CFTR expression but not Cl- transport is involved in the stimulatory effect of bile acids on apical Cl-/HCO3- exchange activity in human pancreatic duct cells.
Pancreas 2009;
38:921-9. [PMID:
19752774 DOI:
10.1097/mpa.0b013e3181b65d34]
[Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
OBJECTIVES
Low doses of chenodeoxycholate (CDC) stimulate apical anion exchange and HCO3(-) secretion in guinea pig pancreatic duct cells (Gut. 2008;57:1102-1112). We examined the effects of CDC on intracellular pH (pHi), intracellular Ca(2+) concentration ([Ca(2+)]i), and apical Cl(-)/HCO3(-) exchange activity in human pancreatic duct cells and determined whether any effects were dependent on cystic fibrosis transmembrane conductance regulator (CFTR) expression and Cl(-) channel activity.
METHODS
Polarized CFPAC-1 cells (expressing F508del CFTR) were transduced with Sendai virus constructs containing complementary DNAs for either wild-type CFTR or beta-galactosidase. Microfluorimetry was used to record pHi and [Ca(2+)]i and apical Cl(-)/HCO3(-) exchange activity. Patch clamp experiments were performed on isolated guinea pig duct cells.
RESULTS
Chenodeoxycholate induced a dose-dependent intracellular acidification and a marked increase in [Ca(2+)]i in CFPAC-1 cells. CFTR expression slightly reduced the rate of acidification but did not affect the [Ca(2+)]i changes. Luminal administration of 0.1 mmol/L of CDC significantly elevated apical Cl(-)/HCO3(-) exchange activity but only in cells that expressed CFTR. However, CDC did not activate CFTR Cl(-) conductance.
CONCLUSIONS
Bile salts modulate pHi, [Ca(2+)]i, and apical anion exchange activity in human pancreatic duct cells. The stimulatory effect of CDC on anion exchangers requires CFTR expression but not CFTR channel activity.
Collapse