Membrane chloride conductance and capacitance in Jurkat T lymphocytes during osmotic swelling.
Membrane chloride conductance and capacitance in Jurkat T lymphocytes during osmotic swelling.
复制标题
渗透膨胀过程中 Jurkat T 淋巴细胞的膜氯电导和电容。
DOI：
10.1016/s0006-3495(94)80754-4
复制
发表时间：
1994
影响因子：
3.4
通讯作者：
Cahalan,MD
中科院分区：
文献类型：
--
作者：
Ross,PE;Garber,SS;Cahalan,MD
采用视频显微镜和全细胞膜片钳记录技术，观察Jurkat T淋巴细胞在渗透压致肿胀过程中相对细胞体积(V/Vo)、氯离子电导(GCL)和膜电容(Cm)的变化。用高渗吸管溶液启动细胞肿胀。V/Vo和GCL的同时检测显示，从肿胀开始到激活外向整流的依赖三磷酸腺苷的氯离子通道之间有59-S延迟。延迟后，V/Vo和GCL的增加是平行进行的。相反，在实现全细胞访问后，衡量细胞表面积的Cm以大约150Ff/min的速度逐渐下降。S的下降持续了200厘米，然后迅速上升(大约750ff/分钟)。Cm的升高与“泄漏”电流的可变增加相一致，GCL增加的速度较慢，在没有ATP的实验中达到较低的峰值；ATP对双相Cm的时间进程没有影响。肿胀期间电导和电容的时间分离表明GCL和Cm是独立变化的，这支持了一种假设，即肿胀期间激活的全细胞Cl-电导的很大一部分(如果不是全部)是由质膜中预先存在的体积敏感的Cl-通道提供的。
Video microscopy and whole-cell patch-clamp recording were used to monitor changes in relative cell volume (V/Vo), chloride conductance (gCl), and membrane capacitance (Cm) during osmotically induced swelling in Jurkat T lymphocytes. Cellular swelling was initiated with hyperosmotic pipette solutions. Simultaneous evaluation of V/Vo and gCl revealed a 59-s delay between the inception of swelling and the activation of outwardly rectifying, ATP-dependent Cl- channels. Following the delay, increases in V/Vo and gCl progressed in parallel. In contrast, Cm, a measure of cell surface area, fell gradually at a rate of approximately 150 fF/min after whole-cell access was achieved. The decline in Cm lasted 200 s and was followed by a rapid rise (approximately 750 fF/min). The rise in Cm coincided with a variable increase in "leak" current, gCl increased at a slower rate and reached lower peak values in experiments performed without ATP; ATP had no effect on the biphasic Cm time course. The temporal separation of conductance and capacitance during swelling suggests that gCl and Cm vary independently, supporting the hypothesis that a large portion, if not all, of the whole-cell Cl- conductance activated during swelling is provided by volume-sensitive Cl- channels preexisting in the plasma membrane.