Infrequent exercise, typically involving eccentric actions, has been shown to cause oxidative stress and to damage muscle tissue. High taurine levels are present in skeletal muscle and may play a role in cellular defences against free radical-mediated damage. This study investigates the effects of taurine supplementation on oxidative stress biomarkers after eccentric exercise (EE). Twenty-four male rats were divided into the following groups (n = 6): control; EE; EE plus taurine (EE + Taurine); EE plus saline (EE + Saline). Taurine was administered as a 1-ml 300 mg kg(-1) per body weight (BW) day(-1) solution in water by gavage, for 15 consecutive days. Starting on the 14th day of supplementation, the animals were submitted to one 90-min downhill run session and constant velocity of 1·0 km h(-1) . Forty-eight hours after the exercise session, the animals were killed and the quadriceps muscles were surgically removed. Production of superoxide anion, creatine kinase (CK) levels, lipoperoxidation, carbonylation, total thiol content and antioxidant enzyme were analysed. Taurine supplementation was found to decrease superoxide radical production, CK, lipoperoxidation and carbonylation levels and increased total thiol content in skeletal muscle, but it did not affect antioxidant enzyme activity after EE. The present study suggests that taurine affects skeletal muscle contraction by decreasing oxidative stress, in association with decreased superoxide radical production.

It has been demonstrated that reactive oxygen species (ROS) formation and oxidative damage markers are increased after muscle damage. Recent studies have demonstrated that low-level laser therapy (LLLT) modulates many biochemical processes mainly those related to reduction of muscular injures, increment of mitochondrial respiration and ATP synthesis, as well as acceleration of the healing process. The objective of the present investigation was to verify the influence of LLLT in some parameters of muscular injury, oxidative damage, antioxidant activity, and synthesis of collagen after traumatic muscular injury. Adult male Wistar rats were divided randomly into three groups (n = 6), namely, sham (uninjured muscle), muscle injury without treatment, and muscle injury with LLLT (GaAs, 904 nm). Each treated point received 5 J/cm(2) or 0.5 J of energy density (12.5 s) and 2.5 J per treatment (five regions). LLLT was administered 2, 12, 24, 48, 72, 96, and 120 h after muscle trauma. The serum creatine kinase activity was used as an index of skeletal muscle injury. Superoxide anion, thiobarbituric acid reactive substance (TBARS) measurement, and superoxide dismutase (SOD) activity were used as indicators of oxidative stress. In order to assess the synthesis of collagen, levels of hydroxyproline were measured. Our results have shown that the model of traumatic injury induces a significant increase in serum creatine kinase activity, hydroxyproline content, superoxide anion production, TBARS level, and activity of SOD compared to control. LLLT accelerated the muscular healing by significantly decreasing superoxide anion production, TBARS levels, the activity of SOD, and hydroxyproline content. The data strongly indicate that increased ROS production and augmented collagen synthesis are elicited by traumatic muscular injury, effects that were significantly decreased by LLLT.

No abstract

RESUMOO presente estudo investigou o efeito de quatro e oito semanas de treinamento físico sobre a atividade dos complexos da cadeia transportadora de elétrons (CTE) e os marcadores de estresse oxidativo em fígado de camundongos. Vinte e um camundongos (CF1, 30-35g) foram distribuídos nos seguintes grupos: não treinado (NT); treinado quatro semanas (T4); treinado oito semanas (T8). Quarenta e oito horas após a última sessão de treinamento os animais foram mortos por decapitação e o fígado foi retirado e estocado em -70ºC para posterior análise. Atividade da succinato desidrogenase (SDH), dos complexos I,II,III e IV da CTE, carbonilação de proteína, conteúdo total de tióis e a atividade da superóxido dismutase foram mensurados. Os resultados demonstram que apenas oito semanas de treinamento aumentam a atividade da SDH, dos quatro complexos da CTE, da superóxido dismutase, e o conteúdo total de tióis em relação ao grupo não treinado. Houve ainda diminuição na carbonilação de proteína no respectivo grupo em relação ao NT. Em conclusão, são necessárias oito semanas de treinamento para que ocorram aumento no funcionamento mitocondrial e melhora nos marcadores de estresse oxidativo em fígado de camundongos. Palavras-chave: treinamento físico, cadeia transportadora de elétrons, estresse oxidativo ABSTRACTThe present study investigated mitochondrial adaptations and oxidative stress markers after four and eight weeks of running training in liver of mice. Twenty-one male mice (CF1, 30-35g) were distributed into the following groups (n=7): untrained (UT); trained -four weeks (T4); trained -eight weeks (T8). Forty-eight hours after the last training session the animals were killed by decapitation and livers were removed and stored at -70ºC. Succinate dehydrogenase (SDH), complexes I, II, II-III and IV, protein carbonyls (PC), total thiol content and superoxide dismutase activity were measured. The results show that endurance training (8-wk) increases the SDH activity and complexes (I, II, III, IV), superoxide dismutase and total thiol content in liver when compared to untrained animals. Decrease in protein carbonylation in the respective group in relation to UT was also observed. It could be concluded that eight weeks of running training are necessary for mitochondrial respiratory chain enzyme activities increase and improvement in oxidative stress markers in liver of mice.Keywords: physical training, electron transport chain, oxidative stress INTRODUÇÃOEstudos têm reportado que o exercício físico aumenta a produção das espécies reativas de oxigênio (ERO) e, consequentemente, estresse oxidativo em diversos órgãos e tecidos (1,2) . Tem sido sugerido que a elevação do consumo de oxigênio induzida pelos exercícios aumenta a atividade mitocondrial, gerando altas concentrações de ERO (3) . O estresse oxidativo (EO) altera a integridade de constituintes celulares e compromete todo o funcionamento celular (1) . Células hepáticas precisam de energia para realizar diversas funções. A alta taxa metabólica do fígado (200kcal/kg/tecido...

To investigate the effects of moderate and intense exercise (ME,IE) and lycopene (L) supplementation on oxidative stress biomarkers in patients with CAD. Rehabilitation clinic.Thirty-two male volunteers with CAD (55.65 ? 2.27 years, 77.27 ? 3.95 kg, 171.9 ? 2.80 cm) were divided into four groups; ME-Placebo (n = 7), ME + L (n = 8), IE-Placebo (n = 8) and IE-L (n = 9). Blood samples (12 mL) were collected before supplementation (one cereal bars – 15 mg of syn-thetic lycopene) and exercise (45 min plus 15 min of stretching, 3/wk) and after five weeks of supplementation and 72 h after exercise. Nitrite/nitrate concentrations (NOx), lipoperoxidation (TBARS levels), protein carbonylation (PC) and superoxide dismutase (SOD) and catalase (CAT) activity were assessed in plasma. NOx decreased significantly in the ME-P, IE-P and ME-L groups at 72 h after exercise and increased in the IE-L 72 h after the last exercise session. The IE-L group demonstrated decreased TBARS at 72 h after the last exercise session. The level of PC increased only in EI-P at 72 h after the last exercise session, while only the EI-L group presented a reduction. SOD increased signifi-cantly in both placebo groups 72 h after the last exercise session and decreased in the ME-L group 72 h after in rela-tion to placebo groups. CAT increased in ME-P, IE-P and IE-L groups only at 72 h after the last exercise session. The lycopene supplementation attenuates some markers of oxidative stress associated with IE Lycopene also had dissimilar effects on some markers of oxidative stress in subjects undertaking ME versus IE