Resposta morfológicas e moleculares do músculo esquelético de ratos idosos submetidos ao treinamento físico após estímulo atrófico

• Ano de defesa: 2015
• Autor(a) principal: Vechetti Júnior, Ivan José [UNESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Envelhecimento; Imobilização animal; Massa muscular; Exercícios físicos; Musculos; Musculoskeletal system
• Link de acesso: http://hdl.handle.net/11449/142962; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/05-07-2016/000865096.pdf

Background: During aging, loss of muscle mass (sarcopenia) is inevitable and contributes to increased morbidity and mortality; thus, the maintenance of skeletal muscle mass is critical for long-term health and quality of life. In addition, physical training has been shown to be important to the control of muscle mass during aging through the activation of several pathways including, IGF1-AKT and PGC-1α. Also, it was demonstrated that LRP130, a component of the PGC-1α complex is important for the PGC-1α- dependent transcription of several mitochondrial genes in vivo. Therefore, we hypothesized that the physical training could improve the muscle recovery possibly through of the LRP130/PGC-1α complex by inhibiting the ubiquitin-proteasome system after disuse-induced atrophy in aged rats. We therefore investigated the effects on muscle recovery after short-term immobilization followed by 3 or 7 days of retraining with aerobic training (AT) or resistance training (RT). Methods: After 7 days of immobilization, the animals underwent the re-growth process with exercise (AT or RT) or without exercise (R) for 3 or 7 days. At the end of the experiment, the animals were sacrificed, and the plantaris (PL) muscle was removed for morphological analyses (assessment of mATPase activity, to assess the total muscle fiber cross sectional area (CSA), and the frequency of specific fiber types), biochemical analyses (Myosin Heavy Chain, MyHC), gene expression of 44 molecular markers of muscle mass (RT-qPCR). To further understand the biological relevance of the mRNA interactions, we performed a search for additional genes that are related to our differentially expressed gene set (GeneMANIA Cytoscape plugin). Differentially expressed genes were submitted to Western blotting analysis. Results: At 7 days after an atrophic stimulus, only PL muscles from animals subjected to AT had recovered their normal CSA patterns. The frequency of fiber types and ...