Navegando por Palavras-chave "Lesão induzida pelo exercício"

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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.