Vladimir Zivkovic

University of Kragujevac, Krabujevac, Central Serbia, Serbia

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Publications (20)25.38 Total impact

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    ABSTRACT: The aim of this study was to assess the oxidative stress status in rheumatoid arthritis (RA) by measuring markers of free radical production, systemic activity of disease, and levels of antioxidant. 52 RA patients and 30 healthy controls were included in the study, and clinical examination and investigations were performed and disease activity was assessed. Peripheral blood samples were used for all the assays. We assessed the markers of oxidative stress, including plasma levels of index of lipid peroxidation-thiobarbituric acid reactive substances (TBARS), hydrogen peroxide (H2O2), superoxide anion radical (O2 (-)), nitric oxide (NO), and superoxide dismutase activity (SOD), catalase activity (CAT) and glutathione levels in erythrocytes. In the RA group, levels of H2O2, O2 (-), and TBARS were significantly higher than in controls (4.08 ± 0.31 vs. 2.39 ± 0.13 nmol/l, p < 0.01; 8.90 ± 1.28 vs. 3.04 ± 0.38 nmol/l, p < 0.01, 3.65 ± 0.55 vs. 1.06 ± 0.17 μmol/l, p < 0.01). RA patients had significantly increased SOD activity compared with healthy controls (2,918.24 ± 477.14 vs. 643.46 ± 200.63UgHbx103, p < 0.001). Patients had significantly higher levels of pro-oxidants (O2 (-), H2O2, and TBARS) compared to controls, despite significantly higher levels of SOD. Significant differences were also observed in serum levels of NO in patients with high-diseases activity. Our findings support an association between oxidative/nitrosative stress and RA. Stronger response in samples with higher diseases activity suggests that oxidative/nitrosative stress markers may be useful in evaluating the progression of RA as well as in elucidating the mechanisms of disease pathogenesis.
    Molecular and Cellular Biochemistry 03/2014; · 2.33 Impact Factor
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    ABSTRACT: Despite the widespread clinical use of cyclooxygenase (COX) inhibitors, dilemmas still exist about potential impact of these drugs on cardiovascular system. The present study was aimed to estimate the effects of different COX inhibitors (meloxicam, acetylsalicylic acid [ASA], and SC-560) on oxidative stress in isolated rat heart, with special focus on L-arginine/NO system. The hearts of male Wistar albino rats (total number n = 96, each group 12 rats, 8 weeks old, body mass 180-200 g) were retrogradely perfused according to the Langendorff technique at gradually increased perfusion pressure (40-120 cmH2O). After control experiments the hearts were perfused with the following drugs: 100 μmol/l ASA (Aspirin), alone or in combination with 30 μmol/l L-NAME, 0.3 μmol/l meloxicam (movalis) with or without 30 μmol/l L-NAME, 3 μmol/l meloxicam (alone or in combination with 30 μmol/l L-NAME), 30 μmol/l L-NAME, and administration of 0.25 μmol/l SC-560. In samples of coronary venous effluent the following oxidative stress markers were measured spectrophotometrically: index of lipid peroxidation (measured as thiobarbituric acid reactive substances [TBARS]), superoxide anion radical release (O2 (-)), and hydrogen peroxide (H2O2). While ASA was found to have an adverse influence on redox balance in coronary circulation, and coronary perfusion, meloxicam and SC-560 do not negatively affect the intact model of the heart. Furthermore, all effects were modulated by NOS inhibition. It seems that interaction between COX and L-arginine/NO system truly exists in coronary circulation, and can be one of the possible causes for achieved effects. That means: those effects induced by different inhibitors of COX are modulated by subsequent inhibition of NOS.
    Molecular and Cellular Biochemistry 06/2013; · 2.33 Impact Factor
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    ABSTRACT: Despite worldwide popularity of soccer, there are still insufficient data about the effects of training process on oxidative stress-induced damage, which may occur during chronic exercise. The present study aimed to determine the effects of a six-month training programme on basal redox status of young male soccer players. The study included 26 male soccer players, aged 12-13, who participated in a six-month training programme, and 26 age-matched non-athletes who were not implemented in the training process. Blood samples were collected (before and after six-month training programme) in order to measure the following oxidative stress markers: index of lipid peroxidation (measured as TBARS), nitrites (NO2-), superoxide anion radical (O2-), hydrogen peroxide (H2O2), superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH) level. After six months, the levels of TBARS and NO2- were significantly increased, while the O2- and H2O2 remained unchanged. On the other hand, SOD and CAT activity increased, while GSH decreased. A carefully prepared training programme could strengthen most components of antioxidant defence systems and, except lipid peroxidation, does not promote oxidative stress in response to regular physical activity. These findings could help in the improvement of training programmes for young athletes.
    Acta Physiologica Hungarica 03/2013; 100(1):64-76. · 0.88 Impact Factor
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    ABSTRACT: Considering the adverse effects of DL-homocysteine thiolactone hydrochloride (DL-Hcy TLHC) on vascular function and the possible role of oxidative stress in these mechanisms, the aim of this study was to assess the influence of DL-Hcy TLHC alone and in combination with specific inhibitors of important gasotransmitters, such as L-NAME, DL-PAG, and PPR IX, on cardiac contractility, coronary flow, and oxidative stress markers in an isolated rat heart. The hearts were retrogradely perfused according to the Langendorff technique at a 70 cm H2O and administered 10 μ M DL-Hcy TLHC alone or in combination with 30 μ M L-NAME, 10 μ M DL-PAG, or 10 μ M PPR IX. The following parameters were measured: dp/dt max, dp/dt min, SLVP, DLVP, MBP, HR, and CF. Oxidative stress markers were measured spectrophotometrically in coronary effluent through TBARS, NO2, O2 (-), and H2O2 concentrations. The administration of DL-Hcy TLHC alone decreased dp/dt max, SLVP, and CF but did not change any oxidative stress parameters. DL-Hcy TLHC with L-NAME decreased CF, O2 (-), H2O2, and TBARS. The administration of DL-Hcy TLHC with DL-PAG significantly increased dp/dt max but decreased DLVP, CF, and TBARS. Administration of DL-Hcy TLHC with PPR IX caused a decrease in dp/dt max, SLVP, HR, CF, and TBARS.
    BioMed research international. 01/2013; 2013:318471.
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    ABSTRACT: Despite the widespread clinical use of cyclooxygenase (COX) inhibitors, dilemmas regarding the potential impact of these drugs on the cardiovascular system persist. To estimate the effects of different COX inhibitors (meloxicam, acetylsalicylic acid [ASA] and SC-560) on cardiac function and coronary flow in isolated rat hearts, with special focus on the L-arginine/nitric oxide system. The hearts of eight-week-old male Wistar albino rats (n=72; 12 rats per group; body mass 180 g to 200 g) were retrogradely perfused according to the Langendorff technique at gradually increased perfusion pressure (40 cmH2O to 120 cmH2O). After control experiments, the hearts were perfused with the following drugs: 100 μM ASA, alone or in combination with 30 μM N(ω)-nitro-L-arginine monomethyl ester (L-NAME), 0.3 μM meloxicam with or without 30 μM L-NAME, 3 μM meloxicam with or without 30 μM L-NAME, 30 μM L-NAME and 0.25 μM SC-560. In the control and experimental groups, the following parameters of heart function were continuously recorded: maximum rate of left ventricular pressure development, minimum rate of left ventricular pressure development, systolic left ventricular pressure, diastolic left ventricular pressure, heart rate and mean blood pressure. Coronary flow was measured flowmetrically. The amount of released NO2 (-) was determined spectrophotometrically in coronary venous effluent. While meloxicam and SC-560 were found to have an adverse influence on cardiac function and coronary perfusion, ASA did not negatively affect the intact model of the heart. It appeared that interaction between COX and the L-arginine/nitric oxide system truly exists in coronary circulation and may explain the causes of the observed effects.
    Experimental and clinical cardiology 01/2013; 18(2):e102-10. · 1.10 Impact Factor
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    ABSTRACT: Cardiovascular (CV) morbidity and mortality are increased in patients with rheumatoid arthritis (RA). Our study aim was to determine the relationship between carotid artery intima-media wall thickness (IMT) and flow-mediated endothelium-dependent vasodilatation (FMD) in a patients with RA, in context with clinical and laboratory measurements. Fifty-two patients with RA and 30 matched healthy controls without clinically evident CV disease were studied. Brachial and carotid ultrasonography was performed to determine FMD and IMT, respectively. We also assayed immunological, inflammatory and metabolic laboratory markers. IMT was significantly higher in RA patients (1.00 ± 0.16 mm) patients than in controls (0.89 ± 0.13 mm) (P = 0.001). FMD was significantly lower in RA (9.16 ± 7.03) as compared to controls (12.60 ± 5.49) (p = 0.005). RA patients had significant positive correlations between erythrocyte sedimentation rate (ESR) (r=0.395 p = 0.021) and IMT and negative correlation between visual analog scale (VAS) (r= -0.311, p= 0.025) and IMT. RA patients who used low doses of corticosteroids have, statistically, significantly better FMD, than those who do not use corticosteroids. Linear regression analysis revealed that IMT was related to tender joint count (p = 0.008), VAS (p < 0.001), ESR (p = 0.048) and total cholesterol/high density lipoprotein cholesterol ratio (p = 0.039). In patients with RA, FMD was impaired and IMT was increased, indicating early endothelial dysfunction and accelerated atherosclerosis. Early treatment of disease may reduce the risk of atherosclerosis in RA.
    VASA.: Zeitschrift für Gefässkrankheiten. Journal for vascular diseases 09/2012; 41(5):343-51. · 1.01 Impact Factor
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    ABSTRACT: Research on the effects of homocysteine on the vascular wall, especially in endothelial and smooth muscle cells, has indicated that increased homocysteine levels lead to cellular stress and cell damage. Considering the adverse effects of homocysteine on vascular function and the role of oxidative stress in these mechanisms, the aim of this study was to estimate the influence of different homocysteine isoforms on cardiac contractility, coronary flow, and oxidative stress markers in isolated rat heart. The hearts of male Wistar albino rats (n = 36, age 8 weeks, body mass 180-200 g), were excised and retrogradely perfused according to the Langendorff technique at a constant perfusion pressure (70 cmH(2)O) and administered with three isoforms of 10 μM homocysteine [DL-Hcy, DL-Hcy thiolactone-hydrochloride (TLHC) and L-Hcy TLHC). After the insertion and placement of the sensor in the left ventricle, the parameters of heart function: maximum rate of pressure development in the left ventricle (dP/dt max), minimum rate of pressure development in the left ventricle (dP/dt min), systolic left ventricular pressure (SLVP), diastolic left ventricular pressure (DLVP), mean blood pressure (MBP) and heart rate (HR)] were continuously registered. Flowmetry was used to evaluate the coronary flow. Markers of oxidative stress: index of lipid peroxidation measured as TBARS, nitric oxide measured through nitrites (NO(2) (-)), superoxide anion radical (O(2) (-)), and hydrogen peroxide (H(2)O(2)) in the coronary venous effluent were assessed spectrophotometrically. Our results showed that administration of Hcy compounds in concentration of 10 μM induced depression of cardiac contractility, manifested by a decrease in dp/dt max after administration of any Hcy compound, decrease in dp/dt min after administration of L-Hcy TLHC, decrease in SLVP after administration of DL-Hcy TLHC and DL-Hcy, and the drop in CF after administration of any Hcy compound. Regarding the effects of Hcy on oxidative stress parameters, only L-Hcy TLHC significantly affected O(2) (-) release. L-Hcy TLHC showed a cardiotoxic effect by affecting heart contractility, but surprisingly, it decreased the release of O(2) (-).
    Molecular and Cellular Biochemistry 07/2012; 370(1-2):59-67. · 2.33 Impact Factor
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    ABSTRACT: In patients with unreconstructable arterial occlusive disease distal venous arterialization (DVA) seems to be a promising option in the treatment. The goals of this prospective study were to assess clinical efficiency and possible impact of DVA on tissue damage by estimating oxidative status of patients with critical limb ischemia treated with this procedure. The subjects were 60 randomized patients: 30 were undergoing DVA and 30 were treated with antiaggregation therapy. During the mean follow-up period (6.13 ± 4.32 months for DVA vs. 6.74 ± 0.5 months for antiaggregation therapy) survival (p < 0.01), limb salvage (p < 0.001), pain relief (p < 0.001) and wound healing (p < 0.001) rates were significantly different between the two groups of patients in favor of the DVA group. Ten minutes after declamping we observed a decreasing trend in the lactate level in the blood of the deep venous system (p < 0.001). Also, on postoperative day 7 digital systolic pressure and digital-brachial index were higher than before the operation (p < 0.001). In blood samples collected immediately before and successively at 1, 3, 5 and 10 min postoperatively, prooxidative status (thiobarbituric acid reactive substances, O(2)(-), H(2)O(2) and nitric oxide) and antioxidative enzymes (superoxide dismutase, catalase and glutathione reductase) were determined spectrophotometrically. Using the nonparametric Friedman test, we noted statistically nonsignificant differences (p > 0.05) in values of both prooxidative parameters and enzymes of the antioxidative defense system, before and successively at 1, 3, 5 and 10 min after operation. These results indicate that there was no statistically significant reperfusion injury after revascularization, which could have been expected after this surgical procedure, thus confirming its validity in these patients.
    European Surgical Research 06/2012; 48(4):200-7. · 0.75 Impact Factor
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    ABSTRACT: The aims of our study were to assess the redox state of adolescent athletes and non-athletes both at rest and after acute exposure to physical load and to find relations between parameters of redox state and morphofunctional characteristics of subjects. 58 young handball players and 37 non-athletes were subjected to body composition analysis, measuring of maximal oxygen consumption and blood sampling immediately before and after a maximal progressive exercise test. At rest, athletes had significantly higher superoxide dismutase (SOD) and catalase (CAT) activity, higher levels of glutathione (GSH) and nitric oxide (NO) and lower levels of lipid peroxidation (TBARS) compared with non-athletes. A maximal exercise test induced statistically significant rise of superoxide anion radical (O2-), hydrogen peroxide (H2O2) and NO levels in non-athletes, while TBARS levels decreased. Athletes experienced the fall in NO levels and the fall in CAT activity. After exercise, athletes had significantly lower levels of O2- compared with non-athletes. Two way repeated measures ANOVA showed that the response of O2-, NO and TBARS to the exercise test was dependent on the sports engagement (training experience) of subjects. Significant correlations between morphofunctional and redox parameters were found. These results suggest that physical fitness affects redox homeostasis.
    General Physiology and Biophysics 06/2012; 31(2):211-9. · 0.85 Impact Factor
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    ABSTRACT: Regular training has been claimed to increase the activity of antioxidant enzymes and, consequently, augments the resistance to oxidative stress; however, large volumes of training performed by elite sportsmen could lead to a chronic oxidative stress state. The aim of our study was to assess the oxidative status of elite athletes at the beginning of the preparatory and the beginning of the competition training phases, so that the influence of three months of programmed physical activity on redox status could be determined. The chronic effects of exercise on the redox state of the athletes were compared to the effects of a single bout of karate training. Thirty elite karate athletes, 16-30 years old, were subjected to maximal graded exercise test to estimate their aerobic capacity; blood sampling was also performed to measure levels of superoxide anion radical (O₂⁻), hydrogen peroxide (H₂O₂), superoxide dismutase activity (SOD) and catalase activity (CAT). The only significant change after the three-month training process was found in the significantly decreased CAT activity (X ± SE: 7.95 ± 0.13 U/g Hb × 10³ in the preparatory period, 6.65 ± 0.28 U/g Hb × 10³ in the competition stage; P < 0.01). After a single karate training session, there was statistically significant decrease of O₂⁻(X ± SE: 32.7 ± 4.9 nmol/ml in the preparatory period, 24.5 ± 2.5 nmol/ml in the competition stage; P < 0.05) and increase of H₂O₂(X ± SE: 11.8 ± 1.0 nmol/ml in the preparatory period, 14.2 ± 0.9 nmol/ml in the competition stage; P < 0.01), as well as significant CAT increase (X ± SE: 6.6 ± 0.6 U/g Hb × 10³ in the preparatory period, 8.5 ± 0.5 U/g Hb × 10³ in the competition stage; P < 0.05). Although the three-month training process induced, at the first sight, negative changes in the redox state, expressed through the decrease in CAT activity, adequate response of the antioxidant system of our athletes to acute exercise was preserved.
    The Chinese journal of physiology 02/2012; 55(1):8-15. · 0.75 Impact Factor
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    ABSTRACT: Тo examine the effects of nitroglycerine on portal vein haemodynamics and oxidative stress in patients with portal hypertension. Thirty healthy controls and 39 patients with clinically verified portal hypertension and increased vascular resistance participated in the study. Liver diameters, portal diameters and portal flow velocities were recorded using color flow imaging/pulsed Doppler detection. Cross-section area, portal flow and index of vascular resistance were calculated. In collected blood samples, superoxide anion radical (O(2) (-)), hydrogen peroxide (H(2)O(2)), index of lipid peroxidation (measured as TBARS) and nitric oxide (NO) as a marker of endothelial response (measured as nitrite-NO(2) (-)) were determined. Time-dependent analysis was performed at basal state and in 10th and 15th min after nitroglycerine (sublingual 0.5 mg) administration. Oxidative stress parameters changed significantly during the study. H(2)O(2) decreased at the end of study, probably via O(2) (-) mediated disassembling in Haber Weiss and Fenton reaction; O(2) (-) increased significantly probably due to increased diameter and tension and decreased shear rate level. Consequently O(2) (-) and H(2)O(2) degradation products, like hydroxyl radical, initiated lipid peroxidation. Increased blood flow was to some extent lower in patients than in controls due to double paradoxes, flow velocity decreased, shear rate decreased significantly indicating non Newtonian characteristics of portal blood flow. This pilot study could be a starting point for further investigation and possible implementation of some antioxidants in the treatment of portal hypertension.
    World Journal of Gastroenterology 01/2012; 18(4):331-9. · 2.55 Impact Factor
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    ABSTRACT: Taken into consideration limited data about effects of palladium on cardiovascular system, the aim of our study was to compare toxicity of inorganic and organic palladium compounds on the isolated rat heart. The hearts (total number n=30, 6 for each experimental group) excised from Wistar albino rats, male sex, age 8 weeks, and body mass 180-200 g, were retrogradely perfused according to the Langendorff technique at constant perfusion pressure (70 cm H2O). After the insertion of sensor in the left ventricle, the parameters of heart function: maximum rate of left ventricular pressure development (dP/dt max), systolic left ventricular pressure (SLVP), diastolic left ventricular pressure (DLVP), mean blood pressure (MBP) and heart rate (HR)), were continuously registered. The experiments were performed during control conditions, and in the presence of perfusion with incresing concentration of the following: (triethanolamine (TEA), triethanolamine acetate (TEAA), palladium(II)chloride (PdCl2), and trans-dichlorobis(triethanolamine-N)palladium(II) complex (trans-[PdCl2(TEA)2])) started every 30 minutes (30, 60, 90, 120 minute). dP/dt max was not affected significantly by either TEAA, TEA, PdCl2 or Pd complex. SLVP was, also, not affected significantly by either TEAA, TEA, PdCl2, or Pd complex. DLVP was significantly decreased by both TEAA and PdCl2, while TEA and Pd complex did not show significant effect. MBP was significantly decreased only by PdCl2, while TEAA, TEA and Pd complex did not show significant effect. HR was significantly decreased by all compounds- PdCl2, TEAA, TEA and Pd complex. In our study, inorganic palladium compound (PdCl2) induced clear depression of the isolated rat heart contractility, manifested as drop in diastolic and mean blood pressure , and as decrease of the heart rate. On the other hand, it seems that palladium, when bound in an organic compound (linked to TEA in Pd complex), does not contribute significantly to cardio-toxicity in our experimental conditions.
    Medicinal chemistry (Shāriqah (United Arab Emirates)) 01/2012; 8(1):9-13. · 1.64 Impact Factor
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    ABSTRACT: The purpose of this study was to assess the influence of sport-specific and nonspecific bouts of exercise on athletes' redox state. Blood samples were collected from 14 handball players immediately before and after graded exercise test on the cycle ergometer and handball training. Levels of superoxide anion radical (O(2) (-)), hydrogen peroxide (H(2)O(2)), nitrites (NO(2) (-)) as markers of nitric oxide, index of lipid peroxidation (TBARs), glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) activity were determined. Exercise intensity was assessed by a system for heart rate (HR) monitoring. Average athletes' HR was not significantly different between protocols, but protocols differed in total time and time and percentage of time that athletes spent in every HR zone. The laboratory exercise test induced a significant increase of H(2)O(2) and TBARs as well as the decrease of the SOD and CAT activity, while after specific handball training, levels of NO(2) (-) were increased and SOD activity decreased. It seems that unaccustomed short intensive physical activity may induce oxidative stress in trained athletes, while sport-specific activity of longer duration and proper warm-up period may not. Further research should show whether the change of protocol testing and the implementation of various supplementations and manual methods can affect the redox equilibrium.
    Oxidative Medicine and Cellular Longevity 01/2012; 2012:805850.
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    ABSTRACT: Maximal workload in elite athletes induces increased generation of reactive oxygen/nitrogen species (RONS) and oxidative stress, but the dynamics of RONS production are not fully explored. The aim of our study was to examine the effects of long-term engagement in sports with different energy requirements (aerobic, anaerobic, and aerobic/anaerobic) on oxidative stress parameters during progressive exercise test. Concentrations of lactates, nitric oxide (NO) measured through stabile end product-nitrites (NO(2) (-)), superoxide anion radical (O(2) (•-)), and thiobarbituric reactive substances (TBARS) as index of lipid peroxidation were determined in rest, after maximal workload, and at 4 and 10th min of recovery in blood plasma of top level competitors in rowing, cycling, and taekwondo. Results showed that sportmen had similar concentrations of lactates and O(2) (•-) in rest. Nitrite concentrations in rest were the lowest in taekwondo fighters, while rowers had the highest levels among examined groups. The order of magnitude for TBARS level in the rest was bicycling > taekwondo > rowing. During exercise at maximal intensity, the concentration of lactate significantly elevated to similar levels in all tested sportsmen and they were persistently elevated during recovery period of 4 and 10 min. There were no significant changes in O(2) (•-), nitrite, and TBARS levels neither at the maximum intensity of exercise nor during the recovery period comparing to the rest period in examined individuals. Our results showed that long term different training strategies establish different basal nitrites and lipid peroxidation levels in sportmen. However, progressive exercise does not influence basal nitrite and oxidative stress parameters level neither at maximal load nor during the first 10 min of recovery in sportmen studied.
    Molecular and Cellular Biochemistry 05/2011; 355(1-2):273-9. · 2.33 Impact Factor
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    ABSTRACT: Considering the role of von Willebrand factor (vWf) in hemostasis, and the role of oxidative stress in the development of endothelial dysfunction and atherosclerotic disease, the aim of our study was to investigate the relationship between vWf, parameters of oxidative stress and different types of acute coronary syndromes (ACS). Levels of vWf activity (vWfAct), vWf antigen (vWfAg), nitric oxide (estimated through nitrites-NO(2)-), superoxide anion radical (O(2)-), hydrogen peroxide (H2O2), index of lipid peroxidation (estimated through thiobarbituric acid reactive substances-TBARS), superoxide dismutase (SOD) and catalase (CAT) activity of 115 patients were compared with those of 40 healthy controls. ACS patients had significantly higher vWfAct and vWfAg levels, as well as TBARS levels, while their levels of NO(2)-, H2O2, SOD and CAT activities were lower than controls'. vWfAg showed high specificity and sensitivity as a test to reveal healthy or diseased subjects. Multivariant logistic regression marked only vWfAg and TBARS as parameters that were under independent effect of ACS type. The results of our study support the implementation of vWf in clinical rutine and into therapeutic targets, and suggest that ACS patients are in need of antioxidant supplementation to improve their impaired antioxidant defence.
    Oxidative Medicine and Cellular Longevity 01/2011; 2011:918312.
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    ABSTRACT: Exercise increases production of reactive oxygen and nitrogen species (RONS) via several mechanisms. Inter alia, increased blood flow during exercise exposes endothelial cells to shear stress, resulting in increased nitric oxide (NO) production. Increased oxygen consumption or hypoxia during exercise induces increased production of superoxide anion radical (O(2) (-)). This study investigates the effects of maximal progressive treadmill exercise test on time-course of peripheral blood NO and O(2) (-) production, as well as the effect of long-term training on NO bioavailability. Blood samples of 19 elite soccer players were gathered immediately before the test, during last 10 sec of every test stage, and during active recovery phases. Significant increase (p<0.05) in NO production (estimated through nitrites (NO(2) (-))), found between stage I (5.69 ± 1.32 nmol/ml) and basal values (5.36 ± 1.25 nmol/ml), was followed by the decrease in stage II (4.21 ± 0.42 nmol/ml) and production lower than basal to the end of the test. Significant increase (p<0.05) in O(2) (-) values was found between stage I (4.18 ± 0.77 nmol/ml) and resting values (4.01 ± 0.69 nmol/ml), and at stages V (4.24 ± 0.85 nmol/ml) and 1st phase of recovery (4.39 ± 0.92 nmol/ml). The regression lines of NO(2) (-) and O(2) (-) crossed at the level of anaerobic threshold, suggesting that anaerobic threshold could be of a crucial importance not only in the anaerobic and aerobic metabolism but in mechanisms of signal transductions as well. Long-term exercise increases NO bioavailability, and there is positive correlation between NO bioavailability and maximal oxygen uptake (VO(2max)).
    The Open Biochemistry Journal 01/2010; 4:100-6.
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    ABSTRACT: Our aim was to investigate the relation between fetal distress and oxidative stress. Fetal distress was associated with increased concentration of superoxide in the fetal blood and with significant increase of the level of H2O2 in both maternal and fetal blood. The activity of superoxide dismutase was increased roughly sixfold (p < 0.01) in the maternal [7330 ± 2240 U/g of hemoglobin in controls (C) and 36811 ± 16862 U/g in fetal distress (FD)] and fetal blood (C: 5930 ± 2641 U/g; FD: 41912 ± 17133 U/g). In contrast, fetal distress was related to a considerable decrease of catalase activity in both maternal (C: 26011 ± 8811 U/g; FD: 7212 ± 1270 U/g) and fetal blood (C: 37194 ± 9191 U/g; FD: 6173 ± 1965 U/g). From this we concluded that in fetal distress, the maternal and fetal bloods are exposed to superoxide- and H2O2-mediated oxidative stress, which could be initiated by hypoxic conditions in the fetal blood and placenta. A tremendous increase/decrease of the activities of superoxide dismutase/catalase in the blood of women bearing a distressed fetus in comparison to healthy subjects implies that the assessment of superoxide dismutase/catalase activity could be of use for establishing a timely and accurate ante- or intrapartum diagnosis of fetal distress.
    Oxidative medicine and cellular longevity 01/2010; 3(3):214-219. · 3.39 Impact Factor
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    ABSTRACT: The myocardial reperfusion following ischemia leads to the ischemic vasodilation by affecting the release of various vasoactive substances, such as free radicals, NO, and histamine. In addition, some evidences suggest that glucagon itself may alter the release of those substances. In this study, we investigated the ischemic vasodilation of the isolated rat heart, as well as the concentrations of NO, TBARS, and histamine in the coronary venous effluent either in the presence or in the absence of glucagon. Our results showed that in the presence of glucagon, there was a faster restoration of coronary perfusion pressure during ischemic vasodilation compared to the absence of glucagon (124 +/- 5.6 versus 81 +/- 5.2 s) with no apparent changes in TBARS concentration. The glucagon's administration leads to the decreased release of histamine by approximately 35%. Biphasic release of NO in the presence of glucagon initially showed augmentation by 60%, followed by the significant attenuation of 45%.
    BioMed Research International 01/2010; 2010:231832. · 2.88 Impact Factor
  • Atherosclerosis Supplements - ATHEROSCLER SUPPL. 01/2009; 10(2).
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    ABSTRACT: The aim of the study was to establish the importance of an additional measurement of subcutaneous adipose tissue thickness (SAT) on a predetermined position on the waistline, and its relation to waist measurements as an improvement of metabolic prediction in equally obese subjects. One hundred and forty two consecutive patients were enrolled in the study: stratified by weight as normal (body mass index — BMI 20–25 kg/m2), overweight (BMI 25–30 kg/m2) and obese (BMI >30 kg/m2); and by fasting glucose level as normoglycemic, impaired fasting glucose (IFG), or with type 2 diabetes mellitus (T2DM). SAT was measured in relaxed expiration, 3 cm left of the umbilicus, with ultrasound. Fasting blood samples for glucose, insulin and HbAlc were taken. Waist circumference was slightly higher in the IFG (112.8 cm) and normoglycemic groups (115.62 cm), compared to T2DM (108.15 cm). The T2DM group had a lower average SAT (2.7 cm) than both the IFG group (3.4 cm, p<0.01) and the normoglycemic group (4.2cm, p=0.001). The homeostatic model of assessment for insulin resistance (HOMA IR) was the lowest in normoglycemic and the highest in IFG group. Waistline radius to SAT ratio provides better insight into the deterioration of glucose metabolism than standard anthropometric markers of abdominal obesity in equally obese patients.
    Central European Journal of Medicine 8(2). · 0.26 Impact Factor