Bases metabólicas do crescimento muscular
DOI:
https://doi.org/10.33233/rbfe.v9i1.3468Abstract
O músculo esquelético é o maior tecido do corpo e guarda relação com a autonomia somatocinética e homeostase metabólica. A miogênese é decorrente da predominância de fatores protéicos miogênicos sobre miostáticos. O crescimento ocorre predominantemente de forma hipertrófica, após o nascimento, pelo predomínio da síntese sobre o catabolismo protéico. A síntese protéica é finamente mantida por cascata de quinases controladas ou controladoras da mTOR. A mTOR controla o complexo iniciador da síntese protéica, sendo influenciada pela contração muscular, fatores de crescimento e a leucina. O estado de privação energética (↑ AMP/ATP) inibe a mTOR pelo aumento da AMPK. A síntese protéica miofibrilar é estimulada por fatores hidratantes celulares (glicose, insulina, creatina, BCAA, glutamina). Seguindo-se a lesão e necrose miofibrilar, há resposta inflamatória e ação dos fagócitos, promovendo a fagocitose tecidual. Posteriormente, os macrófagos alteram seu fenótipo para resolver a inflamação e promover a miogênese e crescimento miofibrilar.
Palavras-chave: músculo esquelético, hipertrofia muscular, anabolismo protéico, mTOR, regeneração muscular.
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