Objective: To determine the behavior of the copper-zinc superoxide dismutase enzyme (SOD/Cu/Zn) in tissue homogenates of rat brains with ischemic lesions produced following the model of global cerebral ischemia without arterial hypotension.
Material and methods: Thirty rats were randomly assigned to five groups of six animals each. Bilateral carotid occlusion was temporarily produced in 24 rats (4 groups) during periods of 5, 15, 30 and 60 minutes, respectively. All the animals were then submitted to reperfusion for 30 minutes and after that, they were sacrificed. A control group of 6 rats was not exposed to arterial occlusion. Cerebral homogenates of the rats' brain were obtained and submitted to spectrophotometer analysis.
Result: The control group showed the lowest mean values in SOD/Cu/Zn activity (40.60+/-11.42 U/mg of protein), while the highest mean values (60.34+/- 13.52 U/mg of protein) corresponded to the rats submitted to ischemia for 60 minutes, what indicates a statistically significant difference (p = 0.016) between the two groups.
Conclusions: SOD/Cu/Zn activity in rats increases during the production of ischemic cerebral lesions. The analysis of SOD/Cu/Zn activity showed an important tendency to rise from the 30 minutes period of ischemic lesion and reached statistically significant values at 60 minutes from the beginning of the ischemic injury. The experimental model of global brain ischemia without arterial hypotension used in this study constitutes a reliable method for researching cerebral ischemia.