Abnormal age-related changes of plasma antioxidant proteins in schizophrenia

Albumin and bilirubin art: metal-binding proteins, shown to possess free ra dical scavenging properties, and may thus be selective antioxidants. Tn the present study we examined whether individual plasma antioxidants such as a lbumin and bilirubin, which significantly contribute to total antioxidant s tatus (TAS), are reduced in patients with schizophrenia. We prospectively s tudied plasma antioxidant proteins, i.e. albumin and bilirubin, in male vet eran schizophrenic patients using a within-subject, repeated measures, on-o ff-on haloperidol treatment design, as well as age- and sex-matched healthy volunteers. Male patients with schizophrenia either during haloperidol tre atment (n = 46) or in a drug-free condition (n = 35) had significantly lowe r, levels of both plasma albumin and bilirubin compared with age- and sex-m atched healthy volunteers (n = 31). Such reductions of plasma antioxidant p roteins in schizophrenic patients appeal to be age-related changes, in cont rast to those observed in healthy volunteers. On the other hand, levels of plasma albumin and bilirubin were not significantly affected by haloperidol treatment, haloperidol withdrawal, or length of drug-free period. Moreover , plasma TAS was not influenced significantly by cigarette smoking, even th ough it may selectively decrease plasma bilirubin but not albumin levels. T he present findings, taken together with our previous results of reduced pl asma TAS and uric acid, as well as an increased Red blood cell superoxide d ismutase, lend further support to the hypothesis that a defect in the antio xidant defense system exists in schizophrenia that may lead to oxidative da mage. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.