低渗诱导人小梁细胞容积敏感性氯电流的电生理学特点

目的：探讨与小梁细胞容积调节有关的氯通道电流的生理学特点，阐明该电流与容积敏感性氯通道电流的关系。方法：体外培养人小梁细胞，全细胞膜片钳记录等渗和低渗条件下小梁细胞膜上的氯通道电流，观察该电流特点。低渗状态下在浴液中加入氯离子通道阻断剂NPPB和他莫昔芬及ATP后记录电流的变化。结果：在等渗条件下，仅观察到微弱且稳定的背景电流，在+100和－100 mV电压钳钳制下，外向和内向电流密度值(pA/pF)分别为1.48±0.36 和－0.91±0.10（n=6）。低渗刺激后，细胞迅速肿胀，电流较等渗时明显增大，呈外向优势，外向和内向电流密度值(pA/pF)分别为19.94±0.87 和－6.53±0.41（n=6，P<0.01）。在低渗状态下的浴液中分别加入NPPB(100 mol/L)、他莫昔芬（50 mol/L）和ATP (2 μmol/L)20　min后，外向和内向电流密度值(pA/pF)分别为7.61±0.50和－3.70±0.25、8.21±0.63和－3.83±0.25、9.08±0.67和3.89±0.22，均较低渗时明显减小（P<0.01）。结论：细胞外低渗诱导人小梁细胞产生呈外向优势氯电流，此电流对细胞容积的改变敏感，可被NPPB、他莫昔芬和ATP抑制，该电
流符合容积敏感性氯电流的特征。

Electrophysiologic characteristics of volume-sensitive chloride currents induced by extracellular hypotonicity in human trabecular meshwork cells

Objective To investigate the electrophysiologic characteristics of volume-sensitive chloride currents in human trabecular meshwork cells and clarify the relationship between this current and the volume-sensitive chloride channel.Methods Human trabecular meshwork cells were culivated in vitro,whole-cell patch-clamp was used to record the current of chloride channel of human trabecular meshwork cell membrane under the isotonic and hypotonic conditions,and the characteristics of the current and the effects of ...