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ARS Home » Plains Area » Houston, Texas » Children's Nutrition Research Center » Research » Publications at this Location » Publication #211718
Title: Stimulation of whole body protein synthesis by insulin in neonates is dependent on the pattern of amino acids available

Author
item ORELLANA, RENAN
item Fiorotto, Marta
item Jahoor, Farook
item Burrin, Douglas - Doug
item NGUYEN, HANH
item Suryawan, Agus
item Davis, Teresa

Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: 2/7/2007
Publication Date: 4/28/2007
Citation: Orellana, R.A., Fiorotto, M.L., Jahoor, F., Burrin, D.G., Nguyen, H.V., Suryawan, A., Davis, T.A. 2007. Stimulation of whole body protein synthesis by insulin in neonates is dependent on the pattern of amino acids available [abstract]. The Federation of American Societies for Experimental Biology Journal. 21(5):A162.

Interpretive Summary:

Technical Abstract: Insulin stimulates muscle protein synthesis in neonatal pigs. To determine insulin's effects on whole body protein turnover, (13)C-leucine was infused for 4 hr during hyperinsulinemic (0, 30, 100, 1000 ng/(kg(0.66)/min))-euglycemic-euaminoacidemic clamps in fasted 7-d-old pigs (n=5/dose). Trophamine was used to clamp amino acids (AA). Plasma insulin levels were 2, 10, 30, and 800 µU/ml. Plasma glucose and essential (E) AA were maintained at fasting levels, but some nonessential (NE) AA decreased. Insulin increased flux (P<.002), reduced proteolysis (P<.02), increased AA oxidation (P<.001), but had no effect on protein synthesis. To determine if the fall in NEAA limited protein synthesis, a new balanced AA mix was developed; protein turnover was determined during hyperinsulinemic (0 vs. 100 ng/(kg(0.66)/min))-euglycemic-euaminoacidemic clamps with either Trophamine or a new AA mix. In contrast to Trophamine, when both plasma EAA and NEAA were maintained at fasting levels with the new AA mix, insulin increased protein synthesis (P<.008). Insulin reduced proteolysis (P<.05) and increased flux and oxidation (P<.05) with both AA mixes, but insulin-stimulated-AA oxidation was less when AA were clamped with the new AA mix (P<.005). The results suggest that the effect of insulin on whole body protein synthesis in neonates depends on the availability of a balanced pattern of EAA and NEAA.