TREATMENT OF HELICOBACTER-PYLORI INFECTION FAVORABLY AFFECTS GASTRIC-MUCOSAL SUPEROXIDE DISMUTASES

Background and aims-Excessive production of reactive oxygen metabolite s (ROMs) by phagocytic cells is thought to contribute to the mucosal p athology of Helicobacter pylori infection. Previously, H pylori infect ion was shown to have a differential effect on some gastric mucosal sc avenger enzymes of ROMs - namely, mitochondrial and cytoplasmic supero xide dismutases - reflected by a large increase in the cytokine induci ble manganese superoxide dismutase and a marginal decrease in the cons titutive copper/zinc superoxide dismutase. The present study was perfo rmed to evaluate whether these altered mucosal superoxide dismutase co ncentrations and activities in H pylori associated gastritis are rever sed to normal by successful treatment of the infection. Patients and m ethods-In two different treatment groups - namely, omeprazole or ranit idine, in combination with clarithromycin and metronidazole (OME/AB (n =33) and RAN/AB (n=30)) - manganese dismutase and copper/zinc dismutas e concentrations were evaluated by enzyme linked immunosorbent assays in homogenates of gastric antrum and corpus biopsy specimens obtained before and eight weeks after successful treatment of H pylori infectio n. Superoxide dismutase activities in these homogenates were determine d spectrophotometrically in eight patients of both groups before and a fter successful treatment. The concentrations of gastric mucosal super oxide dismutases were also determined in 12 patients with a persistent H pylori infection, with (n=4) or without (n=8) eradication therapy. Infection and eradication of H pylori were confirmed by a combination of culture and histology. Results-Concentrations of manganese superoxi de dismutase were significantly lower after than before therapy in ant ral (p<0.001 in both treatment groups) and corpus (p<0.001 in both tre atment groups) mucosa. By contrast, copper/zinc superoxide dismutase c oncentrations were significantly higher (p<0.001) only in antral mucos a of the OME/AB treated group. Manganese superoxide dismutase activity was significantly lower after than before treatment in antral (OME/AB p<0.01, RAN/AB p<0.001), but not in corpus mucosa. Copper/zinc supero xide dismutase activity was not significantly altered by therapy. In t he 12 patients with a persistent H pylori infection no major changes i n the gastric mucosal superoxide dismutase concentrations were found. Conclusions-The raised manganese superoxide dismutase and reduced copp er/ zinc superoxide dismutase concentrations and activities in H pylor i associated gastritis were reversed towards normal by successful trea tment of the infection.