Wang Yan, Zheng Guo-qing, Wei Zong-de
Department of Cardiology, the Second Affiliated Hospital of Wenzhou Medical College, Wenzhou 32501, China.
Zhongguo Ying Yong Sheng Li Xue Za Zhi. 2007 Nov;23(4):395-8.
To study the functional activity of K(cA) on human mesenteric artery smooth muscle cells (SMC) from essential hypertension (EH) patients.
Patch clamp technique with Inside-out mode was used for recording channel activity.
(1) K(CA) from human mesenteric artery SMC was voltage dependent. Single channel conductance was 191.4 pS and 197.7 pS in EH group and normal group respectively. The channel activity was blocked by TEA in cytoplastic side. (2) With the increasing of Ca2+ concentration in the bath solution (fron 0 to 10(-8), 10(-7), 5 x 10(-7), 10(-6) mol/L), the K(Ca) channel open probability (Po) of two groups were increased, Po of EH group increased from 0.016 to 0.023, 0.031, 0.0153, 0.094, Po of normal group increased from 0.004 to 0.023, 0.041, 0.072, 0.184. The mean open time lengthened and the mean close time shortened. (3) Po of K(Ca) of EH group was higher than that of normal group when Ca2+ concentration was 0, but it was equal with or lower than normal group at the other Ca2+ concentrations.
K(Ca) of mesenteric artery SMC from EH group has a lower Ca2+ sensitivity than that of normal person. This might be an active factor for the onset of EH.
研究大电导钙激活钾通道（K(cA)）在原发性高血压（EH）患者肠系膜动脉平滑肌细胞（SMC）中的功能活性。
采用内面向外式膜片钳技术记录通道活性。
（1）人肠系膜动脉SMC的K(CA)具有电压依赖性。EH组和正常组单通道电导分别为191.4 pS和197.7 pS。该通道活性在胞质侧可被四乙铵（TEA）阻断。（2）随着浴液中Ca2+浓度升高（从0到10(-8)、10(-7)、5×10(-7)、10(-6) mol/L），两组的K(Ca)通道开放概率（Po）均增加，EH组Po从0.016增加至0.023、0.031、0.0153、0.094，正常组Po从0.004增加至0.023、0.041、0.072、0.184。平均开放时间延长，平均关闭时间缩短。（3）当Ca2+浓度为0时，EH组K(Ca)的Po高于正常组，但在其他Ca2+浓度时与正常组相等或低于正常组。
EH组肠系膜动脉SMC的K(Ca)对Ca2+的敏感性低于正常人。这可能是EH发病的一个活跃因素。
