Leucine and citrulline modulate muscle function in malnourished aged rats

• Published in: Amino acids 2012-04, Vol.42 (4), p.1425-1433
• Main Authors: Faure, Cécile, Raynaud-Simon, Agathe, Ferry, Arnaud, Daugé, Valérie, Cynober, Luc, Aussel, Christian, Moinard, Christophe
• Format: Article
• Language: English
• Subjects: Aging - metabolism; Amino acids; Analytical Chemistry; Animals; Biochemical Engineering; Biochemistry; Biomedical and Life Sciences; Citrulline - metabolism; Dietary Supplements - analysis; Diets; Humans; Leucine; Leucine - metabolism; Life Sciences; Male; Malnutrition - metabolism; Malnutrition - physiopathology; Motors; Muscle, Skeletal - metabolism; Muscle, Skeletal - physiopathology; Muscles; Neurobiology; Original Article; Protein synthesis; Proteomics; Rats; Rats, Sprague-Dawley
• ISSN: 0939-4451; 1438-2199
• DOI: 10.1007/s00726-011-0841-2

Protein energy malnutrition in the elderly causes preferential loss of muscle mass which is associated with poor functional states. Leucine and citrulline are able to stimulate muscle protein synthesis in aged rats but no study has been undertaken to evaluate their effect on muscle function. Sprague–Dawley male rats aged 23 months were used in the experiment. Part of them were subjected to a dietary restriction for 12 weeks and then assigned to four groups: a group was euthanized (restricted group), and the others were refed for 1 week with either a leucine-, a citrulline-supplemented diet, or a standard diet. The other rats were fed ad libitum. Muscle mass and motor activity significantly increased during the refeeding with either leucine or citrulline (respectively, +51 and +37% for muscle mass, P