Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036341 (schizophrenia)
 60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Some reports have shown that schizophrenia is accompanied by the abnormal metabolism of free radicals. The purpose of this study was to investigate the effect of the atypical antipsychotic drug risperidone on blood superoxide dismutase (SOD), a critical enzyme in the detoxification of superoxide radicals, and to explore the relationship between changes in SOD and the therapeutic outcome. Forty-one inpatients with diagnosed schizophrenia (DSM-III-R) were assigned to 12 weeks of treatment with risperidone at a fixed dosage of 6 mg/d after a 2-week washout period. Clinical efficacy was determined with the Positive and Negative Syndrome Scale (PANSS). Blood SOD was assayed by radioimmunoassay (RIA) in schizophrenic patients before and after the 12-week treatment, and the values were compared with those of 50 age-, sex-, and smoking-matched subjects without schizophrenia. Risperidone treatment significantly decreased the initially high blood SOD levels in schizophrenia. There was a significantly positive relationship between the change in SOD at pretreatment and posttreatment and the reduction in the PANSS negative subscore. These findings suggest that risperidone treatment significantly decreased the blood SOD levels of schizophrenic patients, a change which may be associated with the diminishment of symptoms. The limitations of this study are the measurement of SOD levels by RIA rather than biochemical assay; the 2-week washout, which may not be adequate; and the measurement of only SOD enzyme and not the other antioxidant enzymes.
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PMID:The effect of risperidone treatment on superoxide dismutase in schizophrenia. 1264 Feb 13

Transgenic technology, especially the use of homologous recombination to disrupt specific genes to produce knockout mice, has added considerably to the understanding of dopamine (DA) neuron develop, survival and function. The current review summarizes results from knockout mice with the target disruption of genes involved in the development of DA neurons (engrailed 1 and 2, lmx1b, and Nurr1), in maintaining DA neurotransmission (tyrosine hydroxylase, vesicular monoamine transporter, DA transporter, DA D2 and D3 receptors) and important for DA neuron survival (alpha-synuclein, glia cell line-derived neurotrophic factor and superoxide dismutase). As alterations in DA neurotransmission have been implicated in a number of human neuropathologies including Parkinson's disease, schizophrenia and attention deficit/hyperactivity disorder, understanding how specific genes are involved in the function of DA neurons and the compensatory changes that result from loss or reduction in gene expression could provide important insight for the treatment of these diseases.
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PMID:The control of dopamine neuron development, function and survival: insights from transgenic mice and the relevance to human disease. 1267 88

Glutathione (GSH) is the main non-protein antioxidant and plays a critical role in protecting cells from damage by reactive oxygen species (ROS) generated by dopamine (DA) metabolism. We reported a decrease of GSH levels ([GSH]) in CSF and in prefrontal cortex in vivo in schizophrenics [Eur. J. Neurosci. 12 (2000) 3721]. A GSH deficit may lead to membrane peroxidation and microlesions around dopaminergic terminals, resulting in loss of connectivity. To test this hypothesis, we studied the effect of DA in cultured cortical neurons with low [GSH]. DA alone decreased [GSH] by 40%. This effect appears to result from direct conjugation of DA semiquinone/quinone with GSH. Ethacrynic acid (EA) decreased [GSH] in a concentration-dependent manner. When added to EA, DA further lowers [GSH]. As this additional decrease is blocked by superoxide dismutase (SOD) or D(1)/D(2) receptor antagonists, it likely involves the generation of superoxide via activation of DA receptors. It also reduces the mitochondrial membrane potential. Most interestingly, a significant decrease in number of neuronal processes (spines analogous) was induced by 24-h application of DA only in low [GSH]. These data, compatible with our hypothesis, is consistent with the dendritic spines reduction reported in schizophrenia and could be related to abnormalities in synaptic connectivity.
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PMID:Dopamine-induced oxidative stress in neurons with glutathione deficit: implication for schizophrenia. 1283 17

Neuroanatomical studies suggest that neuronal atrophy and destruction occur over the course of many years in neurodegenerative conditions such as schizophrenia and Alzheimer's disease. In schizophrenia, early intervention with atypical neuroleptics such as olanzapine has been shown to prevent development of some of the more serious and debilitating symptoms in many patients. The mechanisms whereby olanzapine slows or prevents symptom progression in schizophrenia remain unclear. A previous study found that olanzapine increased mRNA for the copper/zinc isoform of the superoxide dismutase enzyme (SOD-1). We investigated the effects of olanzapine in PC12 cells exposed to hydrogen peroxide. We measured cell viability, observed evidence of necrosis and apoptosis, checked the SOD-1 mRNA by Northern blot analyses, and determined SOD-1 enzyme activity. We found that: (1) the decrease in cell viability induced by hydrogen peroxide was attenuated in PC12 cells pretreated with olanzapine; (2) olanzapine increased SOD enzyme activity in PC12 cells; (3) inhibiting SOD activity with diethyldithiocarbamic acid prevented the cytoprotective actions of olanzapine; and (4) the decrease in SOD-1 mRNA level induced by hydrogen peroxide was blocked by pretreatment with olanzapine. These data indicate that the neuroprotective action of olanzapine includes the upregulation of SOD.
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PMID:Olanzapine protects PC12 cells from oxidative stress induced by hydrogen peroxide. 1286 70

Omega-3 (omega-3) is an essential fatty acid (EFA) found in large amounts in fish oil. It contains eicosapentaenoic acid and docosahexaenoic acid (DHA). DHA is one of the building structures of membrane phospholipids of brain and necessary for continuity of neuronal functions. Evidences support the hypothesis that schizophrenia may be the result of increased reactive oxygen species mediated neuronal injury. Recent reports also suggest the protective effect of omega-3 EFA against neuropsychiatric disorders including schizophrenia. This study proposed to assess the changes in antioxidant enzyme and oxidant parameters in the corpus striatum (CS) of rats fed with omega-3 EFA diet (0.4g/kg/day) for 30 days. Eight control rats and nine rats fed with omega-3 were decapitated under ether anesthesia, and CS was removed immediately. Thiobarbituric acid-reactive substances (TBARS) and nitric oxide (NO) levels as well as total superoxide dismutase (t-SOD) and xanthine oxidase (XO) enzyme activities in the CS were measured. Rats treated with omega-3 EFA had significantly lower values of TBARS (P<0.001), NO (P<0.002) and XO (P<0.005) whereas higher values of t-SOD enzyme activity (P<0.002) than the control rats. These results indicate that omega-3 EFA rich fish oil diet reduces some oxidant parameters in CS. This may be revealed by means of reduced CS TBARS levels as an end product of lipid peroxidation of membranes in treated rats. Additionally, reduced XO activity and NO levels may support this notion. On the other hand, although the mechanism is not clear, omega-3 EFA may indirectly enhance the activity of antioxidant enzyme t-SOD. Taken together, this preliminary animal study provides strong support for a therapeutic effect of omega-3 EFA supplemented to classical neuroleptic regimen in the treatment of schizophrenic symptoms and tardive dyskinesia.
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PMID:Potential role of dietary omega-3 essential fatty acids on some oxidant/antioxidant parameters in rats' corpus striatum. 1290 35

There is increasing evidence that psychological stress and depression trigger changes in various biochemical parameters in animals and in human subjects. In order to study these effects, the impact of chronic mild stress (CMS) on rats, and of the subsequent administration of Banxia-houpu decoction and fluoxetine, were studied regarding their effects on the following biochemical parameters: 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) levels in various brain regions, natural killer (NK) cell and lymphokine-activated killer (LAK) cell activities in spleen, serum lipid profiles including total cholesterol (TC), high density lipoprotein cholesterol (HDLc), low density lipoprotein cholesterol (LDLc) and triglyceride (TG), liver superoxide dismutase (SOD) and nitric oxide synthase (NOS) activities, serum malondialdehyde (MDA), and interleukin-2 (IL-2) levels. The effects of drug administration on preference behavior for consumption of sucrose solution were also assessed. Rats subjected to CMS exhibited a reduction in sucrose intake, 5-HT, 5-HIAA, IL-2, TC, HDLc and LDLc levels, as well as, diminished NK cell and LAK cell activities. Conversely, liver SOD and NOS activities and serum TG and MDA levels were increased following CMS exposures. Administration of Banxia-houpu decoction and fluoxetine produced beneficial effects on the stressed rats by improving sucrose consumption. This behavioral change was accompanied by amelioration of numbers CMS-induced biochemical changes. Banxia-houpu decoction is a traditional Chinese prescription containing pinellia tuber, magnolia bark, hoelen, perilla herb and ginger rhizome, and has been used for centuries in China to treat mental diseases including depression and schizophrenia. However, the pharmacological profile of the decoction is different from that of fluoxetine. These findings suggest that the therapeutic actions of Banxia-houpu decoction are due to a combination of multiple biochemical effects, and may help to elucidate the mechanisms through which distinct biochemical parameters play a role in the etiology of depression.
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PMID:Behavioral and biochemical studies on chronic mild stress models in rats treated with a Chinese traditional prescription Banxia-houpu decoction. 1457 13

A role of indices of oxidative stress, oxidative injury, and abnormal membrane phospholipid, specifically the phospholipid essential polyunsaturated fatty acids (EPUFAs) metabolism has been suggested based on studies in separate groups of patients with or without medication. The current study investigated the relationship between these biochemical measures in first-episode psychotic patients (N=16) at baseline and after 6 months of antipsychotic treatment (N=5 each with risperidone and olanzapine) and compared them to matched normal subjects. The indices of oxidative stress included: antioxidant enzymes; superoxide dismutase, glutathione peroxidase and catalase; and the oxidative injury as the levels of plasma lipid peroxides. The key membrane EPUFA's been; linolenic acid, arachidonic acid, nervonic acid, docosapentaenoic acid and docosahexaenoic acid. Furthermore, the changes in these biochemical measures were correlated with clinical symptomatology. Data indicated that, at baseline, reduced levels of antioxidant enzymes were associated with increased plasma lipid peroxides and reduced membrane EPUFAs, particularly omega-3 fatty acids. Furthermore, these biochemical measures normalized after 6 months of antipsychotic treatment. Parallel-improved psychopathology indicated that membrane EPUFA status might be partly affected by oxidative damage, which together may contribute to the pathophysiology and thereby, psychopathology of schizophrenia. These data also support the augmentation of antipsychotic treatment by supplementation with a combination of antioxidants and omega-3 fatty acids.
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PMID:Red blood cell membrane essential fatty acid metabolism in early psychotic patients following antipsychotic drug treatment. 1462 92

Oxidative stress-mediated cell damage has been considered in the pathophysiology of schizophrenia. Abnormal findings have often been considered related to differences in ethnicity, life style, dietary patterns and medications, all of which influence indices of oxidative stress and oxidative cell damage. To minimize these confounds, schizophrenic patients were compared with age-matched control subjects with the same ethnic background and similar lifestyle, as well as with bipolar mood disorder (BMD) patients. Levels of antioxidant defense enzymes (i.e. superoxide dismutase, SOD; catalase, CAT; and glutathione peroxidase, GPx) were lower in schizophrenic patients than in controls, indicating conditions for increased oxidative stress. The contents of plasma thiobarbituric acid reactive substances (TBARS) were only marginally higher in schizophrenic patients, who had normal levels of arachidonic acid (AA), a major source of TBARS, indicating no significant oxidative membrane lipid peroxidation. Levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), however, were significantly lower in schizophrenic patients. When the same indices in BMD patients were compared with findings in matched controls, levels of only SOD and CAT were lower in the patients, whereas GPx was not. Again, as in schizophrenia, the contents of TBARS were marginally higher in BMD patients with no change in levels of AA. Levels of alpha-linolenic acid and EPA were significantly lower and levels of DHA were slightly lower in BMD patients. These data indicate that certain biochemical characteristics may be common to a spectrum of psychiatric disorders, and suggest supplementation of antioxidants and essential fatty acids might affect clinical outcome.
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PMID:Decreased antioxidant enzymes and membrane essential polyunsaturated fatty acids in schizophrenic and bipolar mood disorder patients. 1465 46

There is evidence to suggest the derangement of the oxidant and antioxidant defense system in schizophrenia. The present study examined the effect of atypical antipsychotics on lipid peroxidation, superoxide dismutase (SOD) and ascorbic acid. For this purpose, a prospective, open-label, 8-week study design was utilized. Serum SOD, serum malondialdehyde (MDA) and plasma ascorbic acid were estimated. Schizophrenic patients (n = 48) were compared with age- and sex-matched healthy volunteers (n = 40). There was a significant increase in serum SOD, serum MDA and a decrease in plasma ascorbic acid in schizophrenic patients as compared to control subjects. The trend altered significantly after the treatment with atypical antipsychotics. The results of the Brief Psychiatric Rating Scale for schizophrenia also improved with the treatment. The findings indicate an involvement of free radicals in schizophrenia and its modification by treatment with atypical antipsychotics. This study can also be used as a predictor of drug response by atypical antipsychotics in schizophrenia.
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PMID:Oxidative damage and schizophrenia: the potential benefit by atypical antipsychotics. 1515 99

Phospholipids located in the cellular membrane play a critical role in the fluid-mosaic model of membrane structure and membrane function. Evidence is mounting for the role of abnormal phospholipid metabolism in some neuropsychiatric disorders including schizophrenia. As an important essential fatty acid (EFA), omega-3 (omega-3) fatty acid series are found in large amounts in fish oil. The aim of this experimental study was to assess the changes of some of the oxidant and antioxidant parameters in the hypothalamus of rats fed with omega-3 EFA diet (0.4 g/kg/day) for 30 days. Eight control rats and nine rats fed with omega-3 were decapitated under ether anesthesia, and hypothalamus was removed immediately. Malondialdehyde (MDA) and nitric oxide (NO) levels as well as superoxide dismutase (SOD) and xanthine oxidase (XO) enzyme activities in the hypothalamus were measured. SOD activity was significantly decreased in omega-3 EFA treated group compared to control group (p < 0.014). Tissue MDA and NO levels were also decreased in omega-3 EFA treated group compared to control rats (p < 0.0001). Xanthine oxidase activity was found to be increased in omega-3 EFA treated rats when compared to the control group (p < 0.0001). Taken together, this preliminary animal study provides strong support for a therapeutic effect of omega-3 EFA in some neuropsychiatric disorders in which reactive oxygen species (ROS) are recently accused to be an important physiopathogenetic factor.
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PMID:Hypothalamic superoxide dismutase, xanthine oxidase, nitric oxide, and malondialdehyde in rats fed with fish omega-3 fatty acids. 1527 95


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