title: The role of endogenous free radical scavengers on tissue recovery in the experimental ulcer model.
abstract: The role of lipid peroxidation and endogenous oxygen-derived free radical scavengers on ischemia-reperfusion injury and tissue recovery in rat ulcer model corresponding to the gastric histopathology was investigated. Male Wistar rats weighting 200-250 g were heparinized before occlusion of the celiac axis for 1.5 h. Endogenous CuZn-superoxide dismutase (SOD), Mn-SOD, glutathione peroxidase, fumarase, cytochrome c oxidase, and thiobarbituric acid-reactive compounds as lipid peroxidation products were measured in the gastric tissue at 3 h, and 1, 2, 4, and 7 days after release and in the controls (no occlusion). At 3 h after release, erosion of the gastric mucosa was observed, and gastric ulcers beyond the muscularis mucosae were present in the gastric body 2 days later. Seven days after release, gastric ulcers had disappeared. Activity levels for all five enzymes (CuZn-SOD, Mn-SOD, glutathione peroxidase, fumarase, and cytochrome c oxidase) were low for days 1-4 after release and did not return to control levels by the seventh day. It was observed that the ulcer formation, as evidenced by the histopathology, was significantly related to the levels of endogenous CuZn-SOD, Mn-SOD, glutathione peroxidase, fumarase, and cytochrome c oxidase activities. Thiobarbituric acid-reactive compounds were also low through the entire course of ulcer formation. The study concludes that decreases in the levels of these oxygen-derived free radical scavengers may result in the formation of gastric ulcers; however, endogenous free-radical scavengers may not correspond with tissue recovery. Lipid peroxidation may not be related to ulcer formation.
authors.affiliation: Department of Surgery, Yoshida Hospital, Hokkaido, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Oshima
authors.forename: K
authors.initials: K
authors.lastname: Asayama
authors.forename: N
authors.initials: N
authors.lastname: Sakai
authors.forename: M
authors.initials: M
authors.lastname: Kitajima
mesh_terms: D000818:Animals; D003576:Electron Transport Complex IV / Q000032:analysis; D016166:Free Radical Scavengers; D005649:Fumarate Hydratase / Q000032:analysis; D005753:Gastric Mucosa / Q000098:blood supply / Q000201:enzymology*; D005979:Glutathione Peroxidase / Q000032:analysis; D015227:Lipid Peroxidation / Q000502:physiology; D008099:Liver / Q000201:enzymology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D015427:Reperfusion Injury / Q000201:enzymology* / Q000209:etiology; D013276:Stomach Ulcer / Q000201:enzymology* / Q000209:etiology; D013482:Superoxide Dismutase / Q000032:analysis; D013997:Time Factors
chemical_list: D016166:Free Radical Scavengers; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D003576:Electron Transport Complex IV; D005649:Fumarate Hydratase