Oxidative stress and antioxidant status in non-metastatic prostate cancer and benign prostatic hyperplasia

OBJECTIVES: We undertook the present study to investigate the possible alteration of oxidant/antioxidant status in the circulation of patients with prostate cancer and benign prostatic hyperplasia. DESIGN AND METHODS: Thiobarbituric acid reactive substances (TBARS), the enzyme activities of superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT) and copper (Cu) and zinc (Zn) levels were estimated in the erythrocytes of 25 non-metastatic prostate cancer patients, 36 benign prostatic hyperplasia (BPH) patients and 24 age- and sex-matched healthy subjects (controls). RESULTS: TBARS concentrations were significantly increased, while erythrocyte GPX and SOD activities were significantly decreased in the prostate cancer group versus controls (P < 0.001) and BPH group (P < 0.05). Zn levels were lowered in prostate cancer patients versus controls (P < 0.01) with no significant changes between BPH and cancer groups. Similarly, lipid peroxidation was increased (P < 0.05) with decreased SOD activity and Zn level (P < 0.05) in BPH versus controls. CONCLUSION: These results reveal an alteration in the lipid peroxidation index, with concomitant changes in the antioxidant defense system in prostate cancer patients compared to BPH patients. We hypothesize that an altered prooxidant-antioxidant balance may lead to an increase in oxidative damage and consequently may play an important role in prostate carcinogenesis.     

Erythrocyte antioxidant enzyme activities and lipid peroxidation in patients with types IIb and IV hyperlipoproteinemias

We measured lipid peroxidation and antioxidant enzymes in erythrocytes of types IIb and IV hyperlipoproteinemic (HLP) human subjects in comparison with age-matched controls. Thiobarbituric acid-reactive substances (TBARS), a measure of lipid peroxidation, glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), glutathione reductase (GR), and catalase (CAT) were determined in erythrocytes. We also measured lipid parameters including triglycerides (TG), total cholesterol (TC), HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C), apolipoprotein AI, and apolipoprotein B, and antioxidant related substances such as serum albumin, free iron, ferritin, ceruloplasmin. Thirty-two subjects (females 15, males 17) with type IIb (the mean age 45.6+/-8 [S.E.]), 34 with type IV (females 16, males 18) (the mean age 47+/-10 [S.E.]), and 36 normolipidemic voluntary subjects (females 18, males 18) (the mean age 46+/-8 [S.E.]) were included in the study. Erythrocytes were prepared by classical washing method (0.9% NaCl) from venous blood samples. The mean TBARS levels in plasma and erythrocyte suspensions were found to be significantly higher in both types IIb and IV hyperlipoproteinemics. Erythrocyte SOD and GSH-Px activities were decreased but erythrocyte GR activity did not change in both types IIb and IV hyperlipoproteinemics. Erythrocyte CAT activity was decreased in type IIb, but it was increased in type IV hyperlipoproteinemics. Erythrocyte SOD activity was negatively correlated with plasma TG level, whereas plasma free iron was positively correlated with plasma TBARS level in type IV hyperlipoproteinemics. These results suggest the presence of oxidative injury in patients with type IIb or IV hyperlipoproteinemia, and that the responses of erythrocyte antioxidant enzymes to oxidant stress are different in these conditions.     

Lipid peroxidation, osmotic fragility and antioxidant status in children with acute post-streptococcal glomerulonephritis.

Plasma and erythrocyte samples from acute post-streptococcal glomerulonephritis (APSGN) children and control children were enrolled in this study. Lipid peroxidation (LPO), measured in terms of thiobarbituric acid-reactive substances (TBARS) was found to be significantly increased in plasma and RBCs of APSGN children (P<0.05) than in control children. Osmotic fragility of erythrocytes was examined. RBCs of APSGN patients were found to be osmotically more sensitive towards hypotonic saline (50% hemolysis at 7 g/l saline) when compared to control RBCs (50% hemolysis at 4 g/l saline). The activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferase (GST) were significantly lowered (P<0.05) in APSGN RBCs when compared to control RBCs. Plasma ascorbic acid, reduced glutathione (GSH), RBC ascorbic acid, GSH and RBC total sulphydryl content (TSH) were significantly depleted in APSGN children relative to controls. The susceptibility of RBCs of APSGN children to lipid peroxidation was confirmed in this study.     

The effect of vitamin E supplementation on antioxidant enzyme activities and lipid peroxidation levels in hemodialysis patients

BACKGROUND: This study has been undertaken to investigate the possible alterations of oxidant/antioxidant status in uremic patients undergoing hemodialysis (HD) and the effects of vitamin E supplementation. METHODS: Erythrocyte antioxidant enzyme activities [glutathione peroxidase (GSHPx), superoxide dismutase (SOD) and catalase (CAT)] and thiobarbituric acid reactive substance (TBARS) concentrations as a measure of lipid peroxidation in HD patients have been determined and compared with healthy controls. The patient group consisted of 36 uremic patients 21-75 years of age undergoing maintenance HD three times weekly for an average of 41 months. The efficiency of Vitamin E therapy in dialysis patients was also assessed by re-evaluating antioxidant status of the same patients after supplementation of the vitamin E in a dosage of 600 mg/daily for 14 weeks. RESULTS: A significant decrease in the activities of erythrocyte SOD, CAT and GSHPx and a significant increase in TBARS concentrations were found in patient group compared to control group (p<0.001). A significant correlation between GSHPx activities and duration of HD therapy was also observed (r=-0.46, p<0.01). Vitamin E supplementation caused an increase in GSHPx and SOD activities and a decrease in TBARS concentrations. A slight but not significant increase in CAT activity was also observed by Vitamin E. CONCLUSIONS: The results suggest the presence of an oxidative activity and the possible preventive role of Vitamin E therapy in uremic patients undergoing HD.     

Oxidative stress and nitric oxide related parameters in type II diabetes mellitus: effects of glycemic control

OBJECTIVES: The aim of this study is to investigate the status of oxidative stress and nitric oxide related parameters in type II diabetes mellitus (DM) patients in which heart disease, atherosclerosis, retinopathy, and nephropathy commonly occur, and also to determine the effect of glycemic control on these parameters. DESIGN AND METHODS: Erythrocyte copper zinc-superoxide dismutase (CuZn-SOD), erythrocyte and plasma selenium dependent glutathione peroxidase (Se-GPx), erythrocyte catalase (CAT) activities, erythrocyte and plasma thiobarbituric acid reactive substances (TBARS) levels; nitrite/nitrate (NO(2)(-)/NO(3)(-)), cyclic guanosine monophosphate (cGMP) and nitrotyrosine levels in plasma of type II DM patients were measured. RESULTS: Erythrocyte CuZn-SOD activities in type II DM were significantly higher than those of the control subjects (p < 0.05). TBARS levels in type II DM were significantly higher than the control subjects (p < 0.001). Plasma NO(2)(-)/NO(3)(-) levels in type II DM patients both during poor glycemic control and after three months of oral antidiabetic treatment were significantly higher than those of the control subjects (p < 0.001). Plasma cGMP levels in type II DM patients during poor glycemic control were significantly lower than those of control subjects (p < 0.001). CONCLUSION: These results indicate that oxidative status and nitric oxide metabolism are affected in type II DM patients. We found high CuZn-SOD activity in type II DM patients. This increased activity could not protect the patients against the reactive oxygen species (ROS), since lipid peroxidation (defined by erythrocyte and plasma TBARS levels) still occurs in DM patients. After the therapy with oral antidiabetic agents for three months, erythrocyte SE-GPx and CAT activities were found to be decreased below the control values. Our results suggested that the low cGMP levels in the study may be a good marker of endothelium dysfunction in DM.     

Effect of pentylenetetrazol-induced epileptic seizure on the antioxidant enzyme activities, glutathione and lipid peroxidation levels in rat erythrocytes and liver tissues

OBJECTIVES: In order to clarify whether oxidative stress accompanies epilepsy, we examined the effects of pentylenetetrazol (PTZ)-induced epilepsy on the lipid peroxidation and antioxidant enzyme activities in erythrocytes and liver tissues of adult Wistar rats. MATERIALS AND METHODS: The activities of antioxidative enzymes (glucose-6-phosphate dehydrogenase (G-6-PD)), copper, zinc-superoxide dismutase (Cu,Zn-SOD), catalase (CAT), selenium-dependent glutathione peroxidase (Se-GSH-Px) and the levels of reduced glutathione (GSH) and thiobarbituric acid-reactive substances (TBARS) were measured in erythrocytes and liver tissues of pentylenetetrazol (PTZ)-induced epileptic adult Wistar rats. RESULTS: Single PTZ treatment in a convulsive dose of 50 mg/kg significantly reduced the erythrocyte Cu,Zn-SOD, CAT enzyme activities and GSH levels compared to controls (P < 0.001, P < 0.001, P < 0.05, respectively). Erythrocyte and liver tissue TBARS levels in the epileptic group were significantly higher than controls (P < 0.0001). There was a significant decrease in liver tissue Cu,Zn-SOD activity and GSH levels in the epileptic group (P < 0.0001), whereas significantly higher activities of G-6-PD and Se-GSH-Px were found in the epileptic group. CONCLUSIONS: Our results demonstrate a generalized diminished antioxidant activity and increased TBARS level indicating enhanced oxidative stress in the liver and erythrocytes of epileptic rats. Increased oxidative stress in the liver of epileptic rats might be due to the activation of the recently found glutamate receptors in the liver. These findings suggest that the use of antioxidants with antiepileptic drugs and new drugs such as type-5 metabotropic glutamate receptor (mGlu5) antagonist (MPEP) might protect erythrocytes and liver tissue against anoxic damage and oxidative stress.     

超氧化物歧化酶及其同工酶和超敏C-反应蛋白与冠心病的关系

目的 探讨超氧化物歧化酶(T-SOD)及其同工酶锰超氧化物歧化酶(Mn-SOD)活性、超敏C-反应蛋白(hs-CRP)浓度变化与冠心病(CHD)的关系。方法 共81例冠心病患者及60例健康体检者参与研究,分别采用比色法和胶乳增强免疫比浊法测定被检者血清T-SOD,Mn-SOD和Hs-CRP。结果 和健康对照组相比,冠心病患者组T-SOD和Mn-SOD的活性显著降低(t=9.41,6.34,均P<0.01),Hs-CRP浓度显著增高,差异有统计学意义(t=3.09,P<0.05); T-SOD,Mn-SOD活性和Hs-CRP浓度呈负相关,差异有统计学意义(P<0.01)。结论 T-SOD,Mn-SOD和Hs-CRP水平变化与冠心病的发生、发展密切相关,可作为冠心病患者危险因素评估的重要指标,联合检测分析T-SOD,Mn-SOD和hs-CRP的相关性对冠心病的临床诊治及预后有一定的指导意义。     

Zinc supplementation ameliorates electromagnetic field-induced lipid peroxidation in the rat brain

Extremely low-frequency (0-300 Hz) electromagnetic fields (EMFs) generated by power lines, wiring and home appliances are ubiquitous in our environment. All populations are now exposed to EMF, and exposure to EMF may pose health risks. Some of the adverse health effects of EMF exposure are lipid peroxidation and cell damage in various tissues. This study has investigated the effects of EMF exposure and zinc administration on lipid peroxidation in the rat brain. Twenty-four male Sprague-Dawley rats were randomly allocated to three groups; they were maintained untreated for 6 months (control, n = 8), exposed to low-frequency (50 Hz) EMF for 5 minutes every other day for 6 months (n = 8), or exposed to EMF and received zinc sulfate daily (3 mg/kg/day) intraperitoneally (n = 8). We measured plasma levels of zinc and thiobarbituric acid reactive substances (TBARS), and levels of reduced glutathione (GSH) in erythrocytes. TBARS and GSH levels were also determined in the brain tissues. TBARS levels in the plasma and brain tissues were higher in EMF-exposed rats with or without zinc supplementation, than those in controls (p < 0.001). In addition, TBARS levels were significantly lower in the zinc-supplemented rats than those in the EMF-exposed rats (p < 0.001). GSH levels were significantly decreased in the brain and erythrocytes of the EMF-exposed rats (p < 0.01), and were highest in the zinc-supplemented rats (p < 0.001). Plasma zinc was significantly lower in the EMF-exposed rats than those in controls (p < 0.001), while it was highest in the zinc-supplemented rats (p < 0.001). The present study suggests that long-term exposure to low-frequency EMF increases lipid peroxidation in the brain, which may be ameliorated by zinc supplementation.     

Measurement of erythrocyte lipids,lipid peroxidation,antioxidants and osmotic fragility in cervical cancer patients

BACKGROUND: Our aim was to examine the structural integrity of red blood cells in cervical cancer patients by measuring the concentrations of thiobarbituric acid reactive substances (TBARS), antioxidant status, cholesterol/phospholipid (C/P) molar ratio, enzyme activity and osmotic fragility of erythrocytes. METHODS: This study has been conducted on 32 adult female cervical cancer patients and an equal number of age- and sex-matched normal subjects. Erythrocyte concentrations of lipids, TBARS, vitamin E, reduced glutathione and enzymic activities of catalase and Na(+)K(+)-ATPase were measured as well as plasma concentrations of sodium and potassium. The present study also examined the changes in erythrocyte osmotic fragility in cervical cancer patients and normal subjects. The red cell fluidity and permeability were determined by estimating the C/P ratio and Na(+)K(+)-ATPase activity, respectively. RESULTS: The release of thiobarbituric acid reactive substances was significantly higher in cervical cancer patients as compared to normal subjects. The increased lipid peroxidation with concomitant decrease in antioxidants was notable in cervical cancer patients. Red blood cells of cervical cancer patients were more fragile than those from normal subjects. Increase in red cell membrane C/P ratio and Na(+)K(+)-ATPase activity was noticed in cervical cancer patients as compared to normal subjects. CONCLUSIONS: Increased lipid peroxidation, insufficient antioxidant potential and changes in C/P molar ratio as well as activity of Na(+)K(+)-ATPase cause structural and functional abnormalities in the erythrocytes of cervical cancer patients.     

高压氧治疗脑卒中的剂量研究

观察２２例脑卒中患者在高压氧治疗不同时期体内自由基代谢物质含量的变化。每天用０．２ＭＰａ高压氧稳压治疗４０ｍｉｎ，连续治疗２０天。结果发现，经高压氧连续治疗１０天，患者血浆ＬＰＯ含量的增加和红细胞ＳＯＤ、ＧＳＨＰｘ活性的下降都不明显（Ｐ＞０．０５），仅红细胞明显降低（Ｐ＜０．０５）；连续治疗２０天后，患者血浆ＬＰＯ含量明显增高，红细胞ＳＯＤ和ＧＳＨＰｘ活性及ＧＳＨ含量显著下降（Ｐ＜０．０５）。建议     

锰超氧化物歧化酶基因变异 与血脂和同型半胱氨酸水平的关系研究

目的 探讨锰超氧化物歧化酶(Mn-SOD)9 Ala/Val基因多态性与血脂和同型半胱氨酸(HCY)水平的关系。方法 应用测序法检测137例冠心病患者和85例对照组的Mn-SOD 9 Ala/Val基因多态性的基因型,应用比色法检测血清总超氧化物歧化酶(T-SOD)和Mn-SOD活性,应用终点法测定血清胆固醇(TC)、三酰甘油(TG)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)水平,应用酶法测定血清HCY水平。结果 冠心病组的Mn-SOD 9 VV基因型和V等位基因频率显著高于对照组。冠心病组的T-SOD和Mn-SOD活性显著低于对照组。Mn-SOD 9 VV基因型的T-SOD和Mn-SOD活性显著低于Mn-SOD 9 AA基因型。Mn-SOD 9 VV基因型的血清TC,TG,LDL-C和HCY水平显著高于Mn-SOD 9 AA基因型,HDL-C水平显著低于Mn-SOD 9 AA基因型。Mn-SOD活性与血清TC,TG,LDL-C和HCY水平呈负相关,与血清HDL-C水平呈正相关。结论冠心病患者机体的抗氧化能力降低。Mn-SOD 9 Ala/Val基因多态性通过影响Mn-SOD活性进而导致血脂代谢紊乱,促进冠心病的发生发展。HCY通过自身氧化和抑制Mn-SOD活性,致使体内氧化物质增多,增加冠心病的发病风险。     

Relation of erythrocyte Na+-K+ ATPase activity and cholesterol and oxidative stress in patients with type 2 diabetes mellitus

BACKGROUND: Diabetic patients are at high risk of atherosclerotic complications, and factors associated with this include hypercholesterolemia, hemorheologic disturbances in erythrocytes and oxidative stress. We, therefore, carried out a study in type 2 diabetic patients to determine the relationships of erythrocyte Na+-K+ ATPase activity, plasma cholesterol and oxidative stress in this population. METHODS: Erythrocyte Na+-K+ ATPase activity and its relationship between plasma cholesterol and thiobarbituric acid reactive substance (TBARS, a marker of oxidative stress) were studied in type 2 diabetic patients with (n = 26) or without angiopathy (n = 30). Na+-K+ ATPase activity was measured by a colorimetric enzymatic method. Plasma TBARS levels were determined spectrophotometrically. Diabetic patients were classified according to plasma cholesterol concentrations as normo- or hypercholesterolemic (plasma total cholesterol > 5.18 mmol/L). RESULTS: Diabetic patients with or without angiopathy had lower erythrocyte Na+-K+ ATPase activity (p < 0.001 and p < 0.001 respectively) and higher plasma TBARS levels than healthy subjects (n = 20) (p < 0.001 and p < 0.001 respectively). Na+-K+ ATPase activity in the diabetic patients with angiopathy was lower than in the diabetic patients without angiopathy (p < 0.001). In the diabetic patients both with and without angiopathy, hypercholesterolemic patients had lower erythrocyte Na+-K+ ATPase activity and higher plasma TBARS levels than normocholesterolemic patients (p < 0.001, p < 0.001 respectively) There was no difference in the plasma TBARS concentrations between diabetic patients with and without angiopathy. There were negative correlations between erythrocyte Na+-K+ ATPase activity and both plasma cholesterol (r = -0.72) and plasma TBARS (r = -0.46) and a positive correlation between plasma cholesterol and TBARS (r = 0.42). CONCLUSIONS: Elevated plasma cholesterol may be responsible for the inhibition of erythrocyte Na+-K+ ATPase activity. Together with elevated cholesterol, free radical-induced mechanisms may be involved in the inhibition of Na+-K+ ATPase activity.     

Redox status and lipid peroxidation in alcoholic hypertensive patients and alcoholic hypertensive patients with diabetes

Background: Free radical-mediated oxidative stress has been implicated in the progression of alcoholic hypertension and diabetic hypertension. Methods: The lipid peroxides and antioxidant status of plasma and erythrocytes were investigated in alcoholic hypertensive patients and alcoholic hypertensive patients with diabetes and compared with normal subjects. Results: A significant increase is observed in the levels of glucose, lipid peroxidation (P<0.05) in the alcoholic hypertensive patients with/without diabetes and the increase was significantly higher in alcoholic hypertensive patients with diabetes. The activities of erythrocyte antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and reduced glutathione (GSH) and plasma concentrations of GSH, vitamin C, vitamin E and β-carotene decreased significantly and the level of ceruloplasmin increased in alcoholic hypertensive patients with/without diabetes when compared to normal subjects. Plasma GSH and vitamin E levels exhibited a further decrease in alcoholic hypertensive patients with diabetes. Conclusions: An enhanced lipid peroxidation is observed in alcoholic hypertensive patients with diabetes and a more pronounced decrease in the levels of plasma GSH and vitamin E among antioxidants.     

The effect of dietary treatment on erythrocyte lipid peroxidation, superoxide dismutase, glutathione peroxidase, and serum lipid peroxidation in patients with type 2 diabetes mellitus

Objectives: The aim of the present study was to investigate the effect of dietary treatment on serum and erythrocyte lipid peroxidation and erythrocyte antioxidative enzyme activity of patients with Type 2 diabetes.

Design and methods: A total of 30 patients with newly diagnosed as Type 2 diabetes were enrolled to the study. A total of 30 healthy subjects served as controls. Diabetic patients were given standard dietary treatment that was composed of 50% to 55% carbohydrate and 30% fat for 2 months. No diet was applied for controls. For both groups serum and erythrocyte lipid peroxidation and erythrocyte superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were obtained at first and at the end of 2 months.

Results: Diabetic patients had higher serum and erythrocyte lipid peroxidation than those of controls before dietary treatment(p < 0.05). However, there was no absolute differences in erythrocyte SOD and GSH-Px (p > 0.05). At the end of 2 months of dietary treatment, while diabetics had still higher glucose and erythrocyte lipid peroxidation than controls (p < 0.05), serum lipid peroxidation, erythrocyte SOD, and GSH-Px levels did not differ significantly from those of controls (p > 0.05). In diabetic patients, after 2 months of dietary treatment, whereas serum and erythrocyte lipid peroxidation decreased, erythrocyte SOD and GSH-Px activities showed significant increase (p < 0.05).

Conclusions: Our results showed significant alteration in serum and erythrocyte lipid peroxidation and erythrocyte antioxidant enzyme status of patients with Type 2 diabetes by dietary treatment. However, whether such alterations have clinical importance for diabetic patients needs further investigation.     

The condition of the oxidant-antioxidant system of plasma and of blood erythrocytes in patients with severe renal insufficiency, anuria stage, due to compression trauma

The lipid peroxidation processes as well as the activity of the antioxidant system of plasma and of blood erythrocytes were analyzed in severe renal insufficiency due to acute compression trauma. The levels of diene conjugates, malonic dialdehyde and shiff bases were found to be reliably higher in plasma in the anuria stage; as for erythrocytes, only the level of the final peroxidation products, i.e. shiff bases, turned out to be higher in their case. The antioxidant system reaction was as follows: a reliable decrease of the ceruplasmin level was registered in blood plasma, and a reduced activity of superoxide dismutase was detected in erythrocytes. No changed catalase activity was registered either in plasma or erythrocytes versus the controls. The occurred lipid-peroxidation activation had, in the erythrocyte membranes, a negative effect on the protein-lipid contact zones. According to the obtained results, it is necessary to use antioxidants and activation of the non-enzyme system within the complex therapy for the purpose of preventing the secondary damage to cellular membranes.     

Oxidative stress and antioxidants in epilepsy

In the present study, erythrocyte membrane lipid peroxidation, the percentage hemolysis, erythrocyte enzymes superoxide dismutase (SOD), glutathione peroxidase (GP), glutathione reductase (GR), catalase, and plasma vitamin C, vitamin E, vitamin A and ceruloplasmin activities and concentrations were determined in 29 epileptic patients and 50 normal controls. Ten patients who were treated with phenobarbital and who did not get convulsions for 1 year were considered for followup. Lipid peroxidation and percentage hemolysis in patients with epilepsy was significantly higher when compared to controls. Moreover, plasma ceruloplasmin concentrations were also markedly increased in these cases. Erythrocyte GR and plasma vitamin C and A concentrations were significantly lower in epileptics when compared to controls. In the followup patients, the erythrocyte GR was significantly higher than their pre-treated condition. Furthermore, the plasma vitamin A, E and C concentrations have attained the normal range. This study indicates that the antioxidant status in blood of epileptic patients which was low compared to controls, improved after treatment, suggesting that free radicals may be implicated in epilepsy.     

Leucocyte glutathione peroxidase activity and selenium level in Batten's disease

The glutathione peroxidase (GSHPx) activity was found significantly reduced in whole lymphocytes from patients suffering from Batten's disease. By means of two different procedures for isolation of subcellular fractions of lymphocytes it was possible to demonstrate an increased GSHPx activity of the particulate fractions (20.000 g-av and 105.000 g-av precipitates). However, the GSHPx activity of the supernatants was decreased. The GSHPx activity of the 20.000 g-av supernatant correlated significantly with the serum selenium content both in normal controls and in Batten's disease. A similar correlation was traced with GSHPx activity of erythrocyte haemolysate and serum selenium level in Batten's disease but not in normal controls. The GSHPx activity was also found decreased in the 20.000 g-av and 105.000 g-av supernatants of granulocytes. The abnormal subcellular distribution of GSHPx activities was related to the distribution of enzymes which were used as markers for different subcellular components. The data presented are discussed in relationship to the theory that Batten's disease is due to an increased peroxidation damaging the cellular membranes.     

Erythrocyte superoxide dismutase and glutathione peroxidase activities, and malondialdehyde and reduced glutathione levels in schizophrenic patients.

There is abundant evidence that free radicals are involved in membrane pathology in the central nervous system and that they may play a role in neuropsychiatric disorders, including schizophrenia. In this study, we investigated erythrocyte superoxide dismutase and glutathione peroxidase activities as antioxidant enzymes, malondialdehydes as a sign of lipid peroxidation, and reduced glutathione levels in schizophrenic patients. Activities of superoxide dismutase and levels of malondialdehyde in erythrocytes were greater in all patients (n=48) and in patients with acute (n=16) and chronic schizophrenia (n=32) (p<0.001 for all patients and chronic patient group; p<0.05 for acute patient group). The activities of glutathione peroxidase were lower in patients (p<0.05 for all patients and acute patient group; p=0.051 for chronic patient group) compared with the control group. Mean erythrocyte reduced glutathione was lower in patients than in controls (p<0.05). In the patient group, erythrocyte superoxide dismutase activity was positively correlated with scales and duration of disease and erythrocyte malondialdehyde concentration. These data reveal that antioxidative defense mechanisms might be impaired in schizophrenic patients.     

Comparative analysis of plasma and erythrocyte 7-ketocholesterol as a marker for oxidative stress in patients with diabetes mellitus

OBJECTIVES: To reveal increased lipid peroxidation in diabetics by quantification of cholesterol oxidation products (COPs) not only in plasma, but also in erythrocytes. DESIGN AND METHODS: We quantified 7-ketocholesterol (7-kCho) by gas chromatography-mass spectrometry as a surrogate measure for COPs. These assays were performed on both plasma and erythrocytes in 20 control subjects and 20 treated patients with relatively poorly controlled Type 2 diabetes. RESULTS: Both plasma and erythrocyte 7-kCho levels in diabetics were significantly higher than those in control subjects. Although neither plasma nor erythrocyte 7-kCho levels were associated with markers for glucose tolerance in diabetics, a negative correlation of serum HDL-cholesterol levels with erythrocyte, but not plasma, 7-kCho levels was found. CONCLUSION: Increased oxidative stress in diabetics affects oxidation of cholesterol. Assays of COPs not only in plasma, but also in erythrocytes, may yield complementary information in lipid peroxidation.     

Time-level relationship between indicators of oxidative stress and Glasgow Coma Scale scores of severe head injury patients.

BACKGROUND: Oxidative stress is said to strongly influence the neurological recovery of patients following a severe head injury. Estimation of the markers of oxidative stress in the blood of such patients can hence aid in predicting the prognosis of head injury. METHODS: Erythrocyte thiobarbituric acid-reactive substances (TBARS) and plasma ceruloplasmin (CP) levels were estimated in 24 severe head-injury patients on days 1, 7 and 21 of the post-traumatic period and compared with levels in 25 healthy age- and sex-matched controls. These parameters reflecting oxidative stress status were related to the Glasgow Coma Scale (GCS) scores of patients noted at the same time points of the study period. RESULTS: Lipid peroxidation as indicated by increased levels of erythrocyte TBARS remained significantly elevated in severe head injury patients compared to controls on day 1 (p<0.001), day 7 (p<0.001) and 21 (p<0.001) of the post-traumatic period. Plasma CP levels remained significantly elevated (p<0.001) at these three time points compared to controls. The significant decrease in lipid peroxidation products (p<0.01) and significant increase in CP levels (p<0.001) on day 21 compared to day 1 in head injury patients correlated well with the significant improvement in GCS scores of patients on day 21 compared to day 1 (p<0.05). CONCLUSION: The above results could account for the adaptation of the study patients to severe oxidative stress, as evidenced by their clinical recovery trend during the study period.