Enzyme Activity In Erythrocytes Research Articles

Вплив Т-2 токсину на активність ферментів антиоксидантної системи та процеси пероксидного окиснення ліпідів у еритроцитах щурів

The effect of T-2 toxin on the processes of lipid peroxidation and the activity of antioxidant enzymes in erythrocytes of rats and the neutralizing effect of silica on T-2 toxin action were studied. An increase in concentration of diene conjugates (1–3 days) and TBA-active products (2–4 day experimental period) was established. Besides superoxide dismutase activity decreased in 1–3 days, and activity of catalase increased in 1–4 days of experimental period. Parameters approached the control values on the 5 th day after administration of T-2 toxin. The obtained results indicate activation of lipid peroxidation and disturbance in functioning of certain enzymes of antioxidant system, suggesting a negative effect of T-2 toxin on the morpho-functional state of erythrocytes. Using aerosil together with toxicants normalized the above noted indicators and approached them to values similar to thase observed in control group of animals, suggesting the high sorption capacity of aerosil, towards T-2 toxin. Keywords: T-2 toxin, tryhotethecenes mycotoxins, antioxidant system, lipid per­oxi­dation, erythrocyte.

The Effect of Progressive Resistance Training on Oxidative Stress and Antioxidant Enzyme Activity in Erythrocytes in Untrained Men

This study was undertaken to investigate the effects of progressive resistance-training (PRT) on plasma oxidative stress and antioxidant enzyme activity in erythrocytes. Twenty male volunteers were randomly assigned to 2 groups: PRT and control. Blood samples were collected before and after 8 wk of PRT and analyzed for enzymatic activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) in erythrocytes, plasma total antioxidant capacity (TAC), and malondialdehyde concentration (MDA, an index of lipid per oxida- tion in plasma). Resistance training commenced with 8 exercises on nonconsecutive days for 8 wk at 50% of estimated 1-repetition maximum (E1RM) and reached 80% E1RM by Week 8. The results showed that PRT significantly increased erythrocyte SOD activity (1,323 ± 212.52 vs. 1,449.9 ± 173.8 U/g Hb, p = .014). Plasma concentration of MDA also decreased (5.39 ± 1.7 vs. 3.67.4 ± 0.7 nmol/ml, p = .030), although TAC (1.42 ± 0.21 vs. 1.61 ± 0.19 mmol/L, p = .1530) and GPx (39.87 ± 11.5 vs. 48.18 ± 14.48 U/g Hb, p = .883) activity did not undergo any considerable changes. Based on these data, the authors conclude that an 8-wk program of PRT strengthens the defensive system of erythrocytes against free-radical damage and therefore can be applied as a useful approach to alleviate oxidative stress.

Effect of atypical antipsychotics on antioxidant enzyme activities in human erythrocytes (in vitro study)

This study was set out to examine the impact of atypical antipsychotic drugs: aripiprazole, clozapine, ziprasidone, olanzapine, quetiapine, sertindole and amisulpride on the activity of antioxidant defence enzymes in human erythrocytes in vitro. Cu,Zn-superoxide dismutase (SOD1), catalase (CAT), selenium-dependent glutathione peroxidase and glutathione reductase activities were determined after drugs incubation with blood of 15 apparently healthy non-smoking male volunteers (ages 23-39) for 1 h at 37 °C. A statistically significant increase in SOD1 activity was found in samples incubated with aripiprazole (p < 0.01) and quetiapine (p < 0.05) compared with incubated control. SOD1 activity profile following native polyacrylamide gel electrophoresis indicates that aripiprazole and quetiapine protect enzyme activity from inhibition with hydrogen peroxide. Our results showed that sertindole decreases activity of CAT comparing with control non-treated erythrocytes. Moreover, in sertindole treated erythrocytes, negative correlation between SOD1 and glutathione peroxidase activities was found. Increased amount of hydrogen peroxide in such situation may leave erythrocytes and transform their role in circulation from anti-oxidative to pro-oxidative. Our results indicate that mechanism through sertindole could express its in vivo toxic effects and point toward possible (neuro)protective effects of aripiprazole and quetiapine.

Analysis of novel ARG1 mutations causing hyperargininemia and correlation with arginase I activity in erythrocytes

Hyperargininemia (HA) is an autosomal recessive disease that typically has a clinical presentation that is distinct from other urea cycle disorders. It is caused by the deficient activity of the enzyme arginase I, encoded by the gene ARG1. We screened for ARG1 mutations and measured erythrocyte enzyme activity in a series of 16 Brazilian HA patients. Novel mutations, in addition to previously described missense mutations, were analysed for their effect on the structure, stability and/or function of arginase I (ARG1) using bioinformatics tools. Three previously reported mutations were found (p.R21X; p.I11T and p.W122X), and five novel mutations were identified (p.G27D; p.G74V; p.T134I; p.R308Q; p.I174fs179). The p.T134I mutation was the most frequent in the Brazilian population. Patients carrying the p.R308Q mutation had higher residual ARG1 decreased activity, but presented no distinguishable phenotype compared to the other patients. Bioinformatics analyses revealed that missense mutations (1) affect the ARG1 active site, (2) interfere with the stability of the ARG1 folded conformation or (3) alter the quaternary structure of the ARG1. Our study reinforced the role of Arg308 residue for assembly of the ARG1 homotrimer. The panel of heterogeneous ARG1 mutations that cause HA was expanded, nevertheless a clear genotype–phenotype correlation was not observed in our series.

Adenine phosphoribosyltransferase deficiency in children

Adenine phosphoribosyltransferase (APRT) deficiency is a rare autosomal recessive disorder characterized by 2,8-dihydroxyadenine (2,8-DHA) crystalluria that can cause nephrolithiasis and chronic kidney disease. The aim of our study was to assess the clinical presentation, diagnosis, and outcome of APRT deficiency in a large pediatric cohort. All pediatric cases of APRT deficiency confirmed at the same French reference laboratories between 1978 and 2010 were retrospectively reviewed. Twenty-one patients from 18 families were identified. The median age at diagnosis was 3 years. Diagnosis was made after one or more episodes of nephrolithiasis (17 patients), after urinary tract infection (1 patient), and by family screening (3 patients). The diagnosis was based on stone analysis and microscopic examination of urine and/or enzymatic determination of APRT on red blood cells. All children had null APRT enzyme activity in erythrocytes. APRT gene sequencing was performed on 18 patients, revealing six homozygous and 12 compound heterozygous mutations. At diagnosis, half of the patients had decreased kidney function, and two children presented with acute renal failure. Allopurinol treatment was given to all patients at a median dose of 9 mg/kg/day. After a median follow-up of 5 years, all patients showed stabilization or improvement of kidney function, normal growth and development, and six patients had recurrence of nephrolithiasis. Based on these results, we conclude that an excellent outcome can be achieved in children with APRT deficiency who receive the proper treatment.

Antioxidant enzyme activities in erythrocytes of healthy pregnant women, preeclamptic women and newborns

Preeclampsia is a pregnancy-specific syndrome of unknown etiology and represents multisystem disorder. It is characterized by the increased blood pressure, proteinuria, and edema. Preeclampsia is a great risk for both mother and fetus. Disturbances of the balance between the production of reactive oxygen species antioxidants status is considered to be one of the causes of various pathological conditions of the reproductive system, including preeclampsia. The main objective of this study is to determine the activities of superoxide-dismutase and catalase in peripheral blood erythrocytes of the pregnant women with preeclampsia and healthy pregnant women before delivery and umbilical cord blood erythrocytes of their babies immediately after the delivery. The results showed that the activity of superoxide dismutase in erythrocytes were statistically significantly lower in the group of patients with preeclampsia than in healthy pregnant women, as in the group of their babies compared to the babies of healthy pregnant women. Similarly, catalase activity was significantly lower in women with preeclampsia compared to the controls, as well as in erythrocytes of their babies compared to babies of healthy mothers. An observed difference in the antioxidant enzyme activities suggests a putative association between preeclampsia and decreased antioxidant status. Since the direct application of antioxidants did not give expected results of the data presented indicate the opportunity for the prevention of preeclampsia and alleviation of symptoms by dietary measures and life style changes in the population of pregnant women and women of childbearing age, directy targeting the enzymatic antioxidant system.

Oxidised fish oil does not influence established markers of oxidative stress in healthy human subjects: a randomised controlled trial

Intake of fish oil reduces the risk of CHD and CHD deaths. Marine n-3 fatty acids (FA) are susceptible to oxidation, but to our knowledge, the health effects of intake of oxidised fish oil have not previously been investigated in human subjects. The aim of the present study was to investigate markers of oxidative stress, lipid peroxidation and inflammation, and the level of plasma n-3 FA after intake of oxidised fish oil. In a double-blinded randomised controlled study, healthy subjects (aged 18-50 years, n 54) were assigned into one of three groups receiving capsules containing either 8 g/d of fish oil (1.6 g/d EPA+DHA; n 17), 8 g/d of oxidised fish oil (1.6 g/d EPA+DHA; n 18) or 8 g/d of high-oleic sunflower oil (n 19). Fasting blood and morning spot urine samples were collected at weeks 0, 3 and 7. No significant changes between the different groups were observed with regard to urinary 8-iso-PGF2α; plasma levels of 4-hydroxy-2-hexenal, 4-hydroxy-2-nonenal and α-tocopherol; serum high sensitive C-reactive protein; or activity of antioxidant enzymes in erythrocytes. A significant increase in plasma level of EPA+DHA was observed in both fish oil groups, but no significant difference was observed between the fish oil groups. No changes in a variety of in vivo markers of oxidative stress, lipid peroxidation or inflammation were observed after daily intake of oxidised fish oil for 3 or 7 weeks, indicating that intake of oxidised fish oil may not have unfavourable short-term effects in healthy human subjects.

Effect of Curcumin on LDL Oxidation in Vitro, and Lipid Peroxidation and Antioxidant Enzymes in Cholesterol Fed Rabbits

In this study we examined the antioxidant effect of curcumin on lipid oxidation in vitro and in vivo. In vitro, curcumin at 5 microgM concentration completely prevented low-density lipoprotein (LDL) oxidation by CuS0(4), indicating that curcumin is an effective antioxidant in vitro. In vivo, feeding a pure cholesterol (PC)-rich diet to rabbits significantly increased the plasma and liver lipids as well as thiobarbituric acid reactive substances (TBARS) levels. Addition of curcumin to the PC diet did not show any effect on either plasma lipid and TBARS or liver lipids. Liver TBARS tended to decrease but that decrease was not significant. Erythrocyte glutathione peroxidase (GSH-Px) activity was significantly decreased while catalase activity was significantly increased in rabbits fed a PC diet. The addition of curcumin to a PC diet did not show any significant effect on erythrocyte enzyme activities compared to the rabbits fed a PC diet. The liver GSH-Px and catalase activities were significantly decreased in rabbits fed a PC diet, but the addition of curcumin to the PC diet enhanced the liver GSH-Px activity, which became nonsignificantly different from the control group. These results were discussed considering that curcumin may not be well absorbed and it did not reach a level high enough in vivo to overcome the severe hypercholesterolemia and oxidative stress produced by the PC-rich diet.

Cr(VI) Induces Lipid Peroxidation, Protein Oxidation and Alters the Activities of Antioxidant Enzymes in Human Erythrocytes

The effect of potassium dichromate (K(2)Cr(2)O(7)), a hexavalent chromium compound, on human erythrocytes was studied under in vitro conditions. Incubation of erythrocytes with different concentrations of K(2)Cr(2)O(7) resulted in marked hemolysis in a concentration-dependent manner. K(2)Cr(2)O(7) treatment also caused significant increase in protein oxidation, lipid peroxidation and decrease in total sulfhydryl content, indicating that it causes oxidative stress in human erythrocytes. However, there was no concomitant nitrosative stress as the nitric oxide levels in hemolysates from K(2)Cr(2)O(7)-treated erythrocytes were lower than in control. Exposure of erythrocytes to K(2)Cr(2)O(7) decreased the activities of catalase, glutathione peroxidase, thioredoxin reductase, glucose-6-phosphate dehydrogenase, and glutathione reductase, whereas the activities of Cu-Zn superoxide dismutase and glutathione S-transferase were increased. These results show that K(2)Cr(2)O(7) induces oxidative stress and alters the antioxidant defense mechanism of human erythrocytes.

Experimental evidence that phenylalanine is strongly associated to oxidative stress in adolescents and adults with phenylketonuria

Few studies have looked at optimal or acceptable serum phenylalanine levels in later life in patients with phenylketonuria (PKU). This study examined the oxidative stress status of adolescents and adults with PKU. Forty PKU patients aged over fifteen years were enrolled, and were compared with thirty age-matched controls. Oxidative stress markers, anti-oxidant enzyme activities in erythrocytes, and blood anti-oxidant levels were examined. Nitric oxide (NO) production was also examined as a measure of oxidative stress. Plasma thiobarbituric acid reactive species and serum malondialdehyde-modified LDL levels were significantly higher in PKU patients than control subjects, and correlated significantly with serum phenylalanine level ( P < 0.01). Plasma total anti-oxidant reactivity levels were significantly lower in the patient group, and correlated negatively with phenylalanine level ( P < 0.001). Erythrocyte superoxide dismutase and catalase activities were higher and correlated significantly with phenylalanine level ( P < 0.01). Glutathione peroxidase activity was lower and correlated negatively with phenylalanine level ( P < 0.001). The oxidative stress score calculated from these six parameters was significantly higher in patients with serum phenylalanine of 700–800 μmol/l. Plasma anti-oxidant substances, beta-carotene, and coenzyme Q 10 were also lower (P < 0.001), although the decreases did not correlate significantly with the phenylalanine level. Serum nitrite/nitrate levels, as stable NO products, were higher together with low serum asymmetric dimethylarginine, as an endogenous NO inhibitor. Oxidative stress status is closely linked with serum phenylalanine levels. Phenylalanine level in should be maintained PKU below 700–800 μmol/l even in adult patients.

Phytoestrogens enhance antioxidant enzymes after swimming exercise and modulate sex hormone plasma levels in female swimmers

Our aim was to investigate the effects of diet supplementation with phytoestrogens on sex hormone levels, antioxidant adaptive responses and oxidative damage induced by exercise. Ten female swimmers participated for 26 days in a diet intervention with either a functional beverage rich in vitamins C and E or the same beverage but also supplemented with Lippia citriodora extract (PLX) containing 20 mg/100 ml verbascoside. After the intervention all subjects participated in a swimming session for 30 min maintaining the intensity at about 75-80% of their individual best performance time for a 50-m swim. In lymphocytes, the superoxide dismutase activity increased after exercise, with a higher increase in the PLX group. Swimming increased the erythrocyte activity of glutathione peroxidase and glutathione reductase in the PLX group. Purified glutathione reductase activity increased after an in vitro incubation with PLX. No effects were observed on the lymphocyte levels of malondialdehyde and carbonyls, but exercise increased the percentage of high-damaged lymphocytes 2.8 times in the placebo group and 1.5 times in the PLX group. PLX decreased the levels of 17-β-estradiol and testosterone and increased the levels of the sex hormone binding globulin. In conclusion, supplementation with phytoestrogens enhances the glutathione-dependent enzyme activities in erythrocytes and the superoxide dismutase activity in lymphocytes in response to exercise. PLX also shows direct antioxidant properties, by increasing glutathione reductase enzyme activity in vitro. Supplementation with phytoestrogens also decreases the plasma steroid hormone levels, pointing towards a possible agonistic effect of verbascoside in the hypothalamic regulation of estradiol synthesis.

Subacute effects of 2,4-dichlorophenoxyacetic herbicide on antioxidant defense system and lipid peroxidation in rat erythrocytes

The erythrocyte, due to its role as O2 and CO2 transporter, is under the constant exposure to reactive oxygen species and oxidative stress. The objective of this study was to investigate the ability of 2,4-D to induce oxidative stress in blood of male wistar rats. Rats were randomly divided into four groups: a control group and three treated groups receiving by gavage 15, 75 and 150mg, respectively, of 2,4-D/kg/BW/day for 28days. Results showed that 2,4-D caused significant negative changes in the investigated biochemical parameters. In fact, 2,4-D exposition strongly increases LDH, by contrast, there is a statistically significant decrease in Hgb levels. The malondialdehyde level was significantly increased in 2,4-D treated groups. Fatty acid composition of the erythrocytes was also significantly changed with 2,4-D exposure, in favor of the peroxidation of polyunsaturated fatty acids. Furthermore, antioxidant enzyme (SOD, CAT, GPx, and GR) activities in erythrocytes were significantly decreased. Thus, our results indicated the potential effects of 2,4-D to cause oxidative stress in rat erythrocytes. Therefore, at higher doses, 2,4-D may play an important role in the development of vascular disease via lipid peroxidation and oxidative stress.

Effects of whole-body cryotherapy on a total antioxidative status and activities of antioxidative enzymes in blood of depressive multiple sclerosis patients

Objectives. Oxidative stress (OS) plays an important role in the pathogenesis of multiple sclerosis (MS). In MS patients depression is often observed. Cryotherapy might have an effect on OS. The aim of this study was to compare the effects of whole body cryotherapy (WBCT) on changes in total antioxidative status (TAS) of plasma and activities of antioxidative enzymes in erythrocytes from depressive and non depressive MS patients. Methods. Twenty-two MS patients with secondary progressive disease course (12 depressive and 10 non depressive) were treated with 10 exposures in a cryochamber. Before and after WBCT the plasma TAS and the activities of superoxide dismutase (SOD) and catalase (CAT) in the erythrocytes were measured. Results. The level of TAS in depressive MS group was significantly lower than in non depressive MS (P < 0.0003). WBCT increased the level of TAS in depressive (P < 0.002) more than in non depressive MS patients (P < 0.01). WBCT treatment of MS patients resulted in the significant increase of TAS level in plasma but had no effects on activities of SOD and CAT. Conclusions. Our results indicate that WBCT suppresses OS in MS patients, especially in depressive patients.

A role forITPAvariants in the clinical course of pulmonary Langerhans' cell histiocytosis?

To the Editors: Interstitial lung diseases (ILD) comprise a number of clinical conditions, including sarcoidosis, pulmonary fibrosis and pulmonary Langerhans' cell histiocytosis (PLCH; histiocytosis X). The diagnostic workup for the classification of ILD is often complicated and tedious. PLCH is characterised by the proliferation of Langerhans' cells and their infiltration into pulmonary tissues. In disseminated LCH, additional tissues are affected. PLCH is strongly associated with smoking and the clinical outcome depends upon cessation of smoking 1. Treatment of ILD often requires corticosteroids and immunosuppressant drugs, including thiopurines and biologicals. It is mandatory to exclude genetic polymorphisms in genes involved in metabolism of thiopurine metabolism, because of the pharmacogenetic consequences of the use of thiopurines. The prospective measuring of erythrocyte enzyme activity of thiopurine S -methyltransferase (TPMT) and inosine triphosphatase (ITPase) or molecular analyses of the genes encoding these enzymes is recommended in clinical practice 2. Aberrant enzyme activity of either TPMT or ITPase gives rise to a broad spectrum of adverse drug reactions (ADR) associated with thiopurines, ranging from therapeutic failure to life-threatening leukopenia 3, 4. In order to avoid these ADR, we have incorporated pre-treatment screening of TPMT and ITPase of patients with ILD who are candidates for treatment with thiopurines in our hospital. An unexpectedly high number of decreased ITPase activities in patients with PLCH was found, all of which had an unfavourable outcome. We hypothesised about the role of the ITPA gene in relation to immunity, which might …

Effect of sodium fluoride ingestion on malondialdehyde concentration and the activity of antioxidant enzymes in rat erythrocytes.

Fluoride intoxication has been shown to produce diverse deleterious metabolic alterations within the cell. To determine the effects of sodium fluoride (NaF) treatment on malondialdehyde (MDA) levels and on the activity of antioxidant enzymes in rat erythrocytes, Male Wistar rats were treated with 50 ppm of NaF or were untreated as controls. Erythrocytes were obtained from rats sacrificed weekly for up to eight weeks and the concentration of MDA in erythrocyte membrane was determined. In addition, the activity of the enzymes superoxide, dismutase, catalase, and glutathione peroxidase were determined. Treatment with NaF produces an increase in the concentration of malondialdehyde in the erythrocyte membrane only after the eight weeks of treatment. On the other hand, antioxidant enzyme activity was observed to increase after the fourth week of NaF treatment. In conclusion, intake of NaF produces alterations in the erythrocyte of the male rat, which indicates induction of oxidative stress.

Differences in associations between markers of antioxidative defense and asthma are sex specific

Lungs are exposed to high levels of oxygen, air pollutants, and smoke, all of which stimulate the production of reactive oxygen species (ROS). In addition, inflammatory cells produce ROS, and thus there may be increased demand for antioxidants, including antioxidant enzymes, in inflammatory lung diseases such as asthma. Sex-specific differences have been noted for asthma, which in postpubertal subjects is predominantly found in females. These sex-specific differences may be associated with differences on the molecular level as well. The aim of this cross-sectional study was to examine associations between markers of antioxidative defense and asthma, and to investigate whether these associations were different between women and men. Based on the European Community Respiratory Health Survey protocol, subjects were enrolled in a study of asthma risk factors. The multicenter study was conducted in 5 west Danish counties between 2003 and 2006, and the subjects were recruited as a case-enriched random sample of 10,000 Danish inhabitants aged 20 to 44 years selected by their civil registration number. Participants were identified by positive answers to asthma questions on a screening questionnaire, random sampling, or both. Serum selenium concentrations and antioxidant enzyme activities (superoxide dismutase, glutathione peroxidase [GPX], glutathione reductase [GR], and glucose-6-phosphate dehydrogenase [G6PD]) in erythrocytes were measured. Asthma was defined as either current asthma symptoms with bronchial hyperresponsiveness (BHR) or a continuous asthma score based on 8 questions. A total of 1191 mostly white women and men (mean [SD] age, 34.0 [7.1] and 35.1 [7.1] years, respectively) were enrolled in the study. Current asthma symptoms were present in 29.9% (200/670) of women and 22.5% (117/521) of men, with women reporting more positive answers (51.1% vs 40.9%, respectively; P < 0.01) to asthma questions. Serum selenium concentrations were measured in 1151 subjects (640 women, 511 men), and antioxidant enzyme activities were measured in 295 subjects (161 women, 134 men). Women had higher enzyme activities of most antioxidant enzymes (GPX, P = 0.006; GR, P < 0.001; and G6PD, P = 0.009) than did men. Although the serum selenium concentration was inversely associated with asthma in both sexes, there was a female preponderance, with 3.5% lower serum selenium in subjects with current asthma symptoms with BHR (n = 77) compared with controls (n = 287). GR activity was associated with asthma in men, with 5.7% higher enzyme activity in subjects with current asthma symptoms with BHR (n = 14) compared with controls (n = 77). However, a significant interaction with gender was observed for analyses of GR (P = 0.02), but not for analyses of selenium. In this study of asthma risk factors, women had higher levels of enzyme activities than did men in a randomly selected Danish population, and sex-specific differences were found in the associations between markers of antioxidative defense and asthma.

Melatonin protects the liver and erythrocytes against oxidative stress in cirrhotic rats

Cirrhosis is a progressive chronic hepatopathy which constitutes an irreversible stage of liver dysfunction. To evaluate the oxidative stress in the blood of cirrhotic rats treated with the antioxidant melatonin. Cirrhosis was induced through inhalation of carbon tetrachloride. Liver integrity was evaluated by measuring serum enzymes, oxidative damage measured by lipoperoxidation, and antioxidant enzyme activity in erythrocytes. Lipoperoxidation, total nitrates, collagen, and histology by picrosirius staining were evaluated in the livers of these animals (n = 15), which were divided in three groups: control, carbon tetrachloride, and carbon tetrachloride + melatonin. Melatonin (20 mg/kg) was administered intraperitoneal from week 10 of carbon tetrachloride inhalation. In order to shorten the cirrhosis induction time, phenobarbital (0.3 g/L) was added to the animals' drinking water. A significant impairment in the liver integrity of melatonin-treated animals as compared to cirrhotic animals was observed. In rat erythrocytes and liver, lipoperoxidation was significantly increased in the cirrhotic rats as compared to controls, as measured through thiobarbituric acid reactive substances, and significantly decreased in melatonin-treated animals as compared to cirrhotic ones. In blood, a decrease in superoxide dismutase and glutathione peroxidase enzymes was detected in the cirrhotic group as compared to the control group, with increased superoxide dismutase activity when melatonin was administered. A reduction in the levels of total nitrates was detected in the hepatic tissue of the animals in the carbon tetrachloride group as compared to the control group and an increase of these levels in the carbon tetrachloride + melatonin group. As for hepatic collagen, we found a significant increase in the carbon tetrachloride group as compared to the controls and a regression of these values in the treated group. In histology, the rats in the carbon tetrachloride group showed fibrosis and formation of fibrotic nodules, characterizing liver cirrhosis; there was reduction of nodules and fibrosis in the melatonin treated group. The data allow us to suggest that the observed oxidative stress is related to the damages caused by carbon tetrachloride and that the use of melatonin can minimize these damages.

Erythrocyte Markers of Oxidative Stress in Higher Age-Group Preeclamptic and Normal Pregnant Mothers

Preeclampsia can have significant impact on health of both mother and fetus. It had been proposed that maternal endothelial cell dysfunction is the key event resulting in the diverse clinical manifestations of preeclampsia and evidence has since accumulated. Research in recent times is indicative of the role of oxidative stress in the endothelial cell dysfunction. Preeclampsia is more common in first pregnancy and studies have further shown an increase in risk of preeclampsia with maternal age. The aim of this study was to explore the status of oxidative stress in higher age-group preeclamptic and normal pregnant mother. The study included 20 normal pregnant women and 60 preeclamptic women. They were allocated into 4 subgroups between ages 20–25, 26–30, 31–35, and 36–40. Erythrocytes were analyzed for the following antioxidant enzymes, i.e., glutathione peroxidase, superoxide dismutase and catalase.Lipid peroxidation product, malondialdehyde, was analyzed to determine oxidative stress. The results showed an increase in oxidative stress, and high magnitude suppression/decrease in antioxidant enzymes activities in erythrocytes with increase in age groups in both preeclamptic and normal pregnant women. This indicates that an increase in the risk of preeclampsia with maternal age could be due to an increase in oxidative stress with age. This further attests to the role of oxidative stress in preeclampsia.

Specific and Pronounced Impacts of Lisinopril and Lisinopril Plus Simvastatin on Erythrocyte Antioxidant Enzymes

Angiotensin-converting enzyme inhibitors are effective at reducing blood pressure, whereas statins decrease plasma cholesterol impeding atherosclerosis. It is hypothesized that these medications may improve blood pressure and serum cholesterol by modifying the antioxidative status and energy metabolism of erythrocytes. In this study, the effects of 2 treatments are compared: lisinopril alone versus lisinopril + simvastatin, on erythrocyte antioxidant and energy metabolic enzymes. Patients with atherosclerosis and moderate hypertension are randomly assigned to receive lisinopril 10 to 20 mg/d or lisinopril 10 to 20 mg/d plus simvastatin 20 mg/d for 24 weeks. Higher catalase activity and lower glutathione peroxidase activity are observed in 94% to 100% patients from both groups after 12 and 24 weeks of treatment. Superoxide dismutase activity is increased significantly only after 24 weeks. No changes of glutathione reductase, lactate dehydrogenase, and phosphofructokinase activities are found under any conditions indicated. Both treatments decrease systolic and diastolic blood pressure equally. Only lisinopril + simvastatin treatment decreases plasma total cholesterol and low-density lipoprotein cholesterol. The results show for the first time that lisinopril monotherapy and combined lisinopril + simvastatin therapy exhibit specific and pronounced effects on antioxidant and energy metabolic enzyme activities in erythrocytes of hypertensive patients.

Effects of competitive pentathlon training on the antioxidant defence components

Effects of competitive pentathlon training on the antioxidant defence components Study aim: To assess the effects of training on the activities of antioxidant enzymes in erythrocytes and on the total plasma antioxidant status in competitive pentathletes. Material and methods: A group of 10 senior male pentathletes (P) and of 10 sedentary male subjects (S) participated in the study. Blood was withdrawn from the antecubital vein in the morning, in the preprandial state. The activities of superoxide dismutase (SOD), glutathione reductase (GR) and catalase (CAT) were determined in erythrocyte haemolisates, that of glutathione peroxidase (GPX) in whole blood haemolysate, and the total antioxidant status (TAS) in plasma. Results: The activities of all enzymes were significantly (p&lt;0.05 - 0.001) higher in P than in S group while no significant between-group difference was found for TAS. Conclusions: The pronounced enzymatic antioxidative potential and oxidative stress defence observed in athletes practicing modern pentathlon may be attributed to their extensive training.