Alterations in brain antioxidant status, protein oxidation and lipid peroxidation in response to different stress models.

The aim of this study was to investigate the effects of different stress models on copper, zinc-superoxide dismutase (Cu,Zn-SOD), catalase (CAT) and selenium-dependent glutathione peroxidase (Se-GSH-Px) activities, and reduced glutathione (GSH), protein carbonyl (PC) and lipid peroxidation marker (conjugated diene (CD) and thiobarbituric acid-reactive substances (TBARS)) levels in brain of rats, and to determine the most effective stress model according to each parameter. Rats were divided into four groups as following: control group (C), immobilization stress group (IS), cold stress group (CS) and immobilization-cold stress group (ICS). All stress models increased brain Cu,Zn-SOD and CAT activities, PC, CD and TBARS levels, plasma corticosterone levels and decreased brain GSH concentrations. Se-GSH-Px activity was increased in CS and ICS groups. When all stress models were taken into consideration, the highest increases in Cu,Zn-SOD and Se-GSH-Px activities were found in CS group. The lowest GSH level was seen in IS group. The highest increases in PC and TBARS levels were found in ICS group. The highest increase of CD concentration was seen in IS and ICS groups. Our results suggest that different stress models have different degrees of influences on enzymatic and non-enzymatic antioxidant defense systems, protein oxidation and lipid peroxidation in the brain.