Table 2. Intracellular amino acids contents were measured in C₂C₁₂ myotubes cultivated in various glutamine concentration conditions (no addition, 2, 8 or 16 mM) for 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. Table refers to the following amino acids: L-glutamine, L-glutamate, L-alanine, L-aspartate, L-asparagine, L-alanine, L-proline, L-ornithine and L-arginine. The experimental groups are: (0 mM) no glutamine addition to the medium; 2 mM (reference condition), 8 mM or 16 mM L-glutamine concentration in the medium. Level of amino acids in intracellular are expressed as nmol/mg of protein and in the medium as μM. The findings are presented as mean ± SEM of three independent experiments. Results were analyzed using one-way ANOVA and Tukey post-test. (^#p<0.05) as compared with 2 mM glutamine.