Correlation analysis confirms differences in antioxidant defence in the blood of types I and II schizophrenic male patients treated with anti-psychotic medication.

The activities of antioxidant defence enzymes were determined in erythrocytes isolated from types I and II schizophrenic male patients and from healthy controls. Significant differences in superoxide dismutase (SOD) activity (type I: 3284+/-577; type II: 2959+/-697 compared with controls: 3778+/-577; analysis of variance (ANOVA) P<0.001), catalase (CAT) activity (type I: 17.8+/-1.8 compared to type II: 19.2+/-1.5 and both compared with controls: 19.2+/-1.5; ANOVA P<0.05), glutathione peroxidase (GSH-Px) activity (controls: 17.8+/-2.3; type I: 13.9+/-2.9 and type II: 11.6+/-1.9; ANOVA P<0.001) as well as in glutathione reductase (GR) activity (controls: 5,0+/-0.8; type I: 4.3+/-0.9 and type II: 4.5+/-0.8; ANOVA P<0.01) were apparent. Correlation analysis of antioxidant defence enzymes showed significant negative correlation between GSH-Px and CAT activities (P<0.01) in type I patients. In type II patients, GSH-Px activity was significantly positively correlated with GR (P<0.01). Canonical discriminant analysis separated type I and type II patients from controls (and among each other) with a high degree of certainty according to the overall group composition of antioxidant defence enzymes. Our results indicate differences in the composition of antioxidant defence between controls and anti-psychotic treated type I and type II patients with a possible negative feedback influence on the pathological process, which could provide a rationale for applying antioxidants during schizophrenic therapy.