[Antioxidant enzymatic activity in the limbic-reticular structures of the rat brain after short-term immobilization]

Superoxide dismutase, glutathione peroxidase, and glutathione reductase activities were measured in 15-to 30-mg specimens of the cerebral cortex, amygdala, hypothalamus, and midbrain of adult male August rats subjected to 1-h immobilization stress. Of all these brain regions, the hypothalamus and amygdala had the strongest baseline total antioxidant defenses. However, immobilization inhibited the antioxidant enzymes in hypothalamus to much greater extent (an average of 30%) than in any other brain region (10% to 18%). After immobilization, the activities of glutathione reductase in the four brain regions were strongly and positively correlated. These data are consistent with our earlier findings of rapid accumulation of thiobarbituric acid-reactive material in the rat hypothalamus after a brief immobilization and suggest that hypothalamus is subject to strong pro-oxidant impacts arising at the early stages of immobilization stress.