Helicobacter pylori infection reduces intraluminal nitric oxide.
BACKGROUND
Nitric oxide (NO) plays an important role in gastrointestinal mucosal protection. We have previously shown that Helicobacter pylori infection is associated with a lower concentration of NO in the human stomach. The aim of this study is to explore the pathogenesis of this finding using an animal model.


METHODS
Mongolian gerbils were divided into four groups: H. pylori-negative and -positive, each with and without the intraperitoneal addition of superoxide dismutase (SOD). Intraluminal NO and serum nitrate were measured by using a chemiluminescence system. Inducible nitric oxide synthase (iNOS) levels in gastric mucosa were measured by using the NOSdetect Assay Kit.


RESULTS
iNOS levels in H. pylori-positive gerbils were significantly greater than in those without infection. Intraluminal NO levels in H. pylori-positive gerbils were significantly lower than those in H. pylori-negative ones and increased after SOD administration. Serum nitrate levels in H. pylori-positive gerbils were significantly greater than those in H. pylori negative ones and decreased after SOD administration.


CONCLUSIONS
The low level of NO in the gastric lumen in H. pylori infection is likely a result of superoxide production related to H. pylori-induced inflammation.
Iguchi
M
M
Second Dept. of Internal Medicine, Wakayama Medical College, Japan.
Shiotani
A
A
Nishioka
S
S
D000818:Animals; D005753:Gastric Mucosa / Q000378:metabolism*; D005849:Gerbillinae; D016481:Helicobacter Infections / Q000378:metabolism*; D016480:Helicobacter pylori; D008297:Male; D009566:Nitrates / Q000097:blood; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D013482:Superoxide Dismutase / Q000494:pharmacology
D009566:Nitrates; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D013482:Superoxide Dismutase