Influência do gênero e treinamento físico aeróbio sobre a modulação autonômica cardíaca, pressão arterial e biomarcadores de estado redox em mulheres na perimenopausa e homens

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeitos cardiorrespiratórios promovidos pelo posicionamento trendelenburg reverso a cinco e dez graus em bezerros anestesiados pelo sevofluorano: Marcelo Augusto de Araújo. -

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influência da temperatura e do termoperíodo sobre a taxa metabólica de repouso em cascavéis, Crotalus durissus (Serpentes: Viperidae)

Snakes are ectothermic animals and, therefore, their physiological functions are strongly affected by temperature. For instance, the resting metabolic rate (RMR) of this animals increase with the rise in body temperature. However, metabolic determinations in ectothermic organisms, including snakes, are generally made by submitting the animals to constant temperature regimes. This experimental procedure, although widely used, accepted and certainly suitable in several cases, submit the animals to a very different situation from that experienced by them in nature. In fact, ectothermics are known by presenting extensive variations in their body temperatures trough the day and/or seasons. If this disagreement between the thermal biology of the animals and the experimental conditions, for instance over the circadian cycle, affects the determinations of metabolic rates of ectotherm animals, remains quite uncertain. Thus, this study aimed to test the effects of different thermal regimes (fluctuating vs constant) in different temperature ranges over the TMR of rattlesnakes (Crotalus durissus). Therefore, the TMR of rattlesnakes was measured by the oxygen consumption rates ( V O2) in the constant temperatures of 15°C, 20°C, 25°C, 30°C and 35°C. For fluctuating regimes, snakes were measured in thermoperiods of 12/12 hours, as follows: 15°C and 25°C; 20°C and 30°C; 25°C and 35°C. Our results show that the RMR of C. durissus rises as the temperature increases, regardless of the thermal regime. The obtained RMR in the constant regimes of 20°C and 25°C was not different from that measured in the correspondent fluctuating regimes (i.e., 15 - 25°C e 20 - 30°C). However, at constant 30°C, the RMR was significantly higher than that obtained in the 30°C fluctuating regime (25 - 35ºC). This indicates that the potential effects in submitting of snakes to different thermal regimes of its thermal biology become more important with...

Efeitos da suplementação de taurina ou flavonóides de cacau associado à achocolatado sobre a composição corporal, metabolismo de carboidratos e proteinas, desempenho fisico, dano muscular e estresse oxidativo em atletas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência da temperatura e do termoperíodo sobre a taxa metabólica de repouso em cascavéis, Crotalus durissus (Serpentes: Viperidae)

Snakes are ectothermic animals and, therefore, their physiological functions are strongly affected by temperature. For instance, the resting metabolic rate (RMR) of this animals increase with the rise in body temperature. However, metabolic determinations in ectothermic organisms, including snakes, are generally made by submitting the animals to constant temperature regimes. This experimental procedure, although widely used, accepted and certainly suitable in several cases, submit the animals to a very different situation from that experienced by them in nature. In fact, ectothermics are known by presenting extensive variations in their body temperatures trough the day and/or seasons. If this disagreement between the thermal biology of the animals and the experimental conditions, for instance over the circadian cycle, affects the determinations of metabolic rates of ectotherm animals, remains quite uncertain. Thus, this study aimed to test the effects of different thermal regimes (fluctuating vs constant) in different temperature ranges over the TMR of rattlesnakes (Crotalus durissus). Therefore, the TMR of rattlesnakes was measured by the oxygen consumption rates ( V O2) in the constant temperatures of 15°C, 20°C, 25°C, 30°C and 35°C. For fluctuating regimes, snakes were measured in thermoperiods of 12/12 hours, as follows: 15°C and 25°C; 20°C and 30°C; 25°C and 35°C. Our results show that the RMR of C. durissus rises as the temperature increases, regardless of the thermal regime. The obtained RMR in the constant regimes of 20°C and 25°C was not different from that measured in the correspondent fluctuating regimes (i.e., 15 - 25°C e 20 - 30°C). However, at constant 30°C, the RMR was significantly higher than that obtained in the 30°C fluctuating regime (25 - 35ºC). This indicates that the potential effects in submitting of snakes to different thermal regimes of its thermal biology become more important with...

Efeitos da suplementação de taurina ou flavonóides de cacau associado à achocolatado sobre a composição corporal, metabolismo de carboidratos e proteinas, desempenho fisico, dano muscular e estresse oxidativo em atletas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ontogenetic Variation in Ammonia Excretion during the Early Life Stages of the Amazon River Prawn, Macrobrachium amazonicum

Dry mass (DM) and total ammonia-N (TAN) excretion were determined in embryos, larvae (ZI-ZIX, Z = zoea ), and postlarvae (PL) at 1, 7, and 14 d after metamorphosis (PL1, PL7, and PL14) of Macrobrachium amazonicum. Animals in postmolt-intermolt (A-C) stages were sorted according to their developmental stages, and placed into incubation chambers (similar to 30 mL) for 2 h to quantify TAN excretion. After this period, analyses were carried out using Koroleff`s method for TAN determination. Individual TAN excretion generally increased throughout ontogenetic development and varied from 0.0090 +/- 0.0039 mu g TAN/individual/h in embryo to 1.041 +/- 0.249 mu g TAN/individual/h in PL14. There was no significant difference between embryo-ZIV and ZV-ZIX (P > 0.05), whereas PL1, PL7, and PL14 differed (P < 0.05) from each other. Higher increments in individual ammonia-N excretion were observed between ZIV-ZV, PL1-PL7, and PL7-PL14. Mass-specific excretion rates presented two groups, embryo-ZII (P > 0.05) and ZIII-PL14 (P > 0.05). The lowest value was found in embryo (0.17 +/- 0.07 mu g TAN/mg DM/h) and the maximum values in ZV and PL1 (0.65 +/- 0.25 and 0.64 +/- 0.27 mu g TAN/mg DM/h, respectively). Results indicate that metabolic rate is proportional to the body mass in M. amazonicum, during early life stages. Variations in ammonia excretion during this phase may be associated mainly with body size. Data obtained in the present study may be useful in developing and optimizing rearing techniques of M. amazonicum, such as the proportions between biofilter and rearing tank size, and stocking density in culture tanks or in transport bags.

Respiratory rhythms in stingless bee workers: circadian and ultradian components throughout adult development

The workers of the stingless bee, Melipona quadrifasciata, assume different tasks during their adult life. Newly emerged individuals remain inside the nest, without contact with the external environment. Maturing workers go to more peripheral regions and only the oldest, the foragers, leave the nest. As this diversity of activities implies different metabolic patterns, oxygen consumption has been measured in workers of three different ages: 24-48 h (nurses), 10-15 days (builders), and older than 25 days (foragers). Oxygen consumption of individually isolated workers was determined by intermittent respirometry, under constant darkness and temperature of 25 +/- 1 degrees C. Sets of 24-h measurements were obtained from individuals belonging to each of the three worker groups. Rhythmicity has been assessed in the daily (24 h) and ultradian (5-14 h) domains. This experimental design allowed detection of endogenous rhythms without the influence of the social group and without inflicting stress on the individuals, as would be caused by their longer isolation from the colony. Significant 24-h rhythms in oxygen consumption were present in nurses, builders and foragers; therefore, workers are rhythmic from the age of 24-48 h. However, the amplitude of the circadian rhythm changed according to age: nurses showed the lowest values, while foragers consistently presented the largest ones, about ten times larger than the amplitude of nurses` respiratory rhythm. Ultradian frequencies were detected for all worker groups, the power and frequencies of which varied little with age. This means that the ultradian strength was relatively larger in nurses and apparently maintains some relationship with the queen`s oviposition episodes.

Energy demands in taekwondo athletes during combat simulation

The purpose of this study was to investigate energy system contributions and energy costs in combat situations. The sample consisted of 10 male taekwondo athletes (age: 21 +/- 6 years old; height: 176.2 +/- 5.3 cm; body mass: 67.2 +/- 8.9 kg) who compete at the national or international level. To estimate the energy contributions, and total energy cost of the fights, athletes performed a simulated competition consisting of three 2 min rounds with a 1 min recovery between each round. The combats were filmed to quantify the actual time spent fighting in each round. The contribution of the aerobic (WAER), anaerobic alactic (W-PCR), and anaerobic lactic (Wleft perpendicularLA-right perpendicular) energy systems was estimated through the measurement of oxygen consumption during the activity, the fast component of excess post-exercise oxygen consumption, and the change in blood lactate concentration in each round, respectively. The mean ratio of high intensity actions to moments of low intensity (steps and pauses) was similar to 1:7. The W-AER, W-PCR and (Wleft perpendicularLA-right perpendicular) system contributions were estimated as 120 +/- 22 kJ (66 +/- 6%), 54 +/- 21 kJ (30 +/- 6%), 8.5 kJ (4 +/- 2%), respectively. Thus, training sessions should be directed mainly to the improvement of the anaerobic alactic system (responsible by the highintensity actions), and of the aerobic system (responsible by the recovery process between high- intensity actions).

Exercise training in juvenile dermatomyositis

Objective. To investigate the effects of a supervised exercise training program on health parameters, physical capacity, and health-related quality of life in patients with mild and chronic juvenile dermatomyositis (DM). Methods. This was a prospective longitudinal study following 10 children with mild and chronic juvenile DM (disease duration >1 year). The exercise program consisted of twice-a-week aerobic and resistance training. At baseline and after the 12-week intervention, we assessed muscle strength and function, aerobic conditioning, body composition, juvenile DM scores, and health-related quality of life. Results. Child self-report and parent proxy-report Pediatric Quality of Life Inventory scores were improved after the intervention (-40.3%; P = 0.001 and -48.2%; P = 0.049, respectively). Importantly, after exercise, the Disease Activity Score was reduced (-26.9%; P = 0.026) and the Childhood Muscle Assessment Scale was improved (+2.5%; P = 0.009), whereas the Manual Muscle Test presented a trend toward statistical significance (+2.2%; P = 0.081). The peak oxygen consumption and time-to-exhaustion were increased by 13.3% (P = 0.001) and 18.2% (P = 0.003), respectively, whereas resting heart rate was decreased by 14.7% (P = 0.006), indicating important cardiovascular adaptations to the exercise program. Upper and lower extremity muscle strength and muscle function were also significantly improved after the exercise training (P < 0.05). Both the whole-body and the lumbar spine bone mineral apparent density were significantly increased after training (1.44%; P = 0.044 and 2.85%; P = 0.008, respectively). Conclusion. We showed for the first time that a 12-week supervised exercise program is safe and can improve muscle strength and function, aerobic conditioning, bone mass, disease activity, and health-related quality of life in patients with active and nonactive mild and chronic juvenile DM with near normal physical function and quality of life.

Effects of a combined aerobic and strength training program in youth patients with acute lymphoblastic leukemia

Cure rates of youth with Acute Lymphoblastic Leukemia (ALL) have increased in the past decades, but survivor's quality of life and physical fitness has become a growing concern. Although previous reports showed that resistance training is feasible and effective, we hypothesized that a more intense exercise program would also be feasible, but more beneficial than low- to moderate-intensity training programs. We aimed to examine the effects of an exercise program combining high-intensity resistance exercises and moderate-intensity aerobic exercises in young patients undergoing treatment for ALL. A quasi-experimental study was conducted. The patients (n = 6; 5-16 years of age) underwent a 12-week intra-hospital training program involving high-intensity strength exercises and aerobic exercise at 70% of the peak oxygen consumption. At baseline and after 12 weeks, we assessed sub-maximal strength (10 repetition-maximum), quality of life and possible adverse effects. A significant improvement was observed in the sub maximal strength for bench press (71%), lat pull down (50%), leg press (73%) and leg extension (64%) as a result of the training (p < 0.01). The parents' evaluations of their children's quality of life revealed an improvement in fatigue and general quality of life, but the children's self-reported quality of life was not changed. No adverse effects occurred. A 12-week in-hospital training program including high-intensity resistance exercises promotes marked strength improvements in patients during the maintenance phase of the treatment for Acute Lymphoblastic Leukemia without side-effects. Parents' evaluations of their children revealed an improvement in the quality of life.

beta(1) Adrenergic receptor is key to cold- and diet-induced thermogenesis in mice

Brown adipose tissue (BAT) is predominantly regulated by the sympathetic nervous system (SNS) and the adrenergic receptor signaling pathway. Knowing that a mouse with triple beta-receptor knockout (KO) is cold intolerant and obese, we evaluated the independent role played by the beta(1) isoform in energy homeostasis. First, the 30 min i.v. infusion of norepinephrine (NE) or the beta(1) selective agonist dobutamine (DB) resulted in similar interscapular BAT (iBAT) thermal response in WT mice. Secondly, mice with targeted disruption of the beta(1) gene (KO of beta(1) adrenergic receptor (beta 1KO)) developed hypothermia during cold exposure and exhibited decreased iBAT thermal response to NE or DB infusion. Thirdly, when placed on a high-fat diet (HFD; 40% fat) for 5 weeks, beta 1KO mice were more susceptible to obesity than WT controls and failed to develop diet-induced thermogenesis as assessed by BAT Ucp1 mRNA levels and oxygen consumption. Furthermore, beta 1KO mice exhibited fasting hyperglycemia and more intense glucose intolerance, hypercholesterolemia, and hypertriglyceridemia when placed on the HFD, developing marked non-alcoholic steatohepatitis. In conclusion, the beta(1) signaling pathway mediates most of the SNS stimulation of adaptive thermogenesis. Journal of Endocrinology (2012) 214, 359-365

Exercise-induced bronchoconstriction in elite long-distance runners in Brazil

Objective: To determine the prevalence of exercise-induced bronchoconstriction among elite long-distance runners in Brazil and whether there is a difference in the training loads among athletes with and without exercise-induced bronchoconstriction. Methods: This was a cross-sectional study involving elite long-distance runners with neither current asthma symptoms nor a diagnosis of exercise-induced bronchoconstriction. All of the participants underwent eucapnic voluntary hyperpnea challenge and maximal cardiopulmonary exercise tests, as well as completing questionnaires regarding asthma symptoms and physical activity, in order to monitor their weekly training load. Results: Among the 86 male athletes recruited, participation in the study was agreed to by 20, of whom 5 (25%) were subsequently diagnosed with exercise-induced bronchoconstriction. There were no differences between the athletes with and without exercise-induced bronchoconstriction regarding anthropometric characteristics, peak oxygen consumption, baseline pulmonary function values, or reported asthma symptoms. The weekly training load was significantly lower among those with exercise-induced bronchoconstriction than among those without. Conclusions: In this sample of long-distance runners in Brazil, the prevalence of exercise-induced bronchoconstriction was high.

Aerobic exercise training delays cardiac dysfunction and improves autonomic control of circulation in diabetic rats undergoing myocardial infarction

Background: Exercise training (ET) has been used as a nonpharmacological strategy for treatment of diabetes and myocardial infarction (MI) separately. We evaluated the effects ET on functional and molecular left ventricular (LV) parameters as well as on autonomic function and mortality in diabetics after MI. Methods and Results: Male Wistar rats were divided into control (C), sedentary-diabetic infarcted (SDI), and trained-diabetic infarcted (TDI) groups. MI was induced after 15 days of streptozotocin-diabetes induction. Seven days after MI, the trained group underwent ET protocol (90 days, 50-70% maximal oxygen consumption-VO(2)max). LV function was evaluated noninvasively and invasively; baroreflex sensitivity, pulse interval variability, cardiac output, tissue blood flows, VEGF mRNA and protein, HIF1-alpha mRNA, and Ca2+ handling proteins were measured. MI area was reduced in TDI (21 +/- 4%) compared with SDI (38 +/- 4%). ET induced improvement in cardiac function, hemodynamics, and tissue blood flows. These changes were probable consequences of a better expression of Ca2+ handling proteins, increased VEGF mRNA and protein expression as well as improvement in autonomic function, that resulted in reduction of mortality in TDI (33%) compared with SDI (68%) animals. Conclusions: ET reduced cardiac and peripheral dysfunction and preserved autonomic control in diabetic infarcted rats. Consequently, these changes resulted in improved VO(2)max and survival after MI. (J Cardiac Fail 2012; 18:734-744)

EROD activity and genotoxicity in the seabob shrimp Xiphopenaeus kroyeri exposed to benzo[a]pyrene (BaP) concentrations

Seabob shrimp Xiphopenaeus kroyeri is a marine species that lives in shallow waters of coastal environments, often impacted by polycyclic aromatic hydrocarbons (PAH) pollution. In the present study, seabob shrimp were exposed for 96 h to benzo[a]pyrene (BaP) at the nominal concentrations of 100, 200, 400 and 800 microg.L-1. Animals of the control groups were exposed either to clean water or to the BaP-carrier (DMSO). At the end of the exposures, muscle tissues were sampled for BaP uptake assessment and hepatopancreas and hemolymph for EROD enzyme activity and hemocytes DNA damage, respectively. EROD activity and DNA damage increased significantly as a function of BaP exposure concentrations. Significant correlations between BaP uptake and both EROD activity and DNA damage suggest that they can be used as suitable tools for integrated levels of study on the biomarkers of PAH exposure.