Quantitative measurement of nitric oxide and hydrogen peroxide in Helicobacter pylori-infected Mongolian gerbils in vivo

Abstract

Objective. Peroxynitrite formation, as reflected by nitrotyrosine expression, is low in Helicobacter pylori-infected Mongolian gerbils despite pronounced expression of radical-forming enzymes. The aim of the present study was to investigate in vivo whether H. pylori inhibits either one or both of the nitro- and oxyradical formation pathways. Material and methods. Male Mongolian gerbils were infected with two different H. pylori strains, TN2GF4 and SS1. Six months after inoculation, direct measurement of NO and H₂O₂ was performed in vivo using electrochemical microsensors positioned in close proximity to the gastric mucosa. Results. In the TN2GF4-infected animals the level of NO was significantly lower than that in controls. No significant difference in NO levels was detected between the SS1-infected group and the controls. H₂O₂ was significantly increased in the SS1 animals compared with that in controls after 6 months. The H₂O₂ level in the TN2GF4 group did not differ from that in controls. Conclusions. The results indicate that H. pylori infection is associated with strain-dependent functional inhibition of both the NO and oxyradical formation pathways in the gastric mucosa.

• Animal model
• Helicobacter pylori
• infection
• in vivo
• Mongolian gerbil
• mucosa
• radical
• stomach