Chloride currents in primary cultures of rabbit proximal and distal convoluted tubules
Chloride currents in primary cultures of rabbit proximal and distal convoluted tubules
复制标题
DOI：
10.1152/ajprenal.1998.275.5.f651
复制
发表时间：
1998-11-01
影响因子：
4.2
通讯作者：
Poujeol, P
中科院分区：
文献类型：
--
作者：
Rubera, I;Tauc, M;Poujeol, P
对培养的兔近端曲管(PCT)上皮细胞的CL-电导进行了研究，并与培养的远端明亮曲管(DCTB)上皮细胞的CL-电导进行了比较。应用全细胞膜片钳技术，在DCTb培养细胞中鉴定出三种类型的氯离子电导。这些电流包括容量敏感的、钙激活的和Forsklin激活的氯离子电流。在PCT培养细胞中，仅记录到容量敏感和钙激活的氯电流。PCT细胞的钙激活电流特征与DCTb细胞非常相似。低渗应激可在PCT和DCTb细胞中诱发体积敏感性氯电流。建立了这两种细胞类型的这种电导的药理学特征。Forskolin可激活DCTb细胞的线性氯电流，但不能激活PCT细胞的线性氯电流。这种电导对DDS不敏感，与囊性纤维化跨膜电导调节器(CFTR)样通道相对应。SPQ荧光定量测量表明，只有DCTb细胞的顶膜具有对Forsklin敏感的氯离子途径。RT-PCR实验显示CFTRmRNA在两种培养细胞中都存在，而免疫染色实验显示CFTRmRNA仅在DCTb细胞中表达。讨论了不同类型通道的生理作用。
Cl- conductances were studied in cultured rabbit proximal convoluted tubule (PCT) epithelial cells and compared with those measured in cultured distal bright convoluted tubule (DCTb) epithelial cells. Using the whole cell patch-clamp technique, three types of Cl- conductances were identified in DCTb cultured cells. These consisted of volume-sensitive, Ca2+-activated, and forskolin-activated Cl- currents. In PCT cultured cells, only volume-sensitive and Ca2+-activated Cl- currents were recorded. The characteristics of Ca2+-activated currents in PCT cells closely resembled those in DCTb cells. Volume-sensitive Cl- currents could be elicited both in PCT and in DCTb cells by hypotonic stress. The pharmacological profile of this conductance was established for both cell types. Forskolin activated a linear Cl- current in DCTb cells but not in PCT cells. This conductance was insensitive to DIDS and corresponds to cystic fibrosis transmembrane conductance regulator (CFTR)-like channels. Quantitative measurements of SPQ fluorescence showed that only the apical membrane of DCTb cells possessed a Cl- pathway that was sensitive to forskolin. RT-PCR experiments showed the presence of CFTR mRNA in both cultures, whereas immunostaining experiments revealed the expression of CFTR in DCTb cells only. The physiological role of the different types of channels is discussed.