Gastric injury induced by ethanol and Ischemia-Reperfusion in the rat: Differing roles for lipid peroxidation and oxygen radicals

Gregory S. Smith, David W. Mercer, James M. Cross, Jose C. Barreto, Thomas A. Miller

Research output: Contribution to journalArticle

55 Scopus citations

Abstract

This study determined the role that oxygen-derived free radicals played in the production of gastric injury in rats challenged orally with concentrated ethanol or subjected to vascular compromise. In the ethanol study, rats were pretreated with a variety of free radical scavengers or enzyme inhibitors prior to exposing the stomach to 100% ethanol. At sacrifice, the degree of macroscopic damage to the glandular gastric mucosa was quantified. In separate studies, the effects of ethanol on gastric mucosal levels of enaldehydes (malondialdehyde and 4-hydroxynonenal) were examined as an index of lipid peroxidation. Superoxide dismutase and catalase pretreatment were without benefit in reducing injury in our ethanol model, excluding potential contributory roles for the superoxide anion or hydrogen peroxide, respectively. Dimethyl sulfoxide and desferoxamine were likewise without protective capabilities, eliminating a role for the hydroxyl radical. Allopurinol, a xanthine oxidase inhibitor, provided no protection under-acute conditions, even though partial protection was noted when administered chronically. Further, enaldehyde levels were not increased over control levels in alcohol-exposed mucosa, indicating no enhanced lipid peroxide formation. In contrast, in animals in which ischemia to the stomach was induced followed by reperfusion, marked gastric injury was observed in combination with enhanced enaldehyde levels. Prevention of enaldehyde formation by a 21-aminosteroid concomitantly prevented injury induced by ischemia-reperfusion. These findings support the conclusion that ischemia-reperfusion injury to the stomach is an oxygen-derived free radical process whereas ethanol-induced injury clearly involved some other process. Although allopurinol was partially protective against ethanol damage when administered chronically, observations in other models of injury suggest that this action is independent of its inhibitory effect on xanthine oxidase.

Original languageEnglish (US)
Pages (from-to)1157-1164
Number of pages8
JournalDigestive Diseases and Sciences
Volume41
Issue number6
DOIs
StatePublished - Jul 22 1996

Keywords

  • Ethanol
  • Gastric injury
  • Ischemia-reperfusion
  • Lipid peroxidation
  • Oxygen-derived free radicals

ASJC Scopus subject areas

  • Physiology
  • Gastroenterology

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