Effect of ketamine on inward rectifier potassium currents in isolated rat ventricular myocytes / 中华麻醉学杂志

ABSTRACT

Objective To study the effect of ketamine on inward rectifier potassium currents(I_k1)in isolated rat ventricular myocytes using whole-cell patch clamp technique.Methods Adult Wistar rats of both sexes were anesthetized with pentobarbital.The hearts were removed and ventricular myocytes were prepared by the technique described by Liu et al.Whole-cell patch clamp technique was used to study I_(k1) in isolated rat ventricular myocytes The changes in I_(KI) produced by 100 ?mol?L~(-1) with different holding potentials or by different concentrations of ketamine with holding potential of-120 mV were analyzed.Results Ketamine 100 ?mol?L~(-1) inhibited the Ira without any significant effects on reverse potential (-50--60 mV)and the shape of the Ⅰ-Ⅴ curve.Ketamine inhibited I_(k1) evoked by a holding potential of-120 mV in a dose-dependent manner with a mean IC_(50) value of (162.3?8.4)?mol?L~(-1).Conclusion Ketamine significantly inhibits I_(k1) in ventricular myocytes. This may explain the prolonged duration of action potential of ventricular myocyte produced by ketamine.