Age-Related Alterations in Superoxide Dismutase and Catalase Activities in Rat Brain

Authors: Gülinnaz ALPER, Eser Y. SÖZMEN, Lütfiye KANIT, Gülriz MENTES, Biltan ERSÖZ, Fatma Z. KUTAY

Abstract: Active oxygen species have been proposed to be involved in the aging process of the brain, therefore alterations in the activities of enzymes involved in the defense system against free radicals and other active species could substantially influence the aging process. This study is planned to determine the brain superoxide dismutase (SOD) and catalase activities which defend the components of brain cells against active oxygen species, in order to evaluate whether they play a role in the aging process. The activities of SOD and catalase were measured in the cerebral cortex and cerebellum of Swiss male albino rats aged either 2 months (n=11) or 16 months (n=14). Tissue SOD activities were determined by Misra and Fridovich's method while catalase activities were measued by a modified method of Luck and Aebi. When the results of this study were evaluated regardless of age, it is observed that catalase activity is higher in the cerebellum than the cerebral cortex. Whereas the cerebral cortex showed age-dependent decreases in both SOD (6.01 ± 0.94 vs 4.47 ± 0.34 U/mg protein, p<0.05) and catalase (0.235 ± 0.02 vs 0.145 ± 0.02 U/mg protein, p<0.01) activities, cerebellum showed a decrease only in the catalase activity (0.367 ± 0.05 vs 0.199 ± 0.04 U/mg protein, p<0.01). Due to the fact that SOD and catalase have an important role in free radical detoxification of the brain, the age-related decrease in the expression of these enzymes might predispose this tissue to increased free radical damage.

Keywords: Aging, SOD, catalase, cerebral cortex, cerebellum, brain, rats.

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