title: Effects of fatty acid treatments on the dexamethasone-induced intramuscular lipid accumulation in chickens.
abstract: BACKGROUND
  Glucocorticoid has an important effect on lipid metabolism in muscles, and the type of fatty acid likely affects mitochondrial utilization. Therefore, we hypothesize that the different fatty acid types treatment may affect the glucocorticoid induction of intramuscular lipid accumulation.
  
  
  RESULTS
  The effect of dexamethasone (DEX) on fatty acid metabolism and storage in skeletal muscle of broiler chickens (Gallus gallus domesticus) was investigated with and without fatty acid treatments. Male Arbor Acres chickens (31 d old) were treated with either palmitic acid (PA) or oleic acid (OA) for 7 days, followed by DEX administration for 3 days (35-37 d old). The DEX-induced lipid uptake and oxidation imbalance, which was estimated by increased fatty acid transport protein 1 (FATP1) expression and decreased carnitine palmitoyl transferase 1 activity, contributed to skeletal muscle lipid accumulation. More sensitive than glycolytic muscle, the oxidative muscle in DEX-treated chickens showed a decrease in the AMP to ATP ratio, a decrease in AMP-activated protein kinase (AMPK) alpha phosphorylation and its activity, as well as an increase in the phosphorylation of mammalian target of rapamycin (mTOR) and ribosomal p70S6 kinase, without Akt activation. DEX-stimulated lipid deposition was augmented by PA, but alleviated by OA, in response to pathways that were regulated differently, including AMPK, mTOR and FATP1.
  
  
  CONCLUSIONS
  DEX-induced intramuscular lipid accumulation was aggravated by SFA but alleviated by unsaturated fatty acid. The suppressed AMPK and augmented mTOR signaling pathways were involved in glucocortcoid-mediated enhanced intramuscular fat accumulation.
authors.affiliation: Department of Animal Science, Shandong Agricultural University, Taian, Shandong, People's Republic of China.
authors.forename: Xiao juan
authors.initials: Xj
authors.lastname: Wang
authors.forename: Dai lin
authors.initials: Dl
authors.lastname: Wei
authors.forename: Zhi gang
authors.initials: Zg
authors.lastname: Song
authors.forename: Hong chao
authors.initials: Hc
authors.lastname: Jiao
authors.forename: Hai
authors.initials: H
authors.lastname: Lin
mesh_terms: D000091162:AMP-Activated Protein Kinase Kinases; D000249:Adenosine Monophosphate / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D015153:Blotting, Western; D002645:Chickens / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D003907:Dexamethasone / Q000494:pharmacology*; D005227:Fatty Acids / Q000494:pharmacology*; D050356:Lipid Metabolism / Q000187:drug effects*; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D019301:Oleic Acid / Q000378:metabolism; D019308:Palmitic Acid / Q000494:pharmacology; D011494:Protein Kinases / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D017931:DNA Primers; D005227:Fatty Acids; D019301:Oleic Acid; D019308:Palmitic Acid; D000249:Adenosine Monophosphate; D003907:Dexamethasone; D011494:Protein Kinases; D000091162:AMP-Activated Protein Kinase Kinases