Evidence that the activities of erythrocyte free radical scavenging enzymes and the products of lipid peroxidation ape increased in different forms of schizophrenia

In order to examine antioxidant status and lipid peroxidation in schizophre nia patients, activities of three free radical scavenging enzymes (superoxi de dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT)), an d the level of thiobarbituric acid-reactive substances (TBARS) as an index of lipid peroxidation have been studied in red blood cells. Schizophrenic p atients were divided into three groups (disorganized (n = 21), paranoid (n = 26) and residual types (n = 18)) to determine differences between subgrou ps. SOD, CAT and GSH-Px activities in the control group were found to be 14 61.0 +/- 248.6 U g(-1) Hb, 148.2 +/- 59.3 k g(-1) Hb and 25.87 +/- 4.25 U g (-1) Hb, respectively. We found no significant differences in SOD activitie s between study and control groups. There was a significant increase in SOD activity in the residual group compared to the paranoid group (P < 0.005). CAT activity was found to be increased in disorganized (148%), paranoid (1 47%), and residual (165%) groups compared to the control group. GSH-Px acti vity was markedly increased in the study groups except the paranoid group. Statistically significant (3-4 fold) increases in TBARS levels of red blood cells were found in all the study groups. It is proposed that antioxidant status may be changed in schizophrenia and thus may induce lipid peroxidati on. Therefore, oxidative stress may have a pathophysiological role in all t he subtypes of schizophrenia.