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
Diabetes mellitus is characterized by oxidative stress, which in turn determines endothelial dysfunction. Gliclazide is a sulphonylurea antidiabetic drug with antioxidant effects due to its azabicyclo-octyl ring. It has been reported to potentially protect the vasculature through improvements in plasma lipid levels and platelet function. We hypothesized that gliclazide has a beneficial effect on endothelial function in Goto-Kakizaki rats (GK), an animal model of type 2 diabetes fed an atherogenic diet for 4 months. We evaluated the influence of gliclazide on both metabolic and oxidative status and NO-mediated vasodilation. GKAD rats showed increased oxidative stress and impaired endothelium-dependent vasodilation. GKAD rats treated with gliclazide showed increased sensitivity to NO-mediated vasodilation, a significant decrease in fasting glycemia and insulinemia, and a significant decrease in systemic oxidative stress. In conclusion, our results suggest that gliclazide treatment improves NO-mediated vasodilation in diabetic GK rats with dyslipidemia probably due to its antioxidant effects, although we cannot rule out substantial benefits due to a reduction in fasting blood glucose. The availability of a compound that simultaneously decreases hyperglycemia, hyperinsulinemia, and inhibits oxidative stress is a promising therapeutic candidate for the prevention of vascular complications of diabetes., C. M. Sena ... [et al.]., and Obsahuje seznam literatury
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
Hyperglycemia is known to cause oxidative stress that leads mainly to enhanced production of mitochondrial reactive oxygen species (ROS). It has been demonstrated that hyperbaric oxygen (HBO) treatment also increases the formation of ROS. There are, however, no comprehensive evaluations of such oxidative effects in diabetes which requires HBO treatment. The purpose of this study is to investigate the influence of a clinically-recommended HBO treatment on glucose homeostasis and oxidative stress in rats with streptozotocin (STZ)-induced diabetes. Under the clinically-used HBO exposure protocol, the levels of blood glucose, thiobarbituric acid reactive substances (TBARS) as a lipid peroxidation marker, and the activity of superoxide dismutase (SOD) as an antioxidant enzyme marker were investigated in the erythrocytes, liver, pancreas, skeletal muscle, and brain of rats with STZ-induced diabetes. The levels of blood glucose and TBARS increased significantly (p<0.05), and the activity of SOD decreased significantly (p<0.05) in the erythrocytes and all organs of rats with diabetes subjected to HBO exposure. These results suggested that HBO exposure might boost glucose autoxidation and increase ROS production in STZ-induced diabetes as side-effects of administering HBO treatment for the first time., T. Matsunami ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
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
Pneumatic tourniquets are widely used in pediatric extremity surgery to provide a bloodless field and facilitate dissection. This prospective study was carried out to examine possible effect of different anesthesia techniques on oxidative stress and endothelial dysfunction connected with ischemia-reperfusion injury during extremity operations at children's age. Patients were randomized into three groups of 15 patients each: general inhalational anesthesia with sevoflurane (group S), total intravenous anesthesia with propofol (group T) and regional anesthesia (group R). Venous blood samples for determination of the malondialdehyde in plasma and erythrocytes, protein carbonyl groups concentration as well as plasma nitrites and nitrates level and xanthine oxidase activity were obtained at four time points: be fore peripheral nerve block and induction of general anesthesia (baseline), 1 min before tourniquet release, 5 and 20 min after tourniquet release. This study demonstrates that total intravenous anesthesia with propofol and regional anesthesia techniques provide better antioxidant defense and reduce endothelial dysfunct ion than general inhalational anesthesia with sevoflurane during tourniquet application in pediatric extremity surgery., I. Budic ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
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