Whey protein intake after resistance exercise activates mTOR signaling in a dose-dependent manner in human skeletal muscle.
Eur J Appl Physiol
; 114(4): 735-42, 2014 Apr.
Article
em En
| MEDLINE
| ID: mdl-24384983
ABSTRACT
PURPOSE:
Protein ingestion after resistance exercise increases muscle protein synthesis (MPS) in a dose-dependent manner. However, the molecular mechanism(s) for the dose-dependency of MPS remains unclear. This study aimed to determine the dose response of mammalian target of rapamycin (mTOR) signaling in muscle with ingestion of protein after resistance exercise.METHODS:
Fifteen male subjects performed four sets of six unilateral isokinetic concentric knee extensions. Immediately after exercise, eight subjects consumed water only. The other seven subjects, in a randomized-order crossover design, took either a 10 [3.6 g essential amino acids (EAA)] or 20 g (7.1 g EAA) solution of whey protein. Muscle biopsies from the vastus lateralis muscle were taken 30 min before and 1 h after resistance exercise. Phosphorylation of Akt (Ser473), mTOR (Ser2448), 4E-BP1 (Thr37/46), and S6K1 (Thr389) was measured by western blotting.RESULTS:
Concentric knee extension exercise alone did not increase phosphorylation of Akt and mTOR 1 h after exercise, but ingesting protein after exercise significantly increased the phosphorylation of Akt and mTOR in a dose-dependent manner (P < 0.05). 4E-BP1 phosphorylation significantly decreased after resistance exercise (P < 0.05), but subjects who took 10 or 20 g of protein after exercise showed increased 4E-BP1 from post-exercise dephosphorylation (P < 0.05). S6K1 phosphorylation significantly increased after resistance exercise (P < 0.05), and 20 g of protein further increased S6K1 phosphorylation compared with ingestion of 10 g (P < 0.05).CONCLUSIONS:
These findings suggest that whey protein intake after resistance exercise activates mTOR signaling in a dose-dependent manner in untrained men.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Músculo Esquelético
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Treinamento Resistido
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Serina-Treonina Quinases TOR
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Proteínas do Leite
Tipo de estudo:
Clinical_trials
Limite:
Adult
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Humans
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Male
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article