title: Phytanic acid stimulates glucose uptake in a model of skeletal muscles, the primary porcine myotubes.
abstract: BACKGROUND
  Phytanic acid (PA) is a chlorophyll metabolite with potentials in regulating glucose metabolism, as it is a natural ligand of the peroxisome proliferator-activated receptor (PPAR) that is known to regulate hepatic glucose homeostasis. This study aimed to establish primary porcine myotubes as a model for measuring glucose uptake and glycogen synthesis, and to examine the impact of physiological amounts of PA on glucose uptake and glycogen synthesis either alone or in combination with insulin.
  
  
  METHODS
  Porcine satellite cells were cultured into differentiated myotubes and tritiated 2-deoxyglucose (2-DOG) was used to measure glucose uptake, in relation to PA and 2-DOG exposure times and also in relation to PA and insulin concentrations. The MIXED procedure model of SAS was used for statistical analysis of data.
  
  
  RESULTS
  PA increased glucose uptake by approximately 35%, and the presence of insulin further increased the uptake, but this further increase in uptake was non- additive and less pronounced at high insulin concentrations. There was no effect of PA alone on glycogen synthesis, while the insulin stimulation of glycogen was increased by 20% in the presence of PA. PA neither stimulated glucose uptake nor glycogen synthesis in insulin-resistant myotubes generated by excess glucose exposure.
  
  
  CONCLUSIONS
  Primary porcine myotubes were established as a model of skeletal muscles for measuring glucose uptake and glycogen synthesis, and we showed that PA can play a role in stimulating glucose uptake at no or inadequate insulin concentrations.
authors: Department of Food Science, Aarhus University, Blichers Allé 20, Tjele, 8830, Denmark.
authors: Brita N
authors: BN
authors: Che
authors: Niels
authors: N
authors: Oksbjerg
authors: Lars I
authors: LI
authors: Hellgren
authors: Jacob H
authors: JH
authors: Nielsen
authors: Jette F
authors: JF
authors: Young
mesh_terms: D000818:Animals; D001692:Biological Transport; D002454:Cell Differentiation; D002470:Cell Survival / Q000187:drug effects; D003847:Deoxyglucose / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism; D005260:Female; D006003:Glycogen / Q000096:biosynthesis; D007328:Insulin / Q000378:metabolism / Q000494:pharmacology*; D008954:Models, Biological; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010831:Phytanic Acid / Q000378:metabolism / Q000494:pharmacology*; D061251:Primary Cell Culture; D032496:Satellite Cells, Skeletal Muscle / Q000166:cytology / Q000378:metabolism; D013552:Swine; D014316:Tritium
chemical_list: D005227:Fatty Acids; D007328:Insulin; D014316:Tritium; D010831:Phytanic Acid; D006003:Glycogen; D003847:Deoxyglucose
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