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Insulin and amino acids stimulate whole body protein synthesis in neonates
Author(s) -
Jeyapalan Asumthia,
Orellana Renan A.,
Burrin Douglas G.,
Fiorotto Marta L.,
Jahoor Farook,
Nguyen Hanh V.,
Suryawan Agus,
Davis Teresa A.
Publication year - 2007
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.21.5.a334-c
Subject(s) - hyperinsulinemia , medicine , endocrinology , insulin , proteolysis , protein turnover , chemistry , amino acid , leucine , protein metabolism , metabolism , protein biosynthesis , biology , insulin resistance , biochemistry , enzyme
Insulin and amino acids (AA) stimulate muscle protein synthesis in neonatal pigs. To determine the effects of insulin and AA on whole body protein turnover, hyperinsulinemic (0 and 100 ng/(kg 0.66 /min))‐euglycemic‐AA clamps were performed during euaminoacidemia or hyperaminoacidemia in fasted 7‐d‐old pigs (n=6–9/dose). Whole body protein turnover was determined with 13 C‐leucine and AA were clamped with a balanced AA mixture. Plasma insulin increased from 2 to 30 μU/ml during hyperinsulinemia but did not change with hyperaminoacidemia. Essential (E) AA and nonessential (NE) AA were maintained at fasting levels during euaminoacidemia. Hyperaminoacidemia increased plasma EAA 2‐fold and NEAA 50–100%. Hyperinsulinemia increased flux (P<0.001), AA oxidation (P<0.005), and protein synthesis (P<0.007), reduced proteolysis (P<0.03), and improved protein balance (P<0.005). Hyperaminoacidemia increased flux (P<0.03), protein synthesis (P<0.03), and protein balance (P<0.01) but did not alter proteolysis or AA oxidation. Protein balance was greater in the presence of hyperinsulinemia with hyperaminoacidemia than with hyperinsulinemia (P<0.10) or hyperaminoacidemia (P<0.02) alone. The results suggest that insulin and AA improve whole body protein balance by increasing protein synthesis but only insulin reduces proteolysis in neonates. NIH AR44474, USDA 58‐6250‐6‐001