title: Impact of adrenaline and metabolic stress on exercise-induced intracellular signaling and PGC-1α mRNA response in human skeletal muscle.
abstract: This study tested the hypothesis that elevated plasma adrenaline or metabolic stress enhances exercise-induced PGC-1α mRNA and intracellular signaling in human muscle. Trained (VO2-max: 53.8 ± 1.8 mL min(-1) kg(-1)) male subjects completed four different exercise protocols (work load of the legs was matched): C - cycling at 171 ± 6 W for 60 min (control); A - cycling at 171 ± 6 W for 60 min, with addition of intermittent arm exercise (98 ± 4 W). DS - cycling at 171 ± 6 W interspersed by 30 sec sprints (513 ± 19 W) every 10 min (distributed sprints); and CS - cycling at 171 ± 6 W for 40 min followed by 20 min of six 30 sec sprints (clustered sprints). Sprints were followed by 3:24 min:sec at 111 ± 4 W. A biopsy was obtained from m. vastus lateralis at rest and immediately, and 2 and 5 h after exercise. Muscle PGC-1α mRNA content was elevated (P < 0.05) three- to sixfold 2 h after exercise relative to rest in C, A, and DS, with no differences between protocols. AMPK and p38 phosphorylation was higher (P < 0.05) immediately after exercise than at rest in all protocols, and 1.3- to 2-fold higher (P < 0.05) in CS than in the other protocols. CREB phosphorylation was higher (P < 0.05) 2 and 5 h after exercise than at rest in all protocols, and higher (P < 0.05) in DS than CS 2 h after exercise. This suggests that neither plasma adrenaline nor muscle metabolic stress determines the magnitude of PGC-1α mRNA response in human muscle. Furthermore, higher exercise-induced changes in AMPK, p38, and CREB phosphorylation are not associated with differences in the PGC-1α mRNA response.
authors.affiliation: The August Krogh Centre, Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Nina
authors.initials: N
authors.lastname: Brandt
authors.affiliation: Section for Integrated Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Gunnarsson
authors.affiliation: Section for Integrated Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark Bispebjerg University Hospital, Copenhagen, Denmark.
authors.forename: Morten
authors.initials: M
authors.lastname: Hostrup
authors.affiliation: Section for Integrated Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Jonas
authors.initials: J
authors.lastname: Tybirk
authors.affiliation: Section for Integrated Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Nybo
authors.affiliation: The August Krogh Centre, Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Henriette
authors.initials: H
authors.lastname: Pilegaard
authors.affiliation: Section for Integrated Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark jbangsbo@nexs.ku.dk.
authors.forename: Jens
authors.initials: J
authors.lastname: Bangsbo
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism; D000328:Adult; D001642:Bicycling; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D018592:Cross-Over Studies; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D004734:Energy Metabolism; D004837:Epinephrine / Q000097:blood*; D015444:Exercise; D006801:Humans; D008297:Male; D009119:Muscle Contraction; D010101:Oxygen Consumption; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D010766:Phosphorylation; D052097:Quadriceps Muscle / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D013312:Stress, Physiological; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation; D055815:Young Adult; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D015415:Biomarkers; C115163:CREB1 protein, human; D017362:Cyclic AMP Response Element-Binding Protein; C486497:PPARGC1A protein, human; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D012333:RNA, Messenger; D014157:Transcription Factors; D048051:p38 Mitogen-Activated Protein Kinases; D055372:AMP-Activated Protein Kinases; D004837:Epinephrine
keywords: Exercise; PGC‐1α mRNA; human muscle biopsies; intracellular signaling; metabolic stress