剪切力对大鼠脑微血管内皮细胞膜钾电流影响的研究  

The Effects of Shear Stress on Kalium Ion Currents of Rat Brain Microvascular Endothelial Cell Membrane

作　　者：丁库克[1] 许莉莉[1] 王春燕[1] 刘志翔[1] 胡金麟[2] 常小飞[3] 曾衍钧[3] 

机构地区：[1]首都医科大学生物医学工程学院,北京100069 [2]中国人民解放军总医院微循环研究室,北京100853 [3]北京工业大学生物医学工程中心,北京100022

出　　处：《北京生物医学工程》2006年第6期631-633,657,共4页Beijing Biomedical Engineering

基　　金：国家自然科学基金(39600040;10172096);北京市自然科学基金(3982005)资助

摘　　要：目的以脑微血管内皮细胞为实验对象,研究剪切力对内皮细胞膜电流的影响,并探讨细胞内的信号转导途径。方法在体外培养大鼠脑微血管内皮细胞,利用平行板流动小室装置建立剪切力场,应用全细胞膜片钳的技术研究该细胞离子通道的力学敏感性问题。结果在0.14×10-5N/cm2剪切力的作用下,细胞膜电流明显增加。剪切力诱导的电流有明显短暂的延迟现象,对具有高度特异性,胞外施加20mmol/L的TEA-Cl可明显抑制该电流。该电流具有TEA浓度依赖性,其IC50约为2.0mmol/L,符合延迟整流性钾电流特征(IKv)。实验还表明,在膜电位为30mV、60mV与90mV时,诱导电流分别为(54.1±53.2)pA、(106.1±47.4)pA、(154.0±53.3)pA(n=8,p<0.01)。结论剪切力对脑血管内皮细胞膜电流有影响,存在延迟整流性K+电流,对TEA高度敏感,通过对细胞去极化,可引出明显的内向电流。Objective We do some experiments with rat brain microvascular endothelial cells （RBMEC） in order to determine the effects of shear stress on these ceils membrane currents and to find out signal transduction pathways. Method The major method employed is whole-cells patch clamp technique. In addition, we designed a flow chamber to investigate the current changes of microvascular endothelial cells after a period of shear stress applied. Result In the appearance of shear stress of 0. 14 × 10^- 5 N/cm^2 , the currents of cell membranes a significantly increased. By using the whole-cell patch-clamp technique, currents in rat brain microvascular endothelial cells delayed, which was nearly inhibited by extracellular TEA-Cl. at a concentration of 20mmol/L with an IC50 2.0mmol/L. This currents depend on the concentration of TEA and were defined as delayed rectified K^＋ currents （IKv） and show obvious voltage-dependence. In addition, this experiment show that the induced currents were respectedly （54.1 ± 53.2） pA, （ 106.1 ± 47.4） pA, （ 154.0 ± 53,3） pA with three membrane-voltages of 30mV, 60mV and 90mV （ n = 8, P 〈 0.01 ）. Conclusion These results indicate the shear stress has a profound in fluence on rat bruin mierovascular endothelial cell membrane with delayed rectified K^＋ currents, which are much sensitive to TEA. By depolarizing to cells, the inner currents was brought obviously.

关 键 词：剪切力 内皮细胞 离子通道 膜电流 

分 类 号：R318.01[医药卫生—生物医学工程]