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Effects of leucine-enriched essential amino acid and whey protein bolus dosing upon skeletal muscle protein synthesis at rest and after exercise in older women

BACKGROUND & AIMS: Impaired anabolic responses to nutrition and exercise contribute to loss of skeletal muscle mass with ageing (sarcopenia). Here, we tested responses of muscle protein synthesis (MPS), in the under represented group of older women, to leucine-enriched essential amino acids (EAA...

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Autores principales: Wilkinson, Daniel J., Bukhari, Syed S.I., Phillips, Bethan E., Limb, Marie C., Cegielski, Jessica, Brook, Matthew S., Rankin, Debbie, Mitchell, William K., Kobayashi, Hisamine, Williams, John P., Lund, Jonathan, Greenhaff, Paul L., Smith, Kenneth, Atherton, Philip J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Elsevier 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6295981/
https://www.ncbi.nlm.nih.gov/pubmed/29031484
http://dx.doi.org/10.1016/j.clnu.2017.09.008
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author Wilkinson, Daniel J.
Bukhari, Syed S.I.
Phillips, Bethan E.
Limb, Marie C.
Cegielski, Jessica
Brook, Matthew S.
Rankin, Debbie
Mitchell, William K.
Kobayashi, Hisamine
Williams, John P.
Lund, Jonathan
Greenhaff, Paul L.
Smith, Kenneth
Atherton, Philip J.
author_facet Wilkinson, Daniel J.
Bukhari, Syed S.I.
Phillips, Bethan E.
Limb, Marie C.
Cegielski, Jessica
Brook, Matthew S.
Rankin, Debbie
Mitchell, William K.
Kobayashi, Hisamine
Williams, John P.
Lund, Jonathan
Greenhaff, Paul L.
Smith, Kenneth
Atherton, Philip J.
author_sort Wilkinson, Daniel J.
collection PubMed
description BACKGROUND & AIMS: Impaired anabolic responses to nutrition and exercise contribute to loss of skeletal muscle mass with ageing (sarcopenia). Here, we tested responses of muscle protein synthesis (MPS), in the under represented group of older women, to leucine-enriched essential amino acids (EAA) in comparison to a large bolus of whey protein (WP). METHODS: Twenty-four older women (65 ± 1 y) received (N = 8/group) 1.5 g leucine-enriched EAA supplements (LEAA_1.5), 6 g LEAA (LEAA_6) in comparison to 40 g WP. A primed constant I.V infusion of (13)C(6)-phenylalanine was used to determine MPS at baseline and in response to feeding (FED) and feeding-plus-exercise (FED-EX; 6 × 8 unilateral leg extensions; 75%1-RM). We quantified plasma insulin/AA concentrations, leg femoral blood flow (LBF)/muscle microvascular blood flow (MBF), and anabolic signalling via immunoblotting. RESULTS: Plasma insulineamia and EAAemia were greater and more prolonged with WP than LEAA, although LEAA_6 peaked at similar levels to WP. Neither LEAA or WP modified LBF or MBF. FED increased MPS similarly in the LEAA_1.5, LEAA_6 and WP (P < 0.05) groups over 0–2 h, with MPS significantly higher than basal in the LEAA_6 and WP groups only over 0–4 h. However, FED-EX increased MPS similarly across all the groups from 0 to 4 h (P < 0.05). Only p-p70S6K1 increased with WP at 2 h in FED (P < 0.05), and at 2/4 h in FED-EX (P < 0.05). CONCLUSIONS: In conclusion, LEAA_1.5, despite only providing 0.6 g of leucine, robustly (perhaps maximally) stimulated MPS, with negligible trophic advantage of greater doses of LEAA or even to 40 g WP. Highlighting that composition of EAA, in particular the presence of leucine rather than amount is most crucial for anabolism.
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spelling pubmed-62959812018-12-21 Effects of leucine-enriched essential amino acid and whey protein bolus dosing upon skeletal muscle protein synthesis at rest and after exercise in older women Wilkinson, Daniel J. Bukhari, Syed S.I. Phillips, Bethan E. Limb, Marie C. Cegielski, Jessica Brook, Matthew S. Rankin, Debbie Mitchell, William K. Kobayashi, Hisamine Williams, John P. Lund, Jonathan Greenhaff, Paul L. Smith, Kenneth Atherton, Philip J. Clin Nutr Article BACKGROUND & AIMS: Impaired anabolic responses to nutrition and exercise contribute to loss of skeletal muscle mass with ageing (sarcopenia). Here, we tested responses of muscle protein synthesis (MPS), in the under represented group of older women, to leucine-enriched essential amino acids (EAA) in comparison to a large bolus of whey protein (WP). METHODS: Twenty-four older women (65 ± 1 y) received (N = 8/group) 1.5 g leucine-enriched EAA supplements (LEAA_1.5), 6 g LEAA (LEAA_6) in comparison to 40 g WP. A primed constant I.V infusion of (13)C(6)-phenylalanine was used to determine MPS at baseline and in response to feeding (FED) and feeding-plus-exercise (FED-EX; 6 × 8 unilateral leg extensions; 75%1-RM). We quantified plasma insulin/AA concentrations, leg femoral blood flow (LBF)/muscle microvascular blood flow (MBF), and anabolic signalling via immunoblotting. RESULTS: Plasma insulineamia and EAAemia were greater and more prolonged with WP than LEAA, although LEAA_6 peaked at similar levels to WP. Neither LEAA or WP modified LBF or MBF. FED increased MPS similarly in the LEAA_1.5, LEAA_6 and WP (P < 0.05) groups over 0–2 h, with MPS significantly higher than basal in the LEAA_6 and WP groups only over 0–4 h. However, FED-EX increased MPS similarly across all the groups from 0 to 4 h (P < 0.05). Only p-p70S6K1 increased with WP at 2 h in FED (P < 0.05), and at 2/4 h in FED-EX (P < 0.05). CONCLUSIONS: In conclusion, LEAA_1.5, despite only providing 0.6 g of leucine, robustly (perhaps maximally) stimulated MPS, with negligible trophic advantage of greater doses of LEAA or even to 40 g WP. Highlighting that composition of EAA, in particular the presence of leucine rather than amount is most crucial for anabolism. Elsevier 2018-12 /pmc/articles/PMC6295981/ /pubmed/29031484 http://dx.doi.org/10.1016/j.clnu.2017.09.008 Text en © 2017 The Authors http://creativecommons.org/licenses/by/4.0/ This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Wilkinson, Daniel J.
Bukhari, Syed S.I.
Phillips, Bethan E.
Limb, Marie C.
Cegielski, Jessica
Brook, Matthew S.
Rankin, Debbie
Mitchell, William K.
Kobayashi, Hisamine
Williams, John P.
Lund, Jonathan
Greenhaff, Paul L.
Smith, Kenneth
Atherton, Philip J.
Effects of leucine-enriched essential amino acid and whey protein bolus dosing upon skeletal muscle protein synthesis at rest and after exercise in older women
title Effects of leucine-enriched essential amino acid and whey protein bolus dosing upon skeletal muscle protein synthesis at rest and after exercise in older women
title_full Effects of leucine-enriched essential amino acid and whey protein bolus dosing upon skeletal muscle protein synthesis at rest and after exercise in older women
title_fullStr Effects of leucine-enriched essential amino acid and whey protein bolus dosing upon skeletal muscle protein synthesis at rest and after exercise in older women
title_full_unstemmed Effects of leucine-enriched essential amino acid and whey protein bolus dosing upon skeletal muscle protein synthesis at rest and after exercise in older women
title_short Effects of leucine-enriched essential amino acid and whey protein bolus dosing upon skeletal muscle protein synthesis at rest and after exercise in older women
title_sort effects of leucine-enriched essential amino acid and whey protein bolus dosing upon skeletal muscle protein synthesis at rest and after exercise in older women
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6295981/
https://www.ncbi.nlm.nih.gov/pubmed/29031484
http://dx.doi.org/10.1016/j.clnu.2017.09.008
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