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aguiar_af_dr_botib.pdf: 679778 bytes, checksum: c5aff2254c12cb4b62de64431ebf700b (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Embora fortes evidências demonstrem que os fatores de regulação miogênica (MRFs) e o fator de crescimento semelhante à insulina (IGF-I) apresentem um importante papel na resposta hipertrófica após treinamento resistido (TR) agudo, permanece desconhecido se a resposta dos MRFs e IGF-I também ocorre durante a adaptação ao TR a longo-prazo. Portanto, o objetivo deste estudo foi testar a hipótese de que a resposta hipertrófica e modulação das fibras do músculo esquelético após TR a longo-prazo poderia estar associada ao aumento na expressão gênica dos MRFs e IGF-I. Ratos Wistar (80 dias de idade, 250-300 g) foram divididos em quatro grupos: Controle 8 semana (C8, n = 8), Treinado 8 semanas (T8, n = 8), Controle 12 semanas (C12, n = 8) e Treinado 12 semanas (T12, n = 8). Os grupos T8 e T12 foram submetidos a um programa de TR progressivo (3 dias/semana) durante 8 e 12 semanas, respectivamente. O protocolo de treinamento consistiu de quatro séries de 10-12 repetições, com um período de descanso de 40 segundos entre cada série, realizado a 65-75% de uma repetição máxima (1RM). Ao término do experimento, os animais foram sacrificados e o músculo plantar coletado para as análises morfológica e molecular. O TR durante 8 e 12 semanas não promoveu qualquer alteração (p > 0,05) significante no ganho de peso corporal e consumo alimentar dos grupos T8 e T12 em relação aos grupos C8 e C12, respectivamente. Após 8 e 12 semanas de TR, a força absoluta (T8: 69,7% and T12: 126,0%, p < 0,05) e relativa (T8: 36,1% and T12: 57,7%, p < 0,05) foi significantemente elevada nos grupos T8 e T12, em comparação aos seus respectivos controles. No entanto, houve um similar aumento da área de secção transversal (AST) das fibras musculares (T8: 29% vs. T12: 35%, p > 0,05) entre os grupos T8 e T12, comparados aos grupos C8 e C12, respectivamente... / Although strong evidence show that the myogenic regulatory factors (MRFs) and insulin-like growth factor (IGF-I) have important roles in the hypertrophy response after acute resistance training, it is still unclear if response of MRFs and IGF-I also occurs during the adaptation to prolonged periods of resistance training (RT). Therefore, the purpose of this study was to test the hypothesis that fiber-types transition and hypertrophy during long-term RT could be associated with increased MRFs and IGF-I mRNA expression in the skeletal muscle. Male Wistar rats (80 days old, 250-300 g) were divided into four groups: 8 weeks control (C8, n = 8), 8-weeks trained (T8, n = 8), 12-weeks control (C12, n = 8), 12-weeks trained (T12, n = 8). T8 and T12 groups were submitted to a progressive RT program (3 day/week) for 8 and 12 weeks, respectively. The training protocol consisted of four sets of 10–12 repetitions, with a 40 s rest period between each set, performed at 65–75% of one repetition maximum (1RM). At the end of the experiment, animals were sacrificed and the plantaris muscle collected for morphological and molecular analysis. The RT did not change (p > 0.05) in body weight gain and food intake in the T8 and T12 compared to the C8 and C12 groups, respectively. After 8 and 12 weeks of RT, the absolute (T8: 69.7% vs. T12: 126.0%; p < 0.05) and relative (T8: 36.1% vs. T12: 57.7%; p < 0.05) strength (relative 1RM) was significantly elevated in the T8 e T12 groups, compared to respective control groups. RT for 8 and 12 weeks induced similar increase in myogenin (T8: 44.8% vs. T12: 37.7%; p > 0.05), MyoD (T8: 22.9% vs. T12: 22.3%; p > 0.05) and muscle fiber crosssectional area (CSA) (T8: 29% vs. T12: 35%; p > 0.05) in the T8 and T12, compared to C8 and C12 groups, respectively. After 8 weeks of RT, IGF-I increased in 30.1% in the T8 compared to C8 group, but returned to baseline after 12 weeks... (Complete abstract click electronic access below)
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.unesp.br:11449/100580 |
| Date | 28 February 2011 |
| Creators | Aguiar, Andreo Fernando [UNESP] |
| Contributors | Universidade Estadual Paulista (UNESP), Silva, Maeli Dal Pai [UNESP] |
| Publisher | Universidade Estadual Paulista (UNESP) |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | 74 f. |
| Source | Aleph, reponame:Repositório Institucional da UNESP, instname:Universidade Estadual Paulista, instacron:UNESP |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | -1, -1 |
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