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High levels of leucine are required for the upregulation of amino acid transporters in human skeletal muscle following essential amino acid ingestion
Author(s) -
Dickinson Jared M,
Drummond Micah J,
Fry Christopher S,
Glynn Erin L,
Gundermann David M,
Walker Dillon K,
Timmerman Kyle L,
Volpi Elena,
Rasmussen Blake B
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.233.6
Subject(s) - leucine , amino acid transporter , amino acid , transporter , downregulation and upregulation , ingestion , biochemistry , skeletal muscle , essential amino acid , messenger rna , chemistry , biology , endocrinology , gene
The goal of this study was to determine whether the upregulation of select amino acid transporters in human skeletal muscle is dependent upon the amount of leucine in an essential amino acid (EAA) solution. Young, healthy individuals ingested 10g of EAA with either a leucine concentration similar to high quality protein (CTRL; 1.8g leucine [n=6]) or an increased leucine concentration (LEU; 3.5g leucine [n=7]). Muscle biopsies were obtained prior to and at 1 and 2h following EAA ingestion to examine select amino acid transporter mRNA expression. Following EAA ingestion, CTRL had little change in amino acid transporter mRNA expression, whereas at 1h post ingestion LEU experienced an increase in L‐type (LAT1), sodium‐coupled neutral (SNAT2), and proton‐coupled (PAT1) amino acid transporter mRNA expression. These data highlight an important role for leucine availability in the upregulation of select amino acid transporters. Furthermore, additional leucine may sensitize the muscle cell to subsequent feedings by increasing the availability of amino acid transporters. Funding: NIH/NIAMS R01 AR049877 , NIA P30AG024832, NIH 1UL1RR029876‐01