CuZn-Superoxide Dismutase in Brain of Rats Exposed to Acute, Chronic or Combined Stress

ABSTRACT

CuZn superoxide dismutase (CuZnSOD) activity in hippocampus and brain cortex of Wistar male rats exposed to acute stress (immobilization or cold for 2 h), chronic stress (isolation or social crowding for 21 days), or to their various combinations was examined. The highest CuZnSOD activity in both brain structures was observed in chronic isolation and it decreased after additional exposure to either of the acute stressors. Contrary to that, chronic crowding had no effect on CuZnSOD activity in hippocampus, while in brain cortex it even caused the suppresion of enzyme activity. Additional exposure to acute stresses differently affected the enzyme activity depending on the brain region and type of stress: immobilization increased the activity of CuZnSOD in hippocampus, while cold decreased it in cortex. Acute stress by immobilization caused the elevation of CuZnSOD activity in cortex, and acute cold exposure decreased enzyme activity in hippocampus. The observed region specific alterations of SOD activity indicate that neuroendocrine stress most probably generate cellular imbalance between production and elimination of ROS, which may provide some insights into a variety of neuropsychological processes as well as their treatment.