oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
EFFECTS OF PROLONGED EXERCISE ON OXIDATIVE STRESS AND ANTIOXIDANT DEFENSE IN ENDURANCE HORSE  [cached]
Susanna Kinnunen,Mustafa Atalay,Seppo Hyypp?,Arja Lehmuskero
Journal of Sports Science and Medicine , 2005,
Abstract: Increased oxidative stress during prolonged endurance exercise may end up with muscle damage, fatigue and decreased physical performance. We have recently shown that acute exercise at moderate intensity induced lipid peroxidation, protein oxidation and oxygen radical absorbance capacity (ORAC) in trained trotters. The aim of this study was to measure the changes in oxidative stress and antioxidant defense following an 80-km ride in the blood of endurance horses. Blood samples were collected before and immediately after the ride. Unlike to our previous studies performed on trotters, in endurance horses there were no measurable changes in antioxidants or oxidative stress marker lipid hydroperoxides (LPO) after prolonged exercise. ORAC, vitamin E and lipid hydroperoxide (LPO) concentration or glutathione related enzyme activities were not altered due to the 80-km ride. However, the base line levels of oxidative stress marker were higher in endurance horses compared to trotters. A positive correlation between the pre-ride LPO concentration and erythrocyte glutathione peroxidase (GPx) activity after the ride was observed, which may indicate a protective response of glutathione peroxidase against exercise-induced oxidative stress. Our results suggest that endurance horses have higher oxidative stress levels compared to trotters and a single 80-km ride probably did not suffice to induce oxidative stress and to activate antioxidant defense mechanisms.
DIABETES, OXIDATIVE STRESS AND PHYSICAL EXERCISE  [cached]
Mustafa Atalay,David E. Laaksonen
Journal of Sports Science and Medicine , 2002,
Abstract: Oxidative stress, an imbalance between the generation of reactive oxygen species and antioxidant defense capacity of the body, is closely associated with aging and a number of diseases including cancer, cardiovascular diseases, diabetes and diabetic complications. Several mechanisms may cause oxidative insult in diabetes, although their exact contributions are not entirely clear. Accumulating evidence points to many interrelated mechanisms that increase production of reactive oxygen and nitrogen species or decrease antioxidant protection in diabetic patients. In modern medicine, regular physical exercise is an important tool in the prevention and treatment of diseases including diabetes. Although acute exhaustive exercise increases oxidative stress, exercise training has been shown to up regulate antioxidant protection. This review aims to summarize the mechanisms of increased oxidative stress in diabetes and with respect to acute and chronic exercise
Postprandial Oxidative Stress in Exercise Trained and Sedentary Cigarette Smokers  [PDF]
Richard J. Bloomer,Kelsey H. Fisher-Wellman
International Journal of Environmental Research and Public Health , 2009, DOI: 10.3390/ijerph6020579
Abstract: Cigarette smokers experience an exaggerated triglyceride (TAG) and oxidative stress response to high fat feeding. Exercise training may serve to attenuate the rise in these variables, by improving TAG clearance and antioxidant defense. We compared blood TAG, antioxidant capacity, and oxidative stress biomarkers in exercise trained (>2 hrs per wk) and untrained smokers matched for age, in response to a high fat test meal. We report here that low volume exercise training can attenuate postprandial lipid peroxidation, but has little impact on blood TAG and other markers of oxidative stress. Higher volumes of exercise may be needed to allow for clinically meaningful adaptations in postprandial lipemia and oxidative stress.
Oral Rg1 supplementation strengthens antioxidant defense system against exercise-induced oxidative stress in rat skeletal muscles
Szu-Hsien Yu, Hui-Yu Huang, Mallikarjuna Korivi, Ming-Fen Hsu, Chih-Yang Huang, Chien-Wen Hou, Chung-Yu Chen, Chung-Lan Kao, Ru-Ping Lee, Shin-Da Lee, Chia-Hua Kuo
Journal of the International Society of Sports Nutrition , 2012, DOI: 10.1186/1550-2783-9-23
Abstract: Forty weight-matched rats were evenly divided into control (N?=?20) and Rg1 (N?=?20) groups. Rg1 was orally administered at the dose of 0.1?mg/kg bodyweight per day for 10-week. After this long-term Rg1 administration, ten rats from each group performed an exhaustive swimming, and remaining rats considered as non-exercise control. Tibialis anterior (TA) muscles were surgically collected immediately after exercise along with non-exercise rats.Exhaustive exercise significantly (p<0.05) increased the lipid peroxidation of control group, as evidenced by elevated malondialdehyde (MDA) levels. The increased oxidative stress after exercise was also confirmed by decreased reduced glutathione to oxidized glutathione ratio (GSH/GSSG ratio) in control rats. However, these changes were completely eliminated in Rg1 group. Catalase (CAT) and glutathione peroxidase (GPx) activities were significantly (p<0.05) increased by Rg1 in non-exercise rats, while no significant change after exercise. Nevertheless, glutathione reductase (GR) and glutathione S-transferase (GST) activities were significantly increased after exercise in Rg1 group.This study provide compelling evidences that Rg1 supplementation can strengthen antioxidant defense system in skeletal muscle and completely attenuate the membrane lipid peroxidation induced by exhaustive exercise. Our findings suggest that Rg1 can use as a nutraceutical supplement to buffer the exhaustive exercise-induced oxidative stress.
Role of ghrelin in exhaustive exercise- induced oxidative stress in rat Brain and liver  [cached]
Shereen Samir,Abeer Mostafa
International Journal of Applied Exercise Physiology , 2013,
Abstract: Strenuous exercise increases oxygen consumption and causes disturbance of intracellular pro-oxidant–antioxidant homeostasis. Ghrelin has been reported to possess free radical scavenging and antioxidant effect. in this study we aim to evaluate the beneficial effect of ghrelin on the oxidative stress and antioxidant enzyme systems in brain cortex and liver of rats after exhaustive swimming exercise. Sprague- Dawley rats (50) were subdivided into 3 main groups: control, exercise, exercise and ghrelin (50,100,200 ng) group. Animals in the two exercise groups swam for 5 days/week for 4 weeks. stress induced a decrease in the level of GSH and the activities of SOD, GST and catalase, while the levels of TBARS were found elevated. Ghrelin groups’ animals, especially G3 subgroup, have higher SOD, CAT, GSH and GST activity which reflect higher antioxidant enzyme activity and can be attributed to lower rates of oxidative stress which can be proved by reduced level of TBARS. The results of the study provides evidence that ghrelin pretreatment even in low dose reduces the level of lipid peroxidation and enhances the antioxidant defense against exercise-induced stress oxidative injury in rats’ vital organs like brain and liver.
Diaphragmatic Breathing Reduces Exercise-Induced Oxidative Stress
Daniele Martarelli,Mario Cocchioni,Stefania Scuri,Pierluigi Pompei
Evidence-Based Complementary and Alternative Medicine , 2011, DOI: 10.1093/ecam/nep169
Abstract: Diaphragmatic breathing is relaxing and therapeutic, reduces stress, and is a fundamental procedure of Pranayama Yoga, Zen, transcendental meditation and other meditation practices. Analysis of oxidative stress levels in people who meditate indicated that meditation correlates with lower oxidative stress levels, lower cortisol levels and higher melatonin levels. It is known that cortisol inhibits enzymes responsible for the antioxidant activity of cells and that melatonin is a strong antioxidant; therefore, in this study, we investigated the effects of diaphragmatic breathing on exercise-induced oxidative stress and the putative role of cortisol and melatonin hormones in this stress pathway. We monitored 16 athletes during an exhaustive training session. After the exercise, athletes were divided in two equivalent groups of eight subjects. Subjects of the studied group spent 1 h relaxing performing diaphragmatic breathing and concentrating on their breath in a quiet place. The other eight subjects, representing the control group, spent the same time sitting in an equivalent quite place. Results demonstrate that relaxation induced by diaphragmatic breathing increases the antioxidant defense status in athletes after exhaustive exercise. These effects correlate with the concomitant decrease in cortisol and the increase in melatonin. The consequence is a lower level of oxidative stress, which suggests that an appropriate diaphragmatic breathing could protect athletes from long-term adverse effects of free radicals.
INFLUENCE OF CHRONIC EXERCISE ON RED CELL ANTIOXIDANT DEFENSE, PLASMA MALONDIALDEHYDE AND TOTAL ANTIOXIDANT CAPACITY IN HYPERCHOLESTEROLEMIC RABBITS  [cached]
Mohsen Alipour,Mustafa Mohammadi,Nosratollah Zarghami,Nasser Ahmadiasl
Journal of Sports Science and Medicine , 2006,
Abstract: Despite the knowledge on the antiatherogenic effects of exercise, the mechanism by which exercise reduces atherogenic risk remains unknown. In this study, we investigated the hypothesis that chronic exercise-induced oxidative stress may increase plasma total antioxidant capacity and antioxidant defense in the red cells. For 8 weeks, 60 male Dutch rabbits were fed rabbit chow with or without the addition of 2% cholesterol. The animals were further divided into rest and exercise groups (n = 15 for each group). Animals in exercise groups ran on a rodent treadmill at 15 m/min for 10 to 60 minutes gradually for 5 days per week for a total of 8 weeks. At the end of experiments, blood samples were collected and glutathione peroxidase (GPX), superoxide dismutase (SOD), and catalase (CAT) activities were determined in red blood cells. Total antioxidant capacity (TAC), malondialdehyde (MDA) and total thiol (T-SH) levels were measured in plasma. Thoracic aorta and carotid arteries were isolated for histological examination to evaluate atherosclerosis. Eight weeks of chronic exercise reduced atherogenic diet-induced atherosclerotic lesions in all the arteries studied, along with positive changes in cholesterol profile, especially increase of serum HDL-C level. Plasma MDA, TAC and T-SH concentrations were enhanced by exercise in both control and hypercholesterolemic diet groups. Erythrocyte catalase activity was significantly increased by chronic exercise (p < 0.05), whereas total SOD activity rose with exercise only in the control group. Surprisingly, GPX activity was significantly reduced (P < 0.05) in response to exercise in the control group and also in the high cholesterol diet group. Exercise is a useful tool for the prevention and regression of atherosclerosis which is evident by our findings of the enhancement of plasma TAC and positive change in serum cholesterol profile. However, the effect of exercise on red cell antioxidant activities is limited in the hypercholesterolemic animals compared to control animals, possibly in part because of alterations in the ability to adapt to exercise-induced oxidative stress in high cholesterol diet
OXIDATIVE STRESS AND PHYSICAL ACTIVITY  [PDF]
Marija Stankovi?,Dragan Radovanovi?
SportLogia , 2012, DOI: 10.5550/sgia.120801.en.001s
Abstract: The cells continuously produce free radicals and reactive oxygen species as a part of metabolic processes. Increased aerobic metabolism during exercise is a potential source of oxidative stress. Also, anaerobic physical activity and oxidative stress are interrelated because the intense anaerobic activity leads to damage proteins, lipids and nucleic acids in muscle cells and blood. Complex system of antioxidant defense, which has the enzymatic and non-enzymatic part, has a role in protecting tissues from excessive oxidative damage. Most of the research conducted so far about the impact of various forms of physical activity on levels of oxidative stress is confirmed by changes in biomarkers that indicate lipid peroxidation and proteins modification. Untrained persons, as opposed to trained, are more susceptible to major changes in the body caused by oxidative stress during physical activity. The results of researches have shown that there are no significant differences between the genders in the level of oxidative stress during physical activity and response to antioxidant supplementation possibly applied. It is interesting that, despite of numerous studies, the exact location of oxidative stress origin during physical activity has not been reliably established. In addition, research results provide insufficient evidence on the effectiveness of using antioxidant supplementation to increase the defense against oxidative stress. It is necessary further investigation about the redox status and oxidative stress during physical activity in adolescent athletes.
THE EFFECTS OF TAEKWONDO TRAINING ON OXIDATIVE STRESS LEVELS IN CHILDREN  [cached]
Recep Kürk?ü,Alpay ?akmak,Dost Zeyrek
Erciyes Medical Journal , 2012,
Abstract: Objective: In this study, the objective was to compare the oxidative-antioxidative status and oxidative stress index (OSI) in child athletes who take part ins taekwondo sport, the volunteer group was of the same age and in healthy condition. Also, the other objective was to determine the effect of regular exercise on total oxidative status (TOS)-total antioxidative status (TAC) and oxidative stress index. Material and Method: The experiment group consisted of 16 amateur taekwondo athletes who regularly participated in a 2-hour training per day, 3 days per week for at least 2 years. The control group was formed from 12 healthy adolescents of similar age and same sex who had not had any form of regular sports or exercise and they continued their usual sedentary life. Total antioxidative status (TAC), lipid y hydroperoxide (LOOH), Total oxidative status (TOS) parameters were measured. Percent ratio of total peroxide level to TAC level was accepted as an oxidative stress index (OSI)Results: We found LOOH, TOS, OS and TAC values (p<0.05) at a significantly higer level in the teakwondo group. Conclusion: It is thought that the study results show that the person who does exercise regularly creates oxidative radicals, and also induces antioxidant enzymes in order to increase the antioxidant defense.
Signs of oxidative stress after exercise.  [PDF]
A Wo?niak
Biology of Sport , 2003,
Abstract: Exercise is one of the factors that stimulate the aerobic metabolism, leading to an increased generation of reactive oxygen species (ROS). Mammals, including humans, have a complex antioxidant structure, which protects them against the toxic effects of ROS. This structure includes antioxidant enzymes and non-enzymatic scavengers of oxygen derived free radicals (ODFR). A disturbance in the pro- and antioxidant balance leads to oxidative stress, which often accompanies strenuous exercise. As a result of the excessive generation of ODFR, damage occurs to lipids, nucleic acids and the modification of proteins. Physical training alleviates the results of oxidative stress, mainly through an adaptable increase in the activity of antioxidant enzymes.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.