Reuss L, Costantin J L, Bazile J E
Am J Physiol. 1987 Jul;253(1 Pt 1):C79-89. doi: 10.1152/ajpcell.1987.253.1.C79.
Intracellular microelectrode techniques were employed to study the effects of diphenylamine-2-carboxylate (DPC) on ion transport in Necturus gallbladder epithelium. Under control conditions, addition of DPC to the mucosal bathing solution caused a concentration-dependent, reversible hyperpolarization of both cell membranes with no measurable resistance changes. In addition, DPC caused the following effects, all consistent with inhibition of apical membrane Cl(-)-HCO3- exchange: fall in intracellular Cl- activity (aCli), increase in intracellular pH (pHi), reduction of the changes in aCli and pHi produced by lowering mucosal solution [Cl-], and reduction of the change in pHi produced by lowering mucosal solution [HCO3-]. Similar studies in theophylline-treated preparations indicate that DPC also inhibits anion exchange under these conditions, but has no effect on the apical membrane electrodiffusive Cl- permeability induced by cyclic AMP. Under these conditions, DPC caused cell membrane hyperpolarization but had no effect on the apparent ratio of membrane resistances. In addition, DPC had no effects on the rapid changes in apical membrane voltage elicited by altering mucosal [Cl-], but caused significant reductions of the slower, secondary voltage changes observed in response to changes in mucosal [Cl-], and the changes in aCli and pHi produced by lowering mucosal [Cl-]. Because others have demonstrated that DPC blocks Cl- channels in other epithelia (Distefano, A., M. Wittner, E. Schlatter, H. J. Lang, H. Englert, and R. Greger. Diphenylamine-2-carboxylate, a blocker of the Cl(-)-conductive pathway in Cl(-)-transporting epithelia. Pfluegers++ Arch. 405: S95-S100, 1985), it is possible that the structures of those channels and that induced by cyclic AMP in Necturus gallbladder are different. Because of its relatively high affinity and rapid reversibility, DPC may become useful in studies of anion exchange in other cells.
采用细胞内微电极技术研究二苯胺 -2 - 羧酸盐（DPC）对美西螈胆囊上皮细胞离子转运的影响。在对照条件下，向黏膜浴液中添加DPC会导致两个细胞膜出现浓度依赖性、可逆性超极化，且电阻无明显变化。此外，DPC还产生了以下效应，所有这些效应均与抑制顶端膜Cl⁻ - HCO₃⁻交换一致：细胞内Cl⁻活性（aCli）下降、细胞内pH（pHi）升高、降低黏膜溶液[Cl⁻]所引起的aCli和pHi变化减小，以及降低黏膜溶液[HCO₃⁻]所引起的pHi变化。在茶碱处理的标本中进行的类似研究表明，在这些条件下DPC也抑制阴离子交换，但对环磷酸腺苷诱导的顶端膜电扩散Cl⁻通透性无影响。在这些条件下，DPC导致细胞膜超极化，但对膜电阻的表观比值无影响。此外，DPC对改变黏膜[Cl⁻]所引起的顶端膜电压快速变化无影响，但能显著降低响应黏膜[Cl⁻]变化所观察到的较慢的二次电压变化，以及降低降低黏膜[Cl⁻]所引起的aCli和pHi变化。因为其他人已证明DPC可阻断其他上皮细胞中的Cl⁻通道（Distefano, A., M. Wittner, E. Schlatter, H. J. Lang, H. Englert, and R. Greger. Diphenylamine -2 - carboxylate, a blocker of the Cl⁻ - conductive pathway in Cl⁻ - transporting epithelia. Pfluegers++ Arch. 405: S95 - S100, 1985），所以有可能这些通道的结构与美西螈胆囊中由环磷酸腺苷诱导的通道结构不同。由于其相对较高的亲和力和快速可逆性，DPC可能在其他细胞的阴离子交换研究中变得有用。
