在净电荷转移条件下测量的人红细胞阴离子通透性。

Human erythrocyte anion permeabilities measured under conditions of net charge transfer.

Hunter M J

J Physiol. 1977 Jun;268(1):35-49. doi: 10.1113/jphysiol.1977.sp011845.

Abstract

The permeability of the human erythrocyte to anions has been measured under conditions of net charge transfer: for Cl(-) and HCO(3) (-) ions, at 37 degrees C, this permeability is 5 orders of magnitude too small to account for the rate of the electroneutral anion exchange which is responsible for the chloride, or Hamburger, shift.2. The method is an indirect one in which the ionophore, valinomycin, is used to increase the erythrocyte K(+) permeability: in the absence of permeant cation externally, the rate of the resulting K(+) efflux may be limited by the slowness of the accompanying anion efflux, allowing the true anion permeability to be estimated.3. The average Cl(-) permeability estimated in ACD-stored erythrocytes (seven experiments) and erythrocytes from fresh blood (two experiments) was 2.1 x 10(-8) cm/sec at 37 degrees C and pH 7.4: this may also be expressed as a Cl(-) conductance of about 1.0 x 10(-5) Omega(-1) cm(-2). The apparent activation energy for net efflux of Cl(-) was found to be 3.9 kJ/mole (16.4 kcal/mole).4. In fresh cells, the ratios of Cl(-), HCO(3) (-), Br(-) and I(-) permeabilities (or conductances) were 1:0.8:1.5:5. The three halide ions follow Eisenman's Sequence I, representing a binding site of low field strength.

摘要

已在净电荷转移条件下测量了人类红细胞对阴离子的通透性：对于Cl⁻和HCO₃⁻离子，在37℃时，这种通透性太小，比负责氯化物或汉堡转移的电中性阴离子交换速率低5个数量级。
该方法是一种间接方法，其中使用离子载体缬氨霉素来增加红细胞对K⁺的通透性：在外部不存在渗透性阳离子的情况下，由此产生的K⁺外流速率可能受到伴随的阴离子外流缓慢的限制，从而可以估计真正的阴离子通透性。
在ACD储存的红细胞（七个实验）和新鲜血液中的红细胞（两个实验）中估计的平均Cl⁻通透性在37℃和pH 7.4时为2.1×10⁻⁸ cm/sec：这也可以表示为约1.0×10⁻⁵ Ω⁻¹ cm⁻²的Cl⁻电导率。发现Cl⁻净外流的表观活化能为3.9 kJ/摩尔（16.4 kcal/摩尔）。
在新鲜细胞中，Cl⁻、HCO₃⁻、Br⁻和I⁻的通透性（或电导率）之比为1:0.8:1.5:5。三种卤离子遵循艾森曼序列I，代表低场强的结合位点。