ARS | Publication request: Insulin and amino acids stimulate whole body protein synthesis in neonates

Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: February 7, 2007
Publication Date: April 28, 2007
Citation: Jeyapalan, A., Orellana, R.A., Burrin, D.G., Fiorotto, M.L., Jahoor, F., Nguyen, H.V., Suryawan, A., Davis, T.A. 2007. Insulin and amino acids stimulate whole body protein synthesis in neonates [abstract]. The Federation of American Societies for Experimental Biology Journal. 21(5):A334.

Technical Abstract: 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 30µU/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.