Artículos de revistas
Effect of eccentric exercise velocity on akt/mtor/p70(s6k) signaling in human skeletal muscle
Fecha
2011Registro en:
APPLIED PHYSIOLOGY NUTRITION AND METABOLISM-PHYSIOLOGIE APPLIQUEE NUTRITION ET METABOLISME, v.36, n.2, p.283-290, 2011
1715-5312
10.1139/H10-111
Autor
ROSCHEL, Hamilton
UGRINOWISTCH, Carlos
BARROSO, Renato
BATISTA, Mauro A. B.
SOUZA, Eduardo O.
AOKI, Marcelo S.
SIQUEIRA-FILHO, Mario A.
ZANUTO, Ricardo
CARVALHO, Carla R. O.
NEVES JR., Manoel
MELLO, Marco T.
TRICOLI, Valmor
Institución
Resumen
It has been suggested that muscle tension plays a major role in the activation of intracellular pathways for skeletal muscle hypertrophy via an increase in mechano growth factor (MGF) and other downstream targets. Eccentric exercise (EE) imposes a greater amount of tension on the active muscle. In particular, high-speed EE seems to exert an additional effect on muscle tension and, thus, on muscle hypertrophy. However, little is known about the effect of EE velocity on hypertrophy signaling. This study investigated the effect of acute EE-velocity manipulation on the Akt/mTORCI/p70(S6K) hypertrophy pathway. Twenty subjects were assigned to either a slow (20 degrees.s(-1); ES) or fast EE (210 degrees.s(-1); EF) group. Biopsies were taken from vastus lateralis at baseline (B), immediately after (T1), and 2 h after (T2) the completion of 5 sets of 8 repetitions of eccentric knee extensions. Akt, mTOR, and p70(S6K) total protein were similar between groups, and did not change postintervention. Further, Akt and p70(S6K) protein phosphorylation were higher at T2 than at B for ES and EF. MGF messenger RNA was similar between groups, and only significantly higher at T2 than at B in ES. The acute manipulation of EE velocity does not seem to differently influence intracellular hypertrophy signaling through the Akt/mTORCI/p70S6K pathway.