The role of oxygen-derived free radicals and the effect of free radical scavengers on skeletal muscle ischemia/reperfusion injury.

The aim of this study was to clarify the role of oxygen-derived free radicals and the effect of free radical scavengers on skeletal muscle ischemia/reperfusion injury. Male Wistar rats were divided into a complete ischemia group (C-group) and an incomplete ischemia group (IC-group) and each animal was subjected to 2 h of ischemia and 1 h of reperfusion. In an attempt to decrease reperfusion injury, the rats were given free radical scavengers either as allopurinol 50 mg/kg for 2 days or as superoxide dismutase 60,000 units/kg plus catalase 500,000 units/kg. Tissue malondialdehyde, a product of lipid peroxidation, was measured as an indicator of free radicals, with higher levels indicating higher concentrations of free radicals. The malondialdehyde level in the gastrocnemius muscle after 1 h of reperfusion increased significantly in both groups when compared to the levels before and 2 h after ischemia, although there was no significant difference between the two groups. The water content of the gastrocnemius muscle and serum creatinine phosphokinase MM isoenzyme (CPK-MM) in both groups, and GOT in the C-group, increased significantly after 1 h of reperfusion when compared the values before and 2 h after ischemia. In the C-group, these values were significantly higher than in the IC-group. The administration of free radical scavengers suppressed the increase in malondialdehyde in the gastrocnemius muscle after reperfusion in both groups. The increase in water content and CPK-MM after reperfusion was also suppressed by free radical scavengers in the IC-group, but not in the C-group.(ABSTRACT TRUNCATED AT 250 WORDS)