Browse by author
Lookup NU author(s): Professor Adrian Allen
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
Secretion of bicarbonate into the adherent layer of mucus gel creates a pH gradient with a near-neutral pH at the epithelial surfaces in stomach and duodenum, providing the first line of mucosal protection against luminal acid. The continuous adherent mucus layer is also a barrier to luminal pepsin, thereby protecting the underlying mucosa from proteolytic digestion. In this article we review the present state of the gastroduodenal mucus bicarbonate barrier two decades after the first supporting experimental evidence appeared. The primary function of the adherent mucus gel layer is a structural one to create a stable, unstirred layer to support surface neutralization of acid and act as a protective physical barrier against luminal pepsin. Therefore, the emphasis on mucus in this review is on the form and role of the adherent mucus gel layer. The primary function of the mucosal bicarbonate secretion is to neutralize acid diffusing into the mucus gel layer and to be quantitatively sufficient to maintain a near-neutral pH at the mucus-mucosal surface interface. The emphasis on mucosal bicarbonate in this review is on the mechanisms and control of its secretion and the establishment of a surface pH gradient. Evidence suggests that under normal physiological conditions, the mucus bicarbonate barrier is sufficient for protection of the gastric mucosa against acid and pepsin and is even more so for the duodenum.
Author(s): Allen A, Flemstrom G
Publication type: Review
Publication status: Published
Journal: American Journal of Physiology: Cell Physiology
Year: 2005
Volume: 288
Issue: 1
Pages: C1-C19
ISSN (print): 0363-6143
ISSN (electronic): 1522-1563
URL: http://dx.doi.org/10.1152/ajpcell.00102.2004
DOI: 10.1152/ajpcell.00102.2004
PubMed id: 15591243
