Resistance Training's Ability to Prevent Cancer-induced Muscle Atrophy Extends Anabolic Stimulus.
Med Sci Sports Exerc
; 53(8): 1572-1582, 2021 08 01.
Article
em En
| MEDLINE
| ID: mdl-33731662
ABSTRACT
PURPOSE:
This study aimed to determine the role of mammalian target of rapamycin (mTORC1) activation and catabolic markers in resistance training's (RT) antiatrophy effect during cachexia-induced muscle loss.METHODS:
Myofiber atrophy was induced by injecting Walker 256 tumor cells into rats exposed or not exposed to the RT protocol of ladder climbing. The role of RT-induced anabolic stimulation was investigated in tumor-bearing rats with the mTORC1 inhibitor rapamycin, and cross-sectional areas of skeletal muscle were evaluated to identify atrophy or hypertrophy. Components of the mTORC1 and ubiquitin-proteasome pathways were assessed by real-time polymerase chain reaction or immunoblotting.RESULTS:
Although RT prevented myofiber atrophy and impaired the strength of tumor-bearing rats, in healthy rats, it promoted activated mTORC1, as demonstrated by p70S6K's increased phosphorylation and myofiber's enlarged cross-sectional area. However, RT promoted no changes in the ratio of p70S6K to phospho-p70S6K protein expression while prevented myofiber atrophy in tumor-bearing rats. Beyond that, treatment with rapamycin did not preclude RT's preventive effect on myofiber atrophy in tumor-bearing rats. Thus, RT's ability to prevent cancer-induced myofiber atrophy seems to be independent of mTORC1's and p70S6K's activation. Indeed, RT's preventive effect on cancer-induced myofiber atrophy was associated with its capacity to attenuate elevated tumor necrosis factor α and interleukin 6 as well as to prevent oxidative damage in muscles and an elevated abundance of atrogin-1.CONCLUSIONS:
By inducing attenuated myofiber atrophy independent of mTORC1's signaling activation, RT prevents muscle atrophy during cancer by reducing inflammation, oxidative damage, and atrogin-1 expression.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Atrofia Muscular
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Músculo Esquelético
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Treinamento Resistido
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Serina-Treonina Quinases TOR
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Neoplasias
Tipo de estudo:
Guideline
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Prognostic_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article