CFTR-mediated anion conductance regulates Na+-K+-pump activity in Calu-3 human airway cells
CFTR-mediated anion conductance regulates Na+-K+-pump activity in Calu-3 human airway cells
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DOI：
10.1006/bbrc.2000.3125
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发表时间：
2000-07-21
影响因子：
3.1
通讯作者：
Yamaki, K
中科院分区：
文献类型：
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作者：
Ito, Y;Mizuno, Y;Yamaki, K
我们研究了 CFTR 在 Calu-3 人气道细胞 Na+-K+ 泵活性中的作用。为了估计基底外侧膜上的 Na+-K+ 泵活性，在用制霉菌素（一种 Na+ 离子载体）透化顶膜后测量短路电流（Isc）的哇巴因敏感分量。 Na+-K+-泵活性可被选择性CFTR阻滞剂（格列本脲）或非特异性Cl-通道抑制剂（NPPB和DPC）减弱，但不会被外向整流Cl-通道阻滞剂（DNDS、DIDS）减弱。 8-溴环 AMP (8Br-cAMP, 1 mM) 增强阴离子电导，增强了 Na+-K+ 泵活性，而 Na+-K+ 泵活性可通过阻断 CFTR 或用葡萄糖酸（一种膜渗透性较差的阴离子）替代 Cl- 来降低。 Na+-K+-泵活性不受用 NO 替代 Cl- 的影响，NO 具有相同的 CFTR 渗透性。这些结果表明，通过 CFTR 的阴离子运动可能通过调节 Na+ 进入的速率来促进 Calu-3 细胞中 Na+-K+ 泵的活性。 (C) 2000 年学术出版社。
We studied the role of CFTR in the Na+-K+-pump activity of Calu-3 human airway cells. To estimate the Na+-K+-pump activity on the basolateral membrane, the ouabain-sensitive component of the short-circuit current (Isc) was measured after permeabilization of the apical membrane with nystatin, a Na+ ionophore. The Na+-K+-pump activity was diminished by a selective CFTR blocker (glybenclamide) or nonspecific Cl- channel inhibitors (NPPB and DPC) but not by outwardly rectifying Cl- channel blockers (DNDS, DIDS). Augmentation of anion conductance by 8-bromo-cyclic AMP (8Br-cAMP, 1 mM) potentiated the Na+-K+-pump activity that was reduced by blocking CFTR or by the replacement of Cl- with gluconate, a less membrane-permeant anion. The Na+-K+-pump activity was unaffected by the replacement of Cl- with NO, that has equal permeability through the CFTR. These results suggest that the anion movement through the CFTR may contribute to the Na+-K+-pump activity in Calu-3 cells by regulating the rate of Na+ entry. (C) 2000 Academic Press.