Table 1. Intracellular amino acids levels in C₂C₁₂ myotubes cultivated in various glutamine concentrations (0, 2, 8 or 16 mM) during 48 hours. Amino acids uptake (positive value = [amino acid in medium without myotubes] - [amino acid in medium with myotubes] > 0) or export (negative value = [amino acid in medium without myotubes] - [amino acid in medium with myotubes] < 0) were calculated. The table refers to the following amino acids and derivatives: L-leucine, L-isoleucine, L-valine, L-phenylalanine, L-threonine, L-tryptophan, L-histidine, L-methionine, L-tyrosine, L-lysine, L-serine and L-glycine; β-aminoisobutyric acid, taurine, o-phosphoethanolamine and the dipeptide carnosine. The experimental groups are: (0 mM) without glutamine in the medium; 2 mM (reference condition), 8 mM or 16 mM L-glutamine in the medium. Level of amino acids in intracellular are expressed as nmol/mg of protein and in the medium as μM. The results are presented as mean ± SEM of three independent experiments. The results were analyzed using one-way ANOVA and Tukey post-test. ^#p<0.05 versus 2 mM glutamine.