Generation of superoxide anion radicals and platelet glutathione peroxidase activity in patients with schizophrenia

Abstract

Blood platelets are considered to be a peripheral marker in schizophrenia and other psychiatric disorders. Oxidative stress in schizophrenia may be responsible for changes in platelet metabolism and function; therefore, the aim of this study was to examine and compare the generation of superoxide anions and activity of an antioxidant enzyme (glutathione peroxidase [GPx]) in blood platelets in patients with schizophrenia and healthy subjects. The level of superoxide anions generated in platelets after thrombin and platelet-activating factor stimulation and activity of GPx in patients with schizophrenia and healthy volunteers was estimated. The results obtained from the study indicate that the generation of superoxide anions in platelets as a response of platelets in patients with schizophrenia to such activating factors as thrombin or platelet-activating factor is higher than in the response of platelets of healthy subjects. In platelets from schizophrenic patients, suppressed GPx activity of about 67% was observed.

Glutathione redox imbalance in brain disorders

“…Ballesteros et al [43] reported significantly lower GSH and higher GSSG levels in the blood of schizophrenia individuals. Dietrich-Muszalska and Kwiatkowska [44] reported that GPx activity decreased by about 67% in the platelets of individuals with schizophrenia compared with the controls.…”

Oxidative stress, prefrontal cortex hypomyelination and cognitive symptoms in schizophrenia

“…For instance, total antioxidant and glutathione plasma levels are lower in non-medicated, medicated, first-episode as well as chronic SZ patients, 26 , 27 , 28 , 29 in line with the reduced glutathione levels found in the PFC and cerebral spinal fluid of SZ patients 30 , 31 and in post mortem SZ brains, 32 in which abnormal redox-related protein expression has also been found. 33 Furthermore, peripheral levels of ROS are increased, and those of glutathione peroxidase and superoxide dismutase are decreased in SZ patients, 34 , 35 , 36 , 37 , 38 , 39 independent of drug use or disease stage. Hence, both lower levels of antioxidants and higher levels of ROS are core features of the disorder and are not influenced by disease progression or medication use, indicating that redox imbalance is a primary characteristic of the disorder.…”

Role of nitric oxide and related molecules in schizophrenia pathogenesis: biochemical, genetic and clinical aspects

“…However, there are results for both hyperactivity of superoxide dismutase in this disease (Wu et al, 2012 ) and unaltered activity as compared to controls (Raffa et al, 2011 ; Srivastava et al, 2001 ). Results regarding measuring levels of glutation peroxidase (Raffa et al, 2009 , 2012b ; Dietrich-Muszalska and Kwiatkowska, 2014 ) and catalase (Ben Othmen et al, 2008 ; Raffa et al, 2011 , 2012b ) are contradictory. This is covered in more detail in relevant literature reviews (Yao and Keshavan, 2011 ; Wu et al, 2013 ).…”