Brain oxidative damage following acute immobilization and mild emotional stress

We studied the role of free radicals on brain oxidative damage in rats afte r acute immobilization stress (restraint) and mild emotional stress (handli ng). To investigate brain oxidative damage, CuZn and Mn dependent superoxid e dismutase (CuZn SOD, Mn SOD) activities, lipid peroxidation (TBARs), Na+K + ATPase activity, protein carbonyl (PrC), and reduced and oxidized glutath ione (GSH GSSG) levels were measured in the cerebral cortex (CTX), hippocam pus (HIP), and striatum (ST) of the animals after the two different stress stimuli. Because stress produces abnormalities in the hypothalamic-p pituit ary-adrenal axis, the intensity of the two stress conditions were measured by plasmatic corticosteroid (COR) levels: particularly, COR levels doubled in handled rats and increased 15-fold in restrained animals. The SOD activi ties increased in CTX and decreased in HIP of the handled rats, while in ST a significant decrease in handled animals but an increase in restrained an imals occurred. TBARs, GSH, and GSSG levels remained unchanged while an ind ex of glutathione redox decreased significantly in ST of handled animals an d in CTX of restrained ones. Na+K+ ATPase activity increased significantly in the HIP and ST of both groups of stressed rats. The stress induced a rem arkable increase in PrC levels in all studied cerebral areas. These finding s provide evidence to support the idea that stress produces oxidants but th at the oxidative damage in stress differs in cerebral areas and could contr ibute to the degenerative mechanism of aging.