丹参素异丙酯对人肠系膜小动脉平滑肌细胞膜钙激活钾通道影响的研究

Effects of Danshensu isopropyl on calcium-activated potassium channels in human mesenteric arterial smooth muscle cells

目的研究丹参素异丙酯[β-(3,4-二羟基苯基)-α-羟基丙酸异丙酯]对单个人肠系膜小动脉平滑肌细胞膜上钙激活钾通道的影响。方法取急性酶分离的人肠系膜动脉平滑肌细胞,用膜片钳技术记录其全细胞电流,在全细胞记录模式下,观察不同浓度丹参素异丙酯对全细胞钙激活钾电流的影响。结果①比较含三种不同钙浓度电极内液所记录到的外向电流,发现电流密度随钙浓度增加而增加;②丹参素异丙酯采用两种浓度:5mol/L、10mol/L;用药后5min两组IKCa增幅改变值分别为(13±3)和(36±7);③丹参素异丙酯使IKCaI-V曲线(I-V Curve)上移,用药后5min两组IKCa峰值电流密度增幅最大值分别为(19±2)和(40±3)。结论丹参素异丙酯具有激活钙激活通道,促进K+外流的作用,且有浓度依赖性,浓度高者作用更为明显。其促进K+外流的作用可能是其血管舒张的离子基础。

Objective To research the effects of Danshensu isopropyl on calcium-activated potassium channels in human mesenteric arterial smooth muscle cells.Methods The endothelium was removed by rubbing the intimal surface of the artery,and the adventitia was carefully dissected away.All experiments were worked on single smooth muscle cells isolated enzymatically in low-calcium external solution and recorded by using patch clamp whole-cell recording technique.Whole-cell currents were amplified and filtered by patch clamp amplifier,then imported into computer;Effects of Danshensu isopropyl on whole-cell KCacurrent at the different concentrations were observed.Results ①The outward currents under three different calcium ion concentrations of pipette internal solutions were compared,and found that current density increase with calcium ion concentrations.②Danshensu isopropyl concentrations in the experiment were 5mol/L and 10mol/L.Five minutes after administration of Danshensu isopropyl,IKCaincrement value were（13±3）and（36±7）.③Danshensu isopropyl could upward shift I-V Curve.Five minutes after administration of Danshensu isopropyl,IKCapeak current density increment value were（19±2）and（40±3）,respectively.Conclusion Under the concentration studied,in whole-cell patch mode,propofol could activate KCaand enhance K＋ efflux in human mesenteric arterial smooth muscle cells in a concentration-dependent manner.The results suggest that K＋ efflux enhancement may mediate Danshensu isopropl-induced vasodilation.