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Whey protein intake after resistance exercise activates mTOR signaling in a dose-dependent manner in human skeletal muscle.
- Source :
-
European Journal of Applied Physiology . Apr2014, Vol. 114 Issue 4, p735-742. 8p. 1 Color Photograph, 1 Chart. - Publication Year :
- 2014
-
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. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 14396319
- Volume :
- 114
- Issue :
- 4
- Database :
- Academic Search Index
- Journal :
- European Journal of Applied Physiology
- Publication Type :
- Academic Journal
- Accession number :
- 94871885
- Full Text :
- https://doi.org/10.1007/s00421-013-2812-7