Increase in muscle IGF mRNA by creatine

Aims. - Highlighting a mechanism of action of creatine on the muscular anabolism. Synthesis of facts. - Addition of creatine to the differentiation medium of C2C12 cells leads to hypertrophy of the myotubes and increases significantly IGF mRNA level. On this basis, we hypothesized that creatine supplementation would facilitate muscle anabolism by increasing the expression of IGF. In a double-blind cross-over design muscle biopsies were taken from the m. vastus lateralis at rest and post-exercise in subjects who had taken creatine or placebo for 5 days (21 g/day). After creatine supplementation resting muscle expressed more mRNA for IGF mRNA. Exercise caused an increase in IGF, but this effect was not potentiated by creatine. Conclusion. - The increase in lean body mass often reported after creatine supplementation could be mediated by signaling pathway(s) involving IGF. © 2005 Elsevier SAS. Tous droits réservés.