Free oxygen radicals in restraint-induced stress gastritis in the rat.

In this experimental study, the role of free oxygen radicals (FOR) in stress gastritis (SG) was investigated in a restraint stress model for rats. Allopurinol, dimethyl sulfoxide (DMSO), and superoxide dismutase (SOD) were tested as single agents in controlled groups. The portal blood pH values, the ratio of the mucosal erosion area to the gastric mucosal area (EA/MA), the ratio of the depth of mucosal erosions to the concomitant gastric mucosal wall (ED/MD), and concentrations of malondialdehyde (MDA)--a lipid peroxidation coproduct--in the gastric mucosa were used as parameters in the experiment. The EA/MA between the treated and untreated control groups were found to have no statistically significant difference (P > 0.05). ED/MD, a crucial determinant for bleeding probability, was found to be decreased in the SOD group (P < 0.05). SOD, allopurinol, and DMSO reduced the mucosal MDA concentration to lower values than the untreated group (P < 0.05). We concluded that although FOR may not play a dominant role in stress-induced gastric lesions, SOD may be a good candidate for a clinical trial on SG prophylaxis.