Loevsletten 2017 MiP2017

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Loevsletten Nils
Increased glucose and fatty acid metabolism and metabolic flexibility in myotubes from trained subjects.

Link: MiP2017

Loevsletten NG, Lund J, Jensen J, Thoresen GH, Rustan AC (2017)

Event: MiP2017

COST Action MITOEAGLE
Skeletal muscles of healthy young people can have a large variation in oxidative capacity. In this study we compared glucose and fatty acid metabolism in myotubes established from trained and sedentary untrained young male subjects, where untrained was defined as VO2max < 46 ml/kg/min whereas trained was defined as VO2max > 60 ml/kg/min.

Myoblasts were cultured and differentiated to myotubes from satellite cells isolated from biopsies of musculus vastus lateralis. Glucose and fatty acid metabolism was studied in myotubes using D-[14C(U)]glucose, [1-14C]deoxy-D-glucose and [1-14C]oleic acid, respectively. Accumulation of labelled substrates was assessed by scintillation proximity assay. Lipid distribution was measured by thin layer chromatography. Gene and protein expressions were also studied.

Myotubes established from trained subjects showed higher glucose accumulation and fractional glucose oxidation. These cells were also more sensitive to the suppressive action of acutely added oleic acid. There was no difference in basal and insulin-stimulated glycogen synthesis between the two donor groups. Myotubes from trained subjects showed higher fatty acid oxidation, both complete oxidation (CO2 formation) and β-oxidation, compared to myotubes from untrained subjects. Furthermore, myotubes from trained individuals showed lower fatty acid accumulation and lower incorporation of fatty acids into total cellular lipids, triacylglycerol, diacylglycerol and cholesteryl ester.

Myotubes from trained subjects were more flexible to exploit the fuel source available, demonstrated by the suppressive activity of fatty acids on glucose oxidation. Furthermore, myotubes from trained individuals had higher glucose and fatty acid metabolism compared to myotubes from untrained subjects. Whether these properties in the satellite cells are inherent from birth or acquired through lifestyle remains unknown.


Bioblast editor: Kandolf G


Labels: MiParea: Exercise physiology;nutrition;life style 


Organism: Human  Tissue;cell: Skeletal muscle 





Affiliations

Løvsletten NG(1), Lund J(1), Jensen J(2), Thoresen GH(1), Rustan AC(1)
  1. Dept Pharmaceutical Biosciences, School Pharmacy, Univ Oslo
  2. Dept Physical Performance, Norwegian School Sport Sciences; Norway. - n.g.lovsletten@farmasi.uio.no