title: Protein synthesis and the expression of growth-related genes are altered by running in human vastus lateralis and soleus muscles.
abstract: Recent evidence suggests aerobic exercise may help preserve soleus muscle mass during unloading. The purpose of this investigation was to examine the muscle-specific metabolic response to running as it relates to muscle growth. Mixed-muscle protein synthesis [fractional synthetic rate (FSR)] and gene expression (GE) were examined in the vastus lateralis (VL) and soleus (SOL) muscles from eight men (26 +/- 2 yr; Vo(2max) 63 +/- 2 ml.kg(-1).min(-1)) before and after a 45-min level-grade treadmill run at 77 +/- 1% intensity. Muscle glycogen utilization was similar between muscles. Resting FSR was similar between the VL (0.080 +/- 0.007 %/h) and SOL (0.086 +/- 0.008 %/h) and was higher (P < 0.05) 24 h postexercise compared with rest for both muscles. The absolute change in FSR was not different between muscles (0.030 +/- 0.007 vs. 0.037 +/- 0.012 %/h for VL and SOL). At baseline, myostatin GE was approximately twofold higher (P < 0.05) in SOL compared with VL, while no other muscle-specific differences in GE were present. After running, myostatin GE was suppressed (P < 0.05) in both muscles at 4 h and was higher (P < 0.05) than baseline at 24 h for VL only. Muscle regulatory factor 4 mRNA was elevated (P < 0.05) at 4 h in both SOL and VL; MyoD and peroxisome-proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha) were higher (P < 0.05) at 4 h, and forkhead box [FOXO]3A was higher at 24 h in SOL only, while muscle-RING-finger protein-1 (MuRF-1) was higher (P < 0.05) at 4 h in VL only. Myogenin and atrogin-1 GE were unaltered. The similar increases between muscles in FSR support running as part of the exercise countermeasure to preserve soleus mass during unloading. The subtle differences in GE suggest a potential mechanism for muscle-specific adaptations to chronic run training.
authors.affiliation: Ball State Univ., Muncie, IN 47306, USA. mharber@bsu.edu
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Harber
authors.forename: Justin D
authors.initials: JD
authors.lastname: Crane
authors.forename: Jared M
authors.initials: JM
authors.lastname: Dickinson
authors.forename: Bozena
authors.initials: B
authors.lastname: Jemiolo
authors.forename: Ulrika
authors.initials: U
authors.lastname: Raue
authors.forename: Todd A
authors.initials: TA
authors.lastname: Trappe
authors.forename: Scott W
authors.initials: SW
authors.lastname: Trappe
mesh_terms: D000328:Adult; D006003:Glycogen / Q000378:metabolism; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000096:biosynthesis* / Q000235:genetics*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D018485:Muscle Fibers, Skeletal / Q000378:metabolism; D009124:Muscle Proteins / Q000096:biosynthesis* / Q000235:genetics*; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000378:metabolism* / Q000502:physiology*; D018995:Myosin Heavy Chains / Q000096:biosynthesis / Q000235:genetics; D010101:Oxygen Consumption / Q000502:physiology; D010649:Phenylalanine / Q000097:blood; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012420:Running / Q000502:physiology*
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; D009124:Muscle Proteins; D010649:Phenylalanine; D012313:RNA; D006003:Glycogen; D018995:Myosin Heavy Chains