Slegers J F, Moons W M, Idzerda P P, Stadhouders A M
J Membr Biol. 1975;25(3-4):213-36. doi: 10.1007/BF01868576.
Chloride movement across the wall of the rabbit submaxillary duct has been studied. It was shown that the chloride diffusion from blood to luminal side was determined primarily by the existing transmucosal potential difference. From the fact that the ouabain-poisoned duct showed symmetrical behavior with respect to the chloride diffusion potentials in both directions and the fact that the measured chloride flux behaved as predicted according to the Goldman equation, it was suggested that a single barrier, rather than a series membrane system, determined the chloride movement. The permeability coefficients for chloride, in the order of 5.5 x 10(-5) cm sce-1 are much larger than would be expected for cell membranes. These findings in combination with the observations that mannitol permeability is higher during chloride perfusion than during sulfate perfusion and the observed electron-microscopic changes favor the concept of the existence of an extracellular route in chloride diffusion. An equivalent electrical circuit is given in order to evaluate the contribution of the chloride shunt more quantitatively. Calculations showed that the ductal resistivity during sulfate perfusion has a value in the order of 434 omega cm2, while during chloride perfusion this value is lowered to 48 omega cm2, indicating that the ductal wall can change from a tight to a leaky epithelium. The implications of these findings are discussed.
对兔下颌下腺导管壁上氯离子的移动进行了研究。结果表明，氯离子从血液向管腔侧的扩散主要由现有的跨粘膜电位差决定。基于哇巴因中毒的导管在两个方向上对氯离子扩散电位表现出对称行为这一事实，以及所测得的氯离子通量符合根据戈德曼方程预测的情况，有人提出是单一屏障而非串联膜系统决定了氯离子的移动。氯离子的渗透系数约为5.5×10⁻⁵ cm s⁻¹，比细胞膜预期的要大得多。这些发现与以下观察结果相结合：在氯离子灌注期间甘露醇的渗透率高于硫酸盐灌注期间，以及观察到的电子显微镜变化，支持了氯离子扩散中存在细胞外途径这一概念。给出了一个等效电路，以便更定量地评估氯离子分流的作用。计算表明，硫酸盐灌注期间导管电阻值约为434Ω cm²，而氯离子灌注期间该值降至48Ω cm²，表明导管壁可从紧密上皮转变为渗漏上皮。讨论了这些发现的意义。
