Exercise, free radicals and oxidative stress

2002 ◽  
Vol 30 (2) ◽  
pp. 280-285 ◽  
Author(s):  
C. E. Cooper ◽  
N. B. J. Vollaard ◽  
T. Choueiri ◽  
M. T. Wilson

This article reviews the role of free radicals in causing oxidative stress during exercise. High intensity exercise induces oxidative stress and although there is no evidence that this affects sporting performance in the short term, it may have longer term health consequences. The mechanisms of exercise-induced oxidative stress are not well understood. Mitochondria are sometimes considered to be the main source of free radicals, but in vitro studies suggest they may play a more minor role than was first thought. There is a growing acceptance of the importance of haem proteins in inducing oxidative stress. The release of metmyoglobin from damaged muscle is known to cause renal failure in exercise rhabdomyolysis. Furthermore, levels of methaemoglobin increase during high intensity exercise, while levels of antioxidants, such as reduced glutathione, decrease. We suggest that the free-radical-mediated damage caused by the interaction of metmyoglobin and methaemoglobin with peroxides may be an important source of oxidative stress during exercise.

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Xue Geng ◽  
Zhihui Li ◽  
Lin Zhang ◽  
Chenggang Zhang

Objective Exercise-induced oxidative stress is due to the massive increase in free radicals caused by strenuous exercise, which exceeds the ability of self-clearing. It is one of the main causes of sports injury and sports fatigue. Eliminating excessive production of free radicals is the key to alleviating exercise induced oxidative damage. Therefore, the purpose of this study is to study the effect of hydrogen on exercise-induced oxidative damage, to explore its possible mechanism and to explore the best dose of hydrogen with different concentrations. Methods 40 male SD rats (200±20g) were randomly divided into five groups(n=8):sedentary, exercise control, low concentration hydrogen with exercise(H1), medium concentration hydrogen with exercise(H2), high concentration hydrogen with exercise(H3). The rats performed high-intensity exercise for 4 weeks, except the sedentary. rats that with Low, medium and high concentration hydrogen were placed in a hydrogen atmosphere with a concentration of 0.5%, 1% and 1.5% for 1 h immediately after each exercise (keeping the concentration of oxygen and nitrogen in the environment the same as those in the air). The rats were weighed weekly during the experiment. The next day after 4 weeks of training, the samples were collected, and the contents of total superoxide dismutase (T-SOD), catalase (CAT), total antioxidant capacity (T- AOC) and malondialdehyde (MDA) were determined respectively. Results The weight of exercise control was significantly lower than sedentary in the third and fourth weeks of exercise (P<0.05). Compared to sedentary rats, there was no significant difference in the weight of rats between H1, H2 and H3 group. The contents of T-AOC, CAT and T-SOD in exercise control were significantly higher than those in sedentary (P<0.05). The content of CAT in H2 group was significantly decreased compared with exercise control (P<0.01). Compared with exercise control, the T-AOC and T-SOD in the H2 group showed a downward trend but no statistical difference (P>0.05), there was no significant difference between the above indexes, compared with sedentary. In addition, there was no difference in T-SOD and CAT content between H1 group and exercise control; Compared with exercise control, there was no significant difference in T-SOD, T-AOC and CAT in H3 group. At the MDA level, each exercise group increased significantly compared with the sedentary (P<0.05), and the MDA levels in the H1, H2, and H3 groups were decreased compared with the exercise control, but there was no statistical difference. Conclusions It can be seen from the above results that different concentrations of hydrogen intervention can improve the weight loss of rats after intensive exercise. More importantly, the dosage and effect of 1% concentration of hydrogen is easier to remove the excessive radicals produced by intense exercise in the body, avoid the aggravation of oxidative stress, and have very good therapeutic effect. It provides a theoretical basis for the further study of the application of hydrogen in exercise oxidative damage. 


1986 ◽  
Vol 251 (3) ◽  
pp. R552-R559
Author(s):  
J. C. Marker ◽  
D. A. Arnall ◽  
R. K. Conlee ◽  
W. W. Winder

To determine the role of epinephrine in glycogenolysis during high-intensity exercise, rats were adrenodemedullated (ADM) or sham operated (SHAM) and run for either 30 min at 38 m/min or for 5 min at 27, 38, or 48 m/min up a 15% grade. At the end of exercise the rats were anesthetized by intravenous injection of pentobarbital sodium. Liver, blood, and muscle samples were obtained. Plasma epinephrine values were 5.9 and 0.3 nM for SHAM and ADM animals, respectively, after 30 min of exercise. Liver glycogen decreased by 16 and 21 mg/g in the SHAM and ADM groups, respectively, and liver cAMP increased significantly in both groups. Glycogen in the soleus muscle decreased 80% in the SHAM but only 43% in the ADM animals after 30 min of exercise. The exercise-induced hyperglycemia observed in the SHAM animals was not present in the ADM animals. The responses of cyclic AMP, soleus glycogen, and blood glucose were similar in both the 5- and 30-min exercise groups. During intense exercise, epinephrine is unessential for stimulating liver glycogenolysis but does play an important role in stimulating glycogenolysis in the soleus muscle and in establishing exercise-induced hyperglycemia.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yang Mu ◽  
Huang-Guan Dai ◽  
Ling-Bo Luo ◽  
Jing Yang

Abstract Background Infertility is a common complication in obese men. Oxidative stress and testicular apoptosis play critical roles in obesity-induced spermatogenesis dysfunction. It has been reported that irisin, an exercise-induced myokine, may attenuate oxidative damage and testicular apoptosis in several diseases; however, its role in obesity-induced spermatogenesis dysfunction remains unclear. The purpose of this study was to investigate the role and underlying mechanism of irisin in obesity-induced dysfunction of spermatogenesis. Methods Male mice were fed a high-fat diet (HFD) for 24 weeks to establish a model of obesity-induced spermatogenesis dysfunction. To explore the effects of irisin, mice were subcutaneously infused with recombinant irisin for 8 weeks beginning at 16 weeks after starting a HFD. To confirm the role of AMP-activated protein kinase α (AMPKα), AMPKα-deficient mice were used. Results The data showed decreased serum irisin levels in obese patients, which was negatively correlated with sperm count and progressive motility. Irisin was downregulated in the plasma and testes of obese mice. Supplementation with irisin protected against HFD-induced spermatogenesis dysfunction and increased testosterone levels in mice. HFD-induced oxidative stress, endoplasmic reticulum (ER) stress and testicular apoptosis were largely attenuated by irisin treatment. Mechanistically, we identified that irisin activated the AMPKα signalling pathway. With AMPKα depletion, we found that the protective effects of irisin on spermatogenesis dysfunction were abolished in vivo and in vitro. Conclusions In conclusion, we found that irisin alleviated obesity-related spermatogenesis dysfunction via activation of the AMPKα signalling pathway. Based on these findings, we hypothesized that irisin is a potential therapeutic agent against obesity-related spermatogenesis dysfunction.


2021 ◽  
Vol 321 (5) ◽  
pp. R687-R698
Author(s):  
Matthew T. Lewis ◽  
Gregory M. Blain ◽  
Corey R. Hart ◽  
Gwenael Layec ◽  
Matthew J. Rossman ◽  
...  

Recently it was documented that fatiguing, high-intensity exercise resulted in a significant attenuation in maximal skeletal muscle mitochondrial respiratory capacity, potentially due to the intramuscular metabolic perturbation elicited by such intense exercise. With the utilization of intrathecal fentanyl to attenuate afferent feedback from group III/IV muscle afferents, permitting increased muscle activation and greater intramuscular metabolic disturbance, this study aimed to better elucidate the role of metabolic perturbation on mitochondrial respiratory function. Eight young, healthy males performed high-intensity cycle exercise in control (CTRL) and fentanyl-treated (FENT) conditions. Liquid chromatography-mass spectrometry and high-resolution respirometry were used to assess metabolites and mitochondrial respiratory function, respectively, pre- and postexercise in muscle biopsies from the vastus lateralis. Compared with CTRL, FENT yielded a significantly greater exercise-induced metabolic perturbation (PCr: −67% vs. −82%, Pi: 353% vs. 534%, pH: −0.22 vs. −0.31, lactate: 820% vs. 1,160%). Somewhat surprisingly, despite this greater metabolic perturbation in FENT compared with CTRL, with the only exception of respiratory control ratio (RCR) (−3% and −36%) for which the impact of FENT was significantly greater, the degree of attenuated mitochondrial respiratory capacity postexercise was not different between CTRL and FENT, respectively, as assessed by maximal respiratory flux through complex I (−15% and −33%), complex II (−36% and −23%), complex I + II (−31% and −20%), and state 3CI+CII control ratio (−24% and −39%). Although a basement effect cannot be ruled out, this failure of an augmented metabolic perturbation to extensively further attenuate mitochondrial function questions the direct role of high-intensity exercise-induced metabolite accumulation in this postexercise response.


2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Jennifer L MacNicol ◽  
Michael Ivan Lindinger ◽  
Michael I Lindinger ◽  
Anna Kate Shoveller ◽  
John P Cant ◽  
...  

We evaluated the antioxidative and anti-inflammatory potential of daily oral supplementation with a proprietary powdered Cucumis melo pulp (CMP) on exercise-induced markers of articular and muscular oxidative stress and inflammation in 12 horses. Horses performed a high-intensity exercise test immediately prior to, and then following, 3 weeks of daily supplementation of 1 g powdered CMP (CMP; n=8). Controls (Co; n=8) underwent the same exercise and sampling regime but were not supplemented. Blood and synovial fluid (SF) samples were taken 24 h prior to exercise (BL), and at 1 and 24 h following exercise. Plasma and SF were analysed for prostaglandin E2 (PGE2), total antioxidant status (TAS), nitrite and superoxide dismutase (SOD) activity. SF was analysed for glycosaminoglycans (GAG), and plasma was analysed for thiobarbituric acid reactive substances (TBARS). Comparisons were made using repeated measures with the initial exercise test as a covariate. There was an increase in SF SOD activity in the CMP group. Compared to Co at 1 h, CMP reduced nitrite and GAG in SF, as well as maintained plasma TAS and lymphocyte levels. At 24 h, plasma PGE2 and creatine kinase were lower in horses receiving CMP. Three weeks of supplementation with CMP reduced markers of articular and skeletal muscle oxidative stress and inflammation in response to high-intensity exercise in horses. Nutritive antioxidants may provide a useful adjunct to the daily nutrition plan of horses undergoing regular exercise training and competition.


2008 ◽  
Vol 20 (6) ◽  
pp. 694 ◽  
Author(s):  
B. D. Whitaker ◽  
J. W. Knight

The mechanisms of oxidative stress in in vitro maturing porcine oocytes and the effects of anti-oxidant supplementation of the medium in ameliorating these effects were investigated in the present study. In addition to intracellular reduced glutathione (GSH) concentrations and DNA fragmentation, the present study focused on superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase activity. The anti-oxidants used were N-acetylcysteine (NAC) and its derivative NAC-amide (NACA). The results indicate that when SOD is inhibited, supplementation of the maturarion medium with 1.5 mm NAC or NACA compensates for the decrease in SOD activity by reducing the degree of DNA fragmentation (P < 0.05). When GPx is inhibited, supplementation of the maturarion medium with 1.5 mm NAC alleviates the effects of no GPx activity, as indicated by a decrease in the degree of DNA fragmentation (P < 0.05). When the maturarion medium was supplemented with 1.5 mm NACA, intracellular GSH concentrations decreased (P < 0.05) and SOD and catalase activities increased (P < 0.05) along with the degree of DNA fragmentation. These results indicate that the mechanisms of alleviating oxidative stress in porcine oocytes are very complex and supplementing maturing oocytes with anti-oxidants may enhance enzyme activities and eliminate free radicals.


Biology ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1272
Author(s):  
Yining Lu ◽  
Huw D. Wiltshire ◽  
Julien S. Baker ◽  
Qiaojun Wang

Participation in exercise promotes health. High intensity exercise (HIE) has become increasingly popular among the general population, however, its effects on exercise-induced oxidative stress and antioxidant status in untrained humans is not clear. The aim of this systematic review was to investigate the influence of HIE on oxidative stress and antioxidant status in untrained humans. Web of Science, PubMed, MEDLINE, and Scopus were searched until March 2021. A methodological quality assessment valuation/estimation was additionally carried out in the final sample of studies. Following the PRISMA selection process, 21 studies were finally included. There was strong evidence that acute oxidative stress following the cessation of HIE exists when compared to resting states. The HIE-induced oxidative stress is transient and is most likely restored to normal levels within 24 h due to the stimulated endogenous antioxidant system whose response was lagging and lasting. Physically active humans had better antioxidant systems and suffered less oxidative stress after HIE. A physically active lifestyle was considered to enhance antioxidant capacity. For untrained humans, HIE with intensities above 70% VO2max are proposed for initial exercise levels based on the findings reported here.


2021 ◽  
Vol 12 (7) ◽  
pp. 3132-3141
Author(s):  
Hongkang Zhu ◽  
Wenqian Xu ◽  
Ning Wang ◽  
Wenhao Jiang ◽  
Yuliang Cheng ◽  
...  

We investigated the role of Maca aqueous extract on muscle during exercise-induced fatigue both in vivo and in vitro..


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