Dilator effects of nicorandil on isolated perfused coronary arteries of humans.
Vasodilator effects of nicorandil were examined in human isolated epicardial coronary arteries perfused at a constant pressure of 80 mmHg. The administration of prostaglandin F2 alpha (3 x 10(-6) M) reduced the coronary flow substantially from 116 +/- 6 ml/min to 27 +/- 7 ml/min (mean +/- S.E.M., n = 11, p less than 0.01). Periodic fluctuation of flow developed in 7 out of 11 preparations and intermittent cessation of flow was observed in 4 preparations. Coronary arteries were randomly assigned either to the nicorandil group (n = 6) or to the time-matched control group (n = 5). Nicorandil did not significantly change the flow rate at concentrations of 10(-6) M and 10(-5) M, but increased the flow rate up to 94 +/- 4% of the pre-prostaglandin F2 alpha level at 10(-4) M (p less than 0.01 vs time-matched control: 21 +/- 10%). Periodic flow changes were not observed at this concentration. We conclude that contraction of epicardial coronary arteries of humans causes a marked increase in vascular resistance in vitro and that nicorandil can reverse it.
Sakaino
N
N
Department of Pharmacology, Kumamoto University Medical School, Japan.
Araki
H
H
Nishi
K
K
D000368:Aged; D003326:Coronary Circulation / Q000187:drug effects; D003331:Coronary Vessels / Q000187:drug effects*; D015237:Dinoprost / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D009536:Niacinamide / Q000031:analogs & derivatives* / Q000494:pharmacology; D020108:Nicorandil; D005996:Nitroglycerin / Q000494:pharmacology; D010477:Perfusion; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology*
D014665:Vasodilator Agents; D009536:Niacinamide; D020108:Nicorandil; D015237:Dinoprost; D005996:Nitroglycerin