Effects of physical training on hypothalamic neuronal activation and expressions of vasopressin and oxytocin in SHR after running until fatigue.

To assess the influence of physical training on neuronal activation and hypothalamic expression of vasopressin and oxytocin in spontaneously hypertensive rats (SHR), untrained and trained normotensive rats and SHR were submitted to running until fatigue while internal body and tail temperatures were recorded. Hypothalamic c-Fos expression was evaluated in thermoregulatory centers such as the median preoptic nucleus (MnPO), medial preoptic nucleus (mPOA), paraventricular nucleus of the hypothalamus (PVN), and supraoptic nucleus (SON). The PVN and the SON were also investigated for vasopressin and oxytocin expressions. Although exercise training improved the workload performed by the animals, it was reduced in SHR and followed by increased internal body temperature due to tail vasodilation deficit. Physical training enhanced c-Fos expression in the MnPO, mPOA, and PVN of both strains, and these responses were attenuated in SHR. Vasopressin immunoreactivity in the PVN was also increased by physical training to a lesser extent in SHR. The already-reduced oxytocin expression in the PVN of SHR was increased in response to physical training. Within the SON, neuronal activation and the expressions of vasopressin and oxytocin were reduced by hypertension and unaffected by physical training. The data indicate that physical training counterbalances in part the negative effect of hypertension on hypothalamic neuronal activation elicited by exercise, as well as on the expression of vasopressin and oxytocin. These hypertension features seem to negatively influence the workload performed by SHR due to the hyperthermia derived from the inability of physical training to improve heat dissipation through skin vasodilation.

Effects of aerobic exercise training and açai supplementation on cardiac structure and function in rats submitted to a high-fat diet.

This study evaluated the effect of aerobic exercise training (AET) and supplementation with açai on cardiac structure and function in rats submitted to a high-fat diet. Two-month old Fischer male rats were divided into 5 groups: Control (C), High-fat Diet (H), High-fat Diet + Açai (HA), High-fat Diet + AET (HT), High-fat Diet + Açai + AET (HAT). The high-fat diet had 21.8% lard and 1% cholesterol (H and HT), or supplemented with 1% lyophilized açai pulp (HA and HAT). The HT and HAT groups performed AET on a treadmill (5 days/week, 1 h/day, 60% of the maximum running speed) for 8 weeks. Exercise tolerance test were performed, and adiposity index calculated. After euthanasia, the left ventricle (LV) was dissected and processed for histological, single myocyte intracellular calcium ([Ca2+]i) transient and contractility, oxidative stress and gene expression analysis. AET improved running capacity and reduced the adiposity index. Both AET and açai supplementation inhibited the increase in the LV collagen content, the deleterious effects on the [Ca2+]i transient and contractility in cardiomyocytes and the increment in oxidative stress, caused by the consumption of a high-fat diet. Aerobic exercise training and açai supplementation can mitigate damage caused by high-fat diet in cardiac structure and function, though the combination of treatments had no additional effects.

Impaired thermoregulation in spontaneously hypertensive rats during physical exercise is related to reduced hypothalamic neuronal activation.

This study aimed to evaluate the physical exercise-induced neuronal activation in brain nuclei controlling thermoregulatory responses in hypertensive and normotensive rats. Sixteen-week-old male normotensive Wistar rats (NWRs) and spontaneously hypertensive rats (SHRs) were implanted with an abdominal temperature sensor. After recovery, the animals were subjected to a constant-speed treadmill running (at 60% of the maximum aerobic speed) for 30 min at 25 °C. Core (Tcore) and tail-skin (Tskin) temperatures were measured every minute during exercise. Ninety minutes after the exercise, the rats were euthanized, and their brains were collected to determine the c-Fos protein expression in the following areas that modulate thermoregulatory responses: medial preoptic area (mPOA), paraventricular hypothalamic nucleus (PVN), and supraoptic nucleus (SON). During treadmill running, the SHR group exhibited a greater increase in Tcore and an augmented threshold for cutaneous heat loss relative to the NWR group. In addition, the SHRs showed reduced neuronal activation in the mPOA (< 49.7%) and PVN (< 44.2%), but not in the SON. The lower exercise-induced activation in the mPOA and PVN in hypertensive rats was strongly related to the delayed onset of cutaneous heat loss. We conclude that the enhanced exercise-induced hyperthermia in hypertensive rats can be partially explained by a delayed cutaneous heat loss, which is, in turn, associated with reduced activation of brain areas modulating thermoregulatory responses.

Histomorphometric analysis of the Achilles tendon of Wistar rats treated with laser therapy and eccentric exercise / Análise histomorfométrica do tendão calcanear comum de ratos Wistar tratado com laserterapia e exercício excêntrico

Low-level laser therapy is recommended for the treatment of tendinopathies despite the contradictory results related to the ideal dose of energy, wavelength and time of application. This study aimed to assess the effects of laser therapy and eccentric exercise on tendinopathy of the Achilles tendon of Wistar rats. Forty-eight adult male rats were randomly distributed into four groups (L= laser; E= eccentric exercise; LE = laser and eccentric exercise; and R= rest). Laser therapy (904nm/3J/cm2) and/or eccentric exercise (downhill walking; 15o incline treadmill; 12m/min; 50min/day) was started 24h after induction of unilateral tendinopathy and remained for 20 days. At 3, 7, 14 and 21 days after lesion induction, three rats from each group were euthanized and the tendons were collected for histological and morphometric analyses. There was no difference among groups or among times for the characteristics hemorrhage (p=0.4154), fibrinous adhesion formation (p=0.0712), and organization of collagen fibers (p=0.2583) and of the connective tissue (p=0.1046). For these groups, regardless of the time, eccentric exercise led to epitenon thickening (p=0.0204), which was lower in the group treated with laser therapy. Histological analysis revealed differences (p=0.0032) in the number of inflammatory cells over time. They were more numerous in the group that only exercised. This result was confirmed by morphometric analysis, which showed a significant interaction (groups x time) for this characteristic. Eccentric exercise increased (p=0.0014) the inflammatory infiltrate over time (3 and 21 days). However, association with laser therapy reduced inflammatory reaction. On the other hand, the combination of the treatments increased angiogenesis in morphometric (p=0.0000) and histological (p=0.0006) analyses compared with the other groups, while the isolated application of low-level laser reduced this characteristic over time. Animals maintained at rest presented the lowest amount (p=0.0000) of fibroblasts, according to the morphometric analysis. However, histological evaluation showed a significant group x time interaction (p=0.0024). Greater amounts of fibroblasts were observed in groups E, L and LE on the 7th, 14th and 21st days, respectively. The animals that received laser therapy and were exercised showed a greater (p=0.0000) amount of collagen fibers over time. Laser therapy at a dose of 3J and at a wavelength of 904nm, starting 24h after surgical induction of tendinopathy in Wistar rats, is suitable for angiogenesis and prevention of tendon thickening, which can be associated with the intensity of inflammatory process. When associated with eccentric exercise, the therapy has the advantage of increasing the amount of collagen fibers, reducing fibrinous adhesions and inflammatory infiltrate, despite prolonging angiogenesis. Therefore, eccentric exercise performed concomitantly with laser therapy improves the histological properties of the injured tendon.(AU)

O laser de baixa potência é recomendado para o tratamento das tendinopatias apesar dos resultados contraditórios no que se refere a dose de energia ideal, comprimento de onda e tempo de aplicação. O objetivo desse estudo foi avaliar os efeitos da laserterapia e do exercício excêntrico na tendinopatia do tendão calcanear comum de ratos Wistar. Foram utilizados 48 ratos machos adultos. Os animais foram distribuídos aleatoriamente em quatro grupos (L=laser; E=exercício excêntrico; LE=laser e exercício excêntrico, e R=repouso). Após 24h da indução de tendinopatia unilateral, foi iniciada laserterapia (904nm/3J/cm2) e/ou exercício excêntrico (caminhada em declive; esteira com 15o de inclinação; 12m/min; 50min/dia) que permaneceu por 20 dias. Aos 3, 7, 14 e 21 dias após indução da lesão, três ratos de cada grupo foram submetidos à eutanásia, e os tendões foram obtidos para análises histológica e morfométrica. Não houve diferença entre grupos nem entre tempos nas características hemorragia (p=0,4154), formação de aderência fibrinosa (p=0,0712) e organização das fibras colágenas (p=0,2583) e do tecido conjuntivo (p=0,1046). Considerando os grupos, independentemente do tempo, foi observado que o exercício excêntrico ocasionou espessamento do epitendão (p=0,0204), que foi menor no grupo submetido à laserterapia. A análise histológica revelou diferença (p=0,0032) na quantidade de células inflamatórias ao longo do tempo, sendo observado em maior quantidade no grupo apenas exercitado. Esse resultado foi confirmado pela análise morfométrica, que demonstrou haver interação significativa (grupos x tempo) nessa característica, na qual o exercício excêntrico aumentou (p=0,0014) o infiltrado inflamatório ao longo do tempo (3 e 21 dias), porém, quando associado à laserterapia, ocorreu redução da reação inflamatória. Por outro lado, a associação dos tratamentos ocasionou maior angiogênese observada nas análises morfométrica (p=0,0000) e histológica (p=0,0006), quando comparada com os demais grupos, enquanto a aplicação isolada do laser de baixa potência reduziu essa característica ao longo do tempo. Os animais mantidos em repouso foram os que apresentaram menor (p=0,0000) quantidade de fibroblastos, na análise morfométrica, porém na avaliação histológica foi observada interação significativa entre grupo e tempo (p=0,0024). Maior quantidade de fibroblastos foi observada nos grupos E, L e LE, no 7o, 14o e 21o dias, respectivamente. Os animais que receberam laserterapia e foram exercitados apresentaram maior (p=0,0000) quantidade de fibras colágenas ao longo do tempo. A laserterapia na dose de 3J e comprimento de onda de 904nm, iniciada 24h após indução cirúrgica de tendinopatia em ratos Wistar é adequada para angiogênese e para evitar o espessamento do tendão, que pode estar relacionado com a intensidade do processo inflamatório. Quando associada ao exercício excêntrico, a terapia apresenta a vantagem de aumentar a quantidade de fibras colágenas, reduzir a aderência fibrinosa e infiltrado inflamatório, apesar de prolongar a angiogênese. Portanto, o exercício excêntrico realizado concomitantemente com a laserterapia melhora as propriedades histológicas do tendão lesionado.(AU)

Aerobic exercise and not a diet supplemented with jussara açaí (Euterpe edulis Martius) alters hepatic oxidative and inflammatory biomarkers in ApoE-deficient mice.

The pulp of jussara açaí (Euterpe edulis Martius) fruit is rich in anthocyanins that exert antioxidant and anti-inflammatory effects similar to those exerted by aerobic exercise. In the present study, we investigated the effects of jussara açaí fruit pulp consumption, either alone or in combination with aerobic exercise, on the hepatic oxidative and inflammatory status of ApoE-deficient (ApoE - / - ) mice. Male mice were divided into four groups (control (C), control plus açaí, exercise plus açaí (EXA) and exercise (EX)) and fed the AIN-93M diet or the AIN-93M diet formulated to contain 2 % freeze-dried açaí pulp. Mice in the EX and EXA groups were subjected to a progressive running programme (5 d/week, 60 min/d, 16 m/min) for 12 weeks. Mice that were made to exercise exhibited reduced (40·85 %; P< 0·05) hepatic superoxide dismutase activity when compared with the C mice, independent of the açaí diet. Mice in the EX group exhibited a lower (42 %; P< 0·05) mRNA expression of monocyte chemotactic protein-1 in the liver compared with the C mice. Mice in the EXA and EX groups had lower percentages of hepatic lipid droplets (70 % and 56 %, respectively; P< 0·05) when compared with the C mice. Mice in the EX group had smaller (58 %; P< 0·05) area of lesions in the aorta when compared with the C mice. Serum lipid profile was not affected (P>0·05). In conclusion, aerobic exercise training rather than açaí fruit pulp consumption or a combination of both enhances the hepatic oxidative and inflammatory status of ApoE - / - mice.

Efeitos da suplementação com creatina e cafeína sobre a força de fratura óssea em ratos submetidos a exercício de saltos verticais / Effects of creatine and caffeine supplementation on the bone breaking force in rats subjected to vertical jumping exercise

Este estudo investigou se a suplementação com creatina e cafeína, isoladamente ou combinadas, interfere na força de fratura óssea em ratos jovens exercitados. Os ratos foram divididos aleatoriamente em oito grupos: sedentários placebo, exercitado placebo, sedentário creatina, exercitado creatina, sedentário cafeína, exercitado cafeína, sedentário creatina + cafeína e treinado creatina + cafeína. Os grupos suplementados receberam creatina (carga: 0,430g/kg de peso corporal, por sete dias; e manutenção: 0,143g/kg, por 35 dias), cafeína (10mg/100g de peso corporal, por 35 dias) ou creatina+cafeína. Os grupos exercitados executaram saltos verticais na água (4x10 saltos com 1 minuto de intervalo entre séries, 5 dias/sem) por seis semanas. A ingestão de cafeína reduziu a espessura, o peso e a força de fratura do fêmur dos ratos, independentemente do exercício. A cafeína e a creatina+cafeína aumentaram a excreção urinária de cálcio. O exercício de saltos elevou a força de fratura, independentemente da suplementação, mas não alterou o peso e as dimensões do fêmur dos animais.

This study investigated whether supplementation with high doses of creatine and caffeine, alone or in combination, affects the bone breaking force of exercised rats. Rats were randomly divided into 8 groups: Sedentary or Exercised (placebo, creatine, caffeine or creatine plus caffeine). The supplemented groups received creatine (load: 0.430 g/kg body weight, for 7 days; and maintenance: 0.143 g/kg for 35 days), caffeine (10 mg/100g body weight, for 35 days) or creatine plus caffeine. The exercised groups underwent a vertical jump training in water (4 sets of 10 jumps interspersed with 1 min resting intervals, 5 days/wk), for 6 weeks. Caffeine ingestion reduced the femur´s width, weight and breaking force, independently of exercise. Caffeine and creatine plus caffeine increased the urinary calcium excretion. Jumping exercise increased the bone breaking force independently of supplementation; nevertheless it did not change the weight and dimensions of the femur of the animals.

Ácido linoléico conjugado: efeitos no perfil lipídico e na composição corporal de camundongos exercitados / Conjugated linoleic acid: effects on lipid profile and body composition of exercised mice

Objetivo: Avaliar os efeitos do CLA associado à dieta hiperlipídica sobre o perfil lipídico e composição corporal de camundongos knockout para o gene da ApoE exercitados. Métodos: 32 camundongos foram divididos e submetidos à dieta normo e hiperlipídica suplementadas ou não com 1% de CLA. Todos realizaram exercício físico em esteira, durante 12 semanas. Utilizou-se o teste de Kruskal-Wallis ao nível de significância de 5%. Resultados: Os animais que ingeriram dieta hiperlipídica com CLA aumentaram o colesterol total e o LDL, comparado com os alimentados com dieta normolipídica associada ou não ao CLA. Observou-se aumento no ganho de peso dos camundongos que ingeriram dieta hiperlipídica com CLA, comparado com os normolipídicos suplementados com CLA. Conclusões: O CLA na concentração de 1% não alterou nenhum dos parâmetros analisados, independente da dieta, e não foi protetor contra os efeitos da dieta hiperlipídica.

Objective: To evaluate the effects of CLA associated with high-fat diet on lipid profile and body composition of knockout mice for the ApoE gene exercised. Methods: A 32 mice were divided and submitted to a normal-fat diet and high-fat diet supplemented with 1% CLA. All exercise training on a treadmill for 12 weeks. We used the Kruskal-Wallis test at a significance level of 5%. Results: The animals fed high-fat diet with CLA increased total cholesterol and LDL, compared with those fed normal-fat diet associated or not with CLA. There was an increase in weight gain of mice who ate high-fat diet with CLA, compared with normal-fat supplemented with CLA. Conclusions: CLA at a concentration of 1% did not change any of the parameters analyzed, regardless of diet, and was not protective against the effects of high-fat diet.

Suplementação com alta dosagem de cafeína não afeta resistência à fratura óssea em ratas submetidas a treinamento de saltos verticais / Supplementation with high dosage of caffeine do not affect bone breaking force in female rats submitted to a vertical jump training / Suplementación con alta cantidad de cafeína no afecta la resistencia sobre la fractura ósea en ratas sometidas al entrenamiento de saltos verticales

OBJETIVO: testar os efeitos de altas doses de cafeína na resistência óssea à fratura em ratas jovens submetidas a treinamento de saltos verticais. MÉTODOS: ratas jovens foram alocadas em 4 grupos (Fatorial 2 x 2, Cafeína e Exercício). Grupos Cafeína receberam 3 doses (10 mg/100 g m.c.)/semana. Grupos Exercício realizaram treino de saltos verticais na água, 5 sessões/semana, por 6 semanas. Avaliou-se o cálcio urinário, diâmetro, massa e resistência à fratura do fêmur. RESULTADOS: cafeína e exercício aumentaram a excreção de cálcio. Cafeína reduziu a massa femoral, mas não afetou sua resistência à fratura. Exercício aumentou o diâmetro e a resistência femoral à fratura. CONCLUSÃO: cafeína não prejudica a resistência óssea em ratas jovens enquanto saltos verticais fortalecem os ossos.

OBJECTIVE: to test the effects of high dosage of caffeine on the bone breaking force of young female rats submitted to vertical jumping training. METHODS: young female rats were divided into 4 groups (2 x 2 factorial, Caffeine and Exercise). Caffeine groups ingested 3 doses of caffeine (10 mg/100 g bw) weekly. Exercise groups performed vertical jumps in water, 5 days/week, for 6 weeks. Urinary calcium, femur's diameter, mass and breaking force were assessed. RESULTS: caffeine and exercise increased the loss of calcium. Caffeine increased diameter and reduced femur mass, but did not affect its breaking force. Exercise increased bone's diameter and bone breaking force. CONCLUSION: caffeine does not impair bone breaking force in young female rats while vertical jumping enhances bone strength.

OBJETIVO: testar los efectos de la suplementación con alta cantidad de cafeína sobre la resistencia ósea a la fractura en ratas jóvenes sometidas al entrenamiento de saltos verticales. MÉTODOS: ratas jóvenes fueron puestas en 4 grupos (Factorial 2 x 2, Cafeína e Ejercicio). Los grupos cafeína recibieron 3 dosis (10 mg/100 g p.c.) a la semana. Los grupos ejercicio realizaron saltos verticales dentro de la agua, 5 días/semana, durante 6 semanas. Se evaluaron el calcio urinario, el diámetro, masa y resistencia a la fractura del fémur. RESULTADOS: cafeína e ejercicio aumentaron la pérdida de calcio. Cafeína aumentó el diámetro además de disminuir la masa ósea, pero no afectó la resistencia ósea. Ejercicio aumentó el diámetro y la resistencia ósea. CONCLUSIÓN: cafeína no perjudica la resistencia ósea en ratas jóvenes pero saltos verticales fortalecen los huesos.

Influência da suplementação de carboidrato na função imune de judocas durante o treinamento / Influence of carbohydrate supplementation in the immune response of judoists during training

O objetivo deste trabalho foi investigar os efeitos da suplementação de carboidrato, durante uma sessão de treino, sobre a função imune de atletas de judô. Dezesseis judocas do sexo masculino foram submetidos a duas sessões de treinamento de 120 minutos cada, com três dias de intervalo entre elas. Na primeira sessão, oito judocas, separados de forma aleatória, foram suplementados (3mL/kg peso corporal) com solução carboidratada (grupo CHO) e os demais, com solução placebo (grupo PLA), de forma duplo-cega. Na segunda sessão os tratamentos foram invertidos. O número de leucócitos, linfócitos, monócitos, eosinófilos, neutrófilos, os níveis de cortisol e as concentrações de glicose e lactato foram medidos em repouso (Pré-E), imediatamente após (Pós-E) e uma hora após o término da sessão de treino (1h pós-E). Os resultados mostraram que a glicemia aumentou (p < 0,05) durante a sessão de treino no grupo CHO e reduziu-se (p < 0,05) no grupo PLA. O cortisol aumentou (p < 0,05) durante a sessão de treino, independente do tipo de solução consumida, bem como durante a recuperação no grupo PLA. O consumo de CHO resultou em menor (p < 0,05) leucocitose, quando comparado com o PLA, nos períodos Pós-E e 1h Pós-E. A elevação da concentração de lactato sangüíneo decorrente do exercício correlacionou-se positivamente com o aumento dos leucócitos (r = 0,86, p < 0,001) nos dois grupos. Concluiu-se que a ingestão de bebida carboidratada por atletas de judô durante uma sessão de treino resultou em menor perturbação da contagem total de leucócitos e suas subclasses: linfócitos, monócitos, eosinófilos e neutrófilos. Esses resultados sugerem proteção à saúde imunológica de judocas fomentada por essa estratégia nutricional.

The aim of this study was to investigate the effects of carbohydrate supplementation on the immunological function of judoists during a training session. Sixteen male judo athletes were submitted to two 120 min training sessions within 3 days interval. In the first session eight athletes randomly chosen were supplemented (3mL/kg body weight) with a carbohydrate solution (CHO group) while the others ingested a placebo solution (PLA group) in a randomized and double blind way. In the second session, treatments were inverted. Leukocyte, lymphocyte, monocyte, eosinophil and neutrophil were counted and blood levels of cortisol, glucose and lactate were assessed at rest (Pre-E), immediately after the training session (Post-E) and one hour after the training session (1h Post-E). The results showed that the blood glucose levels increased during the training session when athletes were given CHO and decreased when they ingested PLA. Cortisol levels increased during the training session in both conditions and decreased 1h Post-E. Athletes consuming CHO presented a reduced number of leukocytes when compared to those ingesting PLA in both Post-E and 1h Post-E periods. The increase in blood lactate concentration in response to exercise training was positively correlated with the increase in the leukocyte number (r = 0. 86, p<0.001) in both conditions. It was concluded that CHO supplementation during a judo training session resulted in less disturbance of total leukocytes. It suggests that such nutritional strategy protected the athletes' immunological health.

Doping sanguíneo no esporte / Blood doping in sports

"Doping" sangüíneo é a infusao ou reinfusao de sangue no organismo de um atleta. Seu princípio fisiológico é que após a flebotomia o organismo do atleta é exposto a uma hipoxia, que induz uma eritrocitemia, gerando, assim, a produçao de novos eritrócitos. Após a infusao ou reinfusao sangüínea têm-se como conseqüência uma elevada concentraçao de hemoglobina plasmática seguida de uma melhora da "performance". Este procedimento pode ser realizado utilizando-se o sangue da mesma pessoa (reinfusao-autóloga) ou de outra pessoa (infusao-heteróloga). A eritrocitemia pode ser induzida também através da injeçao de eritropoietina recombinante humana (rhEPO). Este hormônio age sobre as colônias formadoras de unidades de eritróides desencadeando a formaçao de novos eritrócitos. Espera-se que indivíduos tratados com rhEPO melhorem sua capacidade de realizar exercícios físicos prolongados. Existe a suspeita de que alguns atletas das provas de resistência aeróbia têm se beneficiado deste recurso. Apesar de estarem sendo pesquisadas algumas formas de detecçao, nao existêm, ainda métodos analíticos de detecçao desta forma de "doping" que possam ser confiáveis.