Format

Send to

Choose Destination
See comment in PubMed Commons below
J Clin Invest. 2001 Dec;108(12):1807-16.

Cellular bicarbonate protects rat duodenal mucosa from acid-induced injury.

Author information

1
Greater Los Angeles Veterans Affairs Healthcare System, University of California, Los Angeles, Los Angeles, California 90073, USA.

Abstract

Secretion of bicarbonate from epithelial cells is considered to be the primary mechanism by which the duodenal mucosa is protected from acid-related injury. Against this view is the finding that patients with cystic fibrosis, who have impaired duodenal bicarbonate secretion, are paradoxically protected from developing duodenal ulcers. Therefore, we hypothesized that epithelial cell intracellular pH regulation, rather than secreted extracellular bicarbonate, was the principal means by which duodenal epithelial cells are protected from acidification and injury. Using a novel in vivo microscopic method, we have measured bicarbonate secretion and epithelial cell intracellular pH (pH(i)), and we have followed cell injury in the presence of the anion transport inhibitor DIDS and the Cl(-) channel inhibitor, 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB). DIDS and NPPB abolished the increase of duodenal bicarbonate secretion following luminal acid perfusion. DIDS decreased basal pH(i), whereas NPPB increased pH(i); DIDS further decreased pH(i) during acid challenge and abolished the pH(i) overshoot over baseline observed after acid challenge, whereas NPPB attenuated the fall of pH(i) and exaggerated the overshoot. Finally, acid-induced epithelial injury was enhanced by DIDS and decreased by NPPB. The results support the role of intracellular bicarbonate in the protection of duodenal epithelial cells from luminal gastric acid.

PMID:
11748264
PMCID:
PMC209463
DOI:
10.1172/JCI12218
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for American Society for Clinical Investigation Icon for PubMed Central
    Loading ...
    Support Center