EXPERIMENTAL EVALUATION OF OXYGEN-FREE RADICAL SCAVENGERS IN THE PREVENTION OF REPERFUSION INJURY IN SKELETAL-MUSCLE

Objective: To evaluate the role of oxygen-derived free radicals in reperfusion injury of skeletal muscle in rabbits. Design: Open experimental study. Setting: Department of experimental surgery. Material. 32 rabbits. Interventions: Four groups according to pretreatment: group I: superoxide dismutase-superoxide scavenger; group II: catalase-hydrogen peroxide scavenger; group III: superoxide dismutase and catalase; group IV: mannitol-hydroxyl scavenger. Amputated hindlimbs were subjected to 4 hours of ischaemia followed by 2 hours of reperfusion. One limb was treated while the other served as a control. Main outcome measures: Muscle water content, energy charge, and muscle injury (uptake of Tc-99m-methylenediphosphonate). Results: Muscle water content was reduced in group III (p < 0.05) and IV (p < 0.05). Energy charge was improved in group IV (p < 0.05). Muscle injury was reduced in groups II (p < 0.05), III (p < 0.05), and IV (p < 0.01), but most in group IV (p < 0.01). Conclusion: Oxygen-derived free radicals seem to be mediators in reperfusion injury of skeletal muscle. The hydroxyl radical seems to be the most important of the xanthine oxidase-derived free radicals.