Oxidative stress in gastric mucosa in Helicobacter pylori infection.
BACKGROUND
Infection with Helicobacter pylori is believed to be associated with generation of reactive oxygen molecules which leads to oxidative stress in the gastric mucosa; but the relation between oxidative stress and gastrointestinal mucosal damage has not been documented.


OBJECTIVE
To look for evidence of oxidative stress and lipid peroxidation in the gastric mucosa in H. pylori-associated peptic ulcer.


METHODS
34 duodenal ulcer (DU) patients with H. pylori infection, 14 DU patients without H. pylori infection and 10 healthy subjects without H. pylori infection were studied. H. pylori infection was diagnosed by histology and rapid urease test on endoscopic biopsies from the gastric body and antrum. Reduced glutathione (GSH) and malondialdehyde (MDA) content were measured in biopsies taken from the gastric antrum. Statistical analysis was done using Student's t test.


RESULTS
Tissue levels of GSH were significantly lower (91.7 [35.4] nmole/100 mg versus 147.3 [41.2] nmole/100 mg; p < 0.001) and MDA higher (163.0 [83.4] nmole/100 mg versus 109.2 [51.3] nmole/100 mg; p < 0.01) in patients with DU associated with H. pylori infection as compared to those without H. pylori infection. GSH levels were significantly lower and MDA levels higher in DU patients with or without H. pylori infection as compared to control subjects. Serum MDA levels in DU patients with H. pylori infection were also significantly higher than in patients without H. pylori infection.


CONCLUSIONS
Depletion of gastric mucosal glutathione in H. pylori-infected DU patients may be due to failure of the antioxidant defense system. Failure of the glutathione-dependent defense system results in accumulation of free radicals which can initiate membrane damage by lipid peroxidation.
Santra
A
A
Department of Gastroenterology, Institute of Post Graduate Medical Education and Research, Calcutta.
Chowdhury
A
A
Chaudhuri
S
S
Das Gupta
J
J
Banerjee
P K
PK
Mazumder
D N
DN
D000328:Adult; D016022:Case-Control Studies; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism*; D005978:Glutathione / Q000032:analysis; D016481:Helicobacter Infections / Q000378:metabolism*; D016480:Helicobacter pylori; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D018384:Oxidative Stress
D005978:Glutathione