Wyniki wyszukiwania - Biblioteka Nauki

1

Changes in the Blood Antioxidant Defense Capacity During a 24 Hour Run

100%

Zbigniew W. , Ewa S.-K. , Barbara K. , Sławomir J. , Małgorzata M. , Katarzyna K. , Stanisław P. , Dagmara G.

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tom 24

65-74

EN

The objective of this study was to determine whether running a 24-h race would cause oxidative damage and changes in the blood antioxidant defense capacity in endurance-trained athletes. Fourteen male amateur runners (mean age 43.0±10.8 y, body weight 64.3±7.2 kg height 171±5 cm, weekly covered distance 81±43 km, training history 8±9 y) who participated in a 24-hr ultra-marathon and volunteered to give blood samples during the race were enrolled for this study. Blood samples were taken before the run, after completing the marathon distance (42.217 km), after 12 h and at the conclusion of the race.The capacity of erythrocyte antioxidant defense system was evaluated by measuring the activities of superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT), glutathione reductase (GR), concentrations of non-enzymatic antioxidants (uric acid and glutathione-GSH), and selected biomarkers of oxidative stress (i.e., plasma level of malondialdehyde (MDA) and plasma antioxidant capacity by FRAP ("ferric-reducing ability of plasma")). Moreover, in order to elucidate between-group differences in the total capacity of the blood antioxidant defense system, an index of antioxidant potential (POTAOX) was calculated as a sum of standardized values of activities of antioxidant enzymes (SOD, CAT, GPX, GR) and non-enzymatic antioxidants (uric acid, GSH).A progressive decline was observed in activities of SOD and CAT with the distance covered during the race, while the opposite trend was found in activities of GPX and GR that tended to increase. A significant decrease was recorded in GSH content after completing the marathon distance, which tended toward slightly higher values, without reaching the baseline level, at the finish of the race. Plasma concentration of uric acid (UA) was not significantly affected, except for the value recorded after 12 h of running that was significantly (p<0.05) lower, while both markers of oxidative stress (FRAP and MDA) increased significantly after completing the marathon distance. Comparison of the calculated values of the POTAOX index recorded pre-race and throughout the competition implies that the most drastic decline in the total antioxidant capacity occurred at mid-race (i.e. after 12 h of running).

2

Involvement of selenium in protective mechanisms of plants under environmental stress conditions-review

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Sieprawska A. , Kornas A. , Filek M.

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nr 1

EN

In recent years there has been growing interest in selenium (Se) as an important micronutrient not only for animals and humans but also for plants. In particular, its protective effect in plants exposed to stress conditions has been suggested. In spite of many studies, the mechanism of Se action is not fully understood. In this review, possible ways of interaction of Se with stress factors leading to optimal growth and development of plants are presented. As the majority of experiments have focused on the effects of Se application under stress conditions induced by heavy metals, special attention is paid to the results obtained in such studies. Changes of physiological and biochemical properties of plant cells, with particular regard to the influence of Se on the activation of enzymatic and non-enzymatic antioxidants under this stress, are summarized. Experiments in which Se was used in some other environmental stresses (drought, UV, cold and high temperature) are also cited. On the basis of the presented literature it is suggested that a positive effect of Se depends on both its doses and on chosen plant genotypes and is mainly connected with activation of antioxidative defense in plant cells.

3

The effects of induced ER stress on ROS regulation and antioxidant defense in Arabidopsis thaliana under osmotic stress

75%

Ozgur R. , Turkan I. , Uzilday B. , Sekmen A.

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nr 2

4

Seasonal changes in antioxidant defence systems in seminal plasma and fluids of the boar reproductive tract

63%

Koziorowska-Gilun M. , Koziorowski M. , Strzezek J. , Fraser L.

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nr 1

5

Comparison of water stress and UV radiation effects on induction of CAM and antioxidative defense in the succulent Rosularia elymaitica (Crassulaceae)

51%

Habibi G. , Hajiboland R.

Acta Biologica Cracoviensia. Series Botanica

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2011

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tom 53

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nr 2

EN

Growth and photosynthetic characteristics, inducibility of the CAM pathway and the functioning of the antioxidant defense system were investigated in Rosularia elymaitica (Crassulaceae) under drought and UV stresses. Drought did not substantially affect the growth of the plants, but it significantly reduced leaf thickness as well as osmotic potential, water potential and relative water content. In contrast, UV radiation treatment affected neither growth nor the water relations of leaves. Water limitation for 12 days caused a significant increase in nighttime PEPC and NAD-MDH activity and an increase in Δtitratable acidity relative to well-watered plants. The nighttime CO2 net assimilation rate increased significantly in drought-stressed plants but was still negative, resembling a C3-like pattern of gas exchange. Twenty days of UV treatment, increased Δtitratable acidity slightly and increased only daytime PEPC activity, and did not affect other parameters of carbon metabolism. As judged by maintenance of membrane integrity and stable amounts of H2O2 under UV stress, the antioxidant defense system effectively protected the plants against UV radiation. In contrast, oxidative stress occurred under severe drought stress (20 days of withholding water). Except for higher daytime APX activity in the UV-treated plants, enzyme activity in the control and in the drought- and UV-stressed plants did not show any diurnal fluctuation during 24 h. Temporal changes in Δtitratable acidity and ΔPEPC activity coincided closely with those of antioxidant enzymes; both started to increase after 12 days of drought stress. These results indicate that drought stress but not UV radiation induced the CAM-cycling pathway in R. elymaitica.

6

Effect of Mn on photosynthetic parameters of C3 Cleome spinosa and C4 Cleome gynandra in conjugation with antioxidant defense

51%

Dinc A. , Turkan I. , Sekmen A. , Uzilday B.

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nr 2

7

Diversity of endurance training effects on antioxidant defenses and oxidative damage in different brain regions of adolescent male rats

51%

Chalimoniuk M. , Jagsz S. , Sadowska-Krepa E. , Chrapusta S. J. , Klapcinska B. , Langfort J.

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2015

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tom 66

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nr 4

8

Expression of superoxide dismutase and matrix metalloproteinase type 2 in diaphragm muscles of young rats

51%

Carmeli E. , Maor M. , Kodesh E.

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nr 5

9

Antioxidative-related activities of lactoferrin and lactoperoxidase in milk from cows with different forms of mastitis

51%

Szczubial M. , Kankofer M. , Dabrowski R.

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2011

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tom 55

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nr 1

EN

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.

10

The response of L5178Y lymphoma sublines to oxidative stress: antioxidant defence, iron content and nuclear translocation of the p65 subunit of NF-kappaB

51%

Bouzyk E. , Gradzka I. , Iwanenko T. , Kruszewski M. , Sochanowicz B. , Szumiel I.

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nr 4

EN

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.

11

Effects of nonylphenol-induced oxidative stress in ovary of cichlid fish, Etroplus maculatus (Bloch, 1795)

44%

Asifa K. P. , Chitra K. C.

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tom 58

EN

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.