钩藤碱对大鼠肺动脉平滑肌细胞钙激活钾通道的影响

Effect of rhynchophylline on calcium activated potassium channels in isolated rat pulmonary smooth muscle cells

用膜片钳单通道记录法研究钩藤碱（Ｒｈｙ）对大鼠肺动脉平滑肌细胞钙激活钾通道（ＫＣａ）的影响．结果：Ｒｈｙ３０，４５和６０μｍｏｌ·Ｌ－１缩短通道的开放时间，但浓度依赖性增加ＫＣａ开放概率，Ｒｈｙ１５，３０，４５和６０μｍｏｌ·Ｌ－１使开放概率由加药前的０．０８５±０．００５分别增加到０．１７６±０．０１１，０．３１５±０．００９，０．４８５±０．０１６和０．７６１±０．０１２（ｘ±ｓ，均Ｐ＜０．０１）．说明Ｒｈｙ有增加肺动脉平滑肌细胞ＫＣａ开放作用．１．４数据处理用ｐＣｌａｍｐ软件对实验记录进行处理．用高斯曲线拟合通道开放的电流幅度，用指数曲线拟合通道的开放和关闭时间，用通道开放的总时间除以总采样时间求出通道的开放概率．并对通道开放进行“爆发开放（ｂｕｒｓｔ）”分析．通道电导（ｇｋ）按下列公式计算：Ｅｋ＝ＲＴ／ＺＦｌｎ［Ｋ＋］ｏ／［Ｋ＋］ｉ，ｇｋ＝△Ｉ／（Ｖｍ－Ｅｋ）．Ｅｋ：平衡电位，Ｒ：气体常数，Ｔ：绝对温度，Ｚ：离子价，Ｆ：法拉第常数，△Ｉ：钳制电位和平衡电位的膜电流差值，Ｖｍ：钳制电位．实验结果以ｘ±ｓ表示．用单因素方差分析进行统计学处理．２实验结果２．１肺动脉平滑肌细胞ＫＣａ的一般特性观察在大鼠肺动?

Using inside out configuration of patch clamp single channel recording technique, the effect of rhynchophylline(Rhy) on calcium activated potassium channels(K Ca ) in isolated rat pulmonary smooth muscle cells was studied. The results showed that Rhy 30, 45 and 60 μmol·L 1 decreased the open time, but increased the open probability of K Ca in concentration dependent manner. Rhy 15, 30, 45 and 60 μmol·L 1 increased the open probability of K Ca from control value 0.085±0.005 to 0.176±0.011, 0.315±0.009, 0.485±0.016 and 0.761±0.012, respectively (all P<0.01). The results indicate that Rhy has opening effects on K Ca in isolated rat pulmonary smooth muscle cells.