Sanders S S, Shoemaker R L, Rehm W S
Am J Physiol. 1977 Oct;233(4):E298-307. doi: 10.1152/ajpendo.1977.233.4.E298.
It has been previously shown that a) thiocyanate (15 mM) inhibits H+ secretion and increases the resistance and potential difference (PD) which is explained on the basis of separate electrogenic mechanisms for H+ and Cl- and b) barium (1 mM) added to the nutrient side produces a large increase in the resistance and little change in the H+ rate and PD, and the site of the increased resistance is the nutrient membrane of the tubular cells. In the present paper we show that a) with Ba2+ on the nutrient side, addition of thiocyanate to the secretory side decreases the H+ rate to about zero and also decreases the resistance; and b) if the site of the decrease in resistance is the secretory membrane of the tubular cells, in which the HCl is produced, then these findings would be contrary to the predictions on the basis of the electrogenic theory. However, the transmucosal resistance is a function of the resistance across the surface epithelial cells and the resistance of the secretory and nutrient membranes of the tubular cells. With a 79 mM K+ pulse technique, the findings indicate that the resistance of the secretory membrane increases, and the decrease in the resistance is due to changes in the resistance of the surface cells and/or the nutrient membrane of the tubular cells.
a) 硫氰酸盐（15 mM）会抑制H⁺分泌，并增加电阻和电位差（PD），这是基于H⁺和Cl⁻各自的电生机制来解释的；b) 添加到营养侧的钡（1 mM）会使电阻大幅增加，而H⁺分泌速率和PD变化不大，且电阻增加的部位是肾小管细胞的营养膜。在本文中我们表明：a) 在营养侧存在Ba²⁺的情况下，向分泌侧添加硫氰酸盐会使H⁺分泌速率降至约零，同时也会降低电阻；b) 如果电阻降低的部位是产生HCl的肾小管细胞的分泌膜，那么这些发现将与基于电生理论的预测相反。然而，跨黏膜电阻是表面上皮细胞的电阻以及肾小管细胞分泌膜和营养膜电阻的函数。采用79 mM K⁺脉冲技术，研究结果表明分泌膜的电阻增加，电阻降低是由于表面细胞和/或肾小管细胞营养膜的电阻变化所致。
