Carbamylated erythropoietin does not alleviate signs of dystrophy in mdx mice

Erythropoietin promotes myoblast proliferation and inhibits fibrosis and thus it could impede the pathogenesis of muscle degenerative diseases. However, its stimulation of erythropoiesis limits its use as a therapeutic agent. An erythropoietin analog, carbamylated erythropoietin (C-EPO), retains these protective actions, yet it does not interact with the erythropoietin receptor. To determine whether treatment with C-EPO alleviates the signs of muscular dystrophy in an animal model of Duchenne muscular dystrophy, we treated mdx mice with intraperitoneal injections of 50 microg/kg and 100 microg/kg C-EPO for 4 and 12 weeks, and we monitored weight, serum creatine kinase levels, and changes in muscle histology. Moderate histological improvement was observed at 4 weeks, which did not translate into a significantly decreased level of serum creatine kinase. At the doses tested, C-EPO is not an effective therapeutic for the treatment of a mouse model of Duchenne muscular dystrophy.