Linsdell P, Hanrahan J W
Department of Physiology, McGill University, Montréal, Québec, Canada H3G 1Y6.
Am J Physiol. 1998 Jul;275(1):C323-6. doi: 10.1152/ajpcell.1998.275.1.C323.
The cystic fibrosis transmembrane conductance regulator (CFTR) forms an ion channel that is permeable both to Cl- and to larger organic anions. Here we show, using macroscopic current recording from excised membrane patches, that the anionic antioxidant tripeptide glutathione is permeant in the CFTR channel. This permeability may account for the high concentrations of glutathione that have been measured in the surface fluid that coats airway epithelial cells. Furthermore, loss of this pathway for glutathione transport may contribute to the reduced levels of glutathione observed in airway surface fluid of cystic fibrosis patients, which has been suggested to contribute to the oxidative stress observed in the lung in cystic fibrosis. We suggest that release of glutathione into airway surface fluid may be a novel function of CFTR.
囊性纤维化跨膜传导调节因子（CFTR）形成一种离子通道，该通道对氯离子和较大的有机阴离子均具有通透性。在此，我们通过对切除的膜片进行宏观电流记录表明，阴离子抗氧化三肽谷胱甘肽在CFTR通道中具有通透性。这种通透性可能解释了在覆盖气道上皮细胞的表面液体中所测得的高浓度谷胱甘肽。此外，这种谷胱甘肽转运途径的丧失可能导致囊性纤维化患者气道表面液体中谷胱甘肽水平降低，而这被认为与囊性纤维化患者肺部所观察到的氧化应激有关。我们认为，谷胱甘肽释放到气道表面液体中可能是CFTR的一种新功能。
