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Abstract

1. Enzymatic and non-enzymatic antioxidant profiles in the various segments of the gastrointestinal tract of male and female rats have been investigated and found to exhibit significant differences (P<0.05). In both sexes, the levels of basal glutathione in the gastric and colonic mucosa are comparable, but lower than those in the proximal and distal segments of the small intestine. The activities of glutathione reductase in various portions of gastrointestinal tract were similar. Glutathione peroxidase showed higher activity in the gastric mucosa than that in other parts of the gastrointestinal tract. No significant differences were found in the activity of superoxide dismutase among the various segments examined. 2. Enzymatic and non-enzymatic antioxidant profiles in the gastric and duodenal mucosa of rabbit, quail, cat, pig and rat have been investigated and found to exhibit significant differences (P<0.05). The levels of basal glutathione were highest in the rat gastric and duodenal mucosa when compared with those in other species. In the duodenal mucosa of all species investigated, the activity of glutathione reductase was higher than that in the corresponding gastric mucosa. The activity of glutathione peroxidase was higher in the gastric mucosa than that in other species examined. Superoxide dismutase showed higher activity in quail duodenal mucosa than in any of the other species studied. 3. The effects of 8% and undiluted ethanol administered by gavage on lesion formation and antioxidant components of the gastric and duodenal mucosa of male and female rats have been examined. Undiluted ethanol produced macroscopic lesions in the body of the stomach in association with decreases in the activity of glutathione reductase and in the level of basal glutathione and an increase in the activity of glutathione peroxidase. Eight percent ethanol produced a small but significant increase (12%) in the level of basal glutathione in rat gastric mucosa when compared with controls. 4. The effects of chronic intermittent stress on the appearance and antioxidant components of the gastric and duodenal mucosa of rats have been examined. No differences in the antioxidant profiles or evidence of macroscopic lesion formation were found.