Linked Life Data

20505962

Source:http://linkedlifedata.com/resource/pubmed/id/20505962

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2011-1-3
pubmed:abstractText
Leucine is unique among the amino acids in its ability to promote protein synthesis by activating translation initiation via the mammalian target of rapamycin (mTOR) pathway. Previously, we showed that leucine infusion acutely stimulates protein synthesis in fast-twitch glycolytic muscle of neonatal pigs but this response cannot be maintained unless the leucine-induced fall in amino acids is prevented. To determine whether leucine can stimulate protein synthesis in muscles of different fiber types and in visceral tissues of the neonate in the long-term if baseline amino acid concentrations are maintained, overnight fasted neonatal pigs were infused for 24 h with saline, leucine (400 micromol kg(-1) h(-1)), or leucine with replacement amino acids to prevent the leucine-induced hypoaminoacidemia. Changes in the fractional rate of protein synthesis and activation of mTOR, as determined by eukaryotic initiation factor 4E binding protein (4E-BP1) and S6 kinase 1 (S6K1) phosphorylation, in the gastrocnemius and masseter muscles, heart, liver, jejunum, kidney, and pancreas were measured. Leucine increased mTOR activation in the gastrocnemius and masseter muscles, liver, and pancreas, in both the absence and presence of amino acid replacement. However, protein synthesis in these tissues was increased only when amino acids were infused to maintain baseline levels. There were no changes in mTOR signaling or protein synthesis in the other tissues we examined. Thus, long-term infusion of leucine stimulates mTOR signaling in skeletal muscle and some visceral tissues but the leucine-induced stimulation of protein synthesis in these tissues requires sustained amino acid availability.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1438-2199
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
40
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
157-65
pubmed:dateRevised
2011-8-1
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Differential effects of long-term leucine infusion on tissue protein synthesis in neonatal pigs.
pubmed:affiliation
Department of Pediatrics, Baylor College of Medicine, United States Department of Agriculture/Agriculture Research Service Children's Nutrition Research Center, Houston, TX, 77030, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural