Concurrent resistance and aerobic exercise stimulates both myofibrillar and mitochondrial protein synthesis in sedentary middle-aged men
Autor: | Nicholas A. Burd, Johann Edge, Cheyne E. Donges, Stuart M. Phillips, Richard W.A. Mackenzie, Rob Duffield, Lindsay D. Plank, Michael J. Short, Daniel W. D. West, Greg C. Smith, Peter R. Shepherd |
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Rok vydání: | 2012 |
Předmět: |
Male
medicine.medical_specialty Physiology Muscle Proteins RNA-binding protein Biology Mitochondrial Proteins Myofibrils Physiology (medical) Signaling proteins Internal medicine Gene expression medicine Humans Aerobic exercise RNA Messenger Phosphorylation Exercise physiology Muscle Skeletal Exercise Heat-Shock Proteins RNA-Binding Proteins Middle Aged Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha Endocrinology Protein Biosynthesis Mitochondrial protein synthesis Carrier Proteins Myofibril Transcription Factors |
Zdroj: | Journal of Applied Physiology. 112:1992-2001 |
ISSN: | 1522-1601 8750-7587 |
Popis: | We determined myofibrillar and mitochondrial protein fractional synthesis rates (FSR), intramuscular signaling protein phosphorylation, and mRNA expression responses after isolated bouts of resistance exercise (RE), aerobic exercise (AE), or in combination [termed concurrent exercise (CE)] in sedentary middle-aged men. Eight subjects (age = 53.3 ± 1.8 yr; body mass index = 29.4 ± 1.4 kg·m2) randomly completed 8 × 8 leg extension repetitions at 70% of one repetition-maximum, 40 min of cycling at 55% peak aerobic power output (AE), or (consecutively) 50% of the RE and AE trials (CE). Biopsies were obtained (during a primed, constant infusion of l-[ ring-13C6]phenylalanine) while fasted, and at 1 and 4 h following postexercise ingestion of 20 g of protein. All trials increased mitochondrial FSR above fasted rates (RE = 1.3-fold; AE = 1.5; CE = 1.4; P < 0.05), although only CE (2.2) and RE (1.8) increased myofibrillar FSR ( P < 0.05). At 1 h postexercise, phosphorylation of Akt on Ser473 (CE = 7.7; RE = 4.6) and Thr308 (CE = 4.4; RE = 2.9), and PRAS40 on Thr246 (CE = 3.8; AE = 2.5) increased ( P < 0.05), with CE greater than AE for Akt Ser473-Thr308 and greater than RE for PRAS40 ( P < 0.05). Despite increased phosphorylation of Akt-PRAS40, phosphorylation of mammalian target of rapamycin (Ser2448) remained unchanged ( P > 0.05), while rpS6 (Ser235/236) increased only in RE (10.4) ( P < 0.05). CE and AE both resulted in increased peroxisome proliferator receptor-γ coactivator 1-α (PGC1α) expression at 1 h (CE = 2.9; AE = 2.8; P < 0.05) and 4 h (CE = 2.6; AE = 2.4) and PGC1β expression at 4 h (CE = 2.1; AE = 2.6; P < 0.05). These data suggest that CE-induced acute stimulation of myofibrillar and mitochondrial FSR, protein signaling, and mRNA expression are equivalent to either isolate mode (RE or AE). These results occurred without an interference effect on muscle protein subfractional synthesis rates, protein signaling, or mRNA expression. |
Databáze: | OpenAIRE |
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