Chen J S, Walser M
J Membr Biol. 1976 Jun 30;27(4):381-91. doi: 10.1007/BF01869147.
Bidirectional sodium fluxes across toad bladder were measured after eliminating active transport with ouabain. Mucosal sodium concentration, Cm, was progressively reduced (from 114 to 3 mM) while serosal sodium remained constant. Potential difference was maintained at zero by current passage. The ratio, Q, of the bulk permeability coefficient for sodium, P, to the tracer sodium permeability coefficient, P, was found to remain constant as Cm decreased. Equations were derived on this basis for bidirectional fluxes and for P and P as functions of Cm, which corresponded closely to the observed data. The explanation for the observed value of Q and its constancy under these conditions is uncertain.
在用哇巴因消除主动转运后，测量了蟾蜍膀胱两侧的双向钠通量。黏膜钠浓度（Cm）逐渐降低（从114 mM降至3 mM），而浆膜钠浓度保持恒定。通过通电流将电位差维持在零。发现钠的总体通透系数（P）与示踪钠通透系数（P）之比（Q）在Cm降低时保持恒定。在此基础上推导出了双向通量以及P和P作为Cm函数的方程，这些方程与观测数据密切相符。对于在这些条件下Q的观测值及其恒定性的解释尚不确定。
