Uric acid is the final product of human purine metabolism. It was pointed out that this compound acts as an antioxidant and is able to react with reactive oxygen species forming allantoin. Therefore, the measurement of allantoin levels may be used for the determination of oxidative stress in humans. The aim of the study was to clarify the antioxidant effect of uric acid during intense exercise. Whole blood samples were obtained from a group of healthy subjects. Allantoin, uric acid, and malondialdehyde levels in plasma and erythrocytes were measured using a HPLC with UV/Vis detection. Statistical significant differences in allantoin and uric acid levels during short-term intense exercise were found. Immediately after intense exercise, the plasma allantoin levels increased on the average of 200 % in comparison to baseline. Plasma uric acid levels increased slowly, at an average of 20 %. On the other hand, there were no significant changes in plasma malondialdehyde. The results suggest that uric acid, important antioxidant, is probably oxidized by reactive oxygen species to allantoin. Therefore allantoin may be suitable candidate for a marker of acute oxidative stress., R. Kanďár, X. Štramová, P. Drábková, J. Křenková., and Obsahuje bibliografii
Oxidative stress is an imbalance between free radicals and antioxidants, and is an important etiological factor in the development of hypertension. Recent experimental evidence suggests that subpressor doses of angiotensin II elevate oxidative stress and blood pressure. We aimed to investigate the oxidative stress related mechanism by which a subpressor dose of angiotensin II induces hypertension in a normotensive rat model. Normotensive male Wistar rats were infused with a subpressor dose of angiotensin II for 28 days. The control group was sham operated and infused with saline only. Plasma angiotensin II and H2O2 levels, whole-blood glutathione peroxidase, and AT-1a, Cu/Zn SOD, and p22phox mRNA expression in the aorta was assessed. Systolic and diastolic blood pressures were elevated in the experimental group. There was no change in angiotensin II levels, but a significant increase in AT-1a mRNA expression was found in the experimental group. mRNA expression of p22phox was increased significantly and Cu/Zn SOD decreased significantly in the experimental group. There was no significant change to the H2O2 and GPx levels. Angiotensin II manipulates the free radical-antioxidant balance in the vasculature by selectively increasing O2 - production and decreasing SOD activity and causes an oxidative stress induced elevation in blood pressure in the Wistar rat., M. M. Govender, A. Nadar., and Obsahuje bibliografii
Acrylamide (AA) is a highly reactive organic compound capable of polymerization to form polyacrylamide, which is commonly used throughout a variety of industries. Given its toxic effect on humans and animals, the last 20 years have seen an increased interest in research devoted to the AA. One of the main sources of AA is food. AA appears in heated food following the reaction between amino acids and reduced sugars. Large concentrations of AA can be found in popular staples such as coffee, bread or potato products. An average daily consumption of AA is between 0.3-2.0 μg/kg b.w. Inhalation of acrylamide is related with occupational exposure. AA delivered with food is metabolized in the liver by cytochrome P450. AA biotransformation and elimination result in formation of toxic glycidamide (GA). Both, AA and GA can be involved in the coupling reaction with the reduced glutathione (GSH) forming glutathione conjugates which are excreted with urine. Biotransformation of AA leads to the disturbance in the redox balance. Numerous research proved that AA and GA have significant influence on physiological functions including signal propagation in peripheral nerves, enzymatic and hormonal regulation, functions of muscles, reproduction etc. In addition AA and GA show neurotoxic, genotoxic and cancerogenic properties. In 1994, International Agency for Research on Cancer (IARC) classified acrylamide as a potentially carcinogenic substance to human., M. Semla, Z. Goc, M. Martiniaková, R. Omelka, G. Formicki., and Obsahuje bibliografii
Objectives of the study were to investigate impact of ischemic preconditioning (Ipre) and sulforaphane (SFN) and combination of them on nuclear factor 2 erythroid related factor 2 (Nrf2) gene and its dependent genes, heme oxygenase-1 (HO1) and NADPHquinone oxidoreductase1 (NQO-1) and inflammatory cytokines TNF-α, IL1β, and intercellular adhesion molecule-1 (ICAM1) and caspase-3 in renal ischemia/reperfusion (I/R) injury. Ninety male Sprague Dawely rats were classified into 5 groups (each consists of 18 rats): sham, control, Ipre, sulforaphane and Sulfo+Ipre. Each group was subdivided into 3 subgroups each containing 6 rats according to time of harvesting kidney and taking blood samples; 24 h, 48 h, and 7 days subgroups. Renal functions including serum creatinine, BUN were measured at basal conditions and by the end of experiment. Expression of Nrf2, HO-1, NQO-1, TNF-α, IL-1β, and ICAM-1 was measured by real time PCR in kidney tissues by the end of experiment. Also, immunohistochemical localization of caspase-3 and chemical assay of malondialdehyde (MDA), GSH and SOD activity were measured in kidney tissues. Both Ipre and SFN improved kidney functions, enhanced the expression of Nrf2, HO-1, and NQO-1, attenuated the expression of inflammatory (TNF-α, IL-1, and ICAM-1) and apoptotic (caspase-3) markers. However, the effect of sulforaphane was more powerful than Ipre. Also, a combination of them caused more improvement in antioxidant genes expression and more attenuation in inflammatory genes but not caspase-3 than each one did separately. Sulforaphane showed more powerful effect in renoprotection against I/R injury than Ipre as well as there might be a synergism between them at the molecular but not at the function level., A. A. Shokeir, N. Barakat, A. M. Hussein, A. Awadalla, A. M. Harraz, S. Khater, K. Hemmaid, A. I. Kamal., and Obsahuje bibliografii
The oxidative stress hypothesis of aging suggests that accumulation of oxidative damage is a key factor of the alterations in physiological function during aging. We studied age-related sensitivity to oxidative modifications of proteins and lipids of cardiac sarcoplasmic reticulum (SR) isolated from 6-, 15- and 26-month-old rats. Oxidative stress was generated in vitro by exposing SR vesicles to 0.1 mmol/l FeSO4/EDTA + 1 mmol/l H2O2 at 37 °C for 60 min. In all groups, oxidative stress was associated with decreased membrane surface hydrophobicity, as detected by 1-anilino-8-naphthalenesulfonate as a probe. Structural changes in SR membranes were accompanied by degradation of tryptophan and significant accumulation of protein dityrosines, protein conjugates with lipid peroxidation products, conjugated dienes and thiobarbituric acid reactive substances. The sensitivity to oxidative damage was most pronounced in SR of 26-month-old rat. Our results indicate that aging and oxidative stress are associated with accumulation of oxidatively damaged proteins and lipids and these changes could contribute to cardiovascular injury., E. Babušíková, M. Jeseňák, D. Dobrota, N. Tribulová, P. Kaplán., and Obsahuje bibliografii a bibliografické odkazy
a1_Modification of low density lipoprotein (LDL) particles due to oxidation, glycation and binding of advanced glycation end-products (AGEs) or malondialdehyde (MDA, a final product of lipid peroxidation) is considered most important in the process of atherogenesis. Oxidatively modified LDL are distinguished by another receptor type, which was discovered on the surface of macrophages and was called the scavenger receptor. Uncontrolled intake of LDL converts macrophages to foam cells; their accumulation under the vascular endothelium is considered as the first stage of atherosclerosis. Oxidation of LDL is a complex process taking place in both the extra- and intracellular space. At the end of this oxidative process, modified LDL particles show chemotactic, cytotoxic and immunogenic properties. Oxidized LDL express a large number of epitopes and cause production of polyclonal autoantibodies against these products, especially against apoB100 modified by MDA and 4-hydroxynonenal. IgoxLDL (antibodies against oxidized LDL) can be demonstrated either directly in intimal lesions or as a component of circulating immune complexes. IgoxLDL do not form a homogeneous group but a varied mixture of antibodies-isoantibodies caused by HDL and LDL polymorphism, antibodies against the lipid phase of LDL and antibodies against modified apoB100 of the immunoglobulin class IgA or IgG. Antibodies against oxLDL were found in many diseases other than atherosclerosis such as diabetes mellitus, renovascular syndrome, uremia, rheumatic fever, morbus Bechtjerev or lupus erythematodes. Newborns have practically the same levels of IgoxLDL as their mothers; however, these values did not differ from those in the healthy population of non-pregnant women of the same age., a2_The decrease in IgoxLDL titer was very slow and lasted many months; that is why this parameter cannot be considered suitable for describing the rapid changes during oxidative stress of the organism. Positive correlation of IgoxLDL with antiphospholipids and other antibodies was repeatedly demonstrated; their determination can thus be used as a marker for the description of total production of autoantibodies in various diseases. The changes and correlations of IgoxLDL, anti-b-2-glycoprotein I IgG and antiphospholipid antibodies support the immunological link between thrombotic and atherosclerotic processes in the human body., A. Steinerová, J. Racek, F. Stožický, T. Zima, L. Fialová, A. Lapin., and Obsahuje bibliografii
The purpose of this study was to determine the effect of a 15-week omega-3 rich diet on age-related differences in myocardial antioxidant defense and inflammation. 20 mature (M) (6 mo.) and 20 old (O) (15 mo.) male Fisher 344 rats were assigned to two diet groups: Control (CON) or Fish Oil (FO). Following the diet, animals were sacrificed and left ventricular (LV) heart tissue was harvested for biochemical assays and western blot analysis. No differences were observed in expression of LV interleukin-6 (IL-6) and tumor necrosis factor-α as well as hydrogen peroxide (H2O2) production between MCON and OCON. However, LV catalase protein expression and activity were increased in OCON vs. MCON and accompanied by increased expression of superoxide dismutase (SOD)-1. In contrast, LV IL-6 was lower in MFO vs. old rats, and LV H2O2 was decreased in MFO and OFO relative to respective control groups. Protein expression and activity of LV catalase and SOD-1 expression were increased in OFO similarly to OCON, but LV SOD activity was also increased in OFO vs. mature rats. In summary, FO supplementation increased myocardial antioxidant defense in all animals and augmented age-associated increases in antioxidant capacity in the absence of changes in inflammation., S. Lennon-Edwards, T. A. Schellhardt, J. M. Kuczmarski., and Obsahuje bibliografii
The consequences of increased oxidative stress, measured as the level of malondialdehyde (MDA) during ischemia/reperfusion, were studied in 48 patients in the acute phase of myocardial infarction (AMI) and a control group (21 blood donors). The serum levels of a-tocopherol and b-carotene were followed. Immediately after the treatment onset the level of a-tocopherol started to decrease, reaching a plateau after 24 h. The consumption of b-carotene was delayed by 90 min. Steady decline was detected during the whole time interval studied (48 h). Glutathione peroxidase (GPx) activity, as a representative of antioxidant enzymes, was estimated in whole blood. The influx of oxygenated blood was accompanied by a stimulation of GPx activity, which reached its maximum at the time of completed reperfusion. When comparing the AMI patients with the control group, the levels of MDA were found significantly increased, which indicates that oxidative stress is already increased during ischemia. Lower antioxidant levels found in the patients might either already be the result of vitamin consumption during ischemia or be a manifestation of their susceptibility to AMI. Monitored consumption of a-tocopherol and b-carotene during reperfusion indicated that in the case of patients, whose level of antioxidant vitamins is below the threshold limit, a further substantial decrease of antioxidant vitamins during reperfusion could enhance the oxidative damage of the myocardium., V. Mužáková, R. Kanďár, P. Vojtíšek, J. Skalický, R. Vaňková, A. Čegan, Z. Červinková., and Obsahuje bibliografii
Present study aimed to explore the levels and correlation of oxidative stress biomarkers with anthropometry in a population of young Saudi females. One hundred six normotensives, non-diabetic Saudi females, with minimally active lifestyle, based on their body mass index (BMI) were divided as; normal-weight (NW; n=52), overweight (OW; n=24) and obese (OB; n=30). Anthropometric measurements [BMI, Waist Circumference (WC), Waist-Hip Ratio (WHR), Body Density (BD), Body Adiposity Index (BAI), % Body fat] and oxidative stress biomarkers; Thiobarbituric acid reactive substances (TBARS), 8-hydroxy-2- deoxyguanosine (8-OH-2dG: indicative of DNA/RNA damage), Superoxide dismutase, Serum total antioxidant capacity) were recorded. There was statistically significant higher 8-OH-2dG (pg/ml) in OB compared to NW (800.63±6.19 vs. 780.22±3.34; p=0.007), as determined by one-way ANOVA and Tukey post hoc test. 8-OH-2dG was significantly and positively associated with BMI (r=0.286, p=0.004), WC (r=0.280, p=0.005), BAI (r=0.26, p=0.008), and % body fat (r=0.27, p=0.006). There may be significantly increased DNA damage in normoglycemic, normotensive obese adolescent females. This can be linked to the amount of adipose tissue in the body as depicted by strong positive association between DNA damage and BMI, WC, BAI, and % body fat., R. Latif, N. Rafique., and Obsahuje bibliografii
Oxidative stress may be caused by an increased rate of ATP resynthesis during physical exercise. The aim of this study was to compare changes in the prooxidant-antioxidant state of blood plasma between men and women after maximal-intensity exercise, and to assess the relationship between these changes and the value of the maximal oxygen uptake (VO2max) as well as between these changes and the value of post-exercise disruptions in acid-base balance. Study participants comprised 10 women (20.7±0.5 years) and 10 men (22.3±0.5 years) who were physically active but did no t engage in competitive sports training. VO2max was determined via treadmill incremental test (VO2max relative to body mass: 44.48±1.21 ml/kg/min and 59.16±1.55 ml/kg/min for women and men, respectively). The level of acid-base balance indicators (ABB), lactate concentration (La-), the level of total oxidative status (TOS), the level of total antioxidative capacity (TAC), an d uric acid (UA) concentration were measured before and after the test. An oxidative stress indicator (OSI) was also calculated. Men showed a significant post-exercise increase in the level of TOS and OSI, while women showed a significant post-exercise increase in the level of TAC. Post-exercise changes in UA concentration were insignificant. Post-exercise changes in TOC in men depended on the absolute values of VO2max , on VO2max/LBM, and on post-exercise changes in La- concentration., M. Wiecek, M. Maciejczyk, J. Szymura, Z. Szygula., and Obsahuje bibliografii