CFTR-Mediated anion conductance regulates Na(+)-K(+)-pump activity in Calu-3 human airway cells

Biochem Biophys Res Commun. 2000 Jul 21;274(1):230-5. doi: 10.1006/bbrc.2000.3125.

Abstract

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(-)(3) 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / pharmacology
  • 8-Bromo Cyclic Adenosine Monophosphate / pharmacology
  • Anions / metabolism*
  • Bronchi / cytology*
  • Calcium Channel Blockers / pharmacology
  • Cell Line
  • Cystic Fibrosis Transmembrane Conductance Regulator / metabolism*
  • Electrophysiology
  • Glyburide / pharmacology
  • Humans
  • Ionophores / pharmacology
  • Nitrobenzoates / pharmacology
  • Nystatin / pharmacology
  • Ouabain / pharmacology
  • Sodium / metabolism
  • Sodium-Potassium-Exchanging ATPase / drug effects
  • Sodium-Potassium-Exchanging ATPase / metabolism*
  • Stilbenes / pharmacology
  • Time Factors
  • ortho-Aminobenzoates / pharmacology

Substances

  • Anions
  • CFTR protein, human
  • Calcium Channel Blockers
  • Ionophores
  • Nitrobenzoates
  • Stilbenes
  • ortho-Aminobenzoates
  • Cystic Fibrosis Transmembrane Conductance Regulator
  • Nystatin
  • 8-Bromo Cyclic Adenosine Monophosphate
  • 5-nitro-2-(3-phenylpropylamino)benzoic acid
  • Ouabain
  • 4,4'-dinitro-2,2'-stilbenedisulfonic acid
  • fenamic acid
  • Sodium
  • Sodium-Potassium-Exchanging ATPase
  • 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid
  • Glyburide