Impact of Hot Environment on Fluid and Electrolyte Imbalance, Renal Damage, Hemolysis, and Immune Activation Postmarathon

Previous studies have demonstrated the physiological changes induced by exercise exposure in hot environments. We investigated the hematological and oxidative changes and tissue damage induced by marathon race in different thermal conditions. Twenty-six male runners completed the São Paulo International Marathon both in hot environment (HE) and in temperate environment (TE). Blood and urine samples were collected 1 day before, immediately after, 1 day after, and 3 days after the marathon to analyze the hematological parameters, electrolytes, markers of tissue damage, and oxidative status. In both environments, the marathon race promotes fluid and electrolyte imbalance, hemolysis, oxidative stress, immune activation, and tissue damage. The marathon runner’s performance was approximately 13.5% lower in HE compared to TE; however, in HE, our results demonstrated more pronounced fluid and electrolyte imbalance, renal damage, hemolysis, and immune activation. Moreover, oxidative stress induced by marathon in HE is presumed to be related to protein/purine oxidation instead of other oxidative sources. Fluid and electrolyte imbalance and protein/purine oxidation may be important factors responsible for hemolysis, renal damage, immune activation, and impaired performance after long-term exercise in HE. Nonetheless, we suggested that the impairment on performance in HE was not associated to the muscle damage and lipoperoxidation

Hydrolyzed whey protein enriched with glutamine dipeptide attenuates skeletal muscle damage and improves physical exhaustion test performance in triathletes

PurposeTo investigate the effects of hydrolyzed whey protein enriched with glutamine dipeptide on the percentage of oxygen consumption, second ventilatory threshold, duration and total distance covered, and skeletal muscle damage during an exhaustion test in elite triathletes.MethodsThe study was a randomized, double-blinded, placebo-controlled, crossover trial. Nine male triathletes performed a progressive incremental test on a treadmill ergometer (1.4 km h−1·3 min−1) 30 min after ingesting either 50 g of maltodextrin plus four tablets of 700 mg hydrolyzed whey protein enriched with 175 mg of glutamine dipeptide diluted in 250 ml of water (MGln) or four tablets of 700 mg maltodextrin plus 50 g maltodextrin diluted in 250 ml of water (M). Each athlete was submitted to the two dietary treatments and two corresponding exhaustive physical tests with an interval of one week between the interventions. The effects of the two treatments were then compared within the same athlete. Maximal oxygen consumption, percentage of maximal oxygen consumption, second ventilatory threshold, and duration and total distance covered were measured during the exhaustion test. Blood was collected before and immediately after the test for the determination of plasma lactate dehydrogenase (LDH) and creatine kinase (CK) activities and lactate concentration (also measured 6, 10, and 15 min after the test). Plasma cytokines (IL-6, IL-1β, TNF-α, IL-8, IL-10, and IL-1ra) and C-reactive protein levels were also measured.ResultsA single dose of MGln increased the percentage of maximal oxygen consumption, second ventilatory threshold duration, and total distance covered during the exhaustion test and augmented plasma lactate levels 6 and 15 min after the test. MGln also decreased plasma LDH and CK activities indicating muscle damage protection. Plasma cytokine and C-reactive protein levels did not change across the study periods.ConclusionConditions including overnight fasting and a single dose of MGln supplementation resulted in exercising at a higher percentage of maximal oxygen consumption, a higher second ventilatory threshold, blood lactate levels, and reductions in plasma markers of muscle damage during an exhaustion test in elite triathletes. These findings support oral glutamine supplementation's efficacy in triathletes, but further studies require

Stretch breaks in the work setting improve flexibility and grip strength and reduce musculoskeletal complaints

AbstractThis study investigated the effect of a stretch break program (SBP) on the flexibility, strength and musculoskeletal complaints of storage (SW) and administrative (AW) sector workers. Twenty-six male workers were randomly selected: 16 workers from the storage sector and ten workers from the administrative sector. We applied the Physical Activity Questionnaire and Musculoskeletal Questionnaire and evaluated flexibility and grip strength before and after 6 months of the SBP. The SPB decreased the SW group members' complaints of paresthesias and numbness in the upper body and total body. The SPB reduced the AW group members' complaints of paresthesias and numbness in the upper body. Furthermore, the SPB improved cervical, trunk and left shoulder flexibility in the SW group and improved cervical and shoulder flexibility and grip strength in the AW group. The SBP contribute to improve flexibility and musculoskeletal complaints in the regions that are affected by higher rates of work-related injuries

Comparative toxicity of fatty acids on a macrophage cell line (J774)

A B S T R A C T In the present study, the cytotoxicity of palmitic, stearic, oleic, linoleic, arachidonic, docosahexaenoic and eicosapentaenoic acids on a macrophage cell line (J774) was investigated. The induction of toxicity was investigated by changes in cell size, granularity, membrane integrity, DNA fragmentation and phosphatidylserine externalization by using flow cytometry. Fluorescence microscopy was used to determine the type of cell death (Acridine Orange/ethidium bromide assay). The possible mechanisms involved were examined by measuring mitochondrial depolarization, lipid accumulation and PPARγ (peroxisome-proliferator-activated receptor γ ) activation. The results demonstrate that fatty acids induce apoptosis and necrosis of J774 cells. At high concentrations, fatty acids cause macrophage death mainly by necrosis. The cytotoxicity of the fatty acids was not strictly related to the number of double bonds in the molecules: palmitic acid > docosahexaenoic acid > stearic acid = eicosapentaenoic acid = arachidonic acid > oleic acid > linoleic acid. The induction of cell death did not involve PPARγ activation. The mechanisms of fatty acids to induce cell death involved changes in mitochondrial transmembrane potential and intracellular neutral lipid accumulation. Fatty acids poorly incorporated into triacylglycerol had the highest toxicity

Modulatory effect of fatty acids on fungicidal activity, respiratory burst and TNF-alpha and IL-6 production in J774 murine macrophages

The reported effects of different families of fatty acids (FA; SFA, MUFA, n-3 and n-6 PUFA) on human health and the importance of macrophage respiratory burst and cytokine release to immune defence led us to examine the influence of palmitic acid (PA), oleic acid (OA), linoleic acid, arachidonic acid, EPA and DHA on macrophage function. We determined fungicidal activity, reactive oxygen species (ROS) and cytokine production after the treatment of J774 cells with non-toxic concentrations of the FA. PA had a late and discrete stimulating effect on ROS production, which may be associated with the reduced fungicidal activity of the cells after treatment with this FA. OA presented a sustained stimulatory effect on ROS production and increased fungicidal activity of the cells, suggesting that enrichment of diets with OA may be beneficial for pathogen elimination. The effects of PUFA on ROS production were time-and dose-dependently regulated, with no evident differences between n-3 and n-6 PUFA. It was worth noting that most changes induced after stimulation of the cells with lipopolysaccharide were suppressed by the FA. The present results suggest that supplementation of the diet with specific FA, not classes of FA, might enable an improvement in host defence mechanisms or a reduction in adverse immunological reactions.FAPESPFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPqCAPESCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Human Leukocyte Death After a Preoperative Infusion of Medium/Long-Chain Triglyceride and Fish Oil Parenteral Emulsions: A Randomized Study in Gastrointestinal Cancer Patients

Background: Parenteral lipid emulsions (LEs) can influence leukocyte functions. The authors investigated the effect of 2 LEs on leukocyte death in surgical patients with gastrointestinal cancer. Material and Methods: Twenty-five patients from a randomized, double-blind clinical trial (ID: NCT01218841) were randomly included to evaluate leukocyte death after 3 days of preoperative infusion (0.2 g fat/kg/d) of an LE composed equally of medium/long-chain triglycerides and soybean oil (MCTs/LCTs) or pure fish oil (FO). Blood samples were collected before (t0) and after LE infusion (t1) and on the third postoperative day (t2). Results: After LE infusion (t1 vs t0), MCTs/LCTs did not influence cell death; FO slightly increased the proportion of necrotic lymphocytes (5%). At the postoperative period (t2 vs t0), MCTs/LCTs tripled the proportion of apoptotic lymphocytes; FO maintained the slightly increased proportion of necrotic lymphocytes (7%) and reduced the percentage of apoptotic lymphocytes by 74%. In the postoperative period, MCT/LCT emulsion increased the proportion of apoptotic neutrophils, and FO emulsion did not change any parameter of apoptosis in the neutrophil population. There were no differences in lymphocyte or neutrophil death when MCT/LCT and FO treatments were compared during either preoperative or postoperative periods. MCT/LCTs altered the expression of 12 of 108 genes related to cell death, with both pro- and antiapoptotic effects; FO modulated the expression of 7 genes, demonstrating an antiapoptotic effect. Conclusion: In patients with gastrointestinal cancer, preoperative MCT/LCT infusion was associated with postoperative lymphocyte and neutrophil apoptosis. FO has a protective effect on postoperative lymphocyte apoptosis. (JPEN J Parenter Enteral Nutr. 2012; 36: 677-684)CNPqCNPqFAPESPFAPESP [08/00163-9]CAPESCAPE

Effect of olive oil-based emulsion on human lymphocyte and neutrophil death

Background The incorporation of lipid emulsions in parenteral diets is a requirement for energy and essential fatty acid supply to critically ill patients. The most frequently used IV lipid emulsions (LE) are composed with long-chain triacylglycerols rich in omega-6 polyunsaturated fatty acids (PUFA) from soybean oil, but these LE promote lymphocyte and neutrophil death. A new emulsion containing 20% soybean oil and 80% olive oil rich in (omega-9 monounsaturated fatty acids (MUFA) has been hypothesized not to cause impairment of immune function. In this study, the toxicity of an olive oil-based emulsion (OOE) on lymphocytes and neutrophils from healthy volunteers was investigated. Methods: Twenty volunteers were recruited and blood was. collected before a 6-hour infusion of an OOE, immediately after infusion, and again 18 hours postinfusion. Lymphocytes and neutrophils were isolated by gradient density. The cells were studied immediately after isolation and after 24 hours or 48 hours in culture. The following determinations were carried out: triacylglycerol levels and fatty acid composition and levels in plasma, lymphocyte proliferation, production of reactive oxygen species, and parameters of lymphocyte and neutrophil death (viability, DNA fragmentation, phosphatidylserine externalization, mitochondrial depolarization, and neutral lipid accumulation). Results: OOE decreased lymphocyte proliferation, provoked lymphocyte necrosis, and had no effect on the proportion of viable neutrophils. The mechanism of cell death induced by OOE involved neutral lipid accumulation but had no effect on mitochondrial membrane depolarization. Conclusions: The OOE given as a single dose of 500 mL induced low toxicity to lymphocytes from healthy volunteers, probably by necrosis

Benefits of Regular Exercise on Inflammatory and Cardiovascular Risk Markers in Normal Weight, Overweight and Obese Adults.

Obesity is a worldwide epidemic that increases the risk of several well-known co-morbidities. There is a complicated relationship between adipokines and low-grade inflammation in obesity and cardiovascular disease (CVD). Physical activity practices have beneficial health effects on obesity and related disorders such as hypertension and dyslipidemia. We investigated the effects of 6 and 12 months of moderate physical training on the levels of adipokines and CVD markers in normal weight, overweight and obese volunteers. The 143 participants were followed up at baseline and after six and twelfth months of moderate regular exercise, 2 times a week, for 12 months. The volunteers were distributed into 3 groups: Normal Weight Group (NWG,), Overweight Group (OVG) and Obese Group (OBG). We evaluated blood pressure, resting heart rate, anthropometric parameters, body composition, fitness capacity (VO2max and isometric back strength), cardiovascular markers (CRP, total cholesterol, LDL-c, HDL-c, homocysteine) and adipokine levels (leptin, adiponectin, resistin, IL-6 and TNF-alpha). There were no significant changes in anthropometric parameters and body composition in any of the groups following 6 and 12 months of exercise training. Leptin, IL-6 levels and systolic blood pressure were significantly elevated in OBG before the training. Regular exercise decreased HDL-c, leptin, adiponectin and resistin levels and diastolic blood pressure in OVG. In OBG, exercise diminished HDL-c, homocysteine, leptin, resistin, IL-6, adiponectin. Moderate exercise had no effect on the body composition; however, exercise did promote beneficial effects on the low-grade inflammatory state and CVD clinical markers in overweight and obese individuals