Relationship between muscle cell proliferation, Insulin Growth Factors and Myostatin expression in Pejerrey during starved periods

SIMO, I.; SCIARA, A.A.; ARRANZ, S.E.

Rosario

Congreso; SAIB; 2014

  Insulin-like growth factors are key elements for the creation and maintenance of skeletal muscle. Myostatin negatively regulates skeletal muscle growth, through the inhibition of myoblast cell cycle progression and the activation of p21 and MyoD for terminal differentiation. Previous data indicate that IGF-1 and MSTN are down regulated during starving conditions. In order to gain insight into the relationship between expression of growth factors and cell proliferation, a new starving experiment was developed.  Two different pool of 200 mg fishes were set: a control group was continuously fed, while the second pool was starved for 2 weeks. At 7 and 10 days after the start of the experiment fishes received and intra peritoneal injection of 5-ethynyl-2'-deoxyuridine in order to track and label proliferative muscle cells. Preliminary results indicate that proliferation of muscle satellite cells continued during starved periods. Both weight and length of starved fishes were significantly lower than to the control group. In addition, the expression level of MSTN was significantly decreased in fasting periods, suggesting that MSTN could be involved in muscle progenitor cells proliferation, regulating muscle growth only under food availability.