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Öğe Evidence that the activities of erythrocyte free radical scavenging enzymes and the products of lipid peroxidation ape increased in different forms of schizophrenia(Springernature, 2001) Herken, H; Uz, E; Özyurt, H; Sögüt, S; Virit, O; Akyol, ÖIn order to examine antioxidant status and lipid peroxidation in schizophrenia patients, activities of three free radical scavenging enzymes (superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT)), and the level of thiobarbituric acid-reactive substances (TBARS) as an index of lipid peroxidation have been studied in red blood cells. Schizophrenic patients were divided into three groups (disorganized (n = 21), paranoid (n = 26) and residual types (n = 18)) to determine differences between subgroups. SOD, CAT and GSH-Px activities in the control group were found to be 1461.0 +/- 248.6 U g(-1) Hb, 148.2 +/- 59.3 k g(-1) Hb and 25.87 +/- 4.25 U g(-1) Hb, respectively. We found no significant differences in SOD activities between study and control groups. There was a significant increase in SOD activity in the residual group compared to the paranoid group (P < 0.005). CAT activity was found to be increased in disorganized (148%), paranoid (147%), and residual (165%) groups compared to the control group. GSH-Px activity was markedly increased in the study groups except the paranoid group. Statistically significant (3-4 fold) increases in TBARS levels of red blood cells were found in all the study groups. It is proposed that antioxidant status may be changed in schizophrenia and thus may induce lipid peroxidation. Therefore, oxidative stress may have a pathophysiological role in all the subtypes of schizophrenia.Öğe Increased nitric oxide and superoxide dismutase levels in euthymic bipolar patients: Impact of past episodes(Federation Amer Soc Exp Biol, 2005) Gergerlioglu, HS; Savas, HA; Armutcu, F; Herken, H; Zoroglu, SS; Tutkun, H; Yilmaz, HR[Abstract Not Available]Öğe The indices of endogenous oxidative and antioxidative processes in plasma from schizophrenic patients The possible role of oxidant/antioxidant imbalance(Pergamon-Elsevier Science Ltd, 2002) Akyol, Ö; Herken, H; Uz, E; Fadillioglu, E; Ünal, S; Sögüt, S; Özyurt, HThere is great evidence in recent years that oxygen free radicals play an important role in the pathophysiology of schizophrenia. The present study was performed to assess the changes in plasma nitric oxide (NO) and thiobarbituric acid-reactive substances (TBARS) levels, and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and xanthine oxidase (XO) activities in schizophrenic patients compared to age- and sex-matched normal controls. A hundred patients with schizophrenia and 51 healthy volunteers were included in the study. XO, SOD, and GSH-Px activities as well as NO and TBARS levels were estimated by standard biochemical techniques in the plasma of normal healthy controls and schizophrenia patients. In schizophrenia, increased plasma XO activity (P<.0001) and NO levels (P<.0001), decreased SOD activity (P<.0001), and unchanged GSH-Px activity were detected compared to control group. Plasma TBARS levels were increased in schizophrenic patients (P<.01), especially in the residual subtype. TBARS levels in nonsmoker schizophrenic patients were found to be higher than nonsmoker controls. Although TBARS levels in both patients and controls were found to be higher in smokers as compared to nonsmokers, it was not statistically significant. No effects of duration of the illness, gender, and low and high dose of daily neuroleptic treatment equivalent to chlorpromazine on oxidant and antioxidant parameters were observed. Because the dose and the duration of treatment with drugs have no influence on the results, it can be interpreted that the findings are more likely to be related mainly to the underlying disease. These findings indicated a possible role of increased oxidative stress and diminished enzymatic antioxidants, both of which may be relevant to the pathophysiology of schizophrenia. On the other hand, increased NO production by nitric oxide synthetases (NOSs) suggests a possible role of NO in the pathophysiological process of schizophrenia. These findings may also suggest some clues for the new treatment strategies with antioxidants and NO synthase (NOS) inhibitors in schizophrenia. (C) 2002 Elsevier Science Inc. All rights reserved.Öğe Is the arginine-nitric oxide pathway involved in the pathogenesis of schizophrenia?(Karger, 2003) Yanik, M; Vural, H; Kocyigit, A; Tutkun, H; Zoroglu, SS; Herken, H; Savas, HAThe reciprocal regulation of arginase and nitric oxide synthase (NOS) in L-arginine-metabolizing pathways has been demonstrated. There are various evidences of the role of the nitric oxide (NO) in several neuropsychiatric disorders including schizophrenia. However, there is no study which has investigated the role of arginase as an important part of the arginine regulatory system affecting NOS activity in schizophrenia. This study aims to investigate arginase, manganese (Mn) and total nitrite levels (a metabolite of NO) and their relationship to the arginine-NO pathway in patients with schizophrenia. Arginase activities, Mn and total nitrite levels were measured in plasma from 46 patients with schizophrenia and 32 healthy control subjects. Plasma arginase activities and Mn were found to be significantly lower and total nitrite level higher in patients with schizophrenia compared with controls. Our results suggest that the arginine-NO pathway is involved in the pathogenesis of schizophrenia. Copyright (C) 2003 S. Karger AG, Basel.Öğe The possible pathophysiological role of plasma nitric oxide and adrenomedullin in schizophrenia(Pergamon-Elsevier Science Ltd, 2002) Zoroglu, SS; Herken, H; Yürekli, M; Uz, E; Tutkun, H; Savas, HA; Bagci, CEvidence is accumulating for a possible role of nitric oxide (NO) in schizophrenia. Adrenomedullin (AM) induces vasorelaxation by activating adenylate cyclase and also by stimulating the release of NO. AM immune reactivity is present in the brain consistent with a role as neurotransmitter. We aimed to examine plasma levels of nitrite (a metabolite of NO) and AM in schizophrenic patients. Eighty-two patients with schizophrenia and 21 healthy control subjects were included in this study. DSM-IV diagnosis of chronic schizophrenia was established on the basis of independent structured clinical interviews and review of records by two qualified psychiatrists which included the Brief Psychiatric Rating Scale (BPRS), The Scale for the Assessment of Negative Symptoms (SANS) and The Scale for the Assessment of Positive Symptoms (SAPS). Total nitrite and AM have been studied in plasma. The mean values of plasma nitrite and AM levels in schizophrenic group were significantly higher than control values, respectively (P = 0.03, P < 0.0001). AM levels of schizophrenic patients were three fold higher than controls. In correlation analyses, there were statistically significant positive correlations between AM level and SAPS-delusion subscale (r = 0.27, P = 0.04); SAPS-bizarre behavior subscale (r = 0.28, P = 0.03) and SAPS-total (r = 0.36, P = 0.005). There is no correlation between total nitrite and AM levels (r = 0.11, P = 0.31). Both NO and AM may have a pathophysiological role in schizophrenia, and clinically symptomatology and prognosis of schizophrenia. This subject needs further study including treatment response and subtypes of schizophrenia. (C) 2002 Elsevier Science Ltd. All rights reserved.Öğe Possible role of nitric oxide and adrenomedullin in bipolar affective disorder(Karger, 2002) Savas, HA; Herken, H; Yürekli, M; Uz, E; Tutkun, H; Zoroglu, SS; Özen, MENitric oxide (NO) has been implicated to play a role in the pathogenesis of depressive disorders. Adrenomedullin (AM) induces vasorelaxation by activating adenylate cyclase and also by stimulating the release of NO. AM immune reactivity is present in the brain, consistent with a role as neurotransmitter. Therefore, it is suggested that these two molecules may play a role together in the brain. We aimed to examine AM and NO in bipolar affective disorder (BPAD). Forty-four patients with BPAD and 21 healthy control subjects were included in this study. DSM-IV diagnosis of bipolar affective disorder (type 1, manic episodes) was independently established by two psychiatrists and the Turkish version of the Bech-Rafaelson Mania Scale was administered. Also, a semistructured form was used to ascertain several sociodemographic and clinical variables of the patients. AM and NO were studied in plasma. The mean value of plasma NO levels in the BPAD group of 46.58 +/- 13.97 mumol/l was significantly higher than that of controls (31.81 +/- 8.14 mumol/l) (z = -4.15, p = 0.000). Mean plasma AM levels were found to be increased in patients with BPAD (35.13 +/- 5.26 pmol/l) compared to controls (16.22 +/- 3.02 pmol/l) (z = -6.16, p = 0.000). AM levels of BPAD patients were approximately 2-fold higher than controls. AM levels were positively correlated with the duration of hospitalization for the current episode and negatively correlated with the total duration of illness. Both NO and AM may have a pathophysiological role in BPAD (type I, manic episodes) and the clinical symptomatology and prognosis of BPAD. Copyright (C) 2002 S. Karger AG, Basel.Öğe Red blood cell nitric oxide levels in patients with schizophrenia(Elsevier Science Bv, 2001) Herken, H; Uz, E; Özyurt, H; Akyol, Ö[Abstract Not Available]Öğe The role of the arginine-nitric oxide pathway in the pathogenesis of bipolar affective disorder(Springer Heidelberg, 2004) Yanik, M; Vural, H; Tutkun, H; Zoroglu, SS; Sava, HA; Herken, H; Koçyigit, AThere is a reciprocal regulation of arginase and nitric oxide synthase (NOS) in L-arginine-metabolizing pathways. Nitric oxide (NO) may be involved in some psychiatric disorders like schizophrenia, depression and bipolar affective disorder (BPAD). To our knowledge, there is no study in the literature in which the role of arginase, an important part of the arginine regulatory system affecting NOS activity, was investigated in BPAD. This study aims to investigate arginase, manganese (Mn) and total nitrite levels (a metabolite of NO) and their relationship to the arginine-NO pathway in patients with BPAD. Arginase activities, Mn and total nitrite levels were measured in plasma from forty-three patients with BPAD (Type one) and thirty-one healthy control subjects. Plasma arginase activities and Mn were found to be significantly lower and total nitrite level higher in patients with BPAD compared with controls. Our results suggest that the arginine-NO pathway is involved in the pathogenesis of BPAD.
