Rückes-Nilges C, Weber U, Lindemann H, Münker G, Clauss W, Weber W M
CF Working Group Giessen, Justus Liebig University, Giessen, Belgium.
Cell Physiol Biochem. 1999;9(1):1-10. doi: 10.1159/000016298.
Na+ and Cl- currents were studied in primary cultures of human nasal epithelium derived from non-cystic fibrosis (non-CF) and cystic fibrosis (CF) patients. We found that Na+ absorption dominates transepithelial transport and the Na+ current contains an amiloride-sensitive and amiloride-insensitive component. In non-CF tissue both components contribute about equally to the entire short-circuit current (ISC), whereas in CF tissues the major part of the current is amiloride-sensitive. Na+ removal reduced ISC to values close to zero. Several Cl- channel blockers were used to identify the remaining tiny Na+-independent current. Under unstimulated, physiological conditions in the presence of Cl- on both sides and amiloride on the apical side of the epithelium diphenylamine-2-carboxic acid (DPC), 4,4'-diisothiocyanatostilbene-2, 2'- disulfonic acid (DIDS) and 5-nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB) failed to induce clearcut inhibition of ISC. cAMP as well as ATP did not affect ISC either in CF or in non-CF epithelia. Reduction of apical Cl- increased ISC and depolarized transepithelial potential; however, the observed increase was insensitive to DIDS, DPC and NPPB. From these data we conclude that Cl- conductances in primary cultures of human nasal epithelium derived from CF patients as well as from non-CF patients are present only in low numbers or do not contribute significantly to transepithelial ion transport.
我们对来自非囊性纤维化（non-CF）和囊性纤维化（CF）患者的人鼻上皮原代培养物中的钠离子（Na⁺）和氯离子（Cl⁻）电流进行了研究。我们发现，Na⁺吸收在跨上皮运输中占主导地位，并且Na⁺电流包含一个对氨氯地平敏感和不敏感的成分。在非CF组织中，这两个成分对整个短路电流（ISC）的贡献大致相等，而在CF组织中，电流的主要部分对氨氯地平敏感。去除Na⁺可使ISC降低至接近零的值。我们使用了几种Cl⁻通道阻滞剂来识别剩余的微小非Na⁺依赖性电流。在未受刺激的生理条件下，上皮细胞两侧存在Cl⁻且顶端侧存在氨氯地平，二苯胺-2-羧酸（DPC）、4,4'-二异硫氰酸根合芪-2,2'-二磺酸（DIDS）和5-硝基-2-（3-苯丙基氨基）苯甲酸（NPPB）未能明显抑制ISC。环磷酸腺苷（cAMP）以及三磷酸腺苷（ATP）在CF或非CF上皮细胞中均不影响ISC。降低顶端Cl⁻会增加ISC并使跨上皮电位去极化；然而，观察到的增加对DIDS、DPC和NPPB不敏感。从这些数据我们得出结论，来自CF患者以及非CF患者的人鼻上皮原代培养物中的Cl⁻电导数量很少，或者对跨上皮离子运输的贡献不大。
