Oxygen free radical induced damage during intestinal ischemia/reperfusion in normal and xanthine oxidase deficient rats.

Abstract

This study looks at the role of xanthine oxidase (XO) in ischemia/reperfusion (I/R) induced intestinal mucosal damage using normal and xanthine oxidase deficient rats. Tungstate feeding for 3 days depleted the intestinal mucosal XO by 80%. A ligated loop of the rat small intestine (both normal and XO-deficient) was subjected to 1 h of total ischemia followed by 5 min revascularisation. The ensuing mucosal damage was assessed by biochemical and histological studies. Ischemia or I/R increased the XO levels in normal rats without any change in XO-deficient rats. Myeloperoxidase (a neutrophil marker) level was increased in both group of rats but it was comparatively higher in the XO-deficient rats. Accumulation of peroxidation products such as malondialdehyde, conjugated diene and increased production of hydroxyl radicals by microsomes were seen after ischemia and I/R and were similar in normal and XO-deficient rats. Studies on other parameters of peroxidation showed a decrease in polyunsaturated fatty acids and alpha-tocopherol, an increase in cysteine and cystine levels after I/R and were similar in both normal and XO-deficient rats. Histological results indicated gross morphological changes in the intestinal mucosa due to ischemia and I/R, and the damage was more severe in XO-deficient rats. These observations suggest that oxygen-derived free radicals are involved in the intestinal mucosal damage during I/R and infiltrated neutrophils rather than XO may be the primary source of free radicals under these conditions.

• Authors: S Nalini, M M Mathan, K A Balasubramanian
• Journal: Molecular and cellular biochemistry (Mol Cell Biochem) Vol. 124 Issue 1 Pg. 59-66 (Jul 07 1993) ISSN: 0300-8177 [Print] Netherlands
• PMID: 8232277 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Free Radicals
• Reactive Oxygen Species
• Xanthine Oxidase

Topics

• Animals
• Free Radicals
• Intestinal Mucosa (blood supply, enzymology, pathology)
• Male
• Rats
• Rats, Sprague-Dawley
• Reactive Oxygen Species (pharmacology)
• Reference Values
• Reperfusion Injury (etiology)
• Xanthine Oxidase (deficiency)