Blood levels of alpha-1-antichymotrypsin and risk factors for Alzheimer's disease: effects of gender and apolipoprotein E genotype

Concentrations of alpha(1)-antichymotrypsin (ACT) were measured in serum or plasma samples from 137 patients with late-onset probable Alzheimer's disease (AD) and 89 controls. Levels of ACT from sera or plasma from both AD or controls were different, being highest in serum samples. Increased levels of serum or plasma ACT and normal levels of C-reactive protein (CRP) were found in AD. Differences in serum ACT levels between AD and controls were statistically significant, while those in plasma ACT were not. ACT serum levels were higher in women with AD that in female and male controls. Apolipoprotein E (APOE) genotypes did not independently affect blood ACT levels in both AD and controls; although, among AD patients, female AD patients with APOE 4,4 showed the highest level of serum ACT. The gender effect appeared to be prominent, since female AD patients with APOE 3,3 had similar ACT levels to those of female AD patients with APOE 4,4.     

帕金森病血抗氧化酶活性的研究

本文报道６７例帕金森病（ＰＤ）患者血超氧化物歧化酶（ＳＯＤ）．谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ），过氧化氢酶（ＣＡＴ）活性及脂质过氧化物（ＬＰＯ）量的测定结果。ＰＤ病人ＳＯＤ和ＧＳＨ－Ｐｘ活性高于正常对照组，但ＳＯＤ，ＧＳＨ－Ｐｘ和ＣＡＴ的活性及ＬＰＯ量与病程长短无明显关系，也与是否服用美多巴无关。研究结果提示，抗氧化酶活性的改变可能与ＰＤ病因有关。     

Increased plasma levels of interleukin-1, interleukin-6 and alpha-1-antichymotrypsin in patients with Alzheimer's disease: peripheral inflammation or signals from the brain?

Plasma concentrations of interleukin-1beta (IL-1beta), interleukin-6 (IL-6), C reactive protein (CRP) and alpha-1-antichymotrypsin (ACT) in 145 patients with probable Alzheimer's disease (AD) and 51 non-demented controls were measured. To investigate the cellular activation of peripheral immune system, plasma levels of neopterin were also investigated. Plasma levels of IL-1 were detectable in 17 patients with AD (13%) and only in one control (2%) and average levels of IL-1 were higher in AD patients than in controls (p < 0.001). IL-6 plasma levels were detectable in a higher proportion of AD and controls (53% and 27%, respectively), and were increased in patients with AD (p < 0.001). Plasma levels of ACT were increased in patients with AD (p < 0.001) and CRP levels were in the normal range. Plasma levels of neopterin were slightly lower in AD patients than in controls, but differences were not statistically significant. No significant correlation was observed between IL-1 and IL-6 levels or neopterin and cytokine levels in plasma from AD patients. Plasma levels of ACT negatively correlated with cognitive performances, as assessed by the mini mental state examination (MMSE; R = -0.26, p < 0.02) and positively correlated with the global deterioration state (GDS) of AD patients (R = 0.30, p < 0.007). Present findings suggested that detectable levels of circulating cytokines and increased ACT might not be derived by activation of peripheral immune system of AD patients. Detection of these molecules might be used for monitoring the progression of brain inflammation associated with AD.     

Altered plasma antioxidant status in subjects with Alzheimer's disease and vascular dementia

Objectives. Oxygen-free radicals and lipid hydroperoxides may have an aetiological role in the development of lesions in the central nervous system in patients with Alzheimer's disease and in those with vascular dementia. This study aimed to make a cross-sectional comparison of blood markers of oxidative stress in two groups of patients with these disorders and a control group. Design. Cross-sectional comparative study. Setting. Established memory clinics in Cardiff organized by a University Department of Geriatric Medicine within an acute care NHS Trust. Methods. Following a dietary assessment, postprandial venous blood samples were obtained from the following: 25 subjects with probable Alzheimer's disease (AD) (mean age 74.3; 10 F, 15 M); 17 subjects with probable vascular dementia (VD) (mean age 75.5; 5 F, 12 M); and 41 controls (mean age 73.4; 24 F, 17 M) for measurement of circulating lipid peroxides (LP), total antioxidant capacity (TAC), vitamin C (VitC), vitamin E (VitE) and beta-carotene (BC). Results. Plasma levels of VitC were significantly lower in subjects with vascular dementia compared with controls (VD, 6.5 (4.8, 8.2); controls, 10.0 (8.38, 11.6); VD vs controls, p=0.015), but no significant difference was seen between controls and patients with Alzheimer's disease (AD, mean 8.3 (6.2, 10.4)). VitE levels were significantly lower in subjects with AD compared with controls (31.1 (28.2, 34.0) vs 36.0 (32.8, 39.2), p=0.035). BC levels were similar in subjects with AD and controls, but significantly elevated in those with VD (AD, 0.28 (0.2, 0.34); VD, 0.40, (0.27, 0.53); controls, 0.28 (0.22, 0.34); VD vs controls, p=0.046). There were no significant differences in LP or TAC between the three groups. Conclusions. Subjects with dementia attributed to Alzheimer's disease or to vascular disease have a degree of disturbance in antioxidant balance which may predispose to increased oxidative stress. This may be a potential therapeutic area for antioxidant supplementation. Copyright © 1998 John Wiley & Sons, Ltd.     

Serum Oxidative Stress Marker Levels in Unmedicated and Medicated Patients with Schizophrenia

Oxidative stress has been suggested to be involved in schizophrenia, but studies have demonstrated inconsistent results on oxidative stress marker level/activity in patients with schizophrenia. In order to clarify the circulating oxidative stress marker level/activity in patients with schizophrenia, this study recruited 80 schizophrenia patients (40 first-episode, drug-free and 40 chronically medicated patients) and 80 controls to analyze serum activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC), and levels of lipid peroxidation marker malondialdehyde (MDA) in schizophrenia patients, and whether they associate with the severity of the disease. We showed that only serum GSH-Px activity was significantly reduced in unmedicated patients with schizophrenia when compared with control subjects, whereas the other three analyzed oxidative stress markers did not show significant differences between cases and controls. Moreover, our results demonstrated that chronic medication increased GSH-Px activity and MDA levels in patients with schizophrenia, but reduced SOD activity in the patients. We also found that short-term antipsychotic treatments on the patients with schizophrenia reduced the SOD activity. Correlation analyses indicated that the oxidative stress marker activity/level is not significantly associated with the severity of schizophrenia, except that SOD level correlated with PANSS positive score significantly. Taken together, the data from the present study suggested that the dysfunctions of oxidative stress markers in patients with schizophrenia were mainly caused by antipsychotics, emphasizing increased oxidative stress as a potential side effect of antipsychotics on the patients.     

Apolipoprotein E and intronic polymorphism of presenilin 1 and alpha-1-antichymotrypsin in Alzheimer's disease and vascular dementia

Apolipoprotein E (ApoE) genotypes, presenilin 1 (PS-1) and alpha(1)-antichymotrypsin (ACT) polymorphism and the association of the genotypes were examined in patients with Alzheimer's disease (AD, n = 121) or vascular dementia (VD, n = 68) in comparison with elderly controls (n = 125). The frequency of the ApoE epsilon 4 allele was significantly increased both in late-onset AD (0.35) and in VD (0.17); the frequency of ApoE epsilon 2 was significantly reduced in AD, but it was similar in VD and controls. The presence of the allele 1 of PS-1 intronic polymorphism was not associated with AD or VD and was not influenced by the ApoE genotypes. Also, the frequency of allele A of the intronic polymorphism of ACT was similar in AD, VD and controls and it was not altered by ApoE or PS-1 genotypes. The results confirm the association between ApoE epsilon 4 and AD and indicate an increase in ApoE epsilon 4 in Vd, too. A potential protective role of ApoE epsilon 2 is also suggested for late-onset AD but not for VD. No association was shown between ACT allele A and PS-1 allele 1 in AD or VD.     

早期阿尔茨海默病血清CRPIL-6 TG及血浆HDL-C诊断分析

目的探讨血清C反应蛋白(CRP)、白细胞介素6(IL-6)、甘油三酯(TG)及血浆高密度脂蛋白胆固醇(HDL-C)在阿尔茨海默病(AD)诊断中的作用。方法选取2014-02—2016-02在我院治疗的AD患者80例(AD组),血管性痴呆(VD)患者73例(VD组),同时选取健康体检者80例为对照组,检测各组CRP、IL-6、TG等指标。结果 AD组和VD组患者CRP、HDL-C和IL-6均明显高于对照组(P0.05),而AD组和VD组患者CRP、HDL-C和IL-6比较差异无统计学意义(P0.05);AD组和VD组TG明显高于对照组(P0.05);VD组TG和低密度脂蛋白胆固醇(LDL-C)明显高于AD组和对照组(P0.05);TG和LDL-C在判断AD和VD的ROC曲线下面积分别为0.777和0.688(P0.05),TG截断值为1.84mmol/L,诊断的灵敏度和特异度分别为64.40%和78.70%;LDL-C截断值为3.25mmol/L,诊断的灵敏度和特异度分别为45.20%和87.50%。结论 TG和LDL-C检测可为AD和VD的诊断提供一定的依据,其中TG的诊断意义更好。     

Plasma and cerebrospinal fluid alpha1-antichymotrypsin levels in Alzheimer's disease: correlation with cognitive impairment

alpha-1-Antichymotrypsin (ACT) is present in neuritic plaques in which it participates in the inflammatory cascade of Alzheimer's disease (AD). Reports of blood ACT levels in AD, and its usefulness as a disease biomarker, have been conflicting. In an effort to clarify this, we measured plasma ACT levels in 516 white subjects including 359 subjects with probable or possible AD, 44 subjects with other late-life dementias, and 113 nondemented people. Subjects with systemic inflammatory diseases or who were taking antiinflammatory medications were excluded. All patients underwent extensive medical and detailed neuropsychological examinations at the time their blood was drawn. We found that plasma ACT levels were elevated in AD patients compared with the control group (p = 0.01) and were associated with severity of AD dementia; there was a negative association with the Mattis Dementia Rating Scale (a global measure of cognition) and a positive association with the Clinical Dementia Rating Scale (a global functional assessment). These relationships remained significant after controlling for demographic and genetic variables. When AD subjects were stratified into subgroups by dementia severity, matched by age, education, and gender, increased serum ACT correlated with Clinical Dementia Rating Scale (p = 0.0041) or Mattis Dementia Rating Scale (p = 0.0031) scores. ACT measurements in cerebrospinal fluid from an additional 34 AD cases and 16 controls showed elevated levels (p = 0.02) in AD. There was a negative correlation (p = 0.037) between cerebrospinal fluid ACT levels and clinical severity as measured by the Mini-Mental State Examination. Our results demonstrate that peripheral ACT levels are elevated in AD, but not in dementias other than AD, and they increase with progression of AD dementia. Although not useful as a diagnostic biomarker, ACT may reflect disease severity and may be helpful as a within subject biomarker in interventions (particularly with antiinflammatory agents) directed at slowing or halting progression of disease.     

Serum levels of coenzyme Q10 in patients with Alzheimer's disease

Summary. We compared serum levels of coenzyme Q₁₀ and the coenzyme Q₁₀/cholesterol ratio in 44 patients with Alzheimer's disease (AD), 17 patients with vascular dementia (VD), and 21 matched controls. The mean serum coenzyme Q₁₀ and cholesterol levels and the coenzyme Q₁₀/cholesterol ratio of patients with AD or VD did not differ significantly from those of controls. Coenzyme Q₁₀ levels and coenzyme Q₁₀/cholesterol ratio of AD or VD patients were not correlated with age, age at onset, duration of the disease or scores of the MiniMental State Examination. These results suggest that these values are not related with the risk for AD or VD. Received July 19, 1999; accepted October 14, 1999     

Serum selenium and plasma malondialdehyde levels and antioxidant enzyme activities in patients with obsessive-compulsive disorder

There is mounting evidence indicating that reactive free radical species are involved in initiation and development of many different forms of human pathologies including psychiatric disorders. In the present study, we aimed to determine whether serum selenium (Se), antioxidant enzyme (glutathione peroxidase, GSH-Px, superoxide dismutase, SOD, and catalase, CAT) activities, and plasma malondialdehyde (MDA) levels, a product of lipid peroxidation, were associated with obsessive-compulsive disorder (OCD). The participants were 28 patients with OCD that were drug-free at least for a month and a control group (n=28) of healthy subjects, matched with respect to age and sex. In both groups, the levels of the erythrocyte MDA, GSH-Px, SOD, Se, and the CAT were measured. The levels of MDA and SOD were statistically significantly higher (p<0.01, p<0.05 respectively) in patients than controls. The activities of CAT, GSH-Px, and serum Se levels were statistically significantly lower (p<0.0001, p<0.001, and p<0.001 respectively) in patients than controls. There was a positive correlation in patients between plasma GSH-Px activity and Se concentration (r=52, p=0.001). However, in patients with OCD, CAT and SOD activities were significantly and negatively correlated with MDA levels (r=-0.45, p=0.017 for CAT and r=-0.54, p=0.020 for SOD). The study shows the presence of a significant relationship of OCD and oxidative stress, and consequently, an involvement of free radicals and of the antioxidant defence.     

自由基与新生儿缺氧缺血性脑病

本文检测了３９例新生儿缺氧缺血性脑病（ＨＩＥ）及３０例足月健康新生儿血中超氧化物歧化酶（ＳＯＤ）、过氧化氢酶（ＣＡＴ）及脂质过氧化物（ＬＰＯ），结果ＨＩＥ患儿血中ＬＰＯ增高，ＳＯＤ、ＣＡＴ下降，而且比较了中度与重度、急性期与恢复期检测结果，表明ＨＩＥ时，自由基参与了该病的发生与发展。     

Impact of gender on upregulation of antioxidant defence mechanisms in Alzheimer’s disease brain

Summary. Since oxidative stress plays an important role in the pathogenesis of Alzheimers disease (AD) and since the age-adjusted incidence of AD is higher in females than males, we examined a possible influence of gender on antioxidant metabolism in brains from male and female AD patients and age-matched controls. Activities of copper/zinc-dependent superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione-disulfide reductase (GR) were elevated in AD samples compared to controls. Upon in vitro stimulation, levels of malondialdehyde formation were significantly lower in AD samples, probably due to the increased antioxidant capacity. Overall, our results indicate that antioxidant metabolism is functionally still intact but increased in AD implying that oxidative damage is caused rather by overproduction than by insufficient detoxification of ROS. Among AD patients, a gender-specific partial upregulation of antioxidant defence was present: activities of SOD and GPx were even further increased in female patients, and levels of 4-hydroxynonenal, a marker of oxidative damage, were higher than in male patients. Importantly, our results are in line with epidemiological studies indicating a higher risk for AD in females. Thus, gender differences in oxidative stress parameters might be related to the higher prevalence of AD in females.Present address: Neurobiology Research Lab, Psychiatric University Clinic, Basel, Switzerland     

The role of oxidative stress in postoperative delirium

AIM: This study aimed to determine a marker that predicts delirium using preoperative oxidative processes in patients undergoing cardiopulmonary bypass surgery. METHOD: Twelve of the 50 patients included in the study showed signs of delirium during postoperative follow-up. The Delirium Rating Scale was used in patients with delirium according to DSM-IV-TR in the postoperative period. Venous blood samples were obtained from the patients the day before and the day after the surgery to determine plasma antioxidant enzyme levels. RESULTS: While there were no differences in preoperative superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) levels in both groups, catalase (CAT) levels were significantly lower in the delirium group. Postoperative SOD and MDA levels were also higher in the delirium group, while the GSH-Px levels were found to be lower when compared with those during the preoperative period. In the nondelirium group, the postoperative MDA and GSH-Px levels were found to be lower than preoperative levels, and postoperative SOD levels were found to be higher than preoperative levels. CAT levels were lower in the delirium group when the pre- and postoperative levels were compared in both groups. The postoperative levels of SOD, GSH-Px and CAT in the nondelirium group and MDA in the delirium group were significantly higher than preoperative levels. CONCLUSION: Patients with low preoperative CAT levels appeared to be more susceptible to delirium than patients with higher CAT levels.     

Impaired antioxidant status and reduced energy metabolism in autistic children

Accumulating evidence suggests that oxidative stress induced mechanisms are believed to be associated with the pathophysiology of autism. In this study, we recruited 19 Omani autistic children with age-matched controls to analyze their plasma and serum redox status and the levels of ATP, NAD⁺ and NADH using well established spectrophotometric assays. A significant decrease was observed in the levels of plasma total antioxidants (TA), reduced glutathione (GSH), superoxide and catalase activity in Omani autistic children as compared to their age-matched controls. In contrary, the level of plasma glutathione peroxidase (GSH-Px) was significantly increased in autistic children. Reduced serum NAD⁺ and ATP levels and lower NAD⁺:NADH ratio were observedin patients with autism compared to controls. Finally, a significant inverse correlation was observed between plasma GSH, SOD, catalase activity, and serum NAD⁺ and ATP levels, and autism severity using Childhood Autism Rating Scale (CARS) scores. The levels of plasma GSH-Px and serum NADH correlated strongly with autism severity whilst no significant correlation was observed for plasma TA. Our data suggests that increased vulnerability to oxidative stress in autism may occur as a consequence of alterations in antioxidant enzymes leading to mitochondrial dysfunction.     

帕金森病血抗氧化系统的变化及临床意义

探讨帕金森病（ＰＤ）患者体内抗氧化系统水平及其在ＰＤ发病中的可能作用。方法观测了７０例ＰＤ患者和７０例正常人的血浆维生素Ｃ、Ｅ浓度（Ｐ－ＶＣ，Ｐ－ＶＥ），血浆及红细胞膜超氧化物歧化酶（Ｐ－ＳＯＤ，Ｅ－ＳＯＤ）活性，血浆及红细胞过氧化脂质（Ｐ－ＬＰＯ，Ｅ－ＬＰＯ）水平的变化。结果与正常对照组相比，ＰＤ患者的Ｐ－ＶＣ、Ｐ－ＶＥ浓度及Ｐ－ＳＯＤ、Ｅ－ＳＯＤ活性均明显降低，而Ｐ－ＬＰＯ、Ｅ－ＬＰＯ水平则显著增高。并且Ｐ－ＶＣ、Ｐ－ＶＥ、Ｅ－ＳＯＤ水平与ＰＤ患者的病情和病程呈负相关。结论提示ＰＤ患者可能存在血抗氧化系统缺陷而使内源性氧自由基堆积，导致黑质神经元退变     

The indices of endogenous oxidative and antioxidative processes in plasma from schizophrenic patients. The possible role of oxidant/antioxidant imbalance

There 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.     

Serum glutathione peroxidase,xanthine oxidase,and superoxide dismutase activities and malondialdehyde levels in patients with Parkinson’s disease

Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc). Oxidative stress has been hypothesized to play a major role in the development of PD in various studies. This study assessed to investigate oxidative and anti-oxidative status in PD patients. We evaluated oxidant/antioxidant status by measuring serum malondialdehyde (MDA) levels, xanthine oxidase (XO) activities, and activities of antioxidant enzymes, namely, glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD). The study included 29 patients with PD and 32 healthy subjects as controls. Comparison of oxidative parameters in the patient and control groups revealed significantly higher GSH-Px and XO activities in the patient group. Serum MDA and SOD activities in PD patients were not significantly different from the controls. MDA was negatively correlated with duration of the PD and positively with age of onset. There was a negative correlation between SOD and Hoehn and Yahr (H&Y) stage. According to these results, we suggest that oxidative stress may contribute to the development of PD.     

Evaluation of intrathecal serum amyloid P (SAP) and C-reactive protein (CRP) synthesis in Alzheimer's disease with the use of index values

Serum amyloid P (SAP) and C-reactive protein (CRP) are proteins involved in innate immunity. The expression of SAP and CRP is increased in Alzheimer's disease (AD) brain tissue, compared to healthy controls. Although both proteins are found in cerebrospinal fluid (CSF), their origin is unclear. We investigated if increased local production of SAP and CRP in AD brain results in higher levels in CSF with the use of index values. To study this, SAP, CRP, and albumin levels were determined in CSF and serum samples of 30 control (65 ± 11 years; 57% female) and 140 AD subjects (65 ± 9 years; 53% female). To correct for inter-individual differences in protein diffusion from blood to CSF, quotients (Q =CSF/serum) of SAP, CRP, and albumin and index values (Qprotein/Qalb) were calculated. The results showed no significant differences in SAP and CRP index values between control and AD subjects, although eight percent of individual AD patients showed evidence of intrathecal SAP or CRP production using the Reiber hyperbolic model. Interestingly, the SAP index value was much lower than expected, based on its molecular size. In conclusion, these data suggest that local production of SAP and CRP in the AD brain does not substantially contribute to the CSF levels.     

Cerebrospinal fluid tau levels in Alzheimer's disease are elevated when compared with vascular dementia but do not correlate with measures of cerebral atrophy

Increased tau levels are a well-established finding in Alzheimer's disease (AD). In contrast, the potential value of tau levels in the differential diagnosis of AD, vascular dementia (VD) and major depression warrants further investigation. The potential impact of psychotropic medication also needs to be established. We investigated cerebrospinal fluid (CSF) tau protein concentrations in 88 patients with AD, 23 patients with VD, 25 patients with major depression and 17 age-paralleled controls without cognitive impairment with respect to important clinical variables, type and dosage of psychotropic medication and cerebral changes as assessed by magnetic resonance imaging (MRI). The AD patients showed significantly elevated tau levels compared with patients with VD or major depression and controls. Tau levels obtained in the VD group were intermediate, with significant differences from both AD patients and patients with major depression and controls. Within the AD group, no significant correlation between tau levels, severity of dementia, age, duration of disease, type and dosage of psychotropic medication or MRI volumetric changes arose. A subgroup of AD patients without increased tau levels was characterized by a significantly larger percentage of patients with presenile onset.     

In vivo dopamine pre-synaptic receptors and antioxidant activities in patients with Alzheimer's disease,dementia with Lewy bodies and in controls. A preliminary report

The degeneration of dopaminergic cells in dementia with Lewy bodies (DLB) may provide an important source of additional free radical generation. As a result, the oxidative stress status in DLB could be significantly enhanced. Subsequently, the levels of endogenous antioxidants, which are an indirect measure of free radical activities, may be different in DLB patients when compared with Alzheimer's disease (AD) patients and controls. In this preliminary study, we measured the activities of superoxide dismutase (SOD), catalase (CAT), glutathione (GLU) and total antioxidant capacity in the blood of DLB, AD and control subjects. The state of nigrostriatal dopaminergic system was also assessed in vivo by using a radioactive ligand with an affinity for the dopamine pre-synaptic receptors and by imaging with single-photon emission tomography. Data obtained showed a decrease in dopamine pre-synaptic receptors in all the brain regions of DLB patients. The levels of SOD did not differ significantly between DLB, AD and control subjects. However, GLU levels were significantly higher in the DLB patients when compared with AD patients (p < 0.05) and controls (p < 0.01). CAT blood levels were also higher in DLB when compared with AD, but this did not reach statistical significance. The results suggest that a different oxidative stress state may exist in DLB. This may occur due to increased free radical production from the degeneration of dopaminergic cells and auto-oxidation of dopamine, the availability of which may be maintained in early-stage DLB disease as a result of the compensatory increase in its turnover from the remaining dopaminergic cells.