家兔肺动脉平滑肌细胞的延迟整流钾电流及白花前胡有效成分Pd-Ia对此电流的作用

Delayed Rectifier Potassium Current of the Smooth Muscle Cell of Rabbit Pulmonary Artery and the Effect of Pb Ia

建立用胰蛋白酶和胶原酶分离制备家兔肺动脉单离平滑肌细胞的方法并以膜片钳制技术观察了此细胞延迟整流钾电流的基本特性及中药白花前胡有效成分Ｐｄ－Ｉａ的作用。结果表明：①将细胞钳制在－４０ｍＶ，当指令电位大于－４０ｍＶ时，可以记录到具时间及电压依赖性的延迟整流钾电流；②Ｐｄ－Ｉａ１０－６ｍｏｌ／Ｌ在指令电位为＋８０ｍＶ时，可以使延迟整流钾电流由给药前的（１．８±０．５）ｎＡ增加至（２．３±０．６）ｎＡ，提示Ｐｄ－Ｉａ可能具有钾通道开放作用。

Smooth muscle cells of rabbit pulmonary arteries were obtained by an enzymatic dissociation method (trypsin and collagenase), delayed rectifier potassium current was determined and the effect of Pb-Ia, an effective component of a Chinese traditional medicine, Bai Hua Qian Hu, was observed. The results showed that: 1.when cell was held at -40 mV and command potential was larger than -50 mV, delayed rectifier outward potassium current could be recorded. This current was time-and voltage-dependent; 2.when command potential was +80 mV, 10 min after Pd-Ia 10 -6 mol/L, this potassium current increased from (1.8±0.5)nA of control to (2.3±0.6)nA, suggesting that Pd-Ia may be an opener of this potassium channel.