中文摘要：

目的：探讨自发性高血压大鼠（SHR）和Wistar大鼠脑动脉（BA）平滑肌细胞膜电流的异同。方法：应用全细胞膜片钳技术研究SHR和Wistar大鼠BA平滑肌细胞在电流密度、电流组成以及自发性瞬时外向K＋电流（STOCs）特性的异同。结果：①当指令电压为0、＋20、＋40和＋60mV时,SHR与Wistar大鼠BA平滑肌细胞间电流密度存在统计学差异（P〈0.01）。②SHR与Wistar大鼠BA平滑肌细胞膜电流都对1 mmol/L电压依赖的K＋通道（Kv）阻断剂4AP和1 mmol/L大电导Ca2＋激活K＋通道（BKCa）阻断剂TEA敏感。③SHR的STOCs发放频率和电流幅度都远大于Wistar大鼠。1 mmol/LTEA基本完全阻断STOCs通道电流,而4-AP对STOCs没有影响。结论：SHR和Wistar大鼠脑动脉平滑肌细胞的电流密度存在差异,两种平滑肌细胞外向电流都由BKCa和Kv通道组成。SHR大鼠平滑肌细胞更易诱发由BKCa通道介导的STOCs。

英文摘要：

Objective： To investigate the difference in membrane current of vascular smooth muscle cells（VSMCs） in brain artery（BA） of spontaneously hypertensive rats（SHR） and Wistar rats.Methods： We compared the properties of spontaneous transient outward K＋ currents（STOCs）,the density and composition of current of VSMCs in BA of SHR and Wistar rats by whole-cell patch clamp technique.Results： ①When the command voltage was 0,＋20,＋40 and ＋60 mV respectively,the current densities of VSMCs in BA of SHR and Wistar rats were significant different（P0.01）.②The whole-cell current of VSMCs was partly inhibited by 1 mmol/L 4-AP（voltage-gated K＋ channel blocker） or 1 mmol/L TEA（big conductance Ca2＋-activated K＋ channel blocker） respectively.③The frequency and amplitude of STOCs in SHR were faster and bigger than those in Wistar rats.1 mmol/L TEA almostly inhibited the STOCs,but not by 4-AP.Conclusion： These results suggest that the current densities of VSMCs in BA of SHR and Wistar rats are significant different,the outward current of VSMCs in BA of SHR and Wistar rats are composed by Kv and BKCa.SHR express more STOCs mediated by BKCa than Wistar rats.