Synchronous deficits in cumulative muscle protein synthesis and ribosomal biogenesis underlie age-related anabolic resistance to exercise in humans.
dc.contributor.author | Mitchell, William K | |
dc.contributor.author | Lund, Jonathan | |
dc.date.accessioned | 2016-09-27T13:52:28Z | |
dc.date.available | 2016-09-27T13:52:28Z | |
dc.date.issued | 2016-09 | |
dc.identifier.citation | J Physiol. 2016 Sep 22. doi: 10.1113/JP272857. [Epub ahead of print] | language |
dc.identifier.uri | http://hdl.handle.net/20.500.12904/1276 | |
dc.description.abstract | Aging is associated with impaired hypertrophic responses to resistance exercise training (RET). Here we investigated the aetiology of "anabolic resistance" in older humans. Twenty healthy male individuals (10 younger (Y: 23 ± 1y)), 10 older (O: 69 ± 3y)) performed 6-wks unilateral RET (6×8 repetition, 75%-1RM 3.wk(-1) ). After baseline bilateral vastus lateralis (VL) muscle biopsies, subjects consumed 150 ml D2 O (70-Atom%; thereafter 50ml·wk(-1) ), further bilateral VL muscle biopsies were taken at 3-and-6-weeks to quantify muscle protein synthesis (MPS) via gas chromatography-pyrolysis-isotope-ratio mass spectrometry. After RET, 1-RM increased in Y: +35 ± 4% and O: +25 ± 3% (P < 0.01), while MVC increased in Y: +21 ± 5% (P < 0.01) but not O: +6 ± 3% (P = NS). In comparison to Y, O displayed blunted RET-induced increases in muscle thickness (Y: +8 ± 1% and +11 ± 2% (P < 0.01) vs. O: +2.6 ± 1% and +3.5 ± 2%, (P = NS) at 3 and 6-wks, respectively). While "basal" longer-term MPS was identical between Y and O (∼1.35 ± 0.1%d(-1) ), MPS increased in response to RET only in Y (3-wks Y: 1.61 ± 0.1%.d(-1 ) vs. O: 1.49 ± 0.1%.d(-1) ). Consistent with this, O exhibited inferior ribosomal biogenesis (RNA:DNA-ratio and c-MYC induction, Y: +4 ± 2 vs. O: +1.9 ± 1), translational efficiency (S6K1 phosphorylation Y: +10 ± 4 vs. O: +4 ± 2) and anabolic hormone milieu (testosterone Y: 367 ± 19 vs. O: 274 ± 19 ng dl(-1) (all P < 0.05). Anabolic resistance is thus, multifactorial. | language |
dc.language.iso | en | language |
dc.subject | Anabolic Resistance | language |
dc.subject | Exercise | language |
dc.title | Synchronous deficits in cumulative muscle protein synthesis and ribosomal biogenesis underlie age-related anabolic resistance to exercise in humans. | language |
dc.type | Article | language |