Toggle Main Menu Toggle Search

Open Access padlockePrints

Cystic fibrosis transmembrane conductance regulator currents in guinea pig pancreatic duct cells: Inhibition by bicarbonate ions

Lookup NU author(s): Dr Catherine O'Reilly, Dr John Winpenny, Professor Barry Argent, Dr Michael Gray

Downloads

Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


Abstract

Background and Aims: Cystic fibrosis transmembrane conductance regulator (CFTR) CI- channels play an important role in HCO3- secretion by pancreatic duct cells (PDCs). Our aims were to characterize the CFTR conductance of guinea pig PDCs and to establish whether CFTR is regulated by HCO3-. Methods: PDCs were isolated from small intralobular and interlobular ducts, and their Cl- conductance was studied using the whole-cell patch clamp technique. Results: Activation of a typical CFTR conductance by adenosine 3',5'-cyclic monophosphate (cAMP) was observed in 114 of 204 cells (56%). A larger (10-fold), time- and voltage-dependent Cl- conductance was activated in 39 of 204 cells (19%). Secretin had a similar effect. Coexpression of both conductances in the same cell was observed, and both conductances had similar anion selectivity and pharmacology. Extracellular HCO3- caused a dose-dependent inhibition of both currents (K(j), ~7 mmol/L), which was independent of intracellular and extracellular pH, and the PCO2 and CO32- content of the bathing solutions. Conclusions: Two kinetically distinct Cl- conductances are activated by cAMP in7 guinea pig PDCs. Because these conductances are coexpressed and exhibit similar characteristics (anion selectivity, pharmacology, and HCO3- inhibition), we conclude that CFTR underlies them both. The inhibition of CFTR by HCO3- has implications for the current model of pancreatic ductal HCO3- secretion.


Publication metadata

Author(s): Winpenny JP; Gray MA; Argent BE; O'Reilly CM

Publication type: Article

Publication status: Published

Journal: Gastroenterology

Year: 2000

Volume: 118

Issue: 6

Pages: 1187-1196

ISSN (print): 0016-5085

ISSN (electronic): 1528-0012

Publisher: W. B. Saunders Co.

URL: http://dx.doi.org/10.1016/S0016-5085(00)70372-6

DOI: 10.1016/S0016-5085(00)70372-6

PubMed id: 10833494


Altmetrics

Altmetrics provided by Altmetric


Share