Huang C J, Palant C E, Craelius W
Department of Biomedical Engineering, Rutgers University, Piscataway, NJ 08854, USA.
Kidney Blood Press Res. 1997;20(5):302-6. doi: 10.1159/000174163.
Several functions of mesangial cells, such as contraction and release of nitric oxide, are dependent on the ambient Cl- concentration. Herein we describe a direct effect of Cl- on mesangial cell membrane conductance. Rat mesangial cells were isolated, cultured, and were patch-clamped in the whole-cell configuration. The external concentration - ([Cl-]o) - of standard Ringer's solutions was changed isotonically from standard of 160 mM to 35 mM while cell membrane conductance was continuously recorded. Results indicated that control I-V curves of the steady state current had a linear slope conductance of 0.95 nS (n = 10, r = 0.9). In low [Cl-]o, conductance outwardly rectified and increased to 4.1 nS between -120 and 0 mV and to 16.8 nS between 0 and 40 mV (n = 10, r = 0.9; p<0.01). The increase in conductance occurred within a few seconds and was reversible. Our results show that a large mesangial cell membrane conductance for cations is activated upon exposure to low [Cl-]o.
系膜细胞的一些功能，如收缩和一氧化氮释放，取决于周围的氯离子浓度。在此我们描述氯离子对系膜细胞膜电导的直接影响。分离、培养大鼠系膜细胞，并采用全细胞模式进行膜片钳记录。标准林格氏液的外部浓度（[Cl-]o）从标准的160 mM等渗变化至35 mM，同时持续记录细胞膜电导。结果表明，稳态电流的对照I-V曲线的线性斜率电导为0.95 nS（n = 10，r = 0.9）。在低[Cl-]o时，电导向外整流，在-120至0 mV之间增加到4.1 nS，在0至40 mV之间增加到16.8 nS（n = 10，r = 0.9；p<0.01）。电导的增加在几秒钟内发生且是可逆的。我们的结果表明，暴露于低[Cl-]o时，系膜细胞膜对阳离子的电导会被激活。
