PMID- 16365096
OWN - NLM
STAT- MEDLINE
DCOM- 20060302
LR  - 20230216
IS  - 0022-3166 (Print)
IS  - 0022-3166 (Linking)
VI  - 136
IP  - 1 Suppl
DP  - 2006 Jan
TI  - Branched-chain amino acids activate key enzymes in protein synthesis after 
      physical exercise.
PG  - 269S-73S
LID - 10.1093/jn/136.1.269S [doi]
AB  - BCAAs (leucine, isoleucine, and valine), particularly leucine, have anabolic 
      effects on protein metabolism by increasing the rate of protein synthesis and 
      decreasing the rate of protein degradation in resting human muscle. Also, during 
      recovery from endurance exercise, BCAAs were found to have anabolic effects in 
      human muscle. These effects are likely to be mediated through changes in 
      signaling pathways controlling protein synthesis. This involves phosphorylation 
      of the mammalian target of rapamycin (mTOR) and sequential activation of 70-kD S6 
      protein kinase (p70 S6 kinase) and the eukaryotic initiation factor 4E-binding 
      protein 1. Activation of p70 S6 kinase, and subsequent phopsphorylation of the 
      ribosomal protein S6, is associated with enhanced translation of specific mRNAs. 
      When BCAAs were supplied to subjects during and after one session of quadriceps 
      muscle resistance exercise, an increase in mTOR, p70 S6 kinase, and S6 
      phosphorylation was found in the recovery period after the exercise with no 
      effect of BCAAs on Akt or glycogen synthase kinase 3 (GSK-3) phosphorylation. 
      Exercise without BCAA intake led to a partial phosphorylation of p70 S6 kinase 
      without activating the enzyme, a decrease in Akt phosphorylation, and no change 
      in GSK-3. It has previously been shown that leucine infusion increases p70 S6 
      kinase phosphorylation in an Akt-independent manner in resting subjects; however, 
      a relation between mTOR and p70 S6 kinase has not been reported previously. The 
      results suggest that BCAAs activate mTOR and p70 S6 kinase in human muscle in the 
      recovery period after exercise and that GSK-3 is not involved in the anabolic 
      action of BCAAs on human muscle.
FAU - Blomstrand, Eva
AU  - Blomstrand E
AD  - Department of Surgical Science, Karolinska Institutet, Stockholm, Sweden. 
      eva.blomstrand@gih.se
FAU - Eliasson, Jorgen
AU  - Eliasson J
FAU - Karlsson, Hakan K R
AU  - Karlsson HK
FAU - Kohnke, Rickard
AU  - Kohnke R
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Review
PL  - United States
TA  - J Nutr
JT  - The Journal of nutrition
JID - 0404243
RN  - 0 (Amino Acids, Branched-Chain)
RN  - EC 2.7.- (Protein Kinases)
RN  - EC 2.7.1.1 (MTOR protein, human)
RN  - EC 2.7.11.1 (Proto-Oncogene Proteins c-akt)
RN  - EC 2.7.11.1 (Ribosomal Protein S6 Kinases, 70-kDa)
RN  - EC 2.7.11.1 (TOR Serine-Threonine Kinases)
RN  - EC 2.7.11.26 (Glycogen Synthase Kinase 3)
RN  - EC 2.7.11.26 (glycogen synthase kinase 3 alpha)
SB  - IM
MH  - Amino Acids, Branched-Chain/*pharmacology
MH  - *Exercise
MH  - Glycogen Synthase Kinase 3/metabolism
MH  - Humans
MH  - Muscle, Skeletal/metabolism
MH  - Phosphorylation
MH  - *Protein Biosynthesis
MH  - Protein Kinases/metabolism
MH  - Proto-Oncogene Proteins c-akt/metabolism
MH  - Ribosomal Protein S6 Kinases, 70-kDa/metabolism
MH  - Signal Transduction
MH  - TOR Serine-Threonine Kinases
RF  - 48
EDAT- 2005/12/21 09:00
MHDA- 2006/03/03 09:00
CRDT- 2005/12/21 09:00
PHST- 2005/12/21 09:00 [pubmed]
PHST- 2006/03/03 09:00 [medline]
PHST- 2005/12/21 09:00 [entrez]
AID - S0022-3166(22)08047-6 [pii]
AID - 10.1093/jn/136.1.269S [doi]
PST - ppublish
SO  - J Nutr. 2006 Jan;136(1 Suppl):269S-73S. doi: 10.1093/jn/136.1.269S.