异丙酚对小鼠脑动脉血管平滑肌细胞自发性瞬时外向钾电流的影响

Effect of propofol on spontaneous transient outward K ＋ currents in mouse cerebral arterial smooth muscle cells

目的探讨异丙酚对小鼠脑动脉血管平滑肌细胞自发性瞬时外向钾电流的影响。方法昆明小鼠，体重18～22g，雌雄不拘，分离脑底部Willis动脉环，经两步法酶消化分离血管平滑肌细胞，选取5个血管平滑肌细胞，采用穿孔全细胞膜片钳技术，于钳制电位为-30mV时记录加入56umol／L异丙酚前后自发性瞬时外向钾电流，分析其幅度、频率、曲线下面积和时间半宽。结果与给药前比较，给药后自发性瞬时外向钾电流的幅度、频率和曲线下面积升高（P〈0．05或0．01），时间半宽差异无统计学意义（P〉0．05）。结论异丙酚可激活小鼠脑动脉血管平滑肌细胞自发性瞬时外向钾电流，诱发血管平滑肌舒张。

Objective To investigate the effects of propofol on the spontaneous transient outward K＋ currents in mouse cerebral arterial smooth muscle cells. Methods Kunming mice of both sexes, weighing 18-22 g, were used in this study. Vascular smooth muscle cells were freshly isolated from cerebral arteries in two steps. Five cells were chosen and studied. When holding potential was - 30 mV, spontaneous transient outward K ＋ currents were recorded before and after the application of 56 umol/L propofol by perforated whole-cell patch-clamp technique. The amplitude, frequency, area under the curve and half time width of spontaneous transient outward K＋ currents were analyzed. Results Propofol 56umol/L significantly increased the amplitude, frequency and area under the curve of spontaneous transient outward K＋ currents. There was no significant change in the half time width of spontaneous transient outward K ＋ currents after administration. Conclusion Propofol can activate spontaneous transient outward K＋ currents in mouse cerebral arterial smooth muscle cells, and thus induces vascular smooth muscle relaxation.