Chloride channels in the apical membrane of cortical collecting duct cells.
Chloride channels in the apical membrane of cortical collecting duct cells.
复制标题
皮质集合管细胞顶膜中的氯离子通道。
DOI：
10.1152/ajprenal.1990.258.2.f273
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Stanton,BA
中科院分区：
文献类型：
--
作者：
Light,DB;Schwiebert,EM;Fejes-Toth,G;Naray-Fejes-Toth,A;Karlson,KH;McCann,FV;Stanton,BA
Ion channels in the apical membrane of cortical collecting duct (CCD) cells in culture were studied by the patch-clamp technique. CCD cells from rabbit kidney were isolated by solid-phase immunoadsorption with a monoclonal antibody. The majority of CCD cells (93%) had phenotypic characteristics similar to intercalated cells (ICC). Although Cl- channels were present in the apical membrane of the ICC cells, they were rarely active in cell-attached patches; however, channels were activated after patch excision. In inside-out patches, the channels exhibited rapid flickering, substrates, and large unitary currents. The single-channel conductance was 303 pS, the Cl(-)-to-Na+ permeability ratio was 10:1 and the Cl(-)-to-HCO3- permeability ratio was 1.5:1. The channel was inhibited by the Cl- channel blockers 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid, diphenylamine carboxylic acid, and 5-nitro-2-(3-phenylpropylamino)-benzoic acid. Although a reduction in the cytoplasmic Ca2+ concentration inhibited channel activity in both inside-out patches and cell-attached patches, alterations of Ca2+ within the physiological range did not change the channel open probability. Finally, changing the cytoplasmic pH (6.5 to 8.0) did not alter the open probability. Thus a large conductance anion channel is present in the apical membrane of CCD cells in culture. This channel may be involved in cell volume regulation or in Cl- and HCO3- secretion.
