Hwang T H, Lee H J, Lee N K, Choi Y C
Department of Pharmacology & Science Institute of Medicine, Dong-A Medical College, Pusan, South Korea 602-103.
J Membr Biol. 2000 Aug 1;176(3):217-21. doi: 10.1007/s00232001091.
The rat primary cultured-airway monolayer had been an excellent model for deciphering the ion channel after nystatin permeabilization of its basolateral or apical membrane (Hwang et al., 1996). After apical membrane permeabilization of rat primary cultured-airway monolayer, 4,4'-diisothiocyanatostilbene-2, 2'-disulfonic acid (DIDS)-sensitive outwardly rectifying depolarization-induced Cl(-) (BORDIC) currents were observed across the basolateral membrane in symmetrical NMG-Cl solution in this study. No significant Cl(-) current induced by the application of voltage clamping was observed across the apical membrane in symmetrical NMG-Cl solution after basolateral membrane permeabilization. The halide permeability sequence for BORDIC current was Br(-) = I(-) > Cl(-). BORDIC current was not affected by basolaterally applied bumetanide (0.5 mm). Basolateral DIDS (0.2 mm) but not apical DIDS inhibited CFTR mediated short-circuit current (I(sc)) in an intact monolayer of rat airway epithelia, a T84 human colonal epithelial cell line, and a Calu-3 human airway epithelial cell line. This is the first report showing that depolarization induced Cl(-) current is present on the basolateral membrane of airway epithelia.
大鼠原代培养气道单层细胞一直是在制霉菌素使其基底外侧或顶端膜通透后用于解析离子通道的优秀模型（Hwang等人，1996年）。在大鼠原代培养气道单层细胞的顶端膜通透后，本研究在对称的NMG-Cl溶液中观察到跨基底外侧膜的4,4'-二异硫氰基芪-2,2'-二磺酸（DIDS）敏感的外向整流去极化诱导的Cl⁻（BORDIC）电流。在基底外侧膜通透后，在对称的NMG-Cl溶液中未观察到通过电压钳施加诱导的跨顶端膜的显著Cl⁻电流。BORDIC电流的卤化物通透性顺序为Br⁻ = I⁻ > Cl⁻。BORDIC电流不受基底外侧施加的布美他尼（0.5 mM）影响。基底外侧DIDS（0.2 mM）而非顶端DIDS抑制大鼠气道上皮细胞、T84人结肠上皮细胞系和Calu-3人气道上皮细胞系完整单层中的CFTR介导的短路电流（Isc）。这是首次报道显示去极化诱导的Cl⁻电流存在于气道上皮细胞的基底外侧膜上。
