Changes in superoxide dismutase and catalase activities of rat brain regions during early global transient ischemia/reperfusion.

It has been widely recognized that the hippocampus and striatum are clearly more susceptible to oxidative stress than the remaining brain regions. However, the mechanism involved is not known. The activities of the antioxidant enzymes CuZn-superoxide dismutase (SOD), Mn-SOD and catalase were measured in the hippocampus and striatum and the results were compared to cortex and cerebellum (less susceptible to oxidative stress) after 3 h of a global transient ischemia/reperfusion. CuZn-SOD activities were reduced in all brain regions, but mainly in the hippocampus and striatum. Mn-SOD activity was lowered in the striatum, whereas catalase activity was reduced in the hippocampus and striatum. Our findings indicate that in the earlier phase of ischemia/reperfusion the decay in activities of catalase and SOD may be related with the high susceptibility of the hippocampus and striatum to oxidative damage.