title: Oleate-enriched diet improves insulin sensitivity and restores muscle protein synthesis in old rats.
abstract: OBJECTIVE
  Age-related inflammation and insulin resistance (IR) have been implicated in the inability of old muscles to properly respond to anabolic stimuli such as amino acids (AA) or insulin. Since fatty acids can modulate inflammation and IR in muscle cells, we investigated the effect of palmitate-enriched diet and oleate-enriched diet on inflammation, IR and muscle protein synthesis (MPS) rate in old rats.
  
  
  METHODS
  Twenty-four 25-month-old rats were fed either a control diet (OC), an oleate-enriched diet (HFO) or a palmitate-enriched diet (HFP) for 16 weeks. MPS using labeled amino acids and mTOR activation were assessed after AA and insulin anabolic stimulation to mimic postprandial state.
  
  
  RESULTS
  IR and systemic and adipose tissue inflammation (TNFα and IL1β) were improved in the HFO group. Muscle genes controlling mitochondrial β-oxidation (PPARs, MCAD and CPT-1b) were up-regulated in the HFO group. AA and insulin-stimulated MPS in the HFO group only, and this stimulation was related to activation of the Akt/mTOR pathway.
  
  
  CONCLUSIONS
  The age-related MPS response to anabolic signals was improved in rats fed an oleate-enriched diet. This effect was related to activation of muscle oxidative pathways, lower IR, and a decrease in inflammation.
authors.affiliation: INRA, UMR 1019, UNH, CRNH Auvergne, F-63000 Clermont-Ferrand, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Tardif
authors.forename: Jérôme
authors.initials: J
authors.lastname: Salles
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Landrier
authors.forename: Isabelle
authors.initials: I
authors.lastname: Mothe-Satney
authors.forename: Christelle
authors.initials: C
authors.lastname: Guillet
authors.forename: Carole
authors.initials: C
authors.lastname: Boue-Vaysse
authors.forename: Lydie
authors.initials: L
authors.lastname: Combaret
authors.forename: Christophe
authors.initials: C
authors.lastname: Giraudet
authors.forename: Véronique
authors.initials: V
authors.lastname: Patrac
authors.forename: Justine
authors.initials: J
authors.lastname: Bertrand-Michel
authors.forename: Carole
authors.initials: C
authors.lastname: Migné
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Chardigny
authors.forename: Yves
authors.initials: Y
authors.lastname: Boirie
authors.forename: Stéphane
authors.initials: S
authors.lastname: Walrand
mesh_terms: D042964:Acyl-CoA Dehydrogenase / Q000096:biosynthesis / Q000235:genetics; D000273:Adipose Tissue / Q000378:metabolism; D000367:Age Factors; D000818:Animals; D002334:Carnitine O-Palmitoyltransferase / Q000096:biosynthesis / Q000235:genetics; D007333:Insulin Resistance; D053583:Interleukin-1beta / Q000378:metabolism; D008297:Male; D009124:Muscle Proteins / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism*; D019301:Oleic Acid / Q000008:administration & dosage*; D047492:Peroxisome Proliferator-Activated Receptors / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D053583:Interleukin-1beta; D009124:Muscle Proteins; D047492:Peroxisome Proliferator-Activated Receptors; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D019301:Oleic Acid; D042964:Acyl-CoA Dehydrogenase; D002334:Carnitine O-Palmitoyltransferase