Abstract:The purpose of the present study was to investigate the effects of taurine supplementation on muscle performance, oxidative stress, and inflammation response after eccentric exercise (EE) in males. Twenty-one participants (mean age, 21 ± 6 years; weight, 78.2 ± 5 kg; height, 176 ± 7 cm) were selected and randomly divided into two groups: placebo (n = 10) and taurine (n = 11). Fourteen days after starting supplementation, subjects performed EE (3 sets until exhaustion, with EE of the elbow flexors on the Scott bench, 80% 1 repetition maximum (RM)). Blood samples were collected and muscle performance was measured on days 1, 14, 16, 18, and 21 after starting the supplements. Then, performance, muscle damage, oxidative stress, and inflammatory markers were analyzed. The taurine supplementation resulted in increased strength levels and thiol total content and decreased muscle soreness, lactate dehydrogenase level, creatine kinase activity, and oxidative damage (xylenol and protein carbonyl). Antioxidant enzymes (superoxide dismutase, catalase, and gluthatione peroxidase) and inflammatory markers (tumor necrosis factor, interleukin-1␤ (IL-1␤), and interleukin-10 (IL-10)) were not altered during the recovery period compared with the placebo group. The results suggest that taurine supplementation represents an important factor in improving performance and decreasing muscle damage and oxidative stress but does not decrease the inflammatory response after EE.Key words: taurine, eccentric exercise, physical performance, oxidative stress, inflammation, supplementation.Résumé : Cette étude se propose d'examiner les effets de la supplémentation en taurine sur la performance musculaire, le stress oxydatif et la réponse inflammatoire à la suite d'un exercice pliométrique chez des hommes. On répartit aléatoirement une sélection de 21 hommes (21 ± 6 ans, 78,2 ± 5 kg, 176 ± 7 cm) dans deux groupes : placebo (n = 10) et taurine (n = 11). Quatorze jours après le début de la supplémentation, les sujets effectuent sur un banc Scott trois séries d'exercices pliométriques des fléchisseurs du coude (80 % 1 RM) jusqu'à épuisement. On prélève des échantillons sanguins et on évalue la performance musculaire aux jours 1, 14, 16, 18 et 21 suivant le début de la supplémentation. Puis on analyse la performance, les lésions musculaires, le stress oxydatif et les marqueurs de l'inflammation. La supplémentation en taurine suscite une augmentation de la force et du contenu total en thiol ainsi qu'une diminution de la douleur musculaire, de la concentration de lactate déshy-drogénase, de l'activité de la créatine kinase et des lésions oxydatives (xylénol et protéine carbonylée). Pendant la période de récupération, on n'observe dans les groupes supplémentés aucune modification de l'activité des enzymes antioxydantes (superoxyde dismutase, catalase et glutathion peroxydase) et des marqueurs de l'inflammation (facteur de nécrose tumorale, interleukine-1␤ (IL-1␤) et interleukine-10 (IL-10)) comparativement au groupe placebo. D'après ces observa...

O procedimento de extração em três etapas sequenciais recomendado pelo Programa de Normas Europeias de Medições e Ensaios (SM&T), anteriormente nomeado por Gabinete Comunitário de Referência (BCR), foi aplicado para a especiação química de metais pesados (Cu, Pb, Cr e Zn) em sedimentos provenientes de diferentes regiões urbanizadas da Cidade de Uberlândia (MG, Brasil). Para obter o balanço de massa, uma quarta etapa, ou seja, a digestão do resíduo foi realizada através do processo de digestão assistida por micro-ondas em meio ácido. Maiores concentrações dos elementos metálicos foram encontradas em pontos de amostragem que recebem descarga de uma área urbana e uma zona industrial. Todos os metais, exceto Zn, estavam presentes em maiores concentrações nas frações residuais (fortemente associados com as estruturas cristalinas dos minerais), indicando que Cu, Pb e Cr foram menos móveis e potencialmente menos biodisponíveis nesses sedimentos. Em sedimentos de zonas de descargas industriais e urbanas, a sequência de mobilidade dos metais estudados foi Pb > Zn > Cu > Cr. Maiores concentrações de Pb foram encontradas nas frações residuais no ponto de amostragem localizado no afluente que drena a zona industrial (102 mg kg -1 ), indicando que este elemento metálico foi fortemente ligado aos sedimentos. Portanto, sob os pontos de vista toxicológico e ambiental, o Pb não causa impacto ao meio ambiente e consequentemente à saúde humana. A soma das quatro frações (solúvel em ácido, redutível, oxidável e residual) apresentou boa concordância com o teor total, o que comprova a exatidão do procedimento de extração por micro-ondas em conjunto com o método analítico FAAS.A three-step sequential extraction procedure recommended by the European Standards, Measurements and Testing (SM&T) Program, formerly the Community Bureau of Reference (BCR), was applied to the chemical speciation of heavy metals (Cu, Pb, Cr and Zn) in sediments from different populated zones of Uberlândia City (MG State, Brazil). To obtain a mass balance, a fourth step, i.e., digestion and analysis of the residue, was performed using a microwave-assisted acid digestion procedure. The highest metallic elements concentrations were observed at one of the sampling points which receive discharge from an urban area and an industrial zone. All metals, except Zn, were present at higher concentrations in the residual fractions (strongly associated with the crystalline structures of the minerals) indicating that Cu, Pb and Cr were less mobile and potentially less bioavailable in these sediments. In sediments from industrial and urban discharge zones the mobility sequence of the heavy metals studied was Pb > Zn > Cu > Cr. The highest Pb concentrations were found in the residual fractions at the sampling point located in the tributary stream that drains the industrial district (102 mg kg -1 ), indicating that this metallic element was strongly bound to the sediments. Therefore, under the contamination and toxicological point of view, Pb has no impact to the environment and...

The present study investigates the effects of incremental exercise test on muscular oxidative metabolism. Thirty-six 2-month-old male Wistar rats were distributed in seven groups that performed exercise at different levels: first level (control), second level (0.6 km/h), third level (0.6 and 0.8 km/h), fourth level (0.6, 0.8 and 1.0 km/h), fifth level (0.6, 0.8, 1.0 and 1.2 km/h), sixth level (0.6, 0.8, 1.0, 1.2 and 1.4 km/h), and seventh level (0.6, 0.8, 1.0, 1.2, 1.4 and 1.6 km/h). At the end of the exercise challenge, level of blood lactate (BL), glycogen content (MG), creatine kinase (CK), complexes (CI, CII, CIII, CIV), oxidative damage, succinate dehydrogenase (SDH), cytochrome c oxidase as well as antioxidant enzymes (SOD and CAT) expression were measured. The speed of 1.0 km/h increased BL level, while 1.2 km/h decreased MG and increased serum CK. Increased SDH expression was observed after intensity levels 6 and 7, and cytochrome c oxidase expression increased after levels 5, 6 and 7, in comparison with lower intensity levels, ETC enzyme activities increased when exercise was applied at intensities of 0.8 km/h (CI), 1.0 km/h (CII and CIII), and 1.2 km/h (CIV). The increase in SOD expression did not occur as observed for superoxide production, except for rats that underwent exercise at level 7, but CAT expression increased significantly in all levels, starting from level 3. Our results show interesting alterations in the muscular metabolism parameters, and suggest a differential response of muscle oxidative metabolism when intense exercise is applied at different speeds.