by Layne E Norton, Gabriel J Wilson, Donald K Layman, Christopher J Moulton and Peter J Garlick
Abstract:
BACKGROUND: Leucine (Leu) regulates muscle protein synthesis (MPS) producing dose-dependent plasma Leu and MPS responses from free amino acid solutions. This study examined the role of Leu content from dietary proteins in regulation of MPS after complete meals. METHODS: Experiment 1 examined 4 protein sources (wheat, soy, egg, and whey) with different Leu concentrations (6.8, 8.0, 8.8, and 10.9% (w/w), respectively) on the potential to increase plasma Leu, activate translation factors, and stimulate MPS. Male rats ( 250 g) were trained for 14 day to eat 3 meals/day consisting of 16/54/30% of energy from protein, carbohydrates and fats. Rats were killed on d14 either before or 90 min after consuming a 4 g breakfast meal. Experiment 2 compared feeding wheat, whey, and wheat + Leu to determine if supplementing the Leu content of the wheat meal would yield similar anabolic responses as whey. RESULTS: In Experiment 1, only whey and egg groups increased post-prandial plasma Leu and stimulated MPS above food-deprived controls. Likewise, greater phosphorylation of p70 S6 kinase 1 (S6K1) and 4E binding protein-1 (4E-BP1) occurred in whey and egg groups versus wheat and soy groups. Experiment 2 demonstrated that supplementing wheat with Leu to equalize the Leu content of the meal also equalized the rates of MPS. CONCLUSION: These findings demonstrate that Leu content is a critical factor for evaluating the quantity and quality of proteins necessary at a meal for stimulation of MPS.
Reference:
Leucine content of dietary proteins is a determinant of postprandial skeletal muscle protein synthesis in adult rats (Layne E Norton, Gabriel J Wilson, Donald K Layman, Christopher J Moulton and Peter J Garlick), In Nutr Metab (Lond), volume 9, 2012.
Bibtex Entry:
@article{Norton:2012aa,
abstract = {BACKGROUND: Leucine (Leu) regulates muscle protein synthesis (MPS) producing dose-dependent plasma Leu and MPS responses from free amino acid solutions. This study examined the role of Leu content from dietary proteins in regulation of MPS after complete meals.
METHODS: Experiment 1 examined 4 protein sources (wheat, soy, egg, and whey) with different Leu concentrations (6.8, 8.0, 8.8, and 10.9% (w/w), respectively) on the potential to increase plasma Leu, activate translation factors, and stimulate MPS. Male rats (~250 g) were trained for 14 day to eat 3 meals/day consisting of 16/54/30% of energy from protein, carbohydrates and fats. Rats were killed on d14 either before or 90 min after consuming a 4 g breakfast meal. Experiment 2 compared feeding wheat, whey, and wheat + Leu to determine if supplementing the Leu content of the wheat meal would yield similar anabolic responses as whey.
RESULTS: In Experiment 1, only whey and egg groups increased post-prandial plasma Leu and stimulated MPS above food-deprived controls. Likewise, greater phosphorylation of p70 S6 kinase 1 (S6K1) and 4E binding protein-1 (4E-BP1) occurred in whey and egg groups versus wheat and soy groups. Experiment 2 demonstrated that supplementing wheat with Leu to equalize the Leu content of the meal also equalized the rates of MPS.
CONCLUSION: These findings demonstrate that Leu content is a critical factor for evaluating the quantity and quality of proteins necessary at a meal for stimulation of MPS.},
author = {Norton, Layne E and Wilson, Gabriel J and Layman, Donald K and Moulton, Christopher J and Garlick, Peter J},
date-added = {2023-07-23 20:37:13 +0100},
date-modified = {2023-07-23 20:37:13 +0100},
doi = {10.1186/1743-7075-9-67},
journal = {Nutr Metab (Lond)},
journal-full = {Nutrition \& metabolism},
keywords = {Protein Synthesis},
month = {Jul},
number = {1},
pages = {67},
pmc = {PMC3488566},
pmid = {22818257},
pst = {epublish},
title = {Leucine content of dietary proteins is a determinant of postprandial skeletal muscle protein synthesis in adult rats},
volume = {9},
year = {2012},
bdsk-url-1 = {https://doi.org/10.1186/1743-7075-9-67}}