Volume- and calcium-activated chloride channels in human umbilical vein endothelial cells  

人脐静脉血管内皮细胞容量激活和钙激活氯离子通道(英文)

作　　者：钟宁[1] 方奇志[2] 张翼[1] 周兆年[1] 

机构地区：[1]中国科学院上海生理研究所 [2]同济医科大学药理教研室

出　　处：《Acta Pharmacologica Sinica》2000年第3期25-30,共6页中国药理学报（英文版）

摘　　要：AIM: To characterize the properties of chloride currents and its modulation in human umbilical vein endothelial cells (HUVEC). METHODS: Using whole-cell patch-clamp recording techniques. RESULTS: Exposure of HUVEC to 13.5 % and 27 % hypotonic solution (HTS) induced a current IC1, vol This current was correlated with the changes in cell volume and showed a modest outward rectification. It was slowly inactivated at positive potential ( > 50 mV), and it was time- and voltage-independent in kinetics. The current densities (pA/pF) were20±3 (13.5 % HTS) and 58±4 (27 % HTS, n = 7), respectively at + 100 mV test potential. Applying GTPγs (300 μmol·L-1) elicited a current similar to Ici, vol, while cAMP (0.5 mmol·L-1) had no effect on the current. Increase in [ Ca2 + ]i, either by directly loading cells with high concentration of Ca2+ (CaCl2), or by perfusing vasoactive agonist ATP (10 μmol·L-1), activated Ici, ca The current density was only (23±5) pA/pF (n = 8 cells). Such current was slowly activated at positive potential, inactivated quickly at negative potential, and showed strong outward rectification. Both currents were inhibited by DIDS and verapamil. Challenging a cell with elevated [Ca2+ ]i and HTS activated Ici, vol on the top of Ici, ca in the same cell, suggested co-existence of these two currents and that they were modulated by different ways, cAMP-regulated chloride ' channel and CIC (chloride channel family) channel were absent. CONCLUSION: HUVEC express two kinds of chloride channels, Ici,vol activated by change in cell volume and Ici, Ca by elevation of [Ca2+ ]i, respectively.目的:研究人脐静脉血管内皮细胞的氯离子通道及其不同的调节机制。方法:全细胞膜片箝技术。结果:13.5％和27％的低渗液体灌流细胞激活一外向电流(I_(Cl·vol))。该电流有弱的外向整流特性,无明显时间和电压依赖性;电流大小为(58±5)pA/pF;分别为(20±3),(58±4)增加细胞内钙或胞外应用ATP能激活I_(Cl,Ca)。该电流幅值较小(23±5)pA/pF;外向整流特性明显,在正电压下缓慢激活。两种电流均被DIDS及维拉帕米抑制。在同一个细胞上,在激活I_(Cl,Ca)的基础上灌流低渗液体可进一步激活I_(Cl,vol)。结论:HUVEC表达有两种氯通道,改变细胞容积可激活I_(Cl,vol),而增加细胞内钙则诱导出I_(Cl,Ca)。

关 键 词：vascular endothelium patch-clamp techniques chloride channels umbilical veins cyclic AMP CALCIUM adenosine triphosphate VERAPAMIL 

分 类 号：R33[医药卫生—人体生理学]