Exercise with low glycogen increases PGC-1α gene expression in human skeletal muscle

• Published in: European journal of applied physiology 2013-04, Vol.113 (4), p.951-963
• Main Authors: Psilander, Niklas, Frank, Per, Flockhart, Mikael, Sahlin, Kent
• Format: Article
• Language: English
• Subjects: Acetyl-CoA Carboxylase - metabolism; AMP-activated protein kinase; AMP-Activated Protein Kinases - metabolism; Analysis of Variance; Bicycling; Biomedical and Life Sciences; Biomedicine; Biopsy; Cross-Over Studies; Diet, Carbohydrate-Restricted; Electron Transport Complex IV - genetics; Exercise; Glutathione - metabolism; Glycogen - deficiency; Glycogen - metabolism; Heat-Shock Proteins - genetics; Human Physiology; Humans; Medicin och hälsovetenskap; Medicin/Teknik; Medicine/Technology; Mitochondria, Muscle - metabolism; Mitochondrial Turnover; Muscle Contraction; Occupational Medicine/Industrial Medicine; Original Article; Oxidative Stress; Oxygen Consumption; p38 Mitogen-Activated Protein Kinases - metabolism; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Phosphorylation; Protein-Serine-Threonine Kinases - genetics; Quadriceps Muscle - metabolism; Reactive Oxygen Species - metabolism; RNA, Messenger - metabolism; Sports Medicine; Sweden; Time Factors; Transcription Factors - genetics; Up-Regulation
• ISSN: 1439-6319; 1439-6327; 1439-6327
• DOI: 10.1007/s00421-012-2504-8

Recent studies suggest that carbohydrate restriction can improve the training-induced adaptation of muscle oxidative capacity. However, the importance of low muscle glycogen on the molecular signaling of mitochondrial biogenesis remains unclear. Here, we compare the effects of exercise with low (LG) and normal (NG) glycogen on different molecular factors involved in the regulation of mitochondrial biogenesis. Ten highly trained cyclists ( V O 2max 65 ± 1 ml/kg/min, W max 387 ± 8 W) exercised for 60 min at approximately 64 % V O 2max with either low [166 ± 21 mmol/kg dry weight (dw)] or normal (478 ± 33 mmol/kg dw) muscle glycogen levels achieved by prior exercise/diet intervention. Muscle biopsies were taken before, and 3 h after, exercise. The mRNA of peroxisome proliferator-activated receptor-γ coactivator-1 was enhanced to a greater extent when exercise was performed with low compared with normal glycogen levels (8.1-fold vs. 2.5-fold increase). Cytochrome c oxidase subunit I and pyruvate dehydrogenase kinase isozyme 4 mRNA were increased after LG (1.3- and 114-fold increase, respectively), but not after NG. Phosphorylation of AMP-activated protein kinase, p38 mitogen-activated protein kinases and acetyl-CoA carboxylase was not changed 3 h post-exercise. Mitochondrial reactive oxygen species production and glutathione oxidative status tended to be reduced 3 h post-exercise. We conclude that exercise with low glycogen levels amplifies the expression of the major genetic marker for mitochondrial biogenesis in highly trained cyclists. The results suggest that low glycogen exercise may be beneficial for improving muscle oxidative capacity.