Reloading is one of the effective interventions for recovery after muscle atrophy. Nutritional strategies also promote this effect. Muscle recovery from atrophy is related to increase the muscular protein synthesis and the number of myonuclei. In addition, the muscle protein synthesis rate is enhanced by amino acids, and myonuclei is increased by nucleotide. Therefore, this study investigated the effect of reloading combined with nucleoprotein supplementation including essential amino acids and nucleotide on muscle recovery. Rats were assigned randomly either to a control (CON), hindlimb unloading (HU), reloading after hindlimb unloading (HUR), and reloaded after hindlimb unloading with nucleoprotein supplementation (HUR+NP). Fiber cross-sectional area (FCSA), ribosomal protein S6 (rpS6), and number of myonuclei were examined in soleus muscle. FCSA, numbers of myonuclei, and the phospholyrated-rpS6 in the HU group were signifi cantly lower than those in the CON group. In addition, FCSA, numbers of myonuclei, and the phospholyrated-rpS6 were signifi cantly higher in the HUR group than in the HU group. Furthermore, FCSA, numbers of myonuclei, and the phospholyrated-rpS6 in the HUR+NP group were significantly higher compared with those in the HUR. These results suggest that reloading could promote recovery from atrophy, and nucleoprotein supplementation combined reloading treatment is effective to promote the recover from atrophy.
