中文摘要：

目的研究奎尼丁对SD大鼠软脑膜动脉平滑肌细胞外向电流的作用及其机制。方法应用单细胞全细胞膜片钳技术，研究给予奎尼丁后大鼠软脑膜动脉单个平滑肌细胞（pial arterysmooth muscle cell，PASMC）外向电流的变化情况。结果 （1）奎尼丁呈电压依赖性增强PASMC的外向电流（n：6，P〈0．01）。（2）奎尼丁呈浓度依赖性增强大鼠PASMC的外向电流（n=6，P〈0．05）。（3）应用BK。。通道特异性阻断剂iberiotoxin（IBTX）后，不仅取消了奎尼丁增强外向电流的作用，而且抑制了对照组的外向电流（n=6，P〈0．01）。结论奎尼丁通过增强BKca通道激活的外向电流，可能参与了舒张大鼠软脑膜动脉。

英文摘要：

Aim To investigate the effect of quinidine on the outward currents of pial artery smooth musclecell （PASMC） in SD rat. Methods The whole-cell patch clamp recording was used to clarify the effect of quinidine on the outward currents of PASMC. Results （1） Quinidine enhanced the outward currents of PASMC in a voltage-dependent manner （n = 6, P 〈 0. 01 ）. （2） Quinidine enhanced the outward currents of PASMC in a concentration-dependent manner （ n = 6, P 〈 0.05 ）. （3） The enhancement of quinidine on the membrane currents of PASMC was totally blockedby 100 nmol . L-1 IBTX ward currents of PASMC （n=6, P〈0.01）. The out-were significantly lower control （n = 6, P 〈 0. 01 ） Conclusion Quinidine en-hances the outward currents of PASMC via activation of BKca channel, which may induce dilatation of pial ar-tery in SD rat