晶状体上皮细胞的容量调节性氯通道

The volume regulated chloride channels in lens epithelial cells

目的 从离子通道水平上探讨晶状体水肿的机制 ,为白内障的病因学研究提供电生理学基础。方法 培养兔晶状体上皮细胞 (LECs) ,采用全细胞膜片钳技术观察LECs静息膜电位和膜上离子通道的活动。结果 培养的LECs静息膜电位为 -17.40mV± 4.67mV(n =15 ) ;LECs膜上存在对低渗敏感的通道 ,在给予 2 5 %低渗液灌流后激活。通道开放具有明显的电压依赖性 ,反转电位为 -5 .5 3mV。此电流可被氯通道特异性阻断剂Tamoxifen( 10 0 μmol/L)明显抑制。结论 LECs膜上存在容量调节性氯通道 。

Objective To investigate the mechanism of lens edema in terms of ionic channel level and to provide electrophysiological basis for the study of the etiology of cataract. Methods Cultured rabbit lens epithelial cells(LECs) were subjected to whole cell patch clamping to measure the membrane resting potential and to observe the activity of ionic channels. Results The membrane resting potential of LECs were -17.40 mV±4.67 mV( n =15).When LECs were exposed to 25% hypotonic solution,a whole cell current was activated.It was clearly voltage dependent.The reversal potential of this current was -5.53*!mV with symmetrical Cl -. The specific blocker of volume regulated chloride channel,Tamoxifen(100*!μmol/L),could apparently block the activity of this channel,while Quinine in various concentrations was ineffective. Conclusion The LECs possess volume regulated chloride channels.The disorder of its function may have close relationship with some types of opacities of lens.