Cyclic nucleotide-gated cation channels mediate sodium absorption by IMCD (mIMCD-K2) cells.
Cyclic nucleotide-gated cation channels mediate sodium absorption by IMCD (mIMCD-K2) cells.
复制标题
环状核苷酸门控阳离子通道介导 IMCD (mIMCD-K2) 细胞的钠吸收。
DOI：
10.1152/ajpcell.1997.272.3.c901
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Stanton,BA
中科院分区：
文献类型：
--
作者：
Vandorpe,DH;Ciampolillo,F;Green,RB;Stanton,BA
The inner medullary collecting duct cell line, mIMCD-K2, absorbs Na+ by an amiloride-sensitive, electrogenic mechanism. The goal of the present study was to characterize the amiloride-sensitive, Na+ -conducting channels responsible for electrogenic Na+ absorption. To this end, we measured Na+ currents in single cells with the patch-clamp technique and Na+ currents across monolayers mounted in Ussing-type chambers. In whole cell patch-clamp experiments, amiloride-sensitive, inward Na+ currents were mediated by nonselective cation channels. In single-channel patch-clamp experiments, amiloride- and guanosine 3',5'-cyclic monophosphate (cGMP)-sensitive, 20-pS nonselective cation channels (i.e., CNG channels) were identified in the apical membrane. CNG channels were inhibited by amiloride, diltiazem, ethylisopropylamiloride (EIPA), and 8-bromo-cGMP and were permeable to Ca2+ and Mg2+. Epithelial Na+ channels were never observed in whole cell or single-channel recordings. Na+ absorption across confluent monolayers was inhibited with a rank order potency of benzamil > amiloride > phenamil >> EIPA > diltiazem. Our data are most consistent with the view that CNG channels mediate electrogenic Na+ absorption across mIMCD-K2 cells.
