EARLY AND TRANSIENT INCREASE IN OXIDATIVE STRESS IN THE CEREBRAL-CORTEX OF SENESCENCE-ACCELERATED MOUSE

Age-related changes in oxidative stress in the cerebral cortex of SAMP 8, a substrain of senescence-accelerated mouse (SAM), were investigate d in comparison with those in SAMR1, which were used as a control. The lipid peroxide and protein carbonyl contents were transiently increas ed in SAMP8 from 4- to 8-weeks of age. The increases in lipid peroxide were seen only in the cerebral cortex and not in other regions of the cerebrum. Furthermore, the net generation of reactive oxygen species in cerebral cells was also increased in SAMP8. In addition, the activi ty of glutamine synthetase, which is known as an enzyme highly sensiti ve to reactive oxygen, was decreased in the cerebral cortex of SAMP8 f rom 4- to 8-weeks of age. These results suggest that oxidative stress may be induced in the cerebral cortex of SAMP8 from 4- to 8-weeks of a ge, preceding the appearance of distinctive deficits in the brain of S AMP8.