异丙酚对人肠系膜小动脉平滑肌细胞膜外向钾通道电流的影响

Effect of Propofol on Outward Potassium Currents in Smooth Muscle Cells Isolated from Human Mesenteric Arterioles

目的 :研究异丙酚对人肠系膜小动脉平滑肌细胞膜外向钾通道电流的影响。方法 :用酶消化法获得急性分离的人肠系膜小动脉平滑肌细胞 ,采用全细胞膜片钳技术记录外向钾通道电流。结果 :在刺激电压 (Vt)- 70mV～ +70mV条件下 ,引发一外向钾电流 ,该电流可被 3mmol/LTEA阻滞 6 1%± 5 % ,异丙酚 (4 3μmol/L、86 μmol/L)分别增加外向钾通道电流幅值达 (13± 3) %和 (36± 7) %。 结论 :异丙酚增强人肠系膜小动脉平滑肌细胞外向钾通道电流 ,提示钾通道开放增加可能介导异丙酚引发的血管扩张。

Objective:To investigate the effects of propofol on outward potassium current in smooth muscle cells isolated from human mesenteric arterioles. Methods:The smooth muscle cells of human mesenteric arterioles were enzymatically dissociated. The whole cell patch-clamp technique was applied to record outward potassium current. Results:Depolarizing pulses from -70 mV to +70 mV elicited an outward current that was blocked 61%±5% by 3mM tetraethylammonium(TEA). Propofol(43 μmol/L and 86 μmol/L)activated the amplitude of outward potassium current by 13%±3% and 36%±7%, respectively. Conclusions:Propofol enhance outward potassium current in smooth muscle cells isolated from human mesenteric arterioles. The results suggested that outward potassium current activation may, in part, mediate propofol induced vasodilation.