Involvement of superoxide anion in the pathogenesis of simple mechanical intestinal obstruction.

BACKGROUND

Mechanism underlying the pathogenesis of mechanical intestinal obstruction has been suggested to be closely associated with bowel inflammatory response in which reactive oxygen metabolites might play an important role. This study was designed to examine the involvement of superoxide anion in the obstruction-induced intestinal injury.

MATERIALS AND METHODS

Rats were randomly aasigned to four groups: sham, obstruction, obstruction with polyethylene glycol (PEG), and obstruction with polyethylene glycol-superoxide dismutase (PEG-SOD) groups. A ligation at the ileum 20 cm proximal to the cecum was created under anesthesia. The superoxide anion production and the pathological manifestations in the obstructed intestine were measured after 24 h of ligation.

RESULTS

There were significant intestinal shortening, distension, fluid accumulation and mucosal damage in the segment proximal to the ligation site. Pronounced generation of superoxide anion was found in the obstructed intestinal segment. Supplement of SOD, a superoxide free radicals scavenger, ameliorated obstruction-induced bowel distension, fluid accumulation and mucosal damage.

CONCLUSION

These data suggest superoxide anion is one of the important mediators in the pathophysiologic changes of simple mechanical intestinal obstruction.