Effect of pharmacological lowering of plasma urate on exercise-induced oxidative stress

2007 ◽  
Vol 32 (6) ◽  
pp. 1148-1155 ◽  
Author(s):  
S. R. McAnulty ◽  
P. A. Hosick ◽  
L. S. McAnulty ◽  
J. C. Quindry ◽  
L. Still ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Capacity ◽  
Repeated Measures ◽  
Lipid Hydroperoxides ◽  
Double Blind ◽  
Reducing Ability ◽  
Plasma Antioxidant Capacity ◽  
Plasma Urate ◽  
Exercise Induced ◽  
The Impact

Urate is a metabolic end product of purine metabolism that contributes about 66% of the antioxidant capacity of plasma. The objective of this study was to evaluate the importance of plasma urate as an antioxidant using pharmacological lowering and examining the impact on plasma antioxidant capacity and oxidative stress after intense exercise. Fifteen subjects ran for 45 min at ~80% VO2 max under the influence of probenecid (1 g/d) (PRO) or placebo (PLA) in a double-blind, crossover design. Blood samples obtained at baseline, pre-exercise, and immediately post-exercise were analyzed for F2-isoprostanes, lipid hydroperoxides (LHs), ferric-reducing ability of plasma (FRAP), urate, ascorbate (AA), and nitrite. A 2 (group) × 2 (time) repeated-measures analysis of variance (ANOVA), one-way ANOVA, Tukey–Kramer multiple comparison tests, and Student’s t tests were used for statistical analysis. PRO exhibited lowered urate and FRAP compared with baseline (p ≤ 0.05), and group effects existed for the exercise trials (p = 0.023 and p ≤ 0.001, respectively) versus PLA. F2-isoprostanes, nitrite, and AA were increased after exercise (p = 0.004, p = 0.001, and p = 0.003, respectively), but the pattern of change was not different between treatments. This study indicates that plasma markers of exercise-induced oxidative stress were not affected by below-normal physiological concentrations of urate and a diminished antioxidant capacity within the plasma compartment.

Acute Hypoxia and Exercise-Induced Blood Oxidative Stress

2014 ◽  
Vol 24 (6) ◽  
pp. 684-693 ◽  
Author(s):  
Graham McGinnis ◽  
Brian Kliszczewiscz ◽  
Matthew Barberio ◽  
Christopher Ballmann ◽  
Bridget Peters ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Steady State ◽  
Repeated Measures ◽  
Acute Hypoxia ◽  
Protein Carbonyls ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Lipid Hydroperoxides ◽  
Oxidative Stress Biomarkers ◽  
Post Exercise ◽  
Reducing Ability

Hypoxic exercise is characterized by workloads decrements. Because exercise and high altitude independently elicit redox perturbations, the study purpose was to examine hypoxic and normoxic steady-state exercise on blood oxidative stress. Active males (n = 11) completed graded cycle ergometry in normoxic (975 m) and hypoxic (3,000 m) simulated environments before programing subsequent matched intensity or workload steady-state trials. In a randomized counterbalanced crossover design, participants completed three 60-min exercise bouts to investigate the effects of hypoxia and exercise intensity on blood oxidative stress. Exercise conditions were paired as such; 60% normoxic VO2peak performed in a normoxic environment (normoxic intensity-normoxic environment, NI-NE), 60% hypoxic VO2peak performed in a normoxic environment (HI-NE), and 60% hypoxic VO2peak performed in a hypoxic environment (HI-HE). Blood plasma samples drawn pre (Pre), 0 (Post), 2 (2HR) and 4 (4HR) hr post exercise were analyzed for oxidative stress biomarkers including ferric reducing ability of plasma (FRAP), trolox equivalent antioxidant capacity (TEAC), lipid hydroperoxides (LOOH) and protein carbonyls (PCs). Repeated-measures ANOVA were performed, a priori significance of p ≤ .05. Oxygen saturation during the HI-HE trial was lower than NI-NE and HI-NE (p < .05). A Time × Trial interaction was present for LOOH (p = .013). In the HI-HE trial, LOOH were elevated for all time points post while PC (time; p = .001) decreased post exercise. As evidenced by the decrease in absolute workload during hypoxic VO2peak and LOOH increased during HI-HE versus normoxic exercise of equal absolute (HI-NE) and relative (NI-NE) intensities. Results suggest acute hypoxia elicits work decrements associated with post exercise oxidative stress.

scholarly journals Effect of Mixed Flavonoids, n-3 Fatty Acids, and Vitamin C on Oxidative Stress and Antioxidant Capacity Before and After Intense Cycling

2011 ◽  
Vol 21 (4) ◽  
pp. 328-337 ◽  
Author(s):  
Steven R. McAnulty ◽  
David C. Nieman ◽  
Lisa S. McAnulty ◽  
Worley S. Lynch ◽  
Fuxia Jin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Fatty Acids ◽  
Vitamin C ◽  
Antioxidant Capacity ◽  
Repeated Measures ◽  
Statistical Design ◽  
Potential Health ◽  
Plasma Antioxidant Capacity ◽  
Plasma Antioxidant ◽  
Post Hoc

Consumption of plant flavonoids, antioxidants, and n-3 fatty acids is proposed to have many potential health benefits derived primarily through antioxidant and anti-inflammatory activities. This study examined the effects of 1,000 mg quercetin + 1,000 mg vitamin C (QC); 1,000 mg quercetin, 1,000 mg vitamin C, 400 mg isoquercetin, 30 mg epigallocatechin gallate, and 400 mg n-3 fatty acids (QFO); or placebo (P), taken each day for 2 wk before and during 3 d of cycling at 57% Wmax for 3 hr, on plasma antioxidant capacity (ferricreducing ability of plasma [FRAP], oxygen-radical absorbance capacity [ORAC]), plasma oxidative stress (F2-isoprostanes), and plasma quercetin and vitamin C levels. Thirty-nine athletes were recruited and randomized to QC, QFO, or P. Blood was collected at baseline, after 2 wk supplementation, immediately postexercise, and 14 hr postexercise. Statistical design used a 3 (groups) × 4 (times) repeated-measures ANOVA with post hoc analyses. Plasma quercetin was significantly elevated in QC and QFO compared with P. Plasma F2-isoprostanes, FRAP, and vitamin C were significantly elevated and ORAC significantly decreased immediately postexercise, but no difference was noted in the overall pattern of change. Post hoc analyses revealed that the QC and QFO groups did not exhibit a significant increase in F2-isoprostanes from baseline to immediately postexercise compared with P. This study indicates that combining flavonoids and antioxidants with n-3 fatty acids is effective in reducing the immediate postexercise increase in F2-isoprostanes. Moreover, this effect occurs independently of changes in plasma antioxidant capacity.

Effects of a freeze-dried juice blend powder on exercise-induced inflammation, oxidative stress, and immune function in cyclists

2014 ◽  
Vol 39 (3) ◽  
pp. 381-385 ◽  
Author(s):  
Amy M. Knab ◽  
David C. Nieman ◽  
Nicholas D. Gillitt ◽  
R. Andrew Shanely ◽  
Lynn Cialdella-Kam ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Immune Function ◽  
Repeated Measures ◽  
Daily Intake ◽  
Protein Carbonyls ◽  
Necrosis Factor Alpha ◽  
Post Exercise ◽  
Reducing Ability ◽  
Freeze Dried ◽  
Exercise Induced

A freeze-dried fruit and vegetable juice powder (JUICE) was investigated as a countermeasure nutritional strategy to exercise-induced inflammation, oxidative stress, and immune perturbations in trained cyclists. Thirty-four cyclists (25 male, 9 female) were randomized to control (nonJUICE) or JUICE for 17 days. JUICE provided 230 mg·day−1 of flavonoids, doubling the typical adult daily intake. During a 3-d period of intensified exercise (days 15–17), subjects cycled at 70%–75% V̇O2max for 2.25 h per day, followed by a 15-min time trial. Blood samples were collected presupplementation, post supplementation (pre-exercise), and immediately and 14-h post exercise on the third day of exercise. Samples were analyzed for inflammation (interleukin (IL)-6, IL-8; tumor necrosis factor alpha (TNFα); monocyte chemoattractant protein-1 (MCP-1)), oxidative stress (oxygen radical absorbance capacity (ORAC), ferric reducing ability of plasma (FRAP), reduced and oxidized glutathione, protein carbonyls), and innate immune function (granulocyte (G-PHAG) and monocyte (M-PHAG) phagocytosis and oxidative burst activity). A 2 (group) × 4 (time points) repeated measures ANOVA revealed significant time effects due to 3 days of exercise for IL-6 (396% increase), IL-8 (78% increase), TNFα (12% increase), MCP-1 (30% increase), G-PHAG (38% increase), M-PHAG (36% increase), FRAP (12.6% increase), ORAC (11% decrease at 14 h post exercise), and protein carbonyls (82% increase at 14 h post exercise) (p < 0.01). No significant interaction effects were found for any of the physiological measures. Although providing 695 gallic acid equivalents of polyphenols per day, JUICE treatment for 17 days did not change exercise-induced alterations in inflammation and oxidative stress or immune function in trained cyclists after a 3-day period of overreaching.

Intermittent hypoxic training: implications for lipid peroxidation induced by acute normoxic exercise in active men

2001 ◽  
Vol 101 (5) ◽  
pp. 465-475 ◽  
Author(s):  
Damian M. BAILEY ◽  
Bruce DAVIES ◽  
Ian S. YOUNG
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Acute Exercise ◽  
Mass Action ◽  
Lipid Hydroperoxides ◽  
Double Blind ◽  
Intermittent Hypoxic Training ◽  
Hypoxic Conditions ◽  
Hypoxic Training ◽  
Exercise Induced

Oxidant generation during regular physical exercise training may influence the adaptive responses that have been shown to confer protection against oxidative stress induced by subsequent acute exercise. To examine this, we randomly assigned 32 males to either a normoxic (n = 14) or a hypoxic (n = 18) group. During the acute phase, subjects in the hypoxic group performed two maximal cycling tests in a randomized double-blind fashion: one under conditions of normoxia and the other under hypoxic conditions (inspired fraction of O2 = 0.21 and 0.16 respectively). During the intermittent phase, the normoxic and hypoxic groups each trained for 4 weeks at the same relative exercise intensity, under conditions of normoxia and hypoxia respectively. During acute exercise under hypoxic conditions, the venous concentrations of lipid hydroperoxides and malondialdehyde were increased, despite a comparatively lower maximal oxygen uptake (o2max) (P < 0.05 compared with normoxia). The increases in lipid hydroperoxides and malondialdehyde were correlated with the exercise-induced decrease in arterial haemoglobin oxygen saturation (r =-0.61 and r =-0.50 respectively; P < 0.05), but not with o2max. Intermittent hypoxic training attenuated the increases in lipid hydroperoxides and malondialdehyde induced by acute normoxic exercise more effectively than did normoxic training, due to a selective mobilization of α-tocopherol (P < 0.05). The latter was related to enhanced exercise-induced mobilization/oxidation of blood lipids due to a selective increase in o2max (P < 0.05 compared with normoxic group). We conclude that lipid peroxidation induced by acute exercise (1) increases during hypoxia; (2) is not regulated exclusively by a mass action effect of o2; and (3) is selectively attenuated by regular hypoxic training. Oxidative stress may thus be considered as a biological prerequisite for adaptation to physical stress in humans.

Oral Quercetin Supplementation and Blood Oxidative Capacity in Response to Ultramarathon Competition

2008 ◽  
Vol 18 (6) ◽  
pp. 601-616 ◽  
Author(s):  
John C. Quindry ◽  
Steven R. McAnulty ◽  
Matthew B. Hudson ◽  
Peter Hosick ◽  
Charles Dumke ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Oxidative Damage ◽  
Antioxidant Capacity ◽  
Aqueous Phase ◽  
Antioxidant Properties ◽  
Oxidative Capacity ◽  
Protein Carbonyls ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Double Blind ◽  
Reducing Ability

Previous research indicates that ultramarathon exercise can result in blood oxidative stress. The purpose of this investigation was to examine the efficacy of oral supplementation with quercetin, a naturally occurring compound with known antioxidant properties, as a potential countermeasure against blood oxidative stress during an ultramarathon competition. In double-blind fashion, 63 participants received either oral quercetin (250 mg, 4×/day; 1,000 mg/day total) or quercetin-free supplements 3 weeks before and during the 160-km Western States Endurance Run. Blood drawn before and immediately after (quercetin finishers n = 18, quercetin-free finishers n = 21) the event was analyzed for changes in blood redox status and oxidative damage. Results show that quercetin supplementation did not affect race performance. In response to the ultramarathon challenge, aqueous-phase antioxidant capacity (ferric-reducing ability of plasma) was similarly elevated in athletes in both quercetin and quercetin-free treatments and likely reflects significant increases in plasma urate levels. Alternatively, trolox-equivalent antioxidant capacity was not altered by exercise or quercetin. Accordingly, neither F2-isoprostances nor protein carbonyls were influenced by either exercise or quercetin supplementation. In the absence of postrace blood oxidative damage, these findings suggest that oral quercetin supplementation does not alter blood plasma lipid or aqueous-phase antioxidant capacity or oxidative damage during an ultramarathon challenge.

scholarly journals One-week cocoa flavanol intake increases prefrontal cortex oxygenation at rest and during moderate-intensity exercise in normoxia and hypoxia

2018 ◽  
Vol 125 (1) ◽  
pp. 8-18 ◽  
Author(s):  
Lieselot Decroix ◽  
Cajsa Tonoli ◽  
Elodie Lespagnol ◽  
Constantino Balestra ◽  
Amandine Descat ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Endothelial Function ◽  
Antioxidant Capacity ◽  
Near Infrared ◽  
Tissue Oxygenation ◽  
Moderate Intensity ◽  
Moderate Intensity Exercise ◽  
Double Blind ◽  
Exercise Induced

During exercise in hypoxia, O2 delivery to brain and muscle is compromised, and oxidative stress is elicited. Cocoa flavanols (CF) have antioxidant capacities and can increase blood flow by stimulating endothelial function. We aimed to examine the effects of 7-day CF intake on oxidative stress, nitric oxide production, and tissue oxygenation in response to exercise in normobaric hypoxia (14.3% O2). In a randomized, double-blind, cross-over study, 14 well-trained male cyclists completed four trials: exercise in normoxia or hypoxia, after 7-day CF or placebo intake. Flow-mediated dilation (FMD) was measured before intake of the last dose CF or placebo. One hundred minutes later, 20-min steady-state (SS; 45% V̇o2max) and 20-min time trial (TT) (cycling) were performed. Blood samples were taken. Prefrontal and muscular oxygenation was assessed by near-infrared spectroscopy. At baseline, FMD was increased by CF. Hypoxia increased exercise-induced elevations in lipid peroxidation and antioxidant capacity. CF suppressed exercise-induced lipid peroxidation but did not influence antioxidant capacity. At rest and during SS, prefrontal and muscular oxygenation was decreased by hypoxia. CF elevated prefrontal oxygenation but did not impact muscular oxygenation. During TT, hypoxia accelerated the exercise-induced decrease in prefrontal oxygenation, but not in muscular oxygenation. During TT, CF did not alter prefrontal and muscular oxygenation. CF did not change plasma nitrite, nitrate, and arginine:citrulline. During high-intensity exercise, CF improved neither tissue oxygenation nor performance in well-trained athletes. At rest and during moderate-intensity exercise, CF reduced exercise-induced lipid peroxidation and partially restored the hypoxia-induced decline in prefrontal oxygenation. NEW & NOTEWORTHY For the first time, we showed that CF had beneficial effects on endothelial function at rest, as well as on prefrontal oxygenation at rest and during moderate-intensity exercise, both in normoxia and hypoxia. Moreover, we showed that CF intake inhibited oxidative stress during exhaustive exercise in hypoxia.

scholarly journals Environmental Temperature and Exercise-Induced Blood Oxidative Stress

2013 ◽  
Vol 23 (2) ◽  
pp. 128-136 ◽  
Author(s):  
John Quindry ◽  
Lindsey Miller ◽  
Graham McGinnis ◽  
Brian Kliszczewiscz ◽  
Dustin Slivka ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Core Temperature ◽  
Stress Responses ◽  
Environmental Temperature ◽  
Protein Carbonyls ◽  
Moderate Intensity ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Lipid Hydroperoxides ◽  
Reducing Ability ◽  
Exercise Induced

Previous research findings indicate that environmental temperature can influence exercise-induced oxidative-stress responses, although the response to variable temperatures is unknown. The purpose of this study was to investigate the effect of warm, cold, and “neutral,” or room, environmental temperatures on the blood oxidative stress associated with exercise and recovery. Participants (N = 12, age 27 ± 5 yr, VO2max = 56.7 ± 5.8 ml · kg-1 · min-1, maximal cycle power output = 300 ± 39 W) completed 3 exercise sessions consisting of a 1-hr ride at 60% Wmax, at 40% relative humidity in warm (33 °C), cold (7 °C), and room-temperature environments (20 °C) in a randomized crossover fashion. Rectal core temperature was monitored continually as participants remained in the respective trial temperature throughout a 3-hr recovery. Blood was collected preexercise and immediately, 1 hr, and 3 hr postexercise and analyzed for oxidative-stress markers including ferric-reducing ability of plasma (FRAP), Trolox-equivalent antioxidant capacity (TEAC), lipid hydroperoxides, and protein carbonyls. Core temperature was significantly elevated by all exercise trials, but recovery core temperatures reflected the given environment. FRAP (p < .001), TEAC (p < .001), and lipid hydroperoxides (p < .001) were elevated after warm exercise while protein carbonyls were not altered (p > .05). These findings indicate that moderate-intensity exercise and associated recovery in a warm environment elicits a blood oxidative-stress response not observed at comparable exercise performed at lower temperatures.

scholarly journals Recovery facilitation with Montmorency cherries following high-intensity, metabolically challenging exercise

2015 ◽  
Vol 40 (4) ◽  
pp. 414-423 ◽  
Author(s):  
Phillip G. Bell ◽  
Ian H. Walshe ◽  
Gareth W. Davison ◽  
Emma J. Stevenson ◽  
Glyn Howatson
Keyword(s):  
High Intensity ◽  
Functional Performance ◽  
High Sensitivity ◽  
Lipid Hydroperoxides ◽  
Necrosis Factor Alpha ◽  
Maximum Voluntary Isometric Contraction ◽  
Exercise Induced ◽  
Post Trial ◽  
S Peak ◽  
The Impact

The impact of Montmorency tart cherry (Prunus cerasus L.) concentrate (MC) on physiological indices and functional performance was examined following a bout of high-intensity stochastic cycling. Trained cyclists (n = 16) were equally divided into 2 groups (MC or isoenergetic placebo (PLA)) and consumed 30 mL of supplement, twice per day for 8 consecutive days. On the fifth day of supplementation, participants completed a 109-min cycling trial designed to replicate road race demands. Functional performance (maximum voluntary isometric contraction (MVIC), cycling efficiency, 6-s peak cycling power) and delayed onset muscle soreness were assessed at baseline, 24, 48, and 72 h post-trial. Blood samples collected at baseline, immediately pre- and post-trial, and at 1, 3, 5, 24, 48, and 72 h post-trial were analysed for indices of inflammation (interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor alpha, high-sensitivity C-reactive protein (hsCRP)), oxidative stress (lipid hydroperoxides), and muscle damage (creatine kinase). MVIC (P < 0.05) did not decline in the MC group (vs. PLA) across the 72-h post-trial period and economy (P < 0.05) was improved in the MC group at 24 h. IL-6 (P < 0.001) and hsCRP (P < 0.05) responses to the trial were attenuated with MC (vs. PLA). No other blood markers were significantly different between MC and PLA groups. The results of the study suggest that Montmorency cherry concentrate can be an efficacious functional food for accelerating recovery and reducing exercise-induced inflammation following strenuous cycling exercise.

Skeletal muscle adaptations to exercise are not influenced by metformin treatment in humans: secondary analyses of two randomised, clinical trials.

2021 ◽  
Author(s):  
Nanna Skytt Pilmark ◽  
Laura Oberholzer ◽  
Jens Frey Halling ◽  
Jonas M. Kristensen ◽  
Christina Pedersen Bønding ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Skeletal Muscle ◽  
Exercise Training ◽  
Human Skeletal Muscle ◽  
Acute Exercise ◽  
Metformin Treatment ◽  
Ampk Activation ◽  
Double Blind ◽  
Parallel Group ◽  
Exercise Induced

Metformin and exercise both improve glycemic control, but in vitro studies have indicated that an interaction between metformin and exercise occurs in skeletal muscle, suggesting a blunting effect of metformin on exercise training adaptations. Two studies (a double-blind, parallel-group, randomized clinical trial conducted in 29 glucose-intolerant individuals and a double-blind, cross-over trial conducted in 15 healthy lean males) were included in this paper. In both studies, the effect of acute exercise +/- metformin treatment on different skeletal muscle variables, previously suggested to be involved in a pharmaco-physiological interaction between metformin and exercise, was assessed. Furthermore, in the parallel-group trial, the effect of 12 weeks of exercise training was assessed. Skeletal muscle biopsies were obtained before and after acute exercise and 12 weeks of exercise training, and mitochondrial respiration, oxidative stress and AMPK activation was determined. Metformin did not significantly affect the effects of acute exercise or exercise training on mitochondrial respiration, oxidative stress or AMPK activation, indicating that the response to acute exercise and exercise training adaptations in skeletal muscle is not affected by metformin treatment. Further studies are needed to investigate whether an interaction between metformin and exercise is present in other tissues, e.g. the gut. Trial registration: ClinicalTrials.gov (NCT03316690 and NCT02951260). Novelty bullets • Metformin does not affect exercise-induced alterations in mitochondrial respiratory capacity in human skeletal muscle • Metformin does not affect exercise-induced alterations in systemic levels of oxidative stress nor emission of reactive oxygen species from human skeletal muscle • Metformin does not affect exercise-induced AMPK activation in human skeletal muscle

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