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Pyruvate is a three-carbon ketoacid that occurs naturally in cells. It is produced through enzymatic reactions in the glycolytic pathway and plays a crucial role in energy metabolism. Despite promising early results, later well-controlled studies of physically active people have shown that pyruvate supplementation lasting more than 1 week has no ergogenic effects. However, some data suggest that ingested pyruvate may be preferentially metabolized without accumulation in the bloodstream. Pyruvate exhibits antioxidant activity and can affect the cellular redox state, and exogenous pyruvate can influence metabolism by affecting the acid-base balance of the blood. This brief review focuses on the potential effects of pyruvate as a supplement for active people. The current state of understanding suggests that studies of the effects of pyruvate supplementation should prioritize investigating the timing of pyruvate intake., Competing Interests: Zsolt Radak is ​an editorial board member for Sports Medicine and Health Science and was not in the editorial review or the decision to publish this article. Otherwise authors declare that they have no competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 Chengdu Sport University. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.)

Background: Higher circulating levels of trimethylamine N-oxide (TMAO), which is a metabolite that can be produced by the gut microbiota from L-carnitine (LC), have been associated with bone mineral density (BMD). Because LC supplementation can improve bone density and microstructural properties in animal models, this study aimed to examine the effects of 12 weeks of LC supplementation on BMD and selected blood markers involved in bone metabolism of postmenopausal women participating in a resistance training (RT) program., Methods: Twenty-seven postmenopausal women, who had not been treated for osteoporosis, with a total T-score above - 3.0 and no diet differences completed 12 weeks of RT. The participants' diets were supplemented with either 1 g of LC-L-tartrate and 3 g of leucine per day (LC group) or 4 g of leucine per day as a placebo (PLA group), in a double-blind fashion., Results: After the intervention in the LC group, plasma total carnitine and serum decorin levels were higher than the corresponding preintervention values (p = 0.040 and p = 0.042, respectively). Moreover, plasma TMAO and serum SPARC levels were higher in the LC group than the corresponding postintervention values in the PLA group (p < 0.001 and p = 0.030, respectively). No changes in the BMD were observed after 3 months of the intervention., Conclusions: Twelve weeks of LC supplementation during RT program increased plasma TMAO levels and appeared to affect signaling molecules, as indicated by the increase in the resting SPARC and decorin levels, with no significant modification in the BMD., Trial Registration: Retrospectively registered at the ClinicalTrials.gov (NCT05120011)., (© 2023. The Author(s).)

Objectives: To evaluate the effect of L-carnitine (LC) in combination with leucine supplementation on muscle strength and muscle hypertrophy in aged women participating in a resistance exercise training (RET) program., Design/setting/participants: Thirty-seven out of sixty (38.3% dropout) healthy women aged 60-75 years (mean 67.6 ± 0.7 years) completed the intervention in one of three groups. One of the supplemented groups received 1 g of L-carnitine-L-tartrate in combination with 3 g of L-leucine per day (LC+L group; n = 12), and the second supplemented group received 4 g of L-leucine per day (L group; n = 13). The control group (CON group; n = 12) received no supplementation., Intervention: All three groups completed the same RET protocol involving exercise sessions twice per week for 24 weeks., Measurements: Before and after the experiment, participants performed isometric and isokinetic muscle strength testing on the Biodex dynamometer. The cross-sectional areas of the major knee extensors and total thigh muscles were assessed using magnetic resonance imaging. Fasting serum levels of insulin-like growth factor-1 (IGF-1), myostatin and decorin, and plasma levels of total carnitine (TC) and trimethylamine-N-oxide (TMAO) levels were measured., Results: The 24-week RET significantly increased muscle strength and muscle volume, but the group and time interactions were not significant for the muscle variables analyzed. Plasma total carnitine increased only in the LC+L group (p = 0.009). LC supplementation also caused a significant increase in plasma TMAO, which was higher after the intervention in the LC+L group than in the L (p &lt; 0.001), and CON (p = 0.005) groups. The intervention did not change plasma TMAO concentration in the L (p = 0.959) and CON (p = 0.866) groups. After the intervention serum decorin level was higher than before in both supplemented groups combined (p = 0.012), still not significantly different to post intervention CON (p = 0.231). No changes in serum IGF-1 and myostatin concentrations and no links between the changes in blood markers and muscle function or muscle volume were observed., Conclusions: LC combined with leucine or leucine alone does not appear to improve the effectiveness of RET.

The early atherosclerotic lesions develop by the accumulation of arterial foam cells derived mainly from cholesterol-loaded macrophages. Therefore, cholesterol and cholesteryl ester transfer protein (CETP) have been considered as causative in atherosclerosis. Moreover, recent studies indicate the role of trimethylamine N-oxide (TMAO) in development of cardiovascular disease (CVD). The current study aimed to investigate the association between TMAO and CETP polymorphisms (rs12720922 and rs247616), previously identified as a genetic determinant of circulating CETP, in a population of coronary artery disease (CAD) patients (n = 394) and control subjects (n = 153). We also considered age, sex, trimethylamine (TMA) levels and glomerular filtration rate (GFR) as other factors that can potentially play a role in this complex picture. We found no association of TMAO with genetically determined CETP in a population of CAD patients and control subjects. Moreover, we noticed no differences between CAD patients and control subjects in plasma TMAO levels. On the contrary, lower levels of TMA in CAD patients respect to controls were observed. Our results indicated a significant correlation between GFR and TMAO, but not TMA. The debate whether TMAO can be a harmful, diagnostic or protective marker in CVD needs to be continued.

Background: L-carnitine (LC) is used as a supplement by recreationally-active, competitive and highly trained athletes. This systematic review aims to evaluate the effect of prolonged LC supplementation on metabolism and metabolic modifications., Methods: A literature search was conducted in the MEDLINE (via PubMed) and Web of Science databases from the inception up February 2020. Eligibility criteria included studies on healthy human subjects, treated for at least 12 weeks with LC administered orally, with no drugs or any other multi-ingredient supplements co-ingestion., Results: The initial search retrieved 1024 articles, and a total of 11 studies were finally included after applying inclusion and exclusion criteria. All the selected studies were conducted with healthy human subjects, with supplemented dose ranging from 1 g to 4 g per day for either 12 or 24 weeks. LC supplementation, in combination with carbohydrates (CHO) effectively elevated total carnitine content in skeletal muscle. Twenty-four-weeks of LC supplementation did not affect muscle strength in healthy aged women, but significantly increased muscle mass, improved physical effort tolerance and cognitive function in centenarians. LC supplementation was also noted to induce an increase of fasting plasma trimethylamine-N-oxide (TMAO) levels, which was not associated with modification of determined inflammatory nor oxidative stress markers., Conclusion: Prolonged LC supplementation in specific conditions may affect physical performance. On the other hand, LC supplementation elevates fasting plasma TMAO, compound supposed to be pro-atherogenic. Therefore, additional studies focusing on long-term supplementation and its longitudinal effect on the cardiovascular system are needed.

Gender differences in the burden of cardiovascular disease (CVD) have been observed worldwide. In this study, plasmatic levels of trimethylamine (TMA) and blood oxidative biomarkers have been evaluated in 358 men (89 controls and 269 CVD patients) and 189 women (64 control and 125 CVD patients). The fluorescence technique was applied to determine erythrocyte membrane fluidity using 1,6-diphenyl-1,3,5-hexatriene (DPH) and Laurdan, while lipid hydroperoxides were assessed by diphenyl-1-pyrenylphosphine (DPPP). Results show that levels of plasmatic TMA were higher in healthy men with respect to healthy women ( p = 0.0001). Significantly lower TMA was observed in male CVD patients (0.609 ± 0.104 μM) compared to healthy male controls (0.680 ± 0.118 μM) ( p < 0.001), while higher levels of TMA were measured in female CVD patients (0.595 ± 0.115 μM) with respect to female controls (0.529 ± 0.073 μM) ( p < 0.001). DPPP was significantly higher in healthy control men than in women ( p < 0.001). Male CVD patients displayed a lower value of DPPP (2777 ± 1924) compared to healthy controls (5528 ± 2222) ( p < 0.001), while no significant changes were measured in females with or without CVD ( p > 0.05). Membrane fluidity was significantly higher ( p < 0.001) in the hydrophobic bilayer only in control male subjects. In conclusion, gender differences were observed in blood oxidative biomarkers, and DPPP value might be suggested as a biomarker predictive of CVD only in men.

The beneficial effects of exercise for the treatment and prevention of metabolic syndrome pathologies have been related to its anti-inflammatory and antioxidant effects. Dietary nitrate supplementation is an emerging treatment strategy to alleviate the symptoms of metabolic syndrome affections and to improve vascular function. In this double-blind crossover trial, metabolic syndrome patients performed two exercise tests for 30 min at 60-70% maximal heart rate after the intake of a placebo or a nitrate-enriched beverage. Acute exercise increased the plasma concentration of TNFα, intercellular adhesion molecule ICAM1, PGE1, PGE2 and the newly detected 16-hydroxypalmitic acid (16-HPAL) in metabolic syndrome patients. The cytokine and oxylipin production by peripheral blood mononuclear cells (PBMCs) and neutrophils could be responsible for the plasma concentrations of TNFα and IL6, but not for the plasma concentration of oxylipins nor its post-exercise increase. The intake of sodium nitrate 30 min before exercise increased the concentration of nitrate and nitrite in the oral cavity and plasma and reduced the oxygen cost of exercise. Additionally, nitrate intake prevented the enhancing effects of acute exercise on the plasma concentration of TNFα, ICAM1, PGE1, PGE2 and 16-HPAL, while reducing the capabilities of PBMCs and neutrophils to produce oxylipins., Competing Interests: The authors declare no conflict of interest.

l-carnitine supplementation has been used for cardiovascular health protection for a long time. Recently, trimethylamine-N-oxide (TMAO), which is an end product of l-carnitine metabolism via the activity of microbiota, has been identified as a cardiovascular disease (CVD) biomarker. The aim of this study was to assess the effect of 6 months of l-carnitine supplementation in a group of aged women engaged in a regular physical training. Platelet mitochondrial DNA methylation, an emerging and innovative biomarker, lipid profile and TMAO levels have been measured. TMAO increased after l-carnitine supplementation (before 344.3 ± 129.8 ng/mL vs. after 2216.8 ± 1869.0 ng/mL; n = 9; paired t-test, p = 0.02). No significant effects on TMAO were exerted by training alone ( n = 9) or by l-leucine supplementation ( n = 12). TMAO levels after 6 months of l-carnitine supplementation were associated with higher low-density lipoprotein-cholesterol (LDL-c) (Spearman Rho = 0.518, p = 0.003) and total cholesterol (TC) (Spearman Rho = 0.407, p = 0.026) levels. l-carnitine supplementation increased D-loop methylation in platelets (+6.63%; paired t-test, p = 0.005). D-loop methylation was not directly correlated to the TMAO augmentation observed in the supplemented group, but its increase inversely correlated with TC (Pearson coefficient = -0.529, p = 0.029) and LDL-c (Pearson coefficient = -0.439, p = 0.048). This evidence supports the hypothesis that the correlation between l-carnitine, TMAO and atherosclerosis might be more complex than already postulated, and the alteration of mitochondrial DNA (mtDNA) methylation in platelets could be involved in the pathogenesis of this multifactorial disease.

There is increasing attention to sprint interval exercise (SIE) training as a time-efficient exercise regime. Recent studies, including our own (Kujach et al., 2018), have shown that acute high-intensity intermittent exercise can improve cognitive function; however, the neurobiological mechanisms underlying the effect still remain unknown. We thus examined the effects of acute SIE on cognitive function by monitoring the peripheral levels of growth and neurotrophic factors as well as blood lactate (LA) as potential mechanisms. Thirty-six young males participated in the current study and were divided into two groups: SIE ( n = 20; mean age: 21.0 ± 0.9 years) and resting control (CTR) ( n = 16; mean age: 21.7 ± 1.3 years). The SIE session consisted of 5 min of warm-up exercise and six sets of 30 s of all-out cycling exercise followed by 4.5 min of rest on a cycling-ergometer. Blood samples to evaluate the changes of serum concentrations of brain-derived neurotrophic factor (BDNF), insulin-like growth factor-1 (IGF-1), vascular endothelial growth factor (VEGF), and blood LA were obtained at three time points: before, immediately after, and 60 min after each session. A Stroop task (ST) and trail making test (TMT) parts A and B were used to assess cognitive functions. Acute SIE shortened response times for both the ST and TMT A and B. Meanwhile, the peripheral levels of BDNF, IGF-1, and VEGF were significantly increased after an acute bout of SIE compared to those in CTR. In response to acute SIE, blood LA levels significantly increased and correlated with increased levels of BDNF, IGF-1, and VEGF. Furthermore, cognitive function and BDNF are found to be correlated. The current results suggest that SIE could have beneficial effects on cognitive functions with increased neuroprotective factors along with peripheral LA concentration in humans., (Copyright © 2020 Kujach, Olek, Byun, Suwabe, Sitek, Ziemann, Laskowski and Soya.)

Increased plasma trimethylamine N-oxide (TMAO) levels have been associated with cardiovascular diseases (CVD). L-carnitine induces TMAO elevation in human blood, and thus, it has been suggested as developing atherosclerosis. The aim of this study was to determine the relation between selected markers of oxidative stress and plasma TMAO concentration induced by L-carnitine supplementation for 24 weeks in healthy aged women. Twenty aged women were supplemented during 24 weeks with either 1500 mg L-carnitine-L-tartrate ( n = 11) or isonitrogenous placebo ( n = 9) per day. Fasting blood samples were taken from antecubital vein. L-carnitine supplementation induced an increase in TMAO, but not in γ -butyrobetaine (GBB). Moreover, there were no significant changes in serum ox-LDL, myeloperoxidase, protein carbonyls, homocysteine, and uric acid concentrations due to supplementation. Significant reduction in white blood cell counts has been observed following 24-week supplementation, but not attributable to L-carnitine. Our results in healthy aged women indicated no relation between TMAO and any determined marker of oxidative stress over the period of 24 weeks. At the same time, plasma GBB levels were not affected by L-carnitine supplementation. Further clinical studies of plasma GBB level as a prognostic marker are needed., Competing Interests: We have not received any financial support or other benefits from commercial sources for the work reported in this manuscript. None of the authors have financial interests that could create a potential conflict of interest or the appearance of a conflict of interest with regard to this work., (Copyright © 2019 Robert Antoni Olek et al.)

L-carnitine supplementation elevates plasma trimethylamine-N-oxide (TMAO), which may participate in atherosclerosis development by affecting cholesterol metabolism. The aim of the current study was to determine the effect of increased plasma TMAO on biochemical markers in the blood following cessation of L-carnitine supplementation. The follow-up measurements were performed on subjects who completed 24 weeks of L-carnitine or placebo supplementation protocol. Blood samples were taken after finishing the supplementation and then 4 and 12 months following the supplementation withdrawal. Four months after cessation of L-carnitine supplementation, plasma TMAO concentration reached a normal level which was stable for the following eight months. During this period, no modifications in serum lipid profile and circulating leukocyte count were noted. TMAO implications in health and disease is widely discussed. The results of this study demonstrate no adverse effects of elevated plasma TMAO, induced by L-carnitine, on the measured parameters at 4 and 12 months after withdrawal of supplementation.

Purpose: The aim of this study was to compare the effect of applying two different rest recovery times in a 10-s sprint interval training session on aerobic and anaerobic capacities as well as skeletal muscle enzyme activities. Methods: Fourteen physically active but not highly trained male subjects (mean maximal oxygen uptake 50.5 ± 1.0 mlO 2 ·kg -1 ·min -1 ) participated in the study. The training protocol involved a series of 10-s sprints separated by either 1-min (SIT10:1) or 4-min (SIT10:4) of recovery. The number of sprints progressed from four to six over six sessions separated by 1-2 days rest. Pre and post intervention anthropometric measurements, assessment of aerobic, anaerobic capacity and muscle biopsy were performed. In the muscle samples maximal activities of citrate synthase (CS), 3-hydroxyacylCoA dehydrogenase (HADH), carnitine palmitoyl-transferase (CPT), malate dehydrogenase (MDH), and its mitochondrial form (mMDH), as well as lactate dehydrogenase (LDH) were determined. Analysis of variance was performed to determine changes between conditions. Results: Maximal oxygen uptake improved significantly in both training groups, by 13.6% in SIT10:1 and 11.9% in SIT10:4, with no difference between groups. Wingate anaerobic test results indicated main effect of time for total work, peak power output and mean power output, which increased significantly and similarly in both groups. Significant differences between training groups were observed for end power output, which increased by 10.8% in SIT10:1, but remained unchanged in SIT10:4. Both training protocols induced similar increase in CS activity (main effect of time p < 0.05), but no other enzymes. Conclusion: Sprint interval training protocols induce metabolic adaptation over a short period of time, and the reduced recovery between bouts may attenuate fatigue during maximal exercise.

Skeletal muscle wasting, associated with aging, may be regulated by the inflammatory cytokines as well as by insulin-like growth factor 1 (IGF-1). l-carnitine possesses anti-inflammatory properties and increases plasma IGF-1 concentration, leading to the regulation of the genes responsible for protein catabolism and anabolism. The purpose of the present study was to evaluate the effect of a 24-week l-carnitine supplementation on serum inflammatory markers, IGF-1, body composition and skeletal muscle strength in healthy human subjects over 65 years of age. Women between 65 and 70 years of age were supplemented for 24 weeks with either 1500 mg l-carnitine-l-tartrate or an isonitrogenous placebo per day in a double-blind fashion. Before and after the supplementation protocol, body mass and composition, as well as knee extensor and flexor muscle strength were determined. In the blood samples, free carnitine, interleukin-6, tumor necrosis factor-α, C-reactive protein and IGF-1 were determined. A marked increase in free plasma carnitine concentration was observed due to l-carnitine supplementation. No substantial changes in other parameters were noted. In the current study, supplementation for 24 weeks affected neither the skeletal muscle strength nor circulating markers in healthy women over 65 years of age. Positive and negative aspects of l-carnitine supplementation need to be clarified., Competing Interests: The authors declare no conflict of interest.

The reduction in cholesterol in mitochondria, observed after exercise, is related to the inhibition of mitochondrial swelling. Caveolin-1 (Cav-1) plays an essential role in the regulation of cellular cholesterol metabolism and is required by various signalling pathways. Therefore, the aim of this study was to investigate the effect of prolonged swimming on the mitochondrial Cav-1 concentration; additionally, we identified the results of these changes as they relate to the induction of changes in the mitochondrial swelling and cholesterol in rat skeletal muscle and liver. Male Wistar rats were divided into a sedentary control group and an exercise group. The exercised rats swam for 3 hours and were burdened with an additional 3% of their body weight. After the cessation of exercise, their quadriceps femoris muscles and livers were immediately removed for experimentation. The exercise protocol caused an increase in the Cav-1 concentration in crude muscle mitochondria; this was related to a reduction in the cholesterol level and an inhibition of mitochondrial swelling. There were no changes in rat livers, with the exception of increased markers of oxidative stress in mitochondria. These data indicate the possible role of Cav-1 in the adaptive change in the rat muscle mitochondria following exercise.

This study examined the effect of a single sodium pyruvate ingestion on a blood acid-base status and exercise metabolism markers. Nine active, but non-specifically trained, male subjects participated in the double-blind, placebo-controlled, crossover study. One hour prior to the exercise, subjects ingested either 0.1 g·kg(-1) of body mass of a sodium pyruvate or placebo. The capillary blood samples were obtained at rest, 60 min after ingestion, and then three and 15 min after completing the workout protocol to analyze acid-base status and lactate, pyruvate, alanine, glucose concentrations. The pulmonary gas exchange, minute ventilation and the heart rate were measured during the exercise at a constant power output, corresponding to ~90% VO2max. The blood pH, bicarbonate and the base excess were significantly higher after sodium pyruvate ingestion than in the placebo trial. The blood lactate concentration was not different after the ingestion, but the post-exercise was significantly higher in the pyruvate trial (12.9 ± 0.9 mM) than in the placebo trial (10.6 ± 0.3 mM, p < 0.05) and remained elevated (nonsignificant) after 15 min of recovery. The blood pyruvate, alanine and glucose concentrations, as well as the overall pulmonary gas exchange during the exercise were not affected by the pyruvate ingestion. In conclusion, the sodium pyruvate ingestion one hour before workout modified the blood acid-base status and the lactate production during the exercise.

The significance of the reduction of the cholesterol pool in heart mitochondria after exercise is still unknown. Recently, published data have suggested that cholesterol may influence the components of mitochondrial contact site and affect mitochondrial swelling. Therefore, the aim of this study was to determine whether the decreased cholesterol content in heart mitochondria caused by prolonged swimming may provoke changes in their bioenergetics and result in an increased resistance to calcium chloride-induced mitochondrial swelling. Male Wistar rats were divided into a sedentary control group and an exercise group. The rats exercised for 3 h, burdened with an additional 3% of their body weight. Their hearts were removed immediately after completing the exercise. The left ventricle was divided and used for experiments. Mitochondrial cholesterol content, membrane fluidity and mitochondrial bioenergetics were measured in the control and exercised rat heart mitochondria. To assess whether mitochondrial modifications are linked to disruption of lipid microdomains, methyl-β-cyclodextrin, a well-known lipid microdomain-disrupting agent and cholesterol chelator, was applied to the mitochondria of the control group. Cholesterol depletion, increased membrane fluidity and increased resistance to calcium chloride-induced swelling were observed in postexercise heart crude mitochondrial fraction. Similar results were achieved in control mitochondria treated with 2% methyl-β-cyclodextrin. All of the mitochondrial bioenergetics parameters were similar between the groups. Therefore, the disruption of raft-like microdomains appears to be an adaptive change in the rat heart following exercise.

Short duration repeated maximal efforts are often used in swimming training to improve lactate tolerance, which gives swimmers the ability to maintain a high work rate for a longer period of time. The aim of the study was to examine the kinematics of swimming and its relation to the changes in blood acid-base status and potassium level. Seven collegiate swimmers, with at least 6 years of training experience, volunteered to participate in the study. The test consisted of 8 x 25 m front crawl performed with maximum effort. The rest period between repetitions was set to five seconds. Blood samples were taken from the fingertip at rest, after warm-up and in the 3rd minute after completion of the test. The swimming was recorded with a video recorder, for later analysis of time, velocity and technique (stroke index). Based on the swimming velocity results, the obtained curve can be divided into rapid decrease of velocity and relatively stable velocities. The breaking point of repetition in swimming velocity was assumed as the swimming velocity threshold and it was highly correlated with the decrease of the blood acid-base status (pH r=0.82, BE r=0.87, HCO3 (-) r=0.76; p<0.05 in all cases). There was no correlation between stroke index or fatigue index and blood acid-base status. Analysis of the swimming speed in the 8 x 25 m test seems to be helpful in evaluation of lactate tolerance (anaerobic capacity) in collegiate swimmers.

This study was aimed to evaluate anti-inflammatory effect of the whole body cryostimulation in obese men. Fourteen subjects (BMI >30 kg m(-2)), divided into two subgroups according to cardiorespiratory fitness: higher (HCF) or lower (LCF), have been exposed to 10 sessions in a cryogenic chamber (-110 °C). Blood samples were collected before, 30 min and 24 h after the first, fifth and last cryostimulation. Coldness exposures affected blood cytokine profile; however, the response depended on subjects' fitness capacity. Concentrations of pro-inflammatory cytokines in the LCF decreased by 19, 6.8, and 7.4 % in IL-6, resistin, and visfatin, respectively. TNFα in the LCF dropped 4.3-fold compared to baseline, while in the HCF, changes were smaller, yet significant. Anti-inflammatory cytokine IL-10 increased in both groups. No changes in adiponectin and leptin were observed in either group. Obtained results suggest that whole body cryostimulation can be a supplementary method for obese in reducing systemic inflammation.

Impaired mitochondrial capacity may be implicated in the pathology of chronic metabolic diseases. To elucidate the effect of ethyl pyruvate supplementation on skeletal muscles metabolism we examined changes in activities of mitochondrial and antioxidant enzymes, as well as sulfhydryl groups oxidation (an indirect marker of oxidative stress) during the development of obesity. After 6 weeks feeding of control or high fat diet, Wistar rats were divided into four groups: control diet, control diet and ethyl pyruvate, high fat diet, and high fat diet and ethyl pyruvate. Ethyl pyruvate was administered as 0.3% solution in drinking water, for the following 6 weeks. High fat diet feeding induced the increase of activities 3-hydroxyacylCoA dehydrogenase, citrate synthase, and fumarase. Moreover, higher catalase and superoxide dismutase activities, as well as sulfhydryl groups oxidation, were noted. Ethyl pyruvate supplementation did not affect the mitochondrial enzymes' activities, but induced superoxide dismutase activity and sulfhydryl groups oxidation. All of the changes were observed in soleus muscle, but not in extensor digitorum longus muscle. Additionally, positive correlations between fasting blood insulin concentration and activities of catalase (p = 0.04), and superoxide dismutase (p = 0.01) in soleus muscle were noticed. Prolonged ethyl pyruvate consumption elevated insulin concentration, which may cause modifications in oxidative type skeletal muscles.

Continuous positive energy imbalance leads to obesity, which increases the risk of developing non-alcoholic fatty liver disease. The hepatoprotective effect of ethyl pyruvate has been revealed in several studies. Therefore, we examined the effect of ethyl pyruvate supplementation on liver cell damage, metabolism, membrane fluidity, and oxidative stress markers in rats fed a high-fat diet. After 6-wk feeding of a control or high-fat diet, Wistar rats were divided into 4 groups: control diet, control diet and ethyl pyruvate, high-fat diet, and high-fat diet and ethyl pyruvate. Ethyl pyruvate was administered as a 0.3% solution in drinking water, for the following 6 wk. Ethyl pyruvate intake attenuated the increase in activities of plasma transaminases and liver TNF-α. However, the supplementation was without effect in the lipid profiles, membrane fluidity or oxidative metabolism in liver induced by the high-fat diet. Our data confirm the potency of ethyl pyruvate against cell liver damage. Nevertheless, prolonged intake did not affect the development of a fatty liver.

Context: Tournament season can provoke overreaching syndrome in professional tennis players, which may lead to deteriorated performance. Thus, appropriate recovery methods are crucial for athletes in order to sustain high-level performance and avoid injuries. We hypothesized that whole-body cryostimulation could be applied to support the recovery process., Objective: To assess the effects of 5 days of whole-body cryostimulation combined with moderate-intensity training on immunologic, hormonal, and hematologic responses; resting metabolic rate; and tennis performance in a posttournament season., Design: Controlled laboratory study., Setting: National Olympic Sport Centre., Patients or Other Participants: Twelve high-ranking professional tennis players., Intervention(s): Participants followed a moderate-intensity training program. A subgroup was treated with the 5-day whole-body cryostimulation (-120°C) applied twice a day. The control subgroup participated in the training only. Main Outcome Measure(s): Pretreatment and posttreatment blood samples were collected and analyzed for tumor necrosis factor α, interleukin 6, testosterone, cortisol, and creatine kinase. Resting metabolic rate and performance of a tennis drill were also assessed., Results: Proinflammatory cytokine (tumor necrosis factor α) decreased and pleiotropic cytokine (interleukin 6) and cortisol increased in the group exposed to cryostimulation. In the same group, greater stroke effectiveness during the tennis drill and faster recovery were observed. Neither the training program nor cryostimulation affected resting metabolic rate., Conclusions: Professional tennis players experienced an intensified inflammatory response after the completed tournament season, which may lead to overreaching. Applying whole-body cryostimulation in conjunction with moderate-intensity training was more effective for the recovery process than the training itself. The 5-day exposure to cryostimulation twice a day ameliorated the cytokine profile, resulting in a decrease in tumor necrosis factor α and an increase in interleukin 6.

The aim of this study was to test the hypothesis that allopurinol ingestion modifies the slow component of V(.)O(2) kinetics and changes plasma oxidative stress markers during severe intensity exercise. Six recreationally active male subjects were randomly assigned to receive a single dose of allopurinol (300 mg) or a placebo in a double-blind, placebo-controlled crossover design, with at least 7 days washout period between the two conditions. Two hours following allopurinol or placebo intake, subjects completed a 6-min bout of cycle exercise with the power output corresponding to 75 % V(.)O(2)max. Blood samples were taken prior to commencing the exercise and then 5 minutes upon completion. Allopurinol intake caused increase in resting xanthine and hypoxanthine plasma concentrations, however it did not affect the slow component of oxygen uptake during exercise. Exercise elevated plasma inosine, hypoxanthine, and xanthine. Moreover, exercise induced a decrease in total antioxidant status, and sulfhydryl groups. However, no interaction treatment x time has been observed. Short term severe intensity exercise induces oxidative stress, but xanthine oxidase inhibition does not modify either the kinetics of oxygen consumption or reactive oxygen species overproduction.

The main purpose of this study was to investigate how extreme physical strain influences cytokine response and oxidative stress markers by examining professional judo athletes during a typical 3-day judo training session (randori combat training). Creatine kinase (CK) activity, a marker of muscle damage, was considerably elevated immediately after randori training. Pro- (IL-1β and TNF-α) and anti-inflammatory (IL-6 and IL-10) cytokines were also increased. The strongest effect was seen in IL-1β concentration, which correlated with CK activity (r = 0.49, P < 0.05). All the observed cytokines returned to baseline (IL-1β) or even dropped below initial levels (TNF-α, IL-6 and IL-10) 12 h after completing the training. Lipid peroxides (LPO), a marker of reactive oxygen species, also decreased below their initial values. LPO levels correlated directly with IL-1β, TNF-α, IL-6 and IL-10. This study is the first to evaluate the effect of a 3-day judo training session on muscle damage by evaluating the release of pro- and anti-inflammatory cytokines and markers of oxidative stress. It is also the first to demonstrate significant changes in the blood cytokine profile that correlate with lipid peroxide levels and muscle damage.

Although a number of studies have focused on the higher ethyl pyruvate antioxidative activity than its sodium salt under various stress conditions, and the greater protective properties of the ester form have been suggested as the effect of better cell membrane penetration, the molecular mechanism has remained unclear. The aim of the present study was therefore to compare the antioxidative activities of sodium and ethyl pyruvate under in vitro conditions by using a liver homogenate as the model for cell membrane transport deletion. The potential effect of ethanol was also evaluated, and hypochlorous acid was used as an oxidant. Our data indicate the concentration-dependent scavenging potency of both sodium and ethyl pyruvate, with the ester having higher activity. This effect was not related to the presence of ethanol. Better protection of the liver homogenate by ethyl pyruvate was also apparent, despite the fact that cell membrane transport was omitted.

There is growing evidence of mitochondrial membrane raft-like microdomains that are involved in the apoptotic pathway. The aim of this study was to investigate the effect of methyl-beta-cyclodextrin (MβCD), being a well-known lipid microdomain disrupting agent and cholesterol chelator, on the structure and bioenergetics of rat liver mitochondria (RLM). We observed that MβCD decreases the function of RLM, induces changes in the mitochondrial configuration state and decreases the calcium chloride-induced swelling. These data suggest that disruption of mitochondrial raft-like microdomains by cholesterol efflux on one hand impairs mitochondrial bioenergetics, but on the other hand it protects the mitochondria from swelling., (Copyright © 2010 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)

Electrical field stimulation of isolated, incubated rodent skeletal muscles is a frequently used model to study the effects of contractions on muscle metabolism. In this study, this model was used to investigate the effects of electrically stimulated contractions on creatine transport. Soleus and extensor digitorum longus muscles of male NMRI mice (35-50 g) were incubated in an oxygenated Krebs buffer between platinum electrodes. Muscles were exposed to [(14)C]creatine for 30 min after either 12 min of repeated tetanic isometric contractions (contractions) or electrical stimulation of only the buffer before incubation of the muscle (electrolysis). Electrolysis was also investigated in the presence of the reactive oxygen species (ROS) scavenging enzymes superoxide dismutase (SOD) and catalase. Both contractions and (to a lesser degree) electrolysis stimulated creatine transport severalfold over basal. The amount of electrolysis, but not contractile activity, induced (determined) creatine transport stimulation. Incubation with SOD and catalase at 100 and 200 U/ml decreased electrolysis-induced creatine transport by approximately 50 and approximately 100%, respectively. The electrolysis effects on creatine uptake were completely inhibited by beta-guanidino propionic acid, a competitive inhibitor of (creatine for) the creatine transporter (CRT), and were accompanied by increased cell surface expression of CRT. Muscle glucose transport was not affected by electrolysis. The present results indicate that electrical field stimulation of incubated mouse muscles, independently of contractions per se, stimulates creatine transport by a mechanism that depends on electrolysis-induced formation of ROS in the incubation buffer. The increased creatine uptake is paralleled by an increased cell surface expression of the creatine transporter.

Exercise induces extensive generation of reactive oxygen species, which are responsible for tissue damage: enzymes inactivation, lipid peroxidation and single strand breaks in DNA. Defense system against free radicals is consisting of enzymes such as superoxide dismutase, catalase, glutathione peroxidase, and numerous non-enzymatic antioxidants. The study was performed to evaluate the effect of a single bout of submaximal running exercise, on the lymphocyte DNA strand breaks and also to test how supplementation with tempol - a membrane-permeable SOD-mimetic (0.2 mmol/kg/day) influences the eventually evoked damage. Male, Wistar rats were challenged with graded 50 min. running on treadmill at intensity up to 75-85% of predicted VO(2)max. The DNA strand breaks in individual lymphocytes were determined by using a gel electrophoretic technique - "comet" assay. We found substantial lymphocyte DNA damage 60 min. after the exercise. Tempol failed to prevent from oxidative damage in rats challenged with exercise. Moreover tempol by itself induced higher DNA damage than the exercise bout.