Vessels / Q000187:drug effects; D004110:Diltiazem / Q000494:pharmacology*; D004347:Drug Interactions; D005260:Female; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009536:Niacinamide / Q000031:analogs & derivatives* / Q000494:pharmacology; D020108:Nicorandil; D005996:Nitroglycerin / Q000494:pharmacology*; D009638:Norepinephrine / Q000037:antagonists & inhibitors*; D010100:Oxygen / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology*; D013552:Swine; D013556:Swine, Miniature
D001552:Benzazepines; D012702:Serotonin Antagonists; D009536:Niacinamide; D020108:Nicorandil; D004110:Diltiazem; D005996:Nitroglycerin; D010100:Oxygen; D009638:Norepinephrine