Superoxide dismutase, catalase, and guanase in traumatic brain injury

Objectives: Reactive oxygen species generated after brain trauma trigger a cascade of events resulting in neuronal death. Despite numerous defenses, the brain is vulnerable to oxidative damage, mainly because of its high content of unsaturated fatty acids. The goal in this experimental study was to demonstrate the activities of antioxidant enzymes, namely, superoxide dismutase, catalase, and guanase, in plasma and brain tissue at 30 minutes and 60 minutes after brain trauma. Methods: Forty adult male Sprague-Dawley rats were used as subjects. Rats in group 1 were subjected to moderate head injury, whereas rats in group 2 were subjected to severe head injury. Eight rats served as a sham operated (control) group. Results: The results of this study showed that there is, in general, an increase in the activities of these 3 enzymes in plasma; however, in the brain tissue, we observed that guanase activities were decreased during the posttraumatic period. Conclusion: These alterations in enzyme activities suggest that lipid peroxidation ensues in the early period of trauma and that treatment strategies aimed to increase antioxidant enzyme activities may prevent the secondary mechanisms resulting in neuronal death.