Suppression of delayed rectifier potassium currents in rat hippocampal neurons by ketamine / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effect of ketamine on the delayed rectifier outward potassium currents (IK) using whole-cell patch clamp technique. Methods Pyramidal neurons were enzymatically isolated from Wistar rat hippocampus. The effect of ketamine on the IK was assessed using whole-cell patch clamp technique. We measured the amplitude of the delayed outward rectifier IK by activating depolarizing pulse from -50 mV to 40 mV. Different concentrations of ketamine were added and potassium currents were measured. Results IK was inhibited by ketamine in a concentration-dependent manner. The five concentrations of ketamine (10, 30, 100, 300, 1000 ?mol/L) reduced peak IK currents by (10 ? 4)% , (19?4)%, (31 ?5)%, (50?7)%, (54?8) % respectively, with a mean IC50 of (100?18)?mol/L and Hill coefficient of 1.33?0.48. The V1/2 of activation curve was shifted from (1.82 ? 0.20) mV to (9.30 ? 1.03) mV (n = 8, P