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SNAT2 and LAT1 transporter abundance is developmentally regulated in skeletal muscle of neonatal pigs
Author(s) -
Suryawan Agus,
Gazzaneo María C.,
Almonaci Rosemarie D.,
Nguyen Hanh V.,
Torrazza Roberto Murgas,
Davis Teresa A.
Publication year - 2010
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.24.1_supplement.331.4
Subject(s) - mtorc1 , amino acid , chemistry , leucine , transporter , amino acid transporter , intracellular , biology , medicine , biochemistry , signal transduction , gene , pi3k/akt/mtor pathway
Previously we demonstrated that the insulin‐ and amino acid–induced activation of the mammalian target of rapamycin complex 1 (mTORC1) is developmentally regulated in neonatal pigs. Recent studies have indicated an important role of the System A transporters (SNAT2 and SLC1A5) and the L transporter (LAT1) in intracellular accumulation of essential amino acids, such as leucine, and in mTORC1 activation. This study aimed to determine the effects of age and the post‐prandial rise in insulin and amino acids on the abundance and activation of SNAT2, SLC1A5 and LAT1. Overnight fasted 6‐ and 26‐day‐old pigs were infused for 2 h with saline, insulin, or amino acids to achieve fed levels. The abundance of SNAT2 and LAT1, but not SLC1A5, was significantly higher in muscle of 6‐ than in 26‐d‐old pigs. The activation of SNAT2, determined by transporter translocation to the plasma membrane, was unaffected by 2 hr infusion of amino acids or insulin. To determine the acute effects of feeding, SNAT2 activation was determined 0, 30, and 60 min after a complete meal. Feeding had no effect on SNAT2 activation at any time point suggesting that SNAT2 activation in vivo may be short‐lived. In conclusion, the elevated abundance of SNAT2 and LAT1 is likely to play a significant role in the enhanced amino acid‐induced activation of mTORC1 in neonatal pigs (Supported by NIH grants AR‐44474 and USDA/ARS 6250510000‐33).