Role of exercise intensities in oxidized low-density lipoprotein-mediated redox status of monocyte in men

The MuCAYAplus Study-Influence of Physical Activity and Metabolic Parameters on the Structure and Function of the Cardiovascular System in Young Athletes

Exercise has a significant impact on the cardiovascular (CV) health of children and adolescents, with resultant alterations in CV structure and function being evident, even at an early age. Engagement in regular, moderate physical activity (PA) is associated with long-term CV health benefits and a reduced risk of CV disease and mortality later in life. However, competitive sports often involve PA training intensities that are beyond recommended levels for young athletes, potentially leading to adverse CV outcomes. This situation emphasizes the importance of early monitoring of CV status, to prevent detrimental adaptations to intense physical exercise. The Munich Cardiovascular Adaptations in Young Athletes Study (MuCAYAplus; NCT06259617) aims to investigate the as-yet-unclear adaptations to intense exercise that occur in young athletes. The study focuses on various factors, including CV health, PA, cardiopulmonary performance, body composition, eating habits, and biochemical markers. In this longitudinal, prospective study, a sample of 250 young competitive athletes (aged 10-17 years) will undergo yearly examinations at the Institute of Preventive Pediatrics at the Technical University of Munich (TUM), over the span of 3 years. The testing protocol includes the following: anthropometric measurements; basic medical examinations; electrocardiography, with blood-pressure and pulse-wave analysis; echocardiography; sonography of the carotid artery; blood sampling for laboratory analysis; cardiopulmonary exercise testing on a bicycle ergometer; and participant completion of questionnaires regarding PA (the Motorik-Modul Longitudinal Study PA Questionnaire [MoMo-PAQ]) and nutrition. Areas that are not yet fully understood are how exercise influences cardiac and vascular remodeling during long-term exercise, and how different biochemical and metabolic parameters, body composition, and nutrition impact such adaptations. The MuCAYAplus study seeks to address these gaps in knowledge and provide comprehensive evidence on the longitudinal effects of exercise on the CV system of young athletes.

The Influence of a Polyphenol-Rich Red Berry Fruit Juice on Recovery Process and Leg Strength Capacity after Six Days of Intensive Endurance Exercise in Recreational Endurance Athletes

BACKGROUND

Various nutritional strategies are increasingly used in sports to reduce oxidative stress and promote recovery. Chokeberry is rich in polyphenols and can reduce oxidative stress. Consequently, chokeberry juices and mixed juices with chokeberry content are increasingly used in sports. However, the data are very limited. Therefore, this study investigates the effects of the short-term supplementation of a red fruit juice drink with chokeberry content or a placebo on muscle damage, oxidative status, and leg strength during a six-day intense endurance protocol.

METHODS

Eighteen recreational endurance athletes participated in a cross-over high intensity interval training (HIIT) design, receiving either juice or a placebo. Baseline and post-exercise assessments included blood samples, anthropometric data, and leg strength measurements.

RESULTS

A significant increase was measured in muscle damage following the endurance protocol in all participants (∆ CK juice: 117.12 ± 191.75 U/L, ∆ CK placebo: 164.35 ± 267.00 U/L; p = 0.001, η2 = 0.17). No group effects were detected in exercise-induced muscle damage (p = 0.371, η2 = 0.010) and oxidative status (p = 0.632, η2 = 0.000). The reduction in strength was stronger in the placebo group, but group effects are missing statistical significance (∆ e1RM juice: 1.34 ± 9.26 kg, ∆ e1RM placebo: -3.33 ± 11.49 kg; p = 0.988, η2 = 0.000).

CONCLUSION

Although a reduction in strength can be interpreted for the placebo treatment, no statistically significant influence of chokeberry could be determined. It appears that potential effects may only occur with prolonged application and a higher content of polyphenols, but further research is needed to confirm this.

Ergothioneine Improves Aerobic Performance Without Any Negative Effect on Early Muscle Recovery Signaling in Response to Acute Exercise

Physical activity is now recognized as an essential element of healthy lifestyles. However, intensive and repeated exercise practice produces a high level of stress that must be managed, particularly oxidative damage and inflammation. Many studies investigated the effect of antioxidants, but reported only few positive effects, or even muscle recovery impairment. Secondary antioxidants are frequently highlighted as a way to optimize these interactions. Ergothioneine is a potential nutritional supplement and a secondary antioxidant that activates the cellular NRF2 pathway, leading to antioxidant response gene activation. Here, we hypothesized that ergothioneine could improve performance during aerobic exercise up to exhaustion and reduce exercise-related stress without impairing early muscle recovery signaling. To test this hypothesis, 5-month-old C56B6J female mice were divided in two groups matched for maximal aerobic speed (MAS): control group (Ctrl; n = 9) and group supplemented with 70 mg ergothioneine/kg/day (ET; n = 9). After 1 week of supplementation (or not), mice performed a maximum time-to-exhaustion test by running on a treadmill at 70% of their MAS, and gastrocnemius and soleus muscles were collected 2 h after exercise. Time to exhaustion was longer in the ET than Ctrl group (+41.22%, p < 0.01). Two hours after exercise, the ET group showed higher activation of protein synthesis and satellite cells, despite their longer effort. Conversely, expression in muscles of metabolic stress and inflammation markers was decreased, as well as oxidative damage markers in the ET group. Moreover, ergothioneine did not seem to impair mitochondrial recovery. These results suggest an important effect of ergothioneine on time-to-exhaustion performance and improved muscle recovery after exercise.

Effect of Physical Exercise Under Different Intensity and Antioxidative Supplementation for Plasma Superoxide Dismutase in Healthy Adults: Systematic Review and Network Meta-Analysis

Background

The dynamic balance between oxidation and anti-oxidation in the body’s internal environment has a significant meaning for human health. Physical exercise and antioxidative supplementation could affect the balance of oxidation and anti-oxidation systems. The evidence on the effects of physical exercise and antioxidative supplementation is mixed.

Aims

To identify the effects of physical exercise, antioxidative supplementation, and their combination on the dynamic balance between oxidation and anti-oxidation in different subgroups of healthy adults.

Methods

All studies which reported randomized controlled trials with healthy participants were screened and included from the databases of PubMed, Medline, Embase, and Ovid. All participants were reclassified according to their different daily life activities. All physical exercise interventions were reclassified according to the intensity. The effect size would be calculated in percent or factor units from the mean level change with its associated random-effect variance.

Result

There were 27 studies included in this review. The agreement between authors by using The Cochrane Collaboration Risk of Bias Assessment Tool reached a kappa-value of 0.72. Maintaining a regular physical exercise routine in an appropriate intensity would be beneficial to the body’s anti-oxidative potential. Anti-oxidative supplementation could have some positive but limited effects on the body’s anti-oxidative status and complex interaction with physical exercise.

Conclusion

Keeping a regular physical exercise routine and gradually increasing its intensity according to the individual’s daily life activity might be a better choice to maintain and enhancing the body’s antioxidation potential, only using anti-oxidative supplementation is not recommended. More research is needed to explore the best combination protocol.

Registration Number

CRD42021241995.

Effects of Ibuprofen Use on Lymphocyte Count and Oxidative Stress in Elite Paralympic Powerlifting

BACKGROUND

Paralympic Powerlifting (PP) training tends to promote fatigue and oxidative stress.

OBJECTIVE

To analyze the effects of ibuprofen use on performance and oxidative stress in post-training PP athletes.

METHODOLOGY

Ten national level PP athletes (age: 27.13 ± 5.57) were analyzed for oxidative stress in post-training. The study was carried out in three weeks, (1) familiarization and (2 and 3) evaluated the recovery with the use of a placebo (PLA) and ibuprofen (IBU), 800 mg. The Peak Torque (PT), Torque Development Rate (TDR), Fatigue Index (FI), reactive substances to thiobarbituric acid (TBARS) and sulfhydryl groups (SH) were evaluated. The training consisted of five sets of five repetitions (80-90%) 1-Repetition Maximum (1-RM) in the bench press.

RESULTS

The IBU showed a higher PT (24 and 48 h, p = 0.04, ɳ2 p = 0.39), a lower FI (24 h, p = 0.01, ɳ2p = 0.74) and an increased lymphocyte count (p < 0.001; ɳ2p = 4.36). There was no change in oxidative stress.

CONCLUSIONS

The use of IBU provided improvements in strength and did not protect against oxidative stress.

Acute Effects of Triathlon Race on Oxidative Stress Biomarkers

The response to strenuous exercise was investigated by reactive oxygen species (ROS) production, oxidative damage, thiol redox status, and inflammation assessments in 32 enrolled triathlon athletes (41.9 ± 7.9 yrs) during Ironman® (IR), or half Ironman® (HIR) competition. In biological samples, inflammatory cytokines, aminothiols (glutathione (GSH), homocysteine (Hcy), cysteine (Cys), and cysteinylglycine (CysGly)), creatinine and neopterin, oxidative stress (OxS) biomarkers (protein carbonyl (PC), thiobarbituric acid-reactive substances (TBARS)), and ROS were assessed. Thirteen HIR and fourteen IR athletes finished the race. Postrace, ROS (HIR +20%; IR +28%; p < 0.0001), TBARS (HIR +57%; IR +101%), PC (HIR +101%; IR +130%) and urinary neopterin (HIR +19%, IR +27%) significantly (range p < 0.05-0.0001) increased. Moreover, HIR showed an increase in total Cys +28%, while IR showed total aminothiols, Cys, Hcy, CysGly, and GSH increase by +48, +30, +58, and +158%, respectively (range p < 0.05-0.0001). ROS production was significantly correlated with TBARS and PC (R 2 = 0.38 and R 2 = 0.40; p < 0.0001) and aminothiols levels (range R 2 = 0.17-0.47; range p < 0.01-0.0001). In particular, ROS was directly correlated with the athletes' age (R 2 = 0.19; p < 0.05), with ultraendurance years of training (R 2 = 0.18; p < 0.05) and the days/week training activity (R 2 = 0.16; p < 0.05). Finally, the days/week training activity (hours/in the last 2 weeks) was found inversely correlated with the IL-6 postrace (R 2 = -0.21; p < 0.01). A strenuous performance, the Ironman® distance triathlon competition, alters the oxidant/antioxidant balance through a great OxS response that is directly correlated to the inflammatory parameters; furthermore, the obtained data suggest that an appropriate training time has to be selected in order to achieve the lowest ROS production and IL-6 concentration at the same time.

Oxidative Stress and Inflammation, Key Targets of Atherosclerotic Plaque Progression and Vulnerability: Potential Impact of Physical Activity

Atherosclerosis, a complex cardiovascular disease, is a leading cause of mortality and morbidity worldwide. Oxidative stress and inflammation are both involved in the development of atherosclerotic plaque as they increase the biological processes associated with this pathology, such as endothelial dysfunction and macrophage recruitment and adhesion. Atherosclerotic plaque rupture leading to major ischemic events is the result of vulnerable plaque progression, which is a result of the detrimental effect of oxidative stress and inflammation on risk factors for atherosclerotic plaque rupture, such as intraplaque hemorrhage, neovascularization, and fibrous cap thickness. Thus, both are key targets for primary and secondary interventions. It is well recognized that chronic physical activity attenuates oxidative stress in healthy subjects via the improvement of antioxidant enzyme capacities and inflammation via the enhancement of anti-inflammatory molecules. Moreover, it was recently shown that chronic physical activity could decrease oxidative stress and inflammation in atherosclerotic patients. The aim of this review is to summarize the role of oxidative stress and inflammation in atherosclerosis and the results of therapeutic interventions targeting them in both preclinical and clinical studies. The effects of chronic physical activity on these two key processes are then reviewed in vulnerable atherosclerotic plaques in both coronary and carotid arteries.

Heat and Hypoxic Acclimation Increase Monocyte Heat Shock Protein 72 but Do Not Attenuate Inflammation following Hypoxic Exercise

Acclimation to heat or hypoxic stress activates the heat shock response and accumulation of cytoprotective heat shock proteins (HSPs). By inhibiting the NF-κB pathway HSP72 can preserve epithelial function and reduce systemic inflammation. The aim of this study was to determine the time course of mHSP72 accumulation during acclimation, and to assess intestinal barrier damage and systemic inflammation following hypoxic exercise. Three groups completed 10 × 60-min acclimation sessions (50% normoxic VO₂peak) in control (n = 7; 18°C, 35% RH), hypoxic (n = 7; F_iO₂ = 0.14, 18°C, 35% RH), or hot (n = 7; 40°C, 25% RH) conditions. Tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), interleukin 10 (IL-10), and intestinal fatty acid binding protein (I-FABP) were determined at rest and following a cycling normoxic stress test (NST; ~2 weeks before acclimation), pre-acclimation hypoxic stress test (HST1; F_iO₂ = 0.14, both at 50% normoxic VO₂peak; ~1 week before acclimation) and post-acclimation HST (48 h; HST2). Monocyte HSP72 (mHSP72) was determined before and after exercise on day 1, 3, 5, 6, and 10 of acclimation. Accumulation of basal mHSP72 was evident from day 5 (p < 0.05) of heat acclimation and increased further on day 6 (p < 0.01), and day 10 (p < 0.01). In contrast, basal mHSP72 was elevated on the final day of hypoxic acclimation (p < 0.05). Following the NST, plasma TNF-α (–0.11 ± 0.27 ng^.mL⁻¹), IL-6 (+0.62 ± 0.67 ng^.mL⁻¹) IL-10 (+1.09 ± 9.06 ng^.mL⁻¹) and I-FABP (+37.6 ± 112.8 pg^.mL⁻¹) exhibited minimal change. After HST1, IL-6 (+3.87 ± 2.56 ng^.mL⁻¹), IL-10 (+26.15 ± 26.06 ng^.mL⁻¹) and I-FABP (+183.7 ± 182.1 pg^.mL⁻¹) were elevated (p < 0.01), whereas TNF-α was unaltered (+0.08 ± 1.27; p > 0.05). A similar trend was observed after HST2, with IL-6 (+3.09 ± 1.30 ng^.mL⁻¹), IL-10 (+23.22 ± 21.67 ng^.mL⁻¹) and I-FABP (+145.9 ±123.2 pg^.mL⁻¹) increased from rest. Heat acclimation induces mHSP72 accumulation earlier and at a greater magnitude compared to matched work hypoxic acclimation, however neither acclimation regime attenuated the systemic cytokine response or intestinal damage following acute exercise in hypoxia.

Oxidative Stress Assessment in Response to Ultraendurance Exercise: Thiols Redox Status and ROS Production according to Duration of a Competitive Race

Purpose. Response to an ultraendurance competitive race on thiols redox status, reactive oxygen species (ROS) production, and oxidative stress (OxS) was investigated according to duration. Methods. Twenty-four elite runners were examined: six completed 50 km and eighteen 100 km. Blood and urine samples were collected before and immediately after the race. Erythrocytes and plasma aminothiols by high-performance liquid chromatography, total antioxidant capacity (TAC), and OxS biomarkers (protein carbonyl (PC), thiobarbituric acid-reactive substances (TBARS), 8-isoprostane (8-iso-PGF2α), and 8-OH-2-deoxyguanosine (8-OH-dG)) by immunoenzymatic assays and ROS production by Electron Paramagnetic Resonance were assessed. Results. Significant increases (P between <0.05 and <0.0001) were recorded in plasma total and oxidized aminothiols concentration and TAC (P < 0.0001) only after 100 km: plasmatic (ROS production (+12 versus +29%), PC (+54 versus +115%), and TBARS (+28 versus +55%)) and urinary (8-OH-dG.creatinine⁻¹ (+71 versus +158%) and 8-iso-PGF2α.creatinine⁻¹ (+43 versus +135%)) concentrations for 50 and 100 km (duration 4 h 3′ versus 8 h 42′), respectively. Conclusion. Very prolonged ultraendurance exercise causes an increase in ROS production and OxS depending on specific biomarker examined but always linearly and directly related to exercise duration. Redox status of erythrocytes was preserved. A relationship between running performance and both prerace ROS production and antioxidant-redox status was found in 100 km race.

Oxidative status of the myocardium in response to different intensities of physical training

The intensity of exercise determines the metabolic pathway and the energetic substrate that is spent. Our study sought to identify the effects of different intensities of swimming on myocardial oxidative status and the blood lipid profile. Eighty Wistar rats (male and female) submitted to different intensities of a swimming regimen (low, LS; moderate, MS; or high, HS) for 16 weeks. Samples of blood and myocardium from the left ventricle were collected to determine lipid profiles and oxidative status. Reactive oxygen species (ROS) and antioxidant capacity against peroxyl radicals (ACAP), lipid profiles and lipid peroxidation was analyzed. ROS levels and ACAP were higher in male rats than in female rats overall (p<0.05). However, ACAP in the myocardium was significantly elevated in LS female rats compared to the MS and HS female rats, which had a significantly lower ACAP compared to all other groups. LS and MS training in both sexes and HS training (in females) led to significant decreases in the heart's lipid peroxidation. Amelioration of the lipid profile and reduction in oxidative damage contributed to a physiological state that benefits cardiovascular function in exercised animals. The results show that low and moderate intensity exercise promotes beneficial adaptations.

Regular physical activity and cardiovascular biomarkers in prevention of atherosclerosis in men: a 25-year prospective cohort study

Background

The purpose of the study was to examine the association between leisure-time physical activity (LTPA), cardiovascular biomarkers and atherosclerosis among asymptomatic men with stable LTPA level throughout the 25-year prospective observation.

Methods

Out of 101 asymptomatic men prospectively observed for their lifestyle and cardiovascular risk factors, the cohort of 62 individuals (mean age 59.9 years) maintained a stable LTPA level during the 25-year observation. Regular check-ups with the assessment of traditional risk factors, detailed measurements of LTPA level and aerobic capacity were performed since baseline. At the latest follow-up (2011/12) a set of cardiovascular biomarkers was measured using enzyme-linked immunosorbent assay. Subclinical atherosclerosis was assessed by means of coronary artery calcification score and intima-media thickness (IMT). Endothelial function was evaluated by means of the reactive hyperemia index. The studied biomarkers and indices were analyzed in the three cohorts representing stable low-tomoderate (<2050 kcal/week), high (2050-3840 kcal/week) and very high LTPA (>3840 kcal/week).

Results

At baseline the three cohorts were comparable in terms of age and clinical characteristics. At follow-up, the cohort with stable high LTPA (2050-3840 kcal/week) had significantly lower concentrations of hs-CRP (2.20 ± 1.0 mg/L), oxidized-LDL (68.35 ± 67.7 ng/mL), leptin (4.71 ± 3.07 ng/mL) and irisin (0.47 ± 0.13 μmol/L), and the most favorable indices of atherosclerosis and endothelial function as compared with other groups (p < 0.05). Regular marathon runners had increased concentrations of hsCRP (3.12 ± 1.4 mg/L), oxidized-LDL (249.8 ± 129 ng/ml), Interleukine-6 (3.74 ± 2.4 pg/ml). A positive correlation was observed between hsCRP and IMT (r = 0.301; p < 0.01), and irisin and IMT (r = 0.223; p < 0.05).

Conclusions

The data suggest that stable high LTPA (2050-3840 kcal/week) is associated with the most favorable profile of key cardiovascular biomarkers and indices of atherosclerosis. Lifetime very high LTPA is associated with increased lowgrade inflammation and may, therefore, exert an atherogenic effect.

Role of reactive oxygen species in regulation of glucose transport in skeletal muscle during exercise

Glucose derived from extracellular sources serves as an energy source in virtually all eukaryotic cells, including skeletal muscle. Its contribution to energy turnover increases with exercise intensity up to moderately heavy workloads. However, at very high workloads, the contribution of extracellular glucose to energy turnover is negligible, despite the high rate of glucose transport. Reactive oxygen species (ROS) are involved in the stimulation of glucose transport in isolated skeletal muscle preparations during intense repeated contractions. Consistent with this observation, heavy exercise is associated with significant production of ROS. However, during more mild to moderate stimulation or exercise conditions (in vitro, in situ and in vivo) antioxidants do not affect glucose transport. It is noteworthy that the production of ROS is limited or not observed under these conditions and that the concentration of the antioxidant used was extremely low. The results to date suggest that ROS involvement in activation of glucose transport occurs primarily during intense short-term exercise and that other mechanisms are involved during mild to moderate exercise. What remains puzzling is why ROS-mediated activation of glucose transport would occur under conditions where glucose transport is highest and utilization (i.e. phosphorylation of glucose by hexokinase) is low. Possibly ROS production is involved in priming glucose transport during heavy exercise to accelerate glycogen biogenesis during the initial recovery period after exercise, as well as altering other aspects of intracellular metabolism.

Effects of normoxic and hypoxic exercise regimens on monocyte-mediated thrombin generation in sedentary men

Exercise and hypoxia paradoxically modulate vascular thrombotic risks. The shedding of procoagulant-rich microparticles from monocytes may accelerate the pathogenesis of atherothrombosis. The present study explores the manner in which normoxic and hypoxic exercise regimens affect procoagulant monocyte-derived microparticle (MDMP) formation and monocyte-promoted thrombin generation (TG). Forty sedentary healthy males were randomized to perform either normoxic (NET; 21% O2, n=20) or hypoxic (HET; 15% O2, n=20) exercise training (60% VO(2max)) for 30 min/day, 5 days/week for 5 weeks. At rest and immediately after HET (100 W under 12% O2 for 30 min), the MDMP characteristics and dynamic TG were measured by flow cytometry and thrombinography respectively. The results demonstrated that acute 12% O2 exercise (i) increased the release of coagulant factor V (FV)/FVIII-rich, phosphatidylserine (PS)-exposed and tissue factor (TF)-expressed microparticles from monocytes, (ii) enhanced the peak height and rate of TG in monocyte-rich plasma (MRP) and (iii) elevated concentrations of norepinephrine/epinephrine, myeloperoxidase (MPO) and interleukin-6 (IL-6) in plasma. Following the 5-week intervention, HET exhibited higher enhancements of peak work-rate and cardiopulmonary fitness than NET did. Moreover, both NET and HET decreased the FV/FVIII-rich, PS-exposed and TF-expressed MDMP counts and the peak height and rate of TG in MRP following the HET. However, HET elicited more suppression for the HE (hypoxic exercise)-enhanced procoagulant MDMP formation and dynamic TG in MPR and catecholamine/peroxide/pro-inflammatory cytokine levels in plasma than NET. Hence, we conclude that HET is superior to NET for enhancing aerobic capacity. Furthermore, HET effectively suppresses procoagulant MDMP formation and monocyte-mediated TG under severe hypoxic stress, compared with NET.

Evidence for cyclooxygenase-dependent sweating in young males during intermittent exercise in the heat

Our recent work implicated nitric oxide (NO) in the control of sweating during intermittent exercise; however, it is unclear if cyclooxygenase (COX) is also involved. On separate days, ten healthy young (24 ± 4 years) males cycled in the heat (35°C). Two 30 min exercise bouts were performed at either a moderate (400 W, moderate heat load) or high (700 W, high heat load) rate of metabolic heat production and were followed by 20 and 40 min of recovery, respectively. Forearm sweating (ventilated capsule) was evaluated at four skin sites that were continuously perfused via intradermal microdialysis with: (1) lactated Ringer solution (Control), (2) 10 mm ketorolac (a non-selective COX inhibitor), (3) 10 mm N G-nitro-l -arginine methyl ester (l -NAME; a non-selective NO synthase inhibitor) or (4) a combination of 10 mm ketorolac + 10 mm l -NAME. During the last 5 min of the first exercise at moderate heat load, forearm sweating (mg min−1 cm−2) was equivalently reduced with ketorolac (0.54 ± 0.08), l -NAME (0.55 ± 0.07) and ketorolac+l -NAME (0.56 ± 0.08) compared to Control (0.67 ± 0.06) (all P  < 0.05). Similar results were obtained for the second exercise at moderate heat load (all P  < 0.05). However, forearm sweating was similar between the four sites during exercise at high heat load and during recovery regardless of exercise intensity (all P  > 0.05). We show that (1) although both COX and NO modulate forearm sweating during intermittent exercise bouts in the heat at a moderate heat load, the effects are not additive, and (2) the contribution of both enzymes to forearm sweating is less evident during intermittent exercise when the heat load is high and during recovery.

Physical and immunological aspects of exercise in chronic diseases

Physical inactivity and sedentary lifestyles are believed to be independent risk factors for the occurrence of numerous diseases, including, obesity, Type 2 diabetes, metabolic syndrome, cardiovascular disease, cancer and mental health, all leading to substantial morbidity and/or premature death. It has been found that regular exercise, is associated with better quality of life and health outcomes, and reduces the risk of cardiovascular disease and cancer. Here, we review the effects regular exercise has on mental health and well-being, on the immune system and in cancer, cardiovascular disease, autoimmunity and metabolic syndrome. Is exercise the new immunotherapy to treat diseases?

Metabolic effects of glycerol supplementation and aerobic physical training on Wistar rats

We evaluated the effects of oral glycerol supplementation on trained rats fed a normal diet. Wistar rats were distributed among 6 groups in a completely randomized 2 × 3 factorial design. The animals were subjected to 6 weeks of aerobic training. In the last 4 weeks, the animals’ diet was supplemented with saline, glucose, or glycerol. Data were subjected to one-way analysis of variance (ANOVA) followed by a Student–Newmann–Keuls test, with values for P < 0.05 considered statistically significant. The change in body mass was lower in the trained groups, and their food and water consumption were higher. Glycerol supplementation resulted in an increase in the levels of triacylglycerol (TAG) and total cholesterol, as well as in the area and diameter of adipocytes. When associated with training, these parameters were similar to those of other trained groups. Levels of low-density lipoprotein + very-low-density lipoprotein cholesterol decreased in the trained animals that received glycerol compared with the non-trained ones. Glycerol consumption caused a reduction in food intake and increased the villous:crypt (V:C) ratio. No changes in glycemia, high density lipoproteins, or density of adipocytes were observed. Supplementation with glycerol together with aerobic physical training promoted beneficial metabolic effects. However, in non-trained rats glycerol increased the diameter and area of adipocytes, as well as the levels of TAG and total cholesterol.

Time-course changes of oxidative stress response to high-intensity discontinuous training versus moderate-intensity continuous training in masters runners

Beneficial systemic effects of regular physical exercise have been demonstrated to reduce risks of a number of age-related disorders. Antioxidant capacity adaptations are amongst these fundamental changes in response to exercise training. However, it has been claimed that acute physical exercise performed at high intensity (>60% of maximal oxygen uptake) may result in oxidative stress, due to reactive oxygen species being generated excessively by enhanced oxygen consumption. The aim of this study was to evaluate the effect of high-intensity discontinuous training (HIDT), characterized by repeated variations of intensity and changes of redox potential, on oxidative damage. Twenty long-distance masters runners (age 47.8 ± 7.8 yr) on the basis of the individual values of gas exchange threshold were assigned to a different 8-weeks training program: continuous moderate-intensity training (MOD, n = 10) or HIDT (n = 10). In both groups before (PRE) and after (POST) training we examined the following oxidative damage markers: thiobarbituric acid reactive substances (TBARS) as marker of lipid peroxidation; protein carbonyls (PC) as marker of protein oxidation; 8-hydroxy-2-deoxy-guanosine (8-OH-dG) as a biomarker of DNA base modifications; and total antioxidant capacity (TAC) as indicator of the overall antioxidant system. Training induced a significant (p<0.05) decrease in resting plasma TBARS concentration in both MOD (7.53 ± 0.30 and 6.46 ± 0.27 µM, PRE and POST respectively) and HIDT (7.21 ± 0.32 and 5.85 ± 0.46 µM, PRE and POST respectively). Resting urinary 8-OH-dG levels were significantly decreased in both MOD (5.50 ± 0.66 and 4.16 ± 0.40 ng mg(-1)creatinine, PRE and POST respectively) and HIDT (4.52 ± 0.50 and 3.18 ± 0.34 ng mg(-1)creatinine, PRE and POST respectively). Training both in MOD and HIDT did not significantly modify plasma levels of PC. Resting plasma TAC was reduced in MOD while no significant changes were observed in HIDT. In conclusion, these results suggest that in masters runners high-intensity discontinuous does not cause higher level of exercise-induced oxidative stress than continuous moderate-intensity training, inducing similar beneficial effects on redox homeostasis.

Hypoxic exercise training improves cardiac/muscular hemodynamics and is associated with modulated circulating progenitor cells in sedentary men

BACKGROUND

Circulating progenitor cells (CPCs) improve cardiovascular function and organ perfusion by enhancing the capacities of endothelial repair and neovasculogenesis. This study investigates whether exercise regimens with/without hypoxia affect cardiac and muscular hemodynamics by modulating CPCs and angiogenic factors.

METHODS

Forty sedentary males were randomly divided into hypoxic (HT, n=20) and normoxic (NT, n=20) training groups. The subjects were trained on a bicycle ergometer at 60%VO(2max) under 15% (HT) or 21% (NT) O2 conditions for 30 min daily, five days weekly for five weeks.

RESULTS

After the five-week interventions, the HT group exhibited a larger improvement in aerobic capacity than the NT group. Furthermore, the HT regimen (i) enhanced cardiac output (Q(H)) and perfusion (Q(M))/oxygenation of vastus lateralis during exercise; (ii) increased levels of CD34(+)/KDR(+)/CD117(+), CD34(+)/KDR(+)/CD133(+), and CD34(+)/KDR(+)/CD31(+) cells in blood; (iii) promoted the proliferative capacity of these CPC subsets, and (iv) elevated plasma nitrite/nitrate, stromal cell-derived factor-1 (SDF-1), matrix metalloproteinase-9 (MMP-9), and vascular endothelial growth factor-A (VEGF-A) concentrations. Despite the lack of changes in Q(H) and the number or proliferative capacity of CD34(+)/KDR(+)/CD117(+) or CD34(+)/KDR(+)/CD31(+) cells, the NT regimen elevated both Q(M) and plasma nitrite/nitrate levels and suppressed the shedding of endothelial cells (CD34(-)/KDR(+)/phosphatidylserine(+) cells).

CONCLUSIONS

The HT regimen improves cardiac and muscular hemodynamic adaptations, possibly by promoting the mobilization/function of CPCs and the production of angiogenic factors.

Cholesterol-induced membrane microvesicles as novel carriers of damage-associated molecular patterns: mechanisms of formation, action, and detoxification

OBJECTIVE

Cholesterol enrichment occurs in vivo when phagocytes ingest retained and aggregated lipoproteins, damaged or senescent cells, and related debris. We previously reported that enrichment of human monocyte/macrophages with unesterified cholesterol (UC) triggers the release of highly procoagulant microvesicles ([MVs], also called microparticles) through induction of apoptosis. We determined whether UC-induced MVs (UCMVs) might transmit endogenous danger signals and, if so, what molecular processes might be responsible for their production, recognition, and detoxification.

METHODS AND RESULTS

Injection of UCMVs into rats provoked extensive leukocyte rolling and adherence to postcapillary venules in vivo. Likewise, exposure of mouse aortic explants or cultured human endothelial cells to UCMVs augmented the adhesion of human monocytes by several fold and increased endothelial cell intercellular adhesion molecule-1 via nuclear factor-κB activation. To explore molecular mechanisms, we found that UC enrichment of human monocytes, in the absence of other stimuli, induced mitochondrial complex II-dependent accumulation of superoxide and peroxides. A subset of these moieties was exported on UCMVs and mediated endothelial activation. Strikingly, aortic explants from mice lacking lectin-like oxidized low-density lipoprotein receptor-1, a pattern-recognition receptor, were essentially unable to respond to UCMVs, whereas simultaneously treated explants from wild-type mice responded robustly by increasing monocyte recruitment. Moreover, high-density lipoprotein and its associated enzyme paraoxonase-1 exerted unexpected roles in the detoxification of UCMVs.

CONCLUSIONS

Overall, our study implicates MVs from cholesterol-loaded human cells as novel carriers of danger signals. By promoting maladaptive immunologic and thrombotic responses, these particles may contribute to atherothrombosis and other conditions in vivo.

Moderate-intensity, premeal cycling blunts postprandial increases in monocyte cell surface CD18 and CD11a and endothelial microparticles following a high-fat meal in young adults

High-fat meals promote transient increases in proatherogenic factors, implicating the postprandial state in cardiovascular disease (CVD) progression. Although low-grade inflammation is associated with CVD, little research has assessed postprandial inflammation. Because of its anti-inflammatory properties, premeal exercise may counteract postprandial inflammation. The purpose of this study was to determine postprandial alterations in monocytes and circulating markers of endothelial stress and inflammation following a high-fat meal in young adults with or without premeal cycle exercise. Each subject completed two trials and was randomized to rest or cycle at a moderate intensity prior to eating a high-fat meal. Flow cytometry was used to assess monocyte cell surface receptor expression and concentration of endothelial microparticles (EMP). Plasma cytokines were assessed using Luminex MagPix. Statistical analysis was completed using separate linear mixed models analyses with first-order autoregressive (AR(1)) heterogeneous covariance structure. Significance was set at P ≤ 0.05. Percentage increases in classic monocyte CD11a and CD18 were greater overall in the postprandial period in the meal-only condition compared with the meal + exercise condition (P < 0.05). EMP concentration was 47% greater 3 h after the meal compared with premeal values in the meal-only condition (P < 0.05); no significant increase was observed in the meal + exercise condition. Premeal cycling blunted postprandial increases in EMP and CD11a and CD18. Acute, moderate-intensity exercise may help counteract possibly deleterious postprandial monocyte and endothelial cell activation.

Redox biology of exercise: an integrative and comparative consideration of some overlooked issues

The central aim of this review is to address the highly multidisciplinary topic of redox biology as related to exercise using an integrative and comparative approach rather than focusing on blood, skeletal muscle or humans. An attempt is also made to re-define ‘oxidative stress’ as well as to introduce the term ‘alterations in redox homeostasis’ to describe changes in redox homeostasis indicating oxidative stress, reductive stress or both. The literature analysis shows that the effects of non-muscle-damaging exercise and muscle-damaging exercise on redox homeostasis are completely different. Non-muscle-damaging exercise induces alterations in redox homeostasis that last a few hours post exercise, whereas muscle-damaging exercise causes alterations in redox homeostasis that may persist for and/or appear several days post exercise. Both exhaustive maximal exercise lasting only 30 s and isometric exercise lasting 1–3 min (the latter activating in addition a small muscle mass) induce systemic oxidative stress. With the necessary modifications, exercise is capable of inducing redox homeostasis alterations in all fluids, cells, tissues and organs studied so far, irrespective of strains and species. More importantly, ‘exercise-induced oxidative stress’ is not an ‘oddity’ associated with a particular type of exercise, tissue or species. Rather, oxidative stress constitutes a ubiquitous fundamental biological response to the alteration of redox homeostasis imposed by exercise. The hormesis concept could provide an interpretative framework to reconcile differences that emerge among studies in the field of exercise redox biology. Integrative and comparative approaches can help determine the interactions of key redox responses at multiple levels of biological organization.

The relationship of oxidative stress and cholesterol with dipping status before and after aerobic exercise training

OBJECTIVE

The purpose of this study was to examine the effects of aerobic exercise training (AEXT) on dipping status in pre-hypertensive and stage-1 hypertensive individuals. A secondary purpose was to evaluate whether AEXT alters oxidative stress and endothelial biomarkers correlated to dipping status.

METHODS

Twenty-three subjects underwent 24-h ambulatory blood pressure monitoring at baseline and after 6 months of AEXT. AEXT consisted of training at 70% VO(2max) 3 days/week for 6 months. Total cholesterol, high-density lipoprotein-cholesterol, low-density lipoprotein (LDL)-cholesterol, oxidized LDL (ox-LDL), triglycerides, urinary and plasma nitric oxide end-products, superoxide dismutase and 8-iso-PGF(2alpha) were measured before and after AEXT. Statistically, ANOVA and linear regression were used.

RESULTS

Before and after AEXT, there were no significant differences between dippers and non-dippers in any of the biomarkers except for total cholesterol following AEXT. In a sub-analysis following AEXT, 14 subjects retained their original dipping status, five subjects changed from dippers to non-dippers and four subjects changed from non-dippers to dippers. Significant differences existed between these groups in changes in total and LDL-cholesterol, ox-LDL, 8-iso-PGF(2alpha) and % Dip.

CONCLUSIONS

Changes in cholesterol levels but not oxidative stress or endothelial biomarkers were related to changes in BP variables following AEXT in dippers and non-dippers.

A influência da intensidade do exercício físico aeróbio no processo aterosclerótico

A aterosclerose é um processo inflamatório crônico e degenerativo que acomete os vasos, sendo caracterizada pelo acúmulo de lipídeos no espaço subendotelial da íntima, acúmulo de células inflamatórias e elementos fibrosos. A oxidação de LDL-c parece ser o principal evento para o início da aterosclerose. O exercício físico aeróbio melhora os sistemas de defesa orgânicos contra aterosclerose, diminuindo o estresse oxidativo e aumentando a síntese de enzimas antioxidantes; aumento da vasodilatação via óxido nítrico (NO) e óxido nítrico sintase endotelial (eNOS) e diminuição da inflamação sistêmica com produção de citocinas pró-inflamatórias e aumento de fatores anti-inflamatórios. Porém, de maneira aguda, o exercício aeróbio de alta intensidade aumenta o risco de desenvolvimento de eventos cardiovasculares e, de forma crônica, pode atuar negativa ou positivamente na prevenção do processo aterosclerótico.

Effects of lifestyle modification on oxidized LDL, reactive oxygen species production and endothelial cell viability in patients with coronary artery disease

OBJECTIVES

We evaluated the effects of lifestyle modification (LM) on lipid profile, oxidative stress and serum-stimulated human coronary artery endothelial cell (HCAEC) viability in coronary artery disease (CAD) patients after 6months.

DESIGN AND METHODS

Thirty patients with CAD were randomly assigned to LM intervention (n=15) and usual care control (n=15) groups. LM-intervened patients were instructed to consume low-fat, high-antioxidants and fiber diets. Moderate exercise and stress management were also advised. Group support to maintain patients' compliance was applied.

RESULTS

Serum cholesterol, triglyceride, oxidized LDL and protein carbonyl were decreased in LM group. Serum triglyceride was increased in control group. HCAEC viability was increased, while intracellular reactive oxygen species was decreased, by serum from the LM group.

CONCLUSION

LM is capable of improving lipid profile, reducing oxidative stress and increasing HCAEC survival in the patients with CAD, hence lowering a risk for the future cardiovascular event.

Exercise-induced immunosuppression: roles of reactive oxygen species and 5'-AMP-activated protein kinase dephosphorylation within immune cells

We previously proposed 5'-AMP-activated protein kinase (AMPK) dephosphorylation within immune cells as an intracellular mechanism linking exercise and immunosuppression. In this study, AMPK phosphorylation underwent transient (<1 h) decreases (53.8+/-7.2% basal) immediately after exercise (45 min of cycling at 70% VO2max) in a cohort of 16 adult male participants. Similar effects were seen with running. However, because exercise-induced inactivation of AMPK was previously shown to occur in an AMP-independent manner, the means by which AMPK is inactivated in this context is not yet clear. To investigate the hypothesis that exercise-induced inactivation of AMPK is mediated via signaling mechanisms distinct from changes in cellular AMP-to-ATP ratios, reactive oxygen species (ROS) and intracellular Ca2+ signaling were investigated in mononuclear cells before and after exercise and in cultured monocytic MM6 cells. In in vitro studies, treatment with an antioxidant (ascorbic acid, 4 h, 50 microM) decreased MM6 cell intracellular ROS levels (88.0+/-5.2% basal) and induced dephosphorylation of AMPK (44.7+/-17.6% basal). By analogy, the fact that exercise decreased mononuclear cell ROS content (32.8+/-16.6% basal), possibly due to downregulation (43.4+/-8.0% basal) of mRNA for NOX2, the catalytic subunit of the cytoplasmic ROS-generating enzyme NADPH oxidase, may provide an explanation for the AMPK-dephosphorylating effect of exercise. In contrast, exercise-induced Ca2+ signaling events did not seem to be coupled to changes in AMPK activity. Thus we propose that the exercise-induced decreases in both intracellular ROS and AMPK phosphorylation seen in this study constitute evidence supporting a role for ROS in controlling AMPK, and hence immune function, in the context of exercise-induced immunosuppression.

Systemic hypoxia promotes lymphocyte apoptosis induced by oxidative stress during moderate exercise

Blood undergoes oxidative stress during severe hypoxia or intense exercise. Excessive exposure to oxidative stress induces replicative senescence and apoptosis of lymphocytes. This study determines how various exercises with/without hypoxia affect lymphocyte subset mobilization and oxidative stress-induced lymphocyte apoptosis. Eighteen sedentary males randomly engaged in two normoxic exercise bouts [severe exercise (SE) (up to VO(2max)) and moderate-intensity exercise (ME) (50%VO(2max)) while exposed to 21%O(2)], two hypoxic exercise bouts (ME while exposed to 12%O(2) and 15%O(2)) and two hypoxic resting conditions (resting while exposed to 12%O(2) and 15%O(2)) in a normobaric hypoxia chamber. Under normoxic conditions, SE but not ME (1) increased the percentages of senescent (CD28(-) and CD57(+))/activated (CD62L(-) and CD11a(+))-form lymphocytes mobilized into the peripheral blood compartment; (2) decreased the levels of surface thiol and intracellular total (t-GSH) and reduced-form glutathione (r-GSH) of lymphocytes in blood; and (3) further enhanced the extents of H(2)O(2)-induced mitochondria trans-membrane potential diminishing, caspases 3/8/9 activation, poly(ADP-ribose) polymerase cleavage and phosphotidyl serine exposure in blood lymphocytes. However, no significant change occurred in the subset mobilization, antioxidant levels or apoptosis of lymphocytes following exposure to either 12%O(2) or 15%O(2). Although both 12%O(2) and 15%O(2) ME increased the mobilization of senescent/activated-form lymphocytes, only 12%O(2) ME enhanced H(2)O(2)-induced lymphocyte thiol, t-GSH and r-GSH consumption and apoptotic responses. Therefore, we conclude that the 12%O(2) exposure increases the mobilization of senescent/activated-form lymphocytes into the peripheral blood compartment and simultaneously enhances oxidative stress-induced lymphocyte apoptosis by diminishing cellular antioxidant levels during exercise.

Effects of acute exercise on atherogenic lipids in untreated mild hypertensive patients

BACKGROUND/AIM

Exercise can positively influence risk factors associated with cardiovascular disease. The mechanisms by which exercise reduces atherogenic risk remain unknown. The aim of the present study was to investigate the effect of acute exercise (cardiopulmonary exercise cycle ergometer test) on atherogenic lipids in untreated mild hypertensive patients with or without hypercholesterolemia. This testing allows determination of exercise capacity, peak heart rate, and ventilation per minute (VE), peak oxygen uptake (pVO2) and exercise time (ET).

METHODS

The study group included 85 untreated mild hypertensive patients (according to VII Joint National Committee--JNC 7) divided into two subgroups: hypertensive hypercholesterolemic and hypertensive normocholesterolemic. The control grouip included 35 normotensive subjects divided into two subgroups: normotensive hypercholesterolemic and normotensive normocholesterolemic. Lipid profiles to determine were oxidized LDL (OxLDL)--a marker of oxidative stress, triglycerides, total cholesterol, LDL cholesterol, and HDL cholesterol, which were measured at rest and 30 minutes after the acute bout of cardiopulmonary exercise cycle ergometer test. Lipids profiles were measured by enzymatic methods. Oxidized LDL was determined by a commercially available sandwich ELISA (Mercodia AB, Uppsala, Sweden). C-reactive protein (CRP) was measured using chemiluminiscent methods (Immulite-DPC).

RESULTS

In our study OxLDL was significantly higher in hypertensive patients with atherogenic lipid profiles in basal condition, compared to the hypertensive patients without atherogenic lipid profiles and controls. There was a significant difference in CRP (p < 0.001) between hypercholesterolemics (hypertensive and normotensive) and normocholesterolemics (hypertensive and normotensive). We found increased OxLDL after exercise in both groups (hypertensive patients and normotensive), but only in the hypertensive hypercholesterolemic patients the difference was statistically significant (90.47 +/- 15.31 vs. 105.94 +/- 14.17 IU/L, p < 0.001). Systolic and diastolic blood pressures were significantly higher during exercise only in the hypertensive patients. There were significantly lower values of pVO2 only in hypertensive hypercholesterolemic patients. There were no significant differences between hypertensive and normotensive ones for ET and VE. In hypertensive ones we found after exercise a negative correlation between pVO2 and OxLDL (r = -0.473; p < 0.05), and pVO2 and CRP (r = -0.478; p < 0.05). We also found in normotensive normocholesterolemic patients a positive correlation between VE and systolic blood pressure (r = 0.420; p < 0.05), a negative correlation between VE and OxLDL (r= -0.421; p < 0.05), and VE and CRP (r = -0.561; p < 0.05).

CONCLUSION

This study showed that acute exercise induces and increases oxidative stress only in untreated mild hypertensive patients with atherogenic lipid profiles. These results imply the need to normalize atherogenic lipid profile in untreated patients with mild hypertension in order to prevent an increased lipid peroxidation under acute exercise.

The combination of alpha-lipoic acid supplementation and aerobic exercise inhibits lipid peroxidation in rat skeletal muscles

We investigated the effect of DL-alpha-lipoic acid (LA) supplementation and regular aerobic exercise on the concentrations of malondialdehyde (MDA) and vitamin E, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx), and the levels of glutathione (GSH) in rat skeletal muscles (soleus and red gastrocnemius). For 8 weeks, rats (n = 7 per group) were (1) exercised on a treadmill for 30 min d(-1), (2) treated with supplemental LA, or (3) exercised and treated with supplemental LA. Control rats (n = 7) did not receive LA and were not exercised. DL-alpha-lipoic acid (100 mg kg(-1)) was administered daily as an oral supplement. The rats were exercised in a graded manner for 5 d wk(-1). The concentration of MDA in the soleus and red gastrocnemius was significantly lower in rats that exercised and received LA than in the other groups. Compared with the other groups, rats that exercised and received LA had a significantly higher vitamin E concentration in the soleus. The SOD and GPx activities in the soleus and red gastrocnemius were significantly higher in rats that exercised and received LA. These results suggest that LA supplementation combined with aerobic treadmill exercise inhibits lipid peroxidation in skeletal muscles. This effect was especially remarkable in the soleus, which is particularly sensitive to oxidative stress, as revealed by the increased vitamin E level and SOD and GPx activities.

Clinical evaluation of oxidative stress in patients with diabetes mellitus type II: Impact of acute exercise

Background/Aim. Exercise is a well recognized model of oxidative stress and, also, an important tool in diabetes management. The aim of our study was to evaluate oxidative stress in patients with diabetes mellitus type 2 and to determine influence of acute exercise training on the investigated parameters. Methods. To evaluate oxidative stress in the patients, we determinated following parameters: triglycerides (TG), total cholesterol, low density lipoprotein cholesterol (LDL), oxidized LDL cholesterol (Ox LDL), superoxide dismutase (SOD), glutathione peroxidase (GSHPx), plasminogen activator inhibitor (PAI) which were measured at rest and immediately after the acute bout of cardiopulmonary exercise cycle-ergometer test. Results. In basal condition, diabetic patients compared to controls have significant higher values of TG (3.12 ? 1.09 vs 1.74 ? 0.9 mmol/L, p < 0.01), Ox LDL (84.73 ? 16.90 vs 79.00 ? 29.26 mmol/L, p < 0.05) and SOD enzyme activity (913.38 ? 120.36 vs 877.14 ? 153.18 U/g Hb, p < 0.05). During the acute exercise test, there was significant increase of Ox LDL in both the study patients (from 84.73 ? 16.90 to 92.33 ? 23.29 mmol/L, p < 0.05) and in the control group (from 79.00 ? 29.26 to 89.30 ? 29.07 mmol/L, p < 0.05). SOD activity was significantly increased in both groups during exercise, in diabetic patients from 913.38 ? 120.36 to 921.50 ? 130.03 U/gHb, p < 0.05, and in the controls from 877.14 ? 153.18 to 895.00 ? 193.49, U/gHb, p < 0.05. GSH-Px activity was significantly increased only in the diabetic patients after the acute exercise (from 45.04 ? 11.19 to 51.81 ? 15.07 U/gHb, p < 0.01), but not in the controls (from 44.63 ? 13.73 to 43.97 ? 25.97 U/gHb, p = ns). PAI significantly decreased during the exercise test, only in the healthy subjects (from 2.60 ? 0.35 to 2.22 ? 0.65, p < 0.05). Type 2 diabetic patients with complications had only significant increase in GSH-Px activity (from 47.10 ? 7.37 to 54.52 ? 11.97 U/gHb, p < 0.01). Conclusion. Elevated Ox LDL, SOD and GSH-Px levels are associated with acute exercise in type 2 diabetic patients. We suggest that it could be a compensatory mechanism to preventing free radicals tissue damage. We hypothesize that a physical training program induces an enhance of muscular and liver antioxidant enzymes activity and reduces oxidative stress. Further studies are needed to explore the relationship between exercise and antioxidant system in diabetic patients with and without complications.

Exercise-induced oxidative DNA damage and lymphocytopenia in sedentary young males

Post high-intensity exercise lymphocytopenia is well documented, but its underlying mechanisms have not been fully elucidated. A possible mechanism is a reactive oxygen species-induced DNA damage after high-intensity exercise. Furthermore, lymphocyte apoptosis related to DNA damage might contribute to exercise-induced lymphocytopenia.

PURPOSE

This study examined lymphocytopenia, lymphocyte oxidative DNA damage, and apoptosis in young healthy sedentary males after acute high-intensity exercise.

METHOD

Fifteen subjects exercised on bicycle ergometers for 1 h at 75% of their VO2max. Venous blood samples were taken before exercise (PRE) and hourly after exercise until 4 h (P0-P4). Lymphocyte counts, oxidative DNA damage evaluated using the Comet assay with human 8-oxoguanine DNA glycosylase, and serum lipid peroxide (LPO) concentration were measured. Furthermore, lymphocyte superoxide, Fas receptor (CD95), and Annexin-V-positive lymphocyte apoptosis cells were measured in 10 subjects who exercised and gave blood samples as described above.

RESULTS

Lymphocyte counts became significantly lower than the PRE value (P < 0.05): 20.4% at P1, 24.3% at P2, and 16.3% at P3. Moreover, LPO significantly increased by P2 (P < 0.05): 1.6-fold. The % DNA in tail, indicating oxidative DNA damage, was significantly higher at P3 (54.3 +/- 12.8%) than at PRE (42.6 +/- 11.1%, P < 0.05). The lymphocyte superoxide level was significantly higher (51.3%) than the PRE value (P < 0.05). Neither CD95 nor Annexin-V-positive cells were significantly different than the PRE value.

CONCLUSION

Results of this study suggest that lymphocyte oxidative DNA damage can relate to lymphocytopenia, although DNA damage was not associated with apoptosis in healthy young sedentary males.

Damaging effects of intense repetitive treadmill running on murine intestinal musculature

Several gastrointestinal symptoms associated with prolonged intense exercise (IE) have been reported, although the mechanisms underlying its effects on the intestine remain poorly understood. The aim of the present study was to investigate whether IE may induce oxidative stress in the intestine, as well as its possible relationship with intestinal signaling impairments, leading to contractile disturbances. C57BL/6 mice were submitted to 4 days (EX.4D) and 10 days (EX.10D) of IE. The daily exercise session consisted of a running session until exhaustion, with the treadmill speed set at 85% of each animal's maximum velocity. The decrease in exhaustion time was exponential, and the reduction in the maximum velocity, as assessed by an incremental test, was higher in EX.4D than in EX.10D animals. The ileum mucosa layer was partially destroyed after 4 days of IE, where 37% and 11% muscle layer atrophies were observed in EX.4D and EX.10D animals, respectively. Ileum contractility was significantly impaired in the EX.4D animal group, with reduced efficacy for carbachol, bradykinin, and KCl signaling associated with a decrease in lipid peroxidation and with no alteration of protein oxidation. Intestinal myocytes from EX.10D animals displayed areas containing structurally disorganized mitochondria, which were associated with increased levels of protein oxidation, without alteration of contractility, except for a reduction in the potency of bradykinin signaling. Finally, no clear relationship between ileum contractility and oxidative stress was shown. Together, these results argue in favor of significant functional, biochemical, and morphological disturbances caused by exercise, thus demonstrating that intestinal tissue is very sensitive to exercise.

NADPH oxidases, reactive oxygen species, and hypertension: clinical implications and therapeutic possibilities

Reactive oxygen species (ROS) influence many physiological processes including host defense, hormone biosynthesis, fertilization, and cellular signaling. Increased ROS production (termed "oxidative stress") has been implicated in various pathologies, including hypertension, atherosclerosis, diabetes, and chronic kidney disease. A major source for vascular and renal ROS is a family of nonphagocytic NAD(P)H oxidases, including the prototypic Nox2 homolog-based NAD(P)H oxidase, as well as other NAD(P)H oxidases, such as Nox1 and Nox4. Other possible sources include mitochondrial electron transport enzymes, xanthine oxidase, cyclooxygenase, lipoxygenase, and uncoupled nitric oxide synthase. NAD(P)H oxidase-derived ROS plays a physiological role in the regulation of endothelial function and vascular tone and a pathophysiological role in endothelial dysfunction, inflammation, hypertrophy, apoptosis, migration, fibrosis, angiogenesis, and rarefaction, important processes underlying cardiovascular and renal remodeling in hypertension and diabetes. These findings have evoked considerable interest because of the possibilities that therapies against nonphagocytic NAD(P)H oxidase to decrease ROS generation and/or strategies to increase nitric oxide (NO) availability and antioxidants may be useful in minimizing vascular injury and renal dysfunction and thereby prevent or regress target organ damage associated with hypertension and diabetes. Here we highlight current developments in the field of reactive oxygen species and cardiovascular disease, focusing specifically on the recently identified novel Nox family of NAD(P)H oxidases in hypertension. We also discuss the potential role of targeting ROS as a therapeutic possibility in the management of hypertension and cardiovascular disease.

Exercise and postprandial lipaemia: effects on peripheral vascular function, oxidative stress and gastrointestinal transit

Postprandial lipaemia may lead to an increase in oxidative stress, inducing endothelial dysfunction. Exercise can slow gastric emptying rates, moderating postprandial lipaemia. The purpose of this study was to determine if moderate exercise, prior to fat ingestion, influences gastrointestinal transit, lipaemia, oxidative stress and arterial wall function. Eight apparently healthy males (age 23.6 ± 2.8 yrs; height 181.4 ± 8.1 cm; weight 83.4 ± 16.2 kg; all data mean ± SD) participated in the randomised, crossover design, where (i) subjects ingested a high-fat meal alone (control), and (ii) ingested a high-fat meal, preceded by 1 h of moderate exercise. Pulse Wave Velocity (PWV) was examined at baseline, post-exercise, and in the postprandial period. Gastric emptying was measured using the ¹³C-octanoic acid breath test. Measures of venous blood were obtained prior to and following exercise and at 2, 4 and 6 hours post-ingestion. PWV increased (6.5 ± 1.9 m/sec) at 2 (8.9 ± 1.7 m/sec) and 4 hrs (9.0 ± 1.6 m/sec) post-ingestion in the control group (time × group interaction, P < 0.05). PWV was increased at 2 hrs post-ingestion in the control compared to the exercise trial; 8.9 ± 1.7 vs. 6.2 ± 1.5 m/sec (time × group interaction, P < 0.05). Lipid hydroperoxides increased over time (pooled exercise and control data, P < 0.05). Serum triacylglycerols were elevated postprandially (pooled exercise and control data, P < 0.05). There were no changes in gastric emptying, cholesterol, or C-reactive protein levels. These data suggest that acute exercise prior to the consumption of a high-fat meal has the potential to reduce vascular impairments.

Chronic intermittent hypoxia modulates eosinophil- and neutrophil-platelet aggregation and inflammatory cytokine secretion caused by strenuous exercise in men

Although acclimatization to intermittent hypoxia (IH) improves exercise performance by increasing oxygen delivery and utilization, the effects of chronic IH on platelet-leukocyte interaction and inflammation-related cytokine secretion caused by strenuous exercise remain unclear. This investigation elucidates how two intensities of IH influence eosinophil- and neutrophil-platelet aggregation (EPA and NPA) as well as pro- and anti-inflammatory cytokines mediated by strenuous exercise. Twenty healthy sedentary men were randomly divided into severe (SIH) and moderate (MIH) IH groups; groups were exposed to 12% O2 (SIH) and 15% O2 (MIH) for 1 h/day, respectively, for 5 days/wk for 8 wk in a normobaric hypoxia chamber. Before IH intervention, 1) exercise up to maximal oxygen consumption promoted shear stress-, LPS-, and N-formyl-methionyl-leucyl-phenylalanine-induced EPA, increased IL-1beta and malondialdehyde levels, and decreased total antioxidant levels in plasma and 2) exposure to 12% O2, but not to 15% O2 for 1 h, enhanced LPS-induced EPA and reduced plasma total antioxidant levels. After IH for 8 wk, hypoxia- and exercise-promoted EPA, IL-1beta, or malondialdehyde levels were suppressed in both MIH and SIH groups, and plasma IL-6 and IL-10 levels in the SIH group were increased. However, the NPA induced by the shear force and chemical agonists was not changed under the two IH regimens. Therefore, both MIH and SIH regimens ameliorate eosinophil- and platelet-related thrombosis, proinflammatory IL-1beta secretion, and lipid peroxidation enhanced by strenuous exercise. Furthermore, SIH simultaneously increases circulatory anti-inflammatory IL-6 and IL-10 concentrations. These findings can help to develop effective IH regimens that improve aerobic fitness and minimize risk of thromboinflammation.

The effect of acute aerobic exercise on pulse wave velocity and oxidative stress following postprandial hypertriglyceridemia in healthy men

Oxidative stress is postulated to be responsible for the postprandial impairments in vascular function. The purpose of this study was to measure pulse wave velocity (PWV) and markers of postprandial oxidative stress before and after an acute bout of moderate exercise. Ten trained male subjects (age 21.5 +/- 2.5 years, VO2 max 58.5 +/- 7.1 ml kg(-1) min(-1)) participated in a randomised crossover design: (1) high-fat meal alone (2) high-fat meal followed 2 h later by a bout of 1 h moderate (60% max HR) exercise. PWV was examined at baseline, 1, 2, 3, and 4 h postprandially. Blood Lipid hydroperoxides (LOOHs), Superoxide dismutase (SOD) and other biochemical markers were measured. PWV increased at 1 h (6.49 +/- 2.1 m s(-1)), 2 h (6.94 +/- 2.4 m s(-1)), 3 h (7.25 +/- 2.1 m s(-1)) and 4 h (7.41 +/- 2.5 m s(-1)) respectively, in the control trial (P < 0.05). There was no change in PWV at 3 h (5.36 +/- 1.1 m s(-1)) or 4 h (5.95 +/- 2.3 m s(-1)) post ingestion in the exercise trial (P > 0.05). LOOH levels decreased at 3 h post ingestion in the exercise trial compared to levels at 3 h (P < 0.05) in the control trial. SOD levels were lower at 3 h post ingestion in the control trial compared to 3 h in the exercise trial (0.52 +/- 0.05 vs. 0.41 +/- 0.1 units mul(-1); P < 0.05). These findings suggest that a single session of aerobic exercise can ameliorate the postprandial impairments in arterial function by possibly reducing oxidative stress levels.