Langridge-Smith J E, Dubinsky W P
J Membr Biol. 1986;94(3):197-204. doi: 10.1007/BF01869715.
Experiments were performed to determine the factors which contribute to the transmembrane pH gradient (delta pH) and the potential gradient (delta psi) in apical plasma membrane vesicles isolated from bovine tracheal epithelium. As indicated by the accumulation of 14C-methylamine, the vesicles maintained a delta pH (inside acidic) which was dependent upon the external pH. The delta pH was also proportional to the ionic strength of the suspending medium, suggesting that the H+ distribution was dictated by a Donnan potential. Measurements of the distribution of 86Rb+ demonstrated an electrical potential gradient across the vesicle membrane, inside negative which was proportional to the medium ionic strength. delta pH changed in parallel with delta psi in response to a variety of imposed conditions. These results are compatible with the existence of a H+ conductance in the vesicle membrane. Thus the endogenous electrical and proton gradients may be manipulated and used as a general experimental tool to complement kinetic analysis in investigations of transport mechanisms using isolated vesicle preparations.
进行实验以确定影响从牛气管上皮分离的顶端质膜囊泡中跨膜pH梯度（ΔpH）和电位梯度（Δψ）的因素。如14C-甲胺的积累所示，囊泡维持了一个依赖于外部pH的ΔpH（内部呈酸性）。ΔpH也与悬浮介质的离子强度成正比，这表明H+的分布由唐南电位决定。86Rb+分布的测量表明，跨囊泡膜存在电位梯度，内部为负，且与介质离子强度成正比。在各种施加条件下，ΔpH与Δψ平行变化。这些结果与囊泡膜中存在H+电导相一致。因此，内源性的电梯度和质子梯度可以被操纵，并用作一种通用的实验工具，以补充在使用分离囊泡制剂研究转运机制时的动力学分析。
