Cardiomyopeptidin decrease transient outward potassium current of rat ventricular myocytes / 基础医学与临床

ABSTRACT

Objective To determine the effect of cardiomyopeptidin on transient outward potassium current(I_(to) of rat ventricular myocytes and its action mechanism on the ion channels of myocardium.Methods Single ventricular myocytes of rats were obtained by enzymatic dissociation.The whole-cell patch-clamp recording technique was used to record the change of transient outward potassium current(I_(to) by different dosages of cardiomyopeptidin.Results Cardiomyopeptidin decreased I_(to) in a dose-dependent manner.Cardiomyopeptidin in dose of 10,50,100,250 and(500 mg/L) decreased I_(to %) by 4,13,22,32 and 38 respectively.Cardiomyopeptidin 50 mg/L moved the current density-voltage curve of I_(to) down,but the shape of the curve had no changes.Cardiomyopeptidin 50 mg/L did not change the steady state activation curve of I_(to).Conclusions Cardiomyopeptidin decreases the I_(to) of rat ventricular myocytes,which might be one of the mechanisms of its antiarrhythmic effect.