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The aim of the study was to evaluate the antioxidative potential of blood during standard physical exercise of horses. The study included 114 clinically healthy horses representing different groups: breeding horses (27), recreation horses (22), and sport horses (65). The group of sport horses consisted of race horses (11), trotters (15), and jumping (25) and driving horses (14). The blood was collected from external jugular vein three times: before exercise, immediately after exercise, and after 30-min rest. The following enzymatic and nonenzymatic antioxidative indices were determined: superoxide dismutase, glutathione peroxidase (GPx), catalase, albumin, total bilirubin, uric acid, and total antioxidant status (TAS). The study demonstrated a temporary post exercise mobilisation of antioxidative mechanisms, especially in cases of intensively trained competitive horses. It was demonstrated that among the antioxidants, the activity of GPx showed the high post-exercise changeability, which suggests a great importance of this enzyme in the protection of the organism from the increased generation of reactive oxygen species. The analysis of results of pre- exercise examination indicated higher rest values of main antioxidative enzymes and TAS in horses trained regularly and intensively than those in animals of a small physical activity. These results prove the positive influence of training on antioxidative potential of blood in horses.
Recent studies demonstrated that the proanthocyanidins (PA), the polymers of flavan-3-ols, naturally occurring plant metabolites widely available in fruits, vegetables, nuts, seeds, flowers and bark, have anti-inflammatory, anticarcinogenic, anti-allergic, antioxidant and vasodilatory actions. We hypothesized that Viburnum opulus PA (VOPA, Caprifoliaceae), due to activation of multifactorial gastrointestinal mucosal defense mechanisms, exert gastroduodenoprotective effects. The aim of the study was: 1) to investigate VOPA effects on gastroduodenal mucosal integrity and pattern of carbohydrate binding proteins and nitric oxide (NO) content in intact mucosa and that exposed to non-topical ulcerogens (stress) in rats without and with capsaicin (125 mg/kg, sc) denervation; and 2), to assess the role of activity of antioxidizing enzymes superoxide dismutase (SOD), catalase (CAT), gluthatione peroxidase (GPx) in VOPA-iduced gastroduodenoprotection against water immersion and restraint stress (WRS) in rats. VOPA was administered orally in dose of 25, 50 or 75 mg/kg body weight. Gastroduodenal mucosal damage detected by routine light microscopic investigation and lectin histochemistry set, purified from plant and animal sources of Carpatian region. NO content, pro-and antioxidant system were determinated by routine laboratory methods. Pretreatment with VOPA afforded gastroduodenoprotection and was accompanied by an increase in NO expression, both changes being reversed by sensory denervation, as well as by the rise of SOD, CAT activity and fall in MDA content. Our study shows that VOPA exerts a potent gastroduodenoprotective activity via an increase in endogenous NO generation, suppression of lipid peroxidation and mobilization of antioxidant activity and changes in glycoconjugate content of the gastroduodenal mucosa of rat.
Mitochondria are strongly involved in production of reactive oxygen species, considered today as the main pathogenic agent of many diseases. A vicious circle of oxidative stress and damage to cellular structures can lead to either cell death by apoptosis or to a cellular energetic decline and ageing. The early involvement of mitochondria in apoptosis includes expression of pro-apoptotic factors, release of cytochrome c from the inter-membrane space and opening of the permeability transition pore: cytochrome c release appears to precede pore opening. The mitochondrial theory of ageing considers somatic mutations (deletions) of mitochondrial DNA induced by oxygen radicals as the primary cause of energy decline; experimentally, Complex I appears to be mostly affected. We have developed the Pasteur effect (enhancement of lactate production by mitochondrial inhibition) as a bio-marker of mitochondrial bioenergetics in human platelets, and found it to be decreased in aged individuals. Cells counteract oxidative stress by antioxidants; among lipophilic antioxidants coenzyme Q is the only one of endogenous biosynthesis; exogenous coenzyme Q, however, may protect cells from oxidative stress in vivo.
Milk samples were taken from cows with acute, subacute, chronic, and subclinical mastitis and from healthy cows. The mean activity of lactoferrin (LF) in milk from mastitic cows ranged from 8.9 ±3.0 to 12.1 ±6.9 mU/g protein and was significantly lower than that in milk from healthy cows (29.5 ±15.0 mU/g protein). In group of mastitic cows the highest LF activity was found in cows with chronic mastitis, and the lowest in those with subclinical mastitis. The lactoperoxidase activity in cows with clinical and subclinical mastitis was significantly higher in comparison with healthy cows (1.3 ±1.1 mU/g protein) ranging from 5.5 ±2.6 mU/g protein in subclinical mastitic cows to 8.4 ±5.0 mU/g protein in chronic mastitic cows. Lower LF activities in cows with mastitis than in healthy animals may lead to a decreased antioxidant defence system in mastitic cows.
We examined the response to hydrogen peroxide of two L5178Y (LY) sublines which are inversely cross-sensitive to hydrogen peroxide and X-rays: LY-R cells are radioresistant and hydrogen peroxide-sensitive, whereas LY-S cells are radiosensitive and hydrogen peroxide-resistant. Higher initial DNA breaks and higher iron content (potentially active in the Fenton reaction) were found in the hydrogen peroxide sensitive LY-R cells than in the hydrogen peroxide resistant LY-S cells, whereas the antioxidant defence of LY-R cells was weaker. In particular, catalase activity is twofold higher in LY-S than in LY-R cells. The content of monobromobimane-reactive thiols is 54% higher in LY-S than in LY-R cells. In contrast, the activity of glutathione peroxidase (GPx) is about two times higher in LY-R than in LY-S cells; however, upon induction with selenium the activity increases 15.6-fold in LY-R cells and 50.3-fold in LY-S cells. Altogether, the sensitivity difference is related to the iron content, the amount of the initial DNA damage, as well as to the efficiency of the antioxidant defence system. Differential nuclear translocation of p65-NF-kappaB in LY sublines is due to the more efficient antioxidant defence in LY-S than in LY-R cells.
The present study was designed to evaluate the effects of nonylphenol in the pro-oxidant/ antioxidant system in ovary of the cichlid fish Etroplus maculatus. Fishes were exposed at two sublethal concentrations (one-fifth and one-tenth of LC50) of nonylphenol for 24, 72 and 96 h maintaining control groups. The oxidative stress indices as the activities of antioxidant enzymes, superoxide dismutase, catalase, glutathione reductase along with the levels of hydrogen peroxide generation and lipid peroxidation were monitored in concentration- and time-dependent manner. Activity of superoxide dismutase significantly (P<0.05) increased at both concentrations in timedependent manner. Meanwhile the activities of catalase and glutathione reductase significantly (P<0.05) decreased after 72 and 96 h of nonylphenol treatment. The levels of hydrogen peroxide generation and lipid peroxidation increased in all treatment groups when compared to controls. The present results demonstrated that the induction of oxidative stress in ovary of fish by the generation of lipid peroxidation could be due to the exposure of environmental contaminant, nonylphenol. Therefore, the observed oxidative stress in ovary can be indicated as a mechanism of toxicity in the fish exposed to nonylphenol.
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