Document Detail


How does Helicobacter pylori cause mucosal damage? Its effect on acid and gastrin physiology.
MedLine Citation:
PMID:  9394759     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Helicobacter pylori infection increases gastric acid secretion in patients with duodenal ulcers but diminishes acid output in patients with gastric cancer and their relatives. Investigation of the basic mechanisms may show how H. pylori causes different diseases in different persons. Infection of the gastric antrum increases gastrin release. Certain cytokines released in H. pylori gastritis, such as tumor necrosis factor alpha and specific products of H. pylori, such as ammonia, release gastrin from G cells and might be responsible. The infection also diminishes mucosal expression of somatostatin. Exposure of canine D cells to tumor necrosis factor alpha in vitro reproduces this effect. These changes in gastrin and somatostatin increase acid secretion and lead to duodenal ulceration. But the acid response depends on the state of the gastric corpus mucosa. The net effect of corpus gastritis is to decrease acid secretion. Specific products of H. pylori inhibit parietal cells. Also, interleukin 1 beta, which is overexpressed in H. pylori gastritis, inhibits both parietal cells and histamine release from enterochromaffin-like cells. H. pylori also promotes gastric atrophy, leading to loss of parietal cells. Factors such as a high-salt diet and a lack of dietary antioxidants, which also increase corpus gastritis and atrophy, may protect against duodenal ulcers by decreasing acid output. However, the resulting increase of intragastric pH may predispose to gastric cancer by allowing other bacteria to persist and produce carcinogens in the stomach.
Authors:
J Calam; A Gibbons; Z V Healey; P Bliss; N Arebi
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Review    
Journal Detail:
Title:  Gastroenterology     Volume:  113     ISSN:  0016-5085     ISO Abbreviation:  Gastroenterology     Publication Date:  1997 Dec 
Date Detail:
Created Date:  1997-12-24     Completed Date:  1997-12-24     Revised Date:  2009-09-29    
Medline Journal Info:
Nlm Unique ID:  0374630     Medline TA:  Gastroenterology     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  S43-9; discussion S50     Citation Subset:  AIM; IM    
Affiliation:
Department of Gastroenterology, Imperial College School of Medicine, Hammersmith Hospital, London, England. jcalam@rpms.ac.uk
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MeSH Terms
Descriptor/Qualifier:
Animals
Gastric Acid / physiology*,  secretion
Gastric Mucosa / microbiology*,  pathology*
Gastrins / physiology*
Gastritis / microbiology
Helicobacter Infections / metabolism*
Helicobacter pylori / physiology*
Humans
Grant Support
ID/Acronym/Agency:
//Wellcome Trust
Chemical
Reg. No./Substance:
0/Gastrins

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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