title: Effects of Exercise Training on Regulation of Skeletal Muscle Glucose Metabolism in Elderly Men.
abstract: BACKGROUND
  The aim was to investigate the molecular mechanisms behind exercise training-induced improvements in glucose regulation in aged subjects.
  
  
  METHODS
  Twelve elderly male subjects completed 8 weeks of exercise training. Before and after the training period, the subjects completed an oral glucose tolerance test (OGTT) and a muscle biopsy was obtained from the vastus lateralis before and 45 minutes into the OGTT. Blood samples were collected before and up to 120 minutes after glucose intake.
  
  
  RESULTS
  Exercise training increased Hexokinase II, GLUT4, Akt2, glycogen synthase (GS), pyruvate dehydrogenase (PDH)-E1α, PDK2 protein, and glycogen content in skeletal muscle. Furthermore, in response to glucose, GS activity was increased and the dephosphorylation of GS site 2 + 2a and 3a was enhanced after the training intervention. The glucose-mediated insulin stimulation of TBC1D4 Thr(642) phosphorylation was increased after exercise training. In the trained state, the PDHa activity was reduced following glucose intake and without changes in phosphorylation level of PDH-E1α.
  
  
  CONCLUSIONS
  The present results suggest that exercise training improves glucose regulation in elderly subjects by enhancing the capacity and acute regulation of glucose uptake and by enhancing intracellular glucose removal to glycogen synthesis rather than glucose oxidation.
authors.affiliation: Centre of Inflammation and Metabolism, The August Krogh Centre, Department of Biology, and.
authors.forename: Rasmus Sjørup
authors.initials: RS
authors.lastname: Biensø
authors.affiliation: Centre of Inflammation and Metabolism, The August Krogh Centre, Department of Biology, and.
authors.forename: Jesper
authors.initials: J
authors.lastname: Olesen
authors.affiliation: The August Krogh Centre, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark.
authors.forename: Lasse
authors.initials: L
authors.lastname: Gliemann
authors.affiliation: The August Krogh Centre, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark.
authors.forename: Jakob Friis
authors.initials: JF
authors.lastname: Schmidt
authors.affiliation: Centre of Inflammation and Metabolism, The August Krogh Centre, Department of Biology, and.
authors.forename: Mikkel Sillesen
authors.initials: MS
authors.lastname: Matzen
authors.affiliation: The August Krogh Centre, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark.
authors.forename: Jørgen F P
authors.initials: JF
authors.lastname: Wojtaszewski
authors.affiliation: The August Krogh Centre, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark.
authors.forename: Ylva
authors.initials: Y
authors.lastname: Hellsten
authors.affiliation: Centre of Inflammation and Metabolism, The August Krogh Centre, Department of Biology, and hpilegaard@bio.ku.dk.
authors.forename: Henriette
authors.initials: H
authors.lastname: Pilegaard
mesh_terms: D000368:Aged; D015331:Cohort Studies; D005081:Exercise Therapy; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test; D051275:Glucose Transporter Type 4 / Q000378:metabolism; D006006:Glycogen Synthase / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism*; D030481:Pyruvate Dehydrogenase (Lipoamide) / Q000378:metabolism
chemical_list: D051275:Glucose Transporter Type 4; D007328:Insulin; D030481:Pyruvate Dehydrogenase (Lipoamide); C065640:pyruvate dehydrogenase E1alpha subunit; D006006:Glycogen Synthase; D005947:Glucose
keywords: Aging; Glycogen synthase; Insulin signaling.; Physical activity; Pyruvate dehydrogenase