Acetaldehyde at Clinically Relevant Concentrations Inhibits Inward Rectifier Potassium Current IK1 in Rat Ventricular Myocytes

Abstract

Considering the effects of alcohol on cardiac electrical behavior as well as the important role of the inward rectifier potassium current IK1 in arrhythmogenesis, this study was aimed at the effect of acetaldehyde, the primary metabolite of ethanol, on IK1 in rat ventricular myocytes. Acetaldehyde induced a reversible inhibition of IK1 with IC50 = 53.7±7.7 µM at –110 mV; a significant inhibition was documented even at clinically-relevant concentrations (at 3 µM by 13.1±3.0 %). The inhibition was voltage-independent at physiological voltages above –90 mV. The IK1 changes under acetaldehyde may contribute to alcohol-induced alterations of cardiac electrophysiology, especially in individuals with a genetic defect of aldehyde dehydrogenase where the acetaldehyde level may be elevated.