CFTR-dependent Cl− secretion in Xenopus laevis lung epithelium

Basolateral Cl−uptake mechanisms in Xenopus laevis lung epithelium

“…Neither under basal conditions nor with secretagogues (chlorzoxazone and forskolin) did we find evidence for the functional involvement of the NKCC in Cl Ϫ secretion. On the one hand, this finding contrasts with studies describing that chlorzoxazone (1,38,39) and/or forskolin (1, 33) activates apical Cl Ϫ secretion and that this effect was sensitive to bumetanide/furosemide, which is a hallmark for the participation of the NKCC (18). On the other hand, similar findings were reported from mouse trachea (16).…”

“…In a prior study the ability of the Xenopus lung epithelium for Cl Ϫ secretion has been shown, including the expression and function of the CFTR in the Xenopus lung (39). Secretion of Cl Ϫ via apical Cl Ϫ channels must involve basolateral uptake mechanisms for Cl Ϫ ions.…”

Mechanical Forces Impair Alveolar Ion Transport Processes – A Putative Mechanism Contributing to the Formation of Pulmonary Edema

“…In the airways it is well accepted that Cl -is secreted via luminal Cl -channels (Smith et al, 1982;Willumsen et al, 1989;Chambers et al, 2007). However the particular role of Cl -channels Cl -in alveolar epithelial cells remains unclear since there is evidence that Cl -is secreted (McCray et al, 1993;Tizzano et al, 1994;Lazrak et al, 2002;Sommer et al, 2007), as well as absorbed (Fang et al, 2002;Fang et al, 2006). There are at least two different Cl -channels identified in the apical membrane of pulmonary epithelial cells -the Ca 2+ dependent Cl -channel (TMEM16a) (Caputo et al, 2008;Schroeder et al, 2008;Yang et al, 2008) and the cAMP dependent CFTR Cl -channel (Riordan et al, 1989;Welsh and Smith, 1993).…”

Lung Diseases - Selected State of the Art Reviews

“…In the airways it is well accepted that Cl -is secreted via luminal Cl -channels (Smith et al, 1982;Willumsen et al, 1989;Chambers et al, 2007). However the particular role of Cl -channels Cl -in alveolar epithelial cells remains unclear since there is evidence that Cl -is secreted (McCray et al, 1993;Tizzano et al, 1994;Lazrak et al, 2002;Sommer et al, 2007), as well as absorbed (Fang et al, 2002;Fang et al, 2006). There are at least two different Cl -channels identified in the apical membrane of pulmonary epithelial cells -the Ca 2+ dependent Cl -channel (TMEM16a) (Caputo et al, 2008;Schroeder et al, 2008; and the cAMP dependent CFTR Cl -channel (Riordan et al, 1989;Welsh and Smith, 1993).…”

“…Most important, the Xenopus pneumocytes expose a Na + reabsorptive phenotype (Fischer et al, 1989;Kim, 1990;Fronius et al, 2003). In addition, expression and function of the CFTR Cl -channel has been detected (Sommer et al, 2007). Recent studies identified the presence of the Na + /K + /2Cl -cotransporter, the function of a HCO 3 -/Cl -exchanger (Berger et al, 2010) and evidence for basolateral Cl -channels (Berger et al, 2011).…”