氯胺酮在细胞膜内对大鼠皮层细胞延迟整流钾通道的影响

Effect of Ketamine on the Delayed Rectifier-like Potassium Current in Cerebral Neurons of Rats Through Inside-out Patch Model

【目的】测定高浓度氯胺酮在细胞膜内对大鼠皮层细胞延迟整流钾通道电导和动力学的影响。【方法】酶解法分离新生SD大鼠大脑皮层细胞,利用自行建立的膜片箝单离子通道检测系统内面向外模式检测其钾通道的特性,挑选出单个的延迟整流钾通道,并观测高浓度氯胺酮经细胞膜内通道内口对该通道的电导及动力学的影响。【结果】钳制电压+80 mV条件下,高浓度(0.5 mg/ml)氯胺酮在细胞膜内面作用前后其延迟整流钾通道的电流,开放、关闭常数及平均开放、关闭时间分别为:(-12.12±1.49)pA、5.490 mS、7.711mS(、12.50±21.71)mS、(8.91±10.34)mS和(-5.01±0.75)pA、0.686mS、3.252mS、(1.74±2.39)mS、(3.72±3.83)mS。【结论】高浓度氯胺酮在细胞膜内面直接使SD大鼠皮层细胞延迟整流钾通道的电导降低,开放、关闭常数及平均开放、关闭时间均减小。

【Objective】To study the effect of high dosage ketamine on the delayed rectifier-like potassium current in cerebral neurons of rats through inside-out patch model of patch-clamp technology.【Methods】Cerebral neurons of SD rats were isolated by enzyme method.Potassium channels were tested by patch-clamp using inside-out patch technique,and single delayed rectifier-like potassium channel was chosen.Then the influences of high dosage ketamine from inside of the channel on electric induction and kinetics were studied.【Results】When holding potential set on ＋80mV,high dosage ketamine（0.5mg/mL） from inside might change the currents,open、close index and open、 close time from（-12.12±1.49）pA、5.490 mS、7.711 mS、（12.50±21.71）mS、（8.91±10.34）mS to（-5.01±0.75）pA、0.686 mS、3.252 mS、（1.74±2.39）mS、（3.72±3.83）mS.【Conclusion】High dosage ketamine from inside of the delayed rectifier-like potassium channel may decrease the currents,open、close index and open、 close time.