5'-AMP-activated protein kinase activity and subunit expression in exercise-trained human skeletal muscle

1 Institute of Exercise and Sport Sciences and 4 August Krogh Institute, Copenhagen Muscle Research Centre, University of Copenhagen, DK-2100 Copenhagen, Denmark; 2 Wellcome Trust Biocentre, Division of Molecular Physiology, University of Dundee, Dundee DD1 4HN, Scotland, United Kingdom; and 3 Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts 02215 5'-AMP-activated protein kinase (AMPK) has been proposed to be a pivotal factor in cellular responses to both acute exercise and exercise training. To investigate whether protein levels and gene expression of catalytic ( 1 , 2 ) and regulatory ( 1 , 2 , 1 , 2 , 3 ) AMPK subunits and exercise-induced AMPK activity are influenced by exercise training status, muscle biopsies were obtained from seven endurance exercise-trained and seven sedentary young healthy men. The 1 - and 2 -AMPK mRNA contents in trained subjects were both 117 ± 2% of that in sedentary subjects (not significant), whereas mRNA for 3 was 61 ± 1% of that in sedentary subjects (not significant). The level of 1 -AMPK protein in trained subjects was 185 ± 34% of that in sedentary subjects ( P