依托咪酯对新生大鼠皮质神经元钙激活性钾通道的作用

采用膜片钳技术的吸附式和内面向外式两种构型研究了依托咪酯对增减的ＳＤ新生鼠皮持 钙激活性钾（ＫＣａ）通道的作用。结果：（１）新生ＳＤ大鼠皮质神经元上存在有单元电导为１７６．６５±３７．９７ｐＳ的ＫＣａ通道；（２）依托咪酯０．８、４、１０、２０四个不同剂量在吸附式构型时浓度依赖性激活ＫＣａ通道，其开放概率较对照组均明显增大，（３）依托咪酯０．８μｍｏｌ／Ｌ在内面向外式构型时对ＫＣａ通道也有明显激活作

Effects of Etomidate on Single Calcium-activated Potassium Channel inNeonatal Rat Sensory Contex Neurones

The effects of etomidate on single calcium-activated potassium (KCa) channel incultured rat sensory cortex neurons were studied using cell-attached and inside-out patch clamp.The results showed that: l . This KCa channel has a slop conductance of 176.65+37.97pS(n=12)under symmetrical high K+ (140mmol/L) solution.2.In cell-attached patches, etomidate 0.8, 4,l0 and 20 Pmol/L respectively i significantly the calcium-activated potassium channels in a concentra-tion-dependent manner. The open probability (Po) increased markedly (P<0.01, n=4).3.In inside-out patches,etomidate 0.8umol/L also significantly activated this channel and increased the openingprobability (P<0.01,n=3).These results indicated that etomidate activated the KCa. channels markedly,and affected KCa. channels or its peripheral membrane directly. It could be related possibly to themechanism of etomidate anesthesia.