Functional recovery after central infusion of alpha-melanocyte-stimulatinghormone in rats with spinal cord contusion injury

Melanocortins, peptides related to alpha-melanocortin-stimulating hormone ( alpha MSH) and adrenocorticotropic hormone (ACTH), are known to improve axo nal regeneration following peripheral nerve injury and stimulate neurite ou tgrowth from central nervous system (CNS) neurons both in vitro and in vivo . The neurite outgrowth promoting capacity of alpha MSH has prompted us to investigate the effects of intrathecal application of alpha MSH on function al and electrophysiological recovery in a well-characterized model of spina l cord contusion injury. Different doses of alpha MSH were applied via osmo tic minipumps into the cisterna magna for 10 days, thereby delivering the p eptide directly into the CNS, Functional recovery was monitored during 8 po stoperative weeks by means of the Basso, Beattie, and Bresnahan locomotor r ating scale, and the thoracolumbar height test, At the end of the study, el ectrophysiological analysis of rubrospinal motor evoked potentials as perfo rmed. Our data showed that application of 3.75 mu g/kg/h alpha MSH resulted in a marked functional recovery, accompanied by a decrease in the latency of the rMEP. This study demonstrates that intrathecal application of alpha MSH results in functional recovery after spinal cord contusion injury, Thes e findings may initiate new treatment strategies and/or the use of melanoco rtins in human spinal cord injury.