Navegando por Palavras-chave "Exercício físico excêntrico"

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    Característica do processo de regeneração de músculos esqueléticos de diferentes origens embrionárias em camundongos mdx submetidos ao treinamento físico aeróbio
    (Universidade Federal de São Paulo (UNIFESP), 2016-03-18) Lazzarin, Mariana Cruz [UNIFESP]; De Oliveira, Flavia [UNIFESP]; http://lattes.cnpq.br/3387760393535776; http://lattes.cnpq.br/1579497511371132; Universidade Federal de São Paulo (UNIFESP)
    Duchenne muscular dystrophy (DMD) is a genetic disorder that generates loss of functionality, with impaired strength and muscle mass. The effect of exercise on muscle dystrophic is not well established. Thus, the aim of this study was to analyze the effects of aerobic exercise training on the morphology and myogenic markers of muscle regeneration and inflammation of skeletal muscles from different embryonic origins in C57BL/10-Dmdmdx mice. Were used male C57BL/10 mice (n = 10) and C57BL/10-Dmdmdx (n = 10), with eight weeks old. They were distributed into four groups (n = 5): Sedentary Control (SC), Trained Control (TC), Sedentary Mdx (S-Mdx) and Trained Mdx (T-Mdx). The trained groups were submitted to seven weeks of aerobic exercise, five times weekly at a high intensity speed for 60 minutes with treadmill downward of -15°. After euthanasia, the gastrocnemius muscles (somitic embryonic origin) and masseter (branchiomeric embryonic origin) were dissected and processed for undergoing: Histopathological; morphometric (cell density of transverse sections and the cross-sectional area of muscle fibers); immunohistochemistry markers for muscle regeneration (MyoD, and Myogenin), inflammation (COX-2) and oxidative stress (8-OHdG). Histopathological results showed morphological changes in Mdx groups as well as the quantification of connective tissue, both in the gastrocnemius muscle and masseter. The morphometric analysis revealed that Mdx groups (S-Mdx and T-Mdx) have heterogeneity in the muscle fibers and the gastrocnemius muscle when compared with masseter muscle, which had a similar pattern to the control groups (SC and TC). Immunohistochemical results showed less nuclear staining MyoD and Myogenin for Mdx groups (SMdx and T-Mdx) when compared with control groups (SC and TC) for gastrocnemius muscle. Masseter muscle, differed between Mdx and Control groups about Myogenin parameter. In both muscles, the Mdx-T group had higher percentage of immunoreactive nuclei Myogenin compared to Mdx-S. Immunohistochemical results of COX-2 were higher for Mdx groups in both muscles, but only the gastrocnemius muscle was influenced training. The immunoreactivity of 8-OHdG showed statistical significance only about physical training and in gastrocnemius muscle. The conclusion of the study showed that the embryonic origin of skeletal muscle influenced the response of muscular dystrophy and exercise. Physical training protocol modified the histopathology and the presence of connective tissue in the masseter muscle. In addition, physical training interfered in increased immunoreactivity of COX-2 in the gastrocnemius muscle dystrophic. Furthermore, it was able to increase Myogenin in both muscles and groups.
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    O efeito da lesão induzida pelo exercício físico agudo downhill sobre a mudança fenotípica de macrófagos, diferenciação e proliferação de células satélites no músculo tríceps de ratos wistar
    (Universidade Federal de São Paulo, 2013-06-26) Minari, André Luis Araújo [UNIFESP]; Santos, Ronaldo Vagner Thomatieli dos [UNIFESP]; Oyama, Lila Missae [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Macrophages (Mϕs) and satellite cells (S.C) are closely related to muscular injury and regeneration. After injury (1 to 2 days) Mϕs type 1 (M1) provide the clearance of injured cells by phagocytosis and impair myogenesis. During regeneration (4 to 7 days), phagocytosis is concluded and Mϕs are simultaneously converted to Mϕs type 2 (M2), which restore the process of myogenesis and enable the development of new structures. OBJECTIVE: identify the moment of Mϕs phenotypic change, the modulation of myogenesis and evaluate the implication of cytokines in triceps brachii long head (TLH) and triceps brachii medial head (TB) of Wistar rats after induced injury. METHODS: Appliance of exercise-induced injury protocol by downhill running; measurement of serum injury markers (CK and LDH), evaluation of gene expression of Mϕs (CD68 + , CD163 and SLPI) and S.C. (MYOD and MYOGENIN) by RT –PCR and cytokine quantification (IL-6, IL-10 and TNF-α). All procedures were evaluated 0h, 24h, 48h and 72h after exercise, both in TLH and TB. Animals were distributed in four experimental groups (G0, G24, G48 and G72) and one control group (CTRL). RESULTS: 48h after induced injury we observed decrease in LDH (G48 vs CTRL and G72, P≤ 0.05). In TLH, the expression of CD68 + was increased in G24 compared to G72 (P≤ 0.05) while the expression of CD163 + was increased in G48 compared to G24 (P≤ 0.05), which demonstrates an inverse correlation of these markers (r=0.61; P≤ 0.001). In TB, the expression of CD68 + was increased 24h after induced injury, compared to G0 (P≤ 0.05) while expression of CD163 + was decreased in G72, compared to G0 (P≤ 0.05). MYOD was more expressed in TLH of G72, compared to G0 (P≤ 0.05) and this parameter presented a positive correlation with levels of TNF-α (r=0.69; P≤ 0.001). Additionally, in the same muscle (TLH) we observed an inhibition of MYOGENIN in G24 compared to CTRL (P≤ 0.05) and its restoration in G72, compared to G24 (P≤ 0.05). In TB, the expression of MYOD was increased 24h after induced injury (G0 VS G24; P≤ 0.05) and no change was observed in the expression of MYOGENIN, which was positively correlated to IL-10 (r=0.56; P≤ 0.002). In TLH, TNF-α was increased in G48 (G48 vs CTRL; G48 vs G0; P≤ 0.001) and in G72 (G72 vs CTRL; G72 vs G0 P≤ 0.001), what influenced IL-10 and IL-6 levels (TNF/IL-10; r= 0.68; P≤ 0.001 e TNF/IL-6 r=0.65; P≤ 0.001). It was also observed a positive correlation among IL-6 and IL-10 in TB (r=0.70; P≤ 0. 001). CONCLUSION: We showed diference behavior between fiber type analized, were TCL is most sensible compare to TB. It is denoted by elevation of TNF-α, with exerts important role in processes of myogenesis in period between 24 to 48h after downhill exercise, wich envolve with Mϕs phenotypic changes. Beside that, we evaluated important evidence among genetic expression of CD163 + immediately after downhill exercise in TB.