Background: Ischemia-reperfusion (IR) injury in skeletal muscle is a pathophysiology which affect quality of life.
Aim of Work: To compare the possible protective mechanisms by which oxytocin and Vitamin E may exert on skeletal muscle IR injury in rat.  Materials and Methods: 28 male rats were divided into: Control (Group A) of 10 rats and IR group (Group B) of 18 rats. Control group underwent the same surgical steps as IR group but without clamping the femoral artery followed by the injection of one of the following [saline (AI), oxytocin (AII) or vitamin E (AIII)]. In the IR group, lower limb ischemia was induced by clamping the femoral artery. After 4h of ischemia, the clamp was removed to allow reperfusion coinciding with the injection of one of the following [saline (BI), Oxytocin (0.5μg/kg) (BII) and Vitamin E (10mg/kg) (BIII)]. After 2 hours of reperfusion, Blood samples were drawn from the femoral vein to measure glutathione (GSH) and malondialdehyde (MDA). Gastrocnemius muscles were obtained for evaluation by light and electron microscopes. Cytochrome C, Myogenin immunohistochemistry and statistical analysis were applied.
Results: A significant increase in GSH and significant decrease in MDA were reported in BII and BIII as compared to BI. Mean area % of cytochrome C in BII and BIII showed a significant decrease compared to BI. Mean number of myogenin immunopositive cells in BII was significantly higher compared to BI. Muscular damage was proved by light and electron microscopic findings in BI. While, BII and BIII encountered evident protection from muscular damage induced by IR injury.  Conclusion: Oxytocin exerts weak protective antioxidant effect against IR injury. However, it activates stem cells to regenerate the damaged muscle.  Vitamin E was better antioxidant which can react as early as 1 hour in the protection of the skeletal muscle against IR injury.