Deletion of Slc26a6 alters the stoichiometry of apical Cl~-/HCO_3~- exchange in mouse pancreatic duct

摘要

It is now generally accepted that in epithelial tissues, including pancreatic duct, apical Cl~-/HCO3_3~- exchange is mediated by members of the SLC26 family of anion transporters (19). Although SLC26A3, SLC26A6, and SLC26A11 have all been identified in pancreatic duct cells (7, 24), there is evidence to suggest that SLC26A6 normally mediates the majority of the Cl~-/HCO_3~- exchange occurring at the apical membrane. This is because 1) the apical CP/HCO3_3~- exchanger, like SLC26A6 but not SLC26A3, is inhibited by dihydro-4,4'-diisothiocyanatos-tilbene-2,2'-disulphonic acid (H_2DIDS; 200 muM; Refs. 4, 10, 25); 2) SLC26A6 and CFTR are colocalized at the apical membrane of rat intralobular ducts (15); and 3) HCO_3~- efflux upon removal of luminal Cl~- is significantly reduced in ducts isolated from Slc26a6-null mice (8).