Premium
Long‐chain omega‐3 fatty acids regulate bovine whole‐body protein metabolism by promoting muscle insulin signalling to the Akt–mTOR–S6K1 pathway and insulin sensitivity
Author(s) -
Gingras AndréeAnne,
White Phillip James,
Chouinard P. Yvan,
Julien Pierre,
Davis Teresa A.,
Dombrowski Luce,
Couture Yvon,
Dubreuil Pascal,
Myre Alexandre,
Bergeron Karen,
Marette André,
Thivierge M. Carole
Publication year - 2007
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2006.121079
Subject(s) - insulin , medicine , endocrinology , polyunsaturated fatty acid , metabolism , insulin resistance , protein metabolism , protein kinase b , pi3k/akt/mtor pathway , biology , insulin receptor , p70 s6 kinase 1 , fatty acid metabolism , amino acid , chemistry , fatty acid , biochemistry , signal transduction
The ability of the skeletal musculature to use amino acids to build or renew constitutive proteins is gradually lost with age and this is partly due to a decline in skeletal muscle insulin sensitivity. Since long‐chain omega‐3 polyunsaturated fatty acids (LC n –3PUFA) from fish oil are known to improve insulin‐mediated glucose metabolism in insulin‐resistant states, their potential role in regulating insulin‐mediated protein metabolism was investigated in this study. Experimental data are based on a switchback design composed of three 5 week experimental periods using six growing steers to compare the effect of a continuous abomasal infusion of LC n –3PUFA‐rich menhaden oil with an iso‐energetic control oil mixture. Clamp and insulin signalling observations were combined with additional data from a second cohort of six steers. We found that enteral LC n –3PUFA potentiate insulin action by increasing the insulin‐stimulated whole‐body disposal of amino acids from 152 to 308 μmol kg −1 h −1 ( P = 0.006). The study further showed that in the fed steady‐state, chronic adaptation to LC n –3PUFA induces greater activation ( P < 0.05) of the Akt–mTOR–S6K1 signalling pathway. Simultaneously, whole‐body total flux of phenylalanine was reduced from 87 to 67 μmol kg −1 h −1 ( P = 0.04) and oxidative metabolism was decreased ( P = 0.05). We conclude that chronic feeding of menhaden oil provides a novel nutritional mean to enhance insulin‐sensitive aspects of protein metabolism.