Oxidative stress in blood platelets from schizophrenic patients.

Oxidative stress in blood platelets is observed in various diseases, including neuropsychiatric disorders. The aim of our study was to evaluate oxidative stress in blood platelets from patients with schizophrenic disorders by measuring the activity of the platelet antioxidative enzyme, superoxide dismutase (SOD), concomitant with the level of thiobarbituric acid reactive species (TBARS). In blood platelets obtained from schizophrenic patients (with paranoid schizophrenia according to DSM-IV criteria) and from healthy volunteers the level of reactive oxygen species was also measured via chemiluminescence. In resting blood platelets from schizophrenic patients the chemiluminescence was higher than in platelets from control subjects (P < 0.05), but in thrombin-activated platelets an increase (about 53%) of chemiluminescence was observed, however this increase was lower than in thrombin-stimulated platelets from healthy subjects (101.5%). The results indicate that in platelets from schizophrenic patients generation of reactive oxygen species is enhanced. Moreover, we observed that SOD activity in blood platelets from schizophrenic patients was significantly lower than in control platelets and that a correlation exists between increased lipid peroxidation and inhibition of the activity of this antioxidative enzyme in schizophrenic platelets.