zh1-E-00378-2016-s01.xlsx (11.27 kB)
Dataset for: Post-exercise essential amino acid supplementation amplifies skeletal muscle satellite cell proliferation in older men 24 hours post-exercise
dataset
posted on 2017-06-08, 09:41 authored by Paul T Reidy, Christopher S. Fry, Jared Dickinson, Micah Drummond, Blake RasmussenAged skeletal muscle has an attenuated and delayed ability to proliferate satellite cells in response to resistance exercise. The mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway is a focal point for cell growth, however the effect of post-exercise mTORC1 activation on human skeletal muscle satellite cell (SC) proliferation is unknown. To test the proliferative capacity of skeletal muscle SC in aging muscle to a potent mTORC1 activator (i.e., EAA; essential amino acids) we recruited older (~72y) men to conduct leg resistance exercise (8sets x10reps) without (-EAA;n=8) and with (+EAA:n=11) ingestion of 10g of EAA 1h post exercise. Muscle biopsies were taken before exercise (Pre) and 24h post-exercise (Post) for assessment of expression and fiber type-specific Pax7+ SC, Ki67+Pax7+ SC and MyoD+ SC. -EAA did not show an increase in Pax7+ satellite cells at Post (p>0.82). Although statistical significance for an increase in Pax7+ SC at 24 h post-RE was not observed in +EAA vs –EAA, we observed trends for a treatment difference (p<0.1). When examining the change from Pre to Post trends were demonstrated (#/myofiber:p=0.076; and %/ myonuclei:p=0.065) for a greater increase in +EAA vs –EAA. Notably, we found an increases SC proliferation in +EAA, but not -EAA with increases in Ki67+ SC and MyoD+ cells (p<0.05). Ki67+ SC also exhibited a significant group difference Post (p<0.010). Pax7+ SC in fast twitch myofibers did not change and was not different between groups (p>0.10). CDK2, MEF2C, RB1 mRNA only increased in +EAA (p<0.05). Acute muscle satellite cell proliferative capacity may be partially rescued with post-exercise EAA ingestion in older men.