粉防己碱对猪冠状动脉平滑肌细胞钙激活钾通道的作用

Action of Tetrandrine on Calcium-Activated Potassium Channels in Porcine Coronary Artery Smooth Muscle Cells

目的:研究粉防己碱(Tet)对猪冠状动脉平滑肌细胞(SMC)钙激活钾通道(K_(Ca))的作用。方法:用膜片钳单通道技术确定通道的变化。结果:Tet 浓度依赖性地可逆性阻断 SMC 上的 K_(Ca)。细胞膜内侧面加入 Tet 20、30×10^(-6)mol·L^(-1)可分别使通道开放概率降低(58.2±20.3)%、(64.6±16.6)%,平均开放时间从(2.3±0.7)ms 减少到(2.0±0.8)ms 和(1.6±0.6)ms,平均关闭时间从(68.1±39.3)ms 减少到(64.0±62.4)ms 和(37.0±16.6)ms。随 Tet 浓度的增加,通道活动逐步完全抑制。结论:Tet 是一种天然有效的SMC 上 K_(Ca)抑制剂。

Objective:To study the action of Tetrandrine (Tet) on calcium-activated potassium channels (K_(Ca))in porcine coronary artery smooth muscle cells(SMC).Methods:Changes of channels were determined by patch clamp single channel technique.Results:Tet could reversibly block K_(Ca) in porcine coronary artery SMC in a dose dependent manner.The open probability (Po) of the channel could be reduced 58.2±20.3% and 64.6±16.6% when adding Tet of 20×10~6 ml/L,and 30×10~6 mol/L from medial surface of the cytomembrane.The...