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J Kedziora

Publications and source records attributed to J Kedziora.

At least 19 recordsLinked to original sources

[Evaluation of some selected structural and functional parameters of red blood cells as oxidative stress markers in elderly people].

UNLABELLED: The ageing process induces age-related involutionary changes and leads to increased occurrence of many diseases. One of the most important theories of ageing and development of many pathologies is the free radical theory, which assumes that ageing process leads to lost of oxidative balance. THE AIM: of the research was to evaluate the degree of membrane lipid peroxidation, internal microviscosity, activity of membrane ATPase, both total and Na(+)K(+)-dependent, and markers of oxidative damage in erythrocyte membrane protein in elderly people. MATERIAL: The examination was performed on 35 people. The examined group (15 persons, mean age 71,3) consisted of healthy elderly people. The reference group was formed with younger healthy people (20 persons, mean age 55). RESULTS: Erythrocyte membrane lipid peroxidation was found stronger in the group of elderly people. Erythrocyte internal microviscosity was significantly higher in the elderly. The activity of ATPase, both total and Na(+)K(+)-dependent, appeared remarkably greater in the group of younger people. Stronger membrane lipid damage was observed in older age group, which may be implied by lower--SH group concentration, and higher W/S parameter value. CONCLUSION: The obtained results reveal that in elderly people the intensification of oxidative stress in the entire body occurs, which may be confirmed by structural and functional oxidative erythrocyte damage. This conclusion may be significant for pathogenesis of many diseases in this period of life.

Adenosine Triphosphatases↗

Effect of vitamin E and vitamin C supplementation on antioxidative state and renal glomerular basement membrane thickness in diabetic kidney.

The aim of this study was to analyze the effect of vitamins C and E on malondialdehyde (MDA) content and activities of key antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) as well as glomerular basement membrane (GBM) thickness in streptozotocin-induced diabetic kidney in rats. Wistar male rats were divided into following groups (12 rats each): the control, diabetic rats, diabetic rats whose drinking water was supplemented with vitamin C in a dose of 1.0 g/l or diet was supplemented with 200 mg of vitamin E/100 g fodder. Body weight, blood glucose and HbA1C levels and 24-hour urinary albumin excretion (UAE) were studied every week (0-12 weeks). After 6 and 12 weeks, MDA content and activities of SOD, CAT and GSH-Px were measured in the kidney homogenate supernatants. Electron micrographs of glomeruli were scanned and morphometric investigations were performed by means of computer image analysis system to compare GBM thickness. The blood glucose and HbA1C concentrations and UAE in diabetic rats were significantly higher than in the control group. An increase in the MDA level and decrease in the SOD, CAT and GSH-Px activities in the kidney of diabetic rats were observed after 6 and 12 weeks of experiment. Administration of vitamins C and E did not affect body weight, blood glucose and HbA1C levels. Both vitamin C and vitamin E decreased lipid peroxidation and augmented the activities of antioxidant enzymes studied in the kidneys of diabetic rats as well as reduced UAE, decreased kidney weight and GBM thickness. The results indicate the potential utility of antioxidant vitamins in the protection against the development of diabetic nephropathy.

Albuminuria↗

The effect of verapamil on the antioxidant defence system in diabetic kidney.

BACKGROUND: The aim of this study was to examine the effect of verapamil (VP) on lipid peroxidation and activities of key antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px); as well as on glomerular basement membrane (GBM) thickness in streptozotocin-induced diabetic kidney in rats. METHODS: Wistar male rats were divided into three groups, 12 rats each: the control (C), diabetic rats (DR), and DR receiving VP, 7 mg/kg body weight in drinking water (DR + VP). Blood glucose (BG) and HbA(1c) levels, 24-h urinary albumin excretion (UAE) and body weight (BW) were measured every week (0-12 weeks). After 6 and 12 weeks, the animals were sacrificed and malondialdehyde (MDA) content and activities of SOD, CAT and GSH-Px were determined in the kidney homogenate supernatants. Electron micrographs of the glomeruli were scanned and morphometric investigations were performed by means of a computer image analysis system to compare the glomerular basement basal membrane (GBM) thickness. RESULTS: The levels of BG, HbA(1c) and UAE in DR were significantly higher than in the C group. A progressive increase in the MDA level and a decrease in the SOD, CAT and GSH-Px activities in the kidney of DR were observed after 6 and 12 weeks. VP administration did not affect BW changes, BG and HbA(1c) levels in DR. VP decreased lipid peroxidation and augmented the activities of antioxidant enzymes studied in the kidneys of DR as well as decreased kidney weight, GBM thickness and albuminuria in DR. CONCLUSIONS: These results confirm the role of oxidative stress in the development of diabetic nephropathy and point to the possible antioxidative mechanism of the nephroprotective action of VP.

Albuminuria↗

[Evaluation of oxygen free radical generation and antioxidative enzymatic activity in blood of patients with carcinoma of the larynx (preliminary report)].

The aim of the study were the evaluation of generation of oxygen free radical and antioxidative enzymatic activity in blood of patients with carcinoma of larynx (7 persons, aged 48-68) in comparison with healthy persons (15, aged 21-28). The superoxide anion generation of blood granulocytes described by the rate of the reducted cytochrom C at rest and after stimulation with opsonized zymosan according to Bellavite et al. were measured. The enzymatic activity of superoxide dismutase in blood (method of Misra and Fridovich), catalase (method of Beers and Sizer) and malonyl dialdehyde (method of Placer et al.). The obtained data pointed at the growth of generation of oxygen free radical in blood (at rest and after stimulation with opsonized zymosan) of patients with carcinoma of larynx in comparison with the healthy ones. At the same patients with carcinoma of larynx observed at significant reduction of antioxidative enzymatic activity against the oxygen species generation in blood and significant growth of peroxidation lipids and disturbances of function of cells the human body.

Adult↗

[Estimation of plasma malonyl dialdehyde concentration in patients with pulmonary tuberculosis].

Plasma malonyl dialdehyde (MDA) concentration was determined by Placer method in patients with pulmonary tuberculosis before and during treatment period with tuberculostatic drugs. Patients were divided into three groups. Group I comprised 20 patients (10 men and 10 women) aged 24-74 years (mean 48.3 years) with pulmonary tuberculosis BK(+). Group II comprised 20 patients (15 men and 5 women) aged 19-67 years (mean 45.1 years) with pulmonary tuberculosis BK(0). The control group consisted of 16 clinically healthy persons (12 men and 4 women) aged 28-59 years (mean 42.5 years). In patients blood samples (5 ml) were collected for examination from cubital vein before, after 1-month and 2-month treatment period with tuberculostatic drugs. In the control group blood samples were collected from cubital vein once. Results of our study showed that plasma MDA concentrations in patients with pulmonary tuberculosis, both before and during treatment period with tuberculostatic drugs, were significantly higher, in comparison to the control group.

Adult↗

[Antioxidant enzymatic activity in blood of patients with chronic hypertrophy of the maxillary sinuses and larynx and the carcinoma of the larynx].

The aim of the work was the examinations of antioxidant enzymatic activity in blood of patients with chronic hypertrophic of maxillary sinusitis (15 patients) and laryngitis (10 patients), and carcinoma of larynx (7 patients) in comparison with healthy persons (15). The enzymatic activity of superoxide dismutase in blood (method of Misra and Fridovich), katalase (method of Beers and Sizer) and malonyl dialdehyde (method of Placer) were evaluated. The obtained results pointed at significant reduction of antioxidant enzymatic activity against the oxygen species generation in blood of patients with chronic hypertrophic of maxillary sinusits and laryngitis and mainly with the carcinoma of larynx (in comparison with healthy persons). At the same patients observed the significant growth of peroxydation lipoid and disturbances of function of cells the human body.

Adult↗

[Assessment of nitric oxide level in aqueous humor under physiological conditions and after lens extraction with PMMA during experimental work in rabbits].

PURPOSE: To evaluate the presence of nitric oxide and measure its level in the aqueous humor of the rabbit's eye, in physiological conditions and after extracapsular lens extraction and PMMA artificial lens implantation. We also investigated nitric oxide maintenance during early postoperative period (between 1-5 day after surgery). MATERIAL AND METHODS: We used 30 rabbits (weighing 3.0-3.5 kg) Just before surgery samples of aqueous humor were aspirated by anterior chamber puncture. Lens was extracted with extracapsular (envelope) technique. In 15 eyes PMMA IOL was implanted in the bag and 15 eyes were left aphakic. The aqueous samples were collected on 1st, 3rd, 5th days after surgery. Nitric oxide in each sample was measured with respect to fluorometric assay. RESULTS: In aqueous humor in physiological conditions we detected nitric oxide. Its level was estimated on the value of 26.52 nM/dl. After extracapsular lens extraction in both groups the level of nitric oxide was significantly higher than in control group. The day and value of NO level was different among examined groups. Nitric oxide level diminished significantly on 5th postoperative day. CONCLUSION: We came to conclusion that after ECCE and PMMA IOL implantation NO level was significantly higher as compared with control. This higher NO level after lens extraction can be responsible for the blood aqueous breakdown.

Animals↗

[Assessment of nitric oxide level in aqueous humor under physiological conditions and after lens extraction and artificial foldable acrylic lens implantation during experimental work in rabbits].

PURPOSE: To evaluate the presence of nitric oxide (NO) and its level in the aqueous humor of rabbit's eye physiological conditions and after phacoemulsification and acrylic foldable artificial lens implantation. We also investigated nitric oxide maintenance during early postoperative period (between 1-5 days after surgery). MATERIAL AND METHODS: We examined 30 rabbits (weighing 3.0-3.5 kg) Just before surgery samples of aqueous humor were aspirated. Lens was extracted with phacoemulsification technique. In 15 eyes acrylic foldable IOL (group III) was implanted and 15 eyes were left aphakic (group IV). The aqueous samples were collected on 1, 3, 5 days after surgery. Nitric oxide in each sample was determined with fluorometric assay. RESULTS: The level of NO in aqueous humor in physiological conditions was estimated to 26.52 nM/dl. After phacoemulsification in both groups the level of nitric oxide was higher than in control group. The day and value of the highest NO level was different among examined groups. The highest level of NO was released during 1st day in group III and on the 3rd day in the group IV. CONCLUSION: We came to conclusion that the level of nitric oxide in aqueous humor after phacoemulsification in both groups is higher than in control group but significantly lower than in previously examined groups in which the surgery was made with extracapsular technique.

Animals↗

Luminol luminescence induced by oxidants in antioxidant-deficient yeasts Saccharomyces cerevisiae.

Luminol chemiluminescence induced in the presence of yeast cells and yeast cell homogenates was significantly induced by exogenous oxidants (hydrogen peroxide and menadione). tert-Butyl hydroperoxide did not stimulate chemiluminescence by itself but augmented menadione-induced chemiluminescence. Comparison of yeast strains deficient in catalase, superoxide dismutase or glutathione showed that only glutathione-deficient strains showed elevated chemiluminescence in this system. These results support the idea that more reactive species than hydrogen peroxide and superoxide are critical in the induction of luminol chemiluminescence.

Acatalasia↗

Free radicals generation by granulocytes from men during bed rest.

Phagocytes (granulocytes and macrophages) are one of the most important sources of reactive oxygen species (ROS) in the human body. A stimulated phagocyte reaches within a dozen of seconds the functional state known as the respiratory burst. This phenomenon includes three interrelated processes: 1) a several fold increase in the oxygen uptake, 2) generation of large amounts of ROS, and 3) stimulations of glucose metabolism via the pentose phosphate shunt. The main ROS generated during phagocytosis is the superoxide radical anion O2-. The reaction of dismutation of O2- generates hydrogen peroxide (H2O2). O2- and H2O2 do not have strong cytocidal proerties but are supbstrates for the generation of more active biologically ROS, especially the hydroxyl radical (OH) and hypochlorous acid (HOCl). A stimulated phagocyte (especially neutrophil) generates also vast amounts of nitric oxide (NO-). NO- may react with the superoxide radical anion forming peroxynitrate (ONOO-). Reactivity of ONOO- is comparable to that of the hydroxyl radical. ONOO- plays probably a very important role in the so-called oxygen-dependent killing mechanisms during phagocytosis. The role of NO- in the process of phagocytosis is unclear. However, NO-, apart from other biological functions, inhibits aggregation and adhesion of blood platelets. Morevover, it seems to participate in the slefregulation of granulocyte cativity (probably limiting excessive inflammative reaction). Excess of ROS generated by phagocytes may damage biologically important macromolecules. Membrane lipids are particularly vulnerable to peroxidation. It leads to alterations in membrane fluidity and permeability. ROS excreted to the environment of a phagocyte may impair functions of other morphotic elements of blood (erythrocytes and thromobcytes) in this way. Bed rest covers two conditions: 1) limitation of motoric activity (hypodynamia) and 2) restraining the pressure on bones along parallelly to their long axes (hypogravia). Under bed rest conditions organism is subject to many harmful changes. I.a., bed rest affects also leukocyte functions. However, we were not aware of any sutdies concerning the effect of bed rest on the respiratory burst of granulocytes. This study was aimed at an examination of the effect of bed rest on the generation of O; and H2O2 by neutrophils (PMNL).

Adult↗

Effect of long term bed rest in men on enzymatic antioxidative defence and lipid peroxidation in erythrocytes.

Bed rest is an integral part of treatment of numerous diseases. Typical examples are bone fractures of lower extremities and pelvis. Temporary immobilization is necessary also, e.g., in heart diseases (stroke), backbone and imminent abortion. The sick organism spares energy during the bed rest wich is beneficial. However, bed rest results in many alterations which are disadavantageous. They concern the function of almost all organs and systems but affect most significantly the locomotor and ciruclatory systems. Bed rest brings also about changes in the composition of peripheral blood and functions of the morphotic elements of blood. Red blood cells are subjected to the action of large amounts of reactive oxygen species (ROS). During oxidation of hemoglobin to methemoglobin superoxide radical anion (O2-) is formed: HbFe2+ + O2 --> MetHbFe3+ + O2- (1) Ferrous and ferric ions present in the cytoplasm of red blood cells may be catalysts of the Fenton reaction leading to the production of the hydroxyl radical: O2- + Fe3+ --> O2- + Fe2+ (2) Fe2+ + H2O2 --> Fe3+ + OH + HO- (3) OH shows a tremendous reactivity. It may react with lipids, proteins, nucleic acids and carbohydrates. The process of lipid peroxidation is best understood. It concerns mainly polyunsaturated fatty acids present in cell membranes. Peroxidation of membrane lipids decreases membrane fluidity and impairs its barrier function. The lowered membrane fluidity compromises erythrocyte deormability which in turn disturbs oxygen delivery to the tissues. End productions of lipid peroxidation are low-molecular wieght compounds, among them carbohydrates (ethane and pentane) and aldehydes, e.g. malondialdehyde (MDA). MDA concentration is an acknowldeged marker of the intensity of lipid peroxidation. Erythrocytes contain a complex system of protection against the action of ROS. It includes various enzymatic and non-enzymatic mechanism. The most important antioxidative enzymes of the red blood cells are superoxide dismutase (Cu,Zn-SOD, EC 1.15.1.1) catalase (CAT, EC 1.11.1.6) and glutathione peroxidase (GSH-Px, EC 1.11.1.9). Cu,Zn-SOD catalyzes the dismuation of O2- to hydrogen peroxide (H2O2). Catalase and peroxidase remove H2O2 and, moreover, GSH-Px can reduce lipid peroxides. Under normal conditions an equilibrium exists between the formation and removal ROS. If ROS are formed in excess or the defensive antioxidative mechanism are inefficient, oxidative stress develops. Derangement of the equilibrium between the formation and removal of ROS is important in the pathosgenesis of many diseases, e.g. atherosclerosis, diabetes, Down syndrome and Alzheimer disease. There are literature data on disturbances of enzymatic antioxidant defense mechanism of blood plateless during bed rest. This study was aimed at an examination of the post-traumatic bed rest on the enzymatic antioxidative defense mechanisms and lipid peroxidation in erythrocytes.

Adult↗

[Changes in the antioxidant system of the vitreous in rabbits after administration of sulfur hexafluoride].

PURPOSE: To evaluate the enzymatic activity of antioxidant system of rabbit's vitreous after sulfur hexafluoride (SF6) application. MATERIAL AND METHODS: Activity of CuZn-SOD, catalase and concentration of MDA in fluid and gel fraction of vitreous were determined in 24 rabbits of New Zealand race on the 2nd, 7th and 14th day after SF6 application. Control group consisted of 6 animals which did not undergo any operations. RESULTS: Dismutase and catalase activity as well as MDA concentration were higher in fluid fraction than in gel fraction in animals of control group. After SF6 application the activity of enzymes and MDA concentration did not change, whereas in fluid fraction all these values were statistically significantly reduced in all time intervals. CONCLUSIONS: SF6 leads to disintegration of vitreous structure especially just after its application. Damage to hyalocytes causes dysfunction of enzymatic system. Specific fluid fraction structure and insufficient number of substrates for peroxidation processes are the reasons for simultaneous reduction of MDA concentration.

Animals↗

[Changes in the antioxidant system of the aqueous humor, lens and erythrocytes after sulfur hexafluoride application to the vitreous of rabbits].

AIM: To determine the activity of superoxide dismutase, catalase and the concentration of malondialdehyde (MDA) in aqueous humor, lens and red blood cells after application of sulfur hexafluoride (SF6) into vitreous of rabbits. MATERIAL AND METHODS: 0.5 ml of 100% SF6 was injected into the vitreous of 24 rabbits of New Zealand race. The animals were randomly divided into 3 groups (of 8 rabbits each) depending on the observation day: group 1-2nd day of experiment, group 2-7th day and group 3-14th observation day. The control group (gr. 0) consisted of 6 rabbits that did not undergo any operations. Activity of superoxide dismutase, catalase and MDA concentration were determined in aqueous humor, lens and systemic blood erythrocytes. RESULTS: On the 7th day of observation an increased activity of dismutase and catalase as well as simultaneous increased MDA concentration were observed. In the lens on the 7th day the increased activity of dismutase was significant in relation to the results in the next time interval, whereas MDA concentration was significantly lower in all time intervals of the experiment in comparison with control group. In erythrocytes an increased activity of catalase was noticed on the 2nd and 14th day. CONCLUSIONS: Increased occurrence of active oxygen species in aqueous humor leads to insufficiency of the antioxidant system and intensification of peroxidation processes, which is reflected by increased MDA concentration. However, in the lens of this experimental model a slight stimulation of antioxidant system by a small number of free radicals is observed, which provokes a reaction of sweeping them away. Efficiency of lens antioxidant system is secured by weakening of peroxidation processes, which is expressed in minimal drop of MDA concentration.

Animals↗

Antioxidant and prooxidant properties of captopril and enalapril.

Captopril ([2S]-1-[3-mercapto-2-methyl-propionyl]-L-proline) was found to protect erythrocytes from hemolysis caused by 2,2'-azobis (2-amidinopropane) (AAPH) and hypochlorite, erythrocyte membranes from lipid peroxidation caused by tert-butyl hydroperoxide (tBOOH) and hypochlorite, erythrocyte membrane ATPases from inactivation caused by tBOOH and hemoglobin from oxidation caused by AAPH and tBOOH. In all these systems enalapril ([S]-1-[N-(1-[ethoxycarbonyl]-3-phenylpropyl)-L-alanyl]-L-proline) was not protective or even increased the damage, especially with hypochlorite, probably due to chloramine formation. Captopril but not enalapril inhibited ascorbate autoxidation caused by Cu2+, which indicates that captopril binds Cu2+. On the other hand, deoxyribose degradation caused by iron and copper ions and DNA damage by o-phenanthroline/Cu2+/H2O2/beta-mercaptoethanol was enhanced by both captopril and enalapril. The effect of captopril was usually higher, apparently due to the reducing properties of captopril, which could reduce metal ions enabling their participation in the Fenton reaction. These results indicate that only -SH-group-containing inhibitors of angiotensin-converting enzyme (ACE) may exhibit antioxidant properties, and that the antioxidant/prooxidant action of ACE inhibitors depends on the system studied in vitro.

Adenosine Triphosphatases↗

Nitric oxide release in the peripheral blood during hemodialysis.

These studies evaluated the nitric oxide (NO) release in peripheral blood during a four-hour hemodialysis (HD) with single-used cuprophane (CU), polysulfone (PS) and polyacrylonitrile (PAN) membranes in 10 chronic uremic patients. Continuous monitoring of blood NO concentrations was performed with a sterile NO sensor probe inserted vertically into the arterial blood line between the arteriovenous fistula and dialyzer. In the initial period of HD two peaks of blood NO concentrations were observed: the first occurred at the very start of HD and lasted approximately one minute, and the second peaked to a lesser extent at 20 to 26 minutes after the initiation of HD. The extent of NO release was dependent on the type of dialysis membrane used. Areas under curves for blood NO concentrations (in mumol x min) were as follows: CU, 450.8 +/- 163.3; PS, 247.3 +/- 150.6*; PAN, 200.4 +/- 91.0* (*P < 0.05 vs. CU). During the first hour of HD (N = 6) blood NO concentrations were significantly higher at the outlet of CU dialyzer than those found at the inlet. The areas under their curves (in mumol x min) were 169.1 +/- 1.9 and 107.5 +/- 1.6, respectively (P < 0.001). Areas under curves for blood NO concentrations measured for five minutes following a five-minute in vitro incubation of 5 ml heparinized uremic blood samples (N = 10) with dialysis membranes (50 cm2) were as follows (in nmol x min): CU, 2380 +/- 289*; PS, 1293 +/- 45*; PAN, 1117 +/- 37*; control, 502 +/- 56 (*P < 0.05 vs. control). The addition of sodium heparin to uremic blood platelet suspension induced an immediate rise in NO release in a dose-dependent manner, which proved to be a hyperbolic relationship. During HD with CU (N = 6), PS (N = 6) and PAN (N = 6) membranes blood plasma cGMP concentrations significantly increased, particularly at 20 and 60 minutes of the procedure. No significant differences in blood plasma cGMP levels were found between individual dialysis membranes, and no significant correlations were observed between blood plasma cGMP levels and blood NO concentrations. The results indicate that during HD NO is released in the peripheral blood due to blood-membrane and heparin-blood platelet interactions. The extent of intradialytic NO release is dependent on the type of dialysis membrane used (CU > PS approximately PAN).

Adult↗

Effect of perindopril therapy on fluidity and potential of erythrocyte membrane from individuals with coronary heart disease.

Erythrocyte membrane fluidity and membrane potential were measured in patients suffering from coronary heart disease (CHD) and treated with perindopril. Membrane fluidity was determined using electron paramagnetic resonance (EPR) spectroscopy, and membrane potential was evaluated using potential-sensitive fluorescent dyes. CHD does not change membrane fluidity at the depth of the 5 carbon in the fatty acid chain of membrane phospholipids. However the hydrophobic core of the membrane is altered in CHD. For 19 CHD patients, the correlation times tau B and tau C of a spin label 16DS were higher than for controls: tau B = (1.84 +/- 0.04) x 10(-9) s and tau C = (2.54 +/- 0.04) x 10(-9) s vs. tau B = (1.62 +/- 0.06) x 10(-9) s; and tau C = (2.24 +/- 0.07) x 10(-9) s (results given as mean +/- SEM). Such results indicate the increased microviscosity in hydrophobic regions of CHD erythrocyte membranes in comparison with controls. Perindopril therapy partly abolished these changes. The membrane potential of CHD red blood cells -17.89 +/- 1.36 mV was higher than the control value -9.83 +/- 0.59 mV. Perindopril treatment shifted the membrane potential value to -13.45 +/- 0.99 mV when measured after a single dose of the drug, or even depolarized the membrane after 7 days of therapy -4.95 +/- 0.73 mV. It is concluded that the erythrocyte membrane is more rigid and hyperpolarized in CHD, and perindopril therapy partly abolishes these changes as early as 3 h after administration.

Adult↗

The copper complex of captopril is not a superoxide dismutase mimic. Artefacts in DMPO spin trapping.

The effect of captopril and of its copper complex on several superoxide-dependent reactions used to detect and assay superoxide dismutase activity was studied, including pyrogallol and hematoxylin autoxidation and Nitro Blue Tetrazolium reduction. In none of these systems were superoxide dismutase-like properties of captopril/Cu apparent. Captopril/Cu decreased the yield of DMPO-OH adducts generated by KO2 but this effect may be due to the acceleration of the decay of the adduct by captopril/Cu.

Antioxidants↗

Antioxidative enzymes activities and lipid peroxidation indicators in blood platelets during bed rest.

Our investigations were carried out on blood platelets obtained from 52 males, aged 25-48, free from any systemic disease, hospitalized because of extremities inferioris fractures without clinical complications. The effect of immobilization on oxygen metabolism and function of human blood platelets was studied. Blood was taken from patients after 14, 28 and 90 days of bed rest and platelets were isolated by a differential centrifugation technique. The comparative control group consisted of 41 healthy individuals at their normal physical activity. Short and long term bed rest had different effect on estimated enzymes activities: SOD-1, GPx-SH, Ct (and lipid peroxidation indicators) (MDA-and TXA2). After 14 and 28 days, the enzyme activities significantly decreased, whereas MDA and TXA2 concentrations increased. It was also found that a 14 and 28-day immobilization increased the blood platelets aggregation. However, after 90 days the tendency towards normalization of all the estimated parameters was observed.

Adult↗