[Effects of nicorandil on spontaneous beating and action potentials of cultured myocardial cells of neonatal rats].
OBJECTIVE
To study the anti-arrhythmic mechanism of nicorandil (Nic).


METHODS
The myocardial cells of neonatal rats were cultured and effects of Nic on spontaneous beating and action potential of cultured myocardial cells were observed.


RESULTS
Nic 32 mumol L-1 and 160 mumol L-1 decreased the spontaneous beating rates of cultured myocardial cells of neonatal rats. Nic 64 mumol L-1 prevented the beating rats induced by CaCl2 1 mmol L-1 and isoproterenol 2 mumol L-1. Nic 32 and 160 mumol L-1 reduced the amplitude, maximal rate of rise, and shortened APD50 and APD90 repolarization. Nic prolonged the spontaneous sinus cycle length.


CONCLUSIONS
The antiarrhythmic mechanism of Nic is related to its direct effects on the myocardial cells.
Wang
H X
HX
Department of Pharmacology, Jinzhou Medical College, China.
Wang
W X
WX
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D000831:Animals, Newborn; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D002478:Cells, Cultured; D006321:Heart / Q000187:drug effects*; D009206:Myocardium / Q000166:cytology*; D009536:Niacinamide / Q000031:analogs & derivatives* / Q000494:pharmacology; D020108:Nicorandil; D051381:Rats; D017208:Rats, Wistar
D000889:Anti-Arrhythmia Agents; D009536:Niacinamide; D020108:Nicorandil