Premium
Contrarily to whey and high protein diets, dietary free leucine supplementation cannot reverse the lack of recovery of muscle mass after prolonged immobilization during ageing
Author(s) -
Magne Hugues,
SavaryAuzeloux Isabelle,
Migné Carole,
Peyron MarieAgnès,
Combaret Lydie,
Rémond Didier,
Dardevet Dominique
Publication year - 2012
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.2011.226266
Subject(s) - leucine , anabolism , amino acid , protein catabolism , postprandial , sarcopenia , ageing , chemistry , muscle protein , catabolism , protein metabolism , protein biosynthesis , medicine , endocrinology , skeletal muscle , biochemistry , metabolism , biology , insulin
Key points • During ageing, there is a lack of recovery of muscle mass following immobilization. • We showed, in old rats, an ‘anabolic resistance’ of muscle protein synthesis to food intake during immobilization and only a slight increase of protein synthesis during the recovery, which explain a poor muscle nitrogen balance that is insufficient to induce a muscle mass gain. • A supplementation with free leucine, an essential amino acid known to stimulate muscle protein metabolism, was efficient in inducing a greater anabolism but failed to induce muscle mass recovery. • This discrepancy was explained by a ‘desynchronization’ between the leucine signal and amino acids coming from dietary protein digestion. • An induction of a larger increase and a longer availability of amino acids in the postprandial state with rich‐protein leucine (i.e. whey) and high protein diets were efficient in inducing a muscle mass recovery after immobilization.