[通过具有钠钾泵、钠钾氯协同转运蛋白、钠氯协同转运蛋白以及存在和不存在钾通道非戈德曼整流的离子通道的动物细胞质膜计算钾离子、钠离子和氯离子通量。正常与凋亡]

[Computation of the K+, Na+ and Cl- fluxes through plasma membrane of animal cell with Na+/K+ pump, NKCC, NC cotransporters, and ionic channels with and without non-Goldman rectification in K+ channels. Norma and apoptosis].

作者信息

Rubashkin A A, Iurinskaia V E, Vereninov A A

出版信息

Tsitologiia. 2010;52(7):568-73.

PMID:20799622

Abstract

The balance of K+, Na+ and Cl- fluxes through cell membrane with the Na+/K+ pump, ion channels and NKCC and NC cotransporters is considered. It is shown that all unidirectional K+, Na+ and Cl- fluxes through cell membrane, permeability coefficients of ion channels and membrane potential can be computed for balanced ion distribution between cell and the medium if K+, Na+ and Cl- concentration in cell water and three fluxes are known: total Cl- flux, total K+ influx and ouabain-inhibitable "pump" component of the K+ influx. Changes in the mortovalent ion balance in lymphoid cells U937 induced to apoptosis by 1 microM staurosporine are analyzed as an example. It is found that the apoptotic shift in ion and water balance in studied cells is caused by a decrease in the pump activity which is accompanied by a decrease in the integral permeability of Na+ channels without significant increase in K+ and Cl- channel permeabilities. Computation shows that only a small part of the total fluxes of K+, Na+ and Cl- accounts for the fluxes via NKCC and NC cotransporters. Therefore, cotransport fluxes can not be studied using inhibitors.

摘要

考虑了通过细胞膜的K⁺、Na⁺和Cl⁻通量与Na⁺/K⁺泵、离子通道以及NKCC和NC共转运体之间的平衡。结果表明，如果已知细胞内水的K⁺、Na⁺和Cl⁻浓度以及三种通量：总Cl⁻通量、总K⁺内流和哇巴因抑制的K⁺内流的“泵”成分，那么对于细胞与介质之间平衡的离子分布，可以计算通过细胞膜的所有单向K⁺、Na⁺和Cl⁻通量、离子通道的渗透系数和膜电位。以1微摩尔星形孢菌素诱导淋巴样细胞U937凋亡时单价离子平衡的变化为例进行分析。结果发现，所研究细胞中离子和水平衡的凋亡转变是由泵活性降低引起的，同时伴随着Na⁺通道整体通透性降低，而K⁺和Cl⁻通道通透性没有显著增加。计算表明，K⁺、Na⁺和Cl⁻总通量中只有一小部分是通过NKCC和NC共转运体的通量。因此，不能使用抑制剂来研究共转运通量。