Na+-dependent HCO3- import by the slc4a10 gene product involves Cl- export.

ABSTRACT: The slc4a10 gene encodes an electroneutral Na(+)-dependent HCO(3)(-) importer for which the precise mode of action remains unsettled. To resolve this issue, intracellular pH (pH(i)) recordings were performed upon acidification in the presence of CO(2)/HCO(3)(-) by 2',7'-bis(carboxyethyl)-5,6-carboxyfluorescein (BCECF) fluorometry of stably slc4a10-transfected NIH-3T3 fibroblasts. slc4a10 expression induced a significant Na(+)-dependent pH(i) recovery, which was accompanied by an increase in the intracellular Na(+) concentration evaluated by use of the Na(+)-sensitive fluorophore CoroNa Green. The estimated Na(+):HCO(3)(-) stoichiometry was 1:2. Cl(-) is most likely the counterion maintaining electroneutrality because (i) Na(+)-dependent pH(i) recovery was eliminated in Cl(-)-depleted cells

SUBMITTER: Damkier HH 

PROVIDER: S-EPMC2930699 | biostudies-literature | 2010 Aug

REPOSITORIES: biostudies-literature