Zacopride Exerts an Antiarrhythmic Effect by Specifically Stimulating the Cardiac Inward Rectifier Potassium Current in Rabbits: Exploration of a New Antiarrhythmic Strategy.
Curr Pharm Des
; 26(44): 5746-5754, 2020.
Article
em En
| MEDLINE
| ID: mdl-32611299
ABSTRACT
BACKGROUND:
Zacopride, a potent antagonist of 5-HT3 receptors and an agonist of 5-HT4 receptors, is a gastrointestinal prokinetic agent. In a previous study, we discovered that zacopride selectively stimulated the inward rectifier potassium current (IK1) in the rat and that agonizing IK1 prevented or eliminated aconitine-induced arrhythmias in rats.OBJECTIVE:
Our aims were to confirm that the antiarrhythmic effects of zacopride are mediated by selectively enhancing IK1 in rabbits.METHODS:
The effects of zacopride on the function of the main ion channels were investigated using a whole-cell patch-clamp technique in rabbits. Effects of zacopride on cardiac arrhythmias were also explored experimentally both in vivo and in vitro.RESULTS:
Zacopride moderately enhanced cardiac IK1 but had no apparent action on voltage-gated sodium current (INa), L- type calcium current (ICa-L), sodium-calcium exchange current (INa/Ca), transient outward potassium current (Ito), or delayed rectifier potassium current (IK) in rabbits. Zacopride also had a marked antiarrhythmic effect in vivo and in vitro. We proved that the resting membrane potential (RMP) was hyperpolarized in the presence of 1 µmol/L zacopride, and the action potential duration (APD) at 90% repolarization (APD90) was shortened by zacopride (0.1-10 µmol/L) in a concentration- dependent manner. Furthermore, zacopride at 1 µmol/L significantly decreased the incidence of drug-induced early afterdepolarization (EAD) in rabbit ventricular myocytes.CONCLUSION:
Zacopride is a selective agonist of rabbit cardiac IK1 and that IK1 enhancement exerts potential antiarrhythmic effects.Palavras-chave
Texto completo:
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Potássio
/
Preparações Farmacêuticas
Limite:
Animals
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article