Branched-chain amino acids protect against dexamethasone-induced soleus muscle atrophy in rats

Muscle Nerve. 2010 Jun;41(6):819-27. doi: 10.1002/mus.21621.


We investigated the utility of branched-chain amino acids (BCAA) in dexamethasone-induced muscle atrophy. Dexamethasone (600 microg/kg, intraperitoneally) and/or BCAA (600 mg/kg, orally) were administered for 5 days in rats, and the effect of BCAA on dexamethasone-induced muscle atrophy was evaluated. Dexamethasone decreased total protein concentration of rat soleus muscles. Concomitant administration of BCAA reversed the decrease. Dexamethasone decreased mean cross-sectional area of soleus muscle fibers, which was reversed by BCAA. Dexamethasone increased atrogin-1 expression, which has been reported to play a pivotal role in muscle atrophy. The increased expression of atrogin-1 mRNA was significantly attenuated by BCAA. Furthermore, dexamethasone-induced conversion from microtubule-associated protein 1 light chain 3 (LC3)-I to LC3-II, which is an indicator of autophagy, was blocked by BCAA. These findings suggest that BCAA decreased protein breakdown to prevent muscle atrophy. BCAA administration appears to be useful for prevention of steroid myopathy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids, Branched-Chain / therapeutic use*
  • Animals
  • Body Size
  • DNA Primers
  • Dexamethasone / administration & dosage
  • Dexamethasone / adverse effects*
  • Glyceraldehyde-3-Phosphate Dehydrogenases / genetics
  • Injections, Intraperitoneal
  • Male
  • Muscle Proteins / genetics
  • Muscle, Skeletal / anatomy & histology
  • Muscle, Skeletal / drug effects
  • Muscle, Skeletal / pathology*
  • Muscular Atrophy / chemically induced*
  • Muscular Atrophy / prevention & control*
  • Organ Size
  • RNA, Messenger / genetics
  • RNA, Messenger / isolation & purification
  • Rats
  • Rats, Sprague-Dawley
  • Reverse Transcriptase Polymerase Chain Reaction
  • SKP Cullin F-Box Protein Ligases / genetics
  • Tripartite Motif Proteins
  • Ubiquitin-Protein Ligases / genetics


  • Amino Acids, Branched-Chain
  • DNA Primers
  • Muscle Proteins
  • RNA, Messenger
  • Tripartite Motif Proteins
  • Dexamethasone
  • Glyceraldehyde-3-Phosphate Dehydrogenases
  • Fbxo32 protein, rat
  • SKP Cullin F-Box Protein Ligases
  • Trim63 protein, rat
  • Ubiquitin-Protein Ligases