Erythropoietin is a hormone that stimulate bone marrow to produce more blood cells. It has been reported to be neuroprotective in spinal cord injury models. This study report that it improves recovery in neonatal mice that had been subjected to hypoxic-ischemic brain injury and that it protects against loss of dopaminergic neurons.

[*] Demers EJ, McPherson RJ and Juul SE (2005). Erythropoietin protects dopaminergic neurons and improves neurobehavioral outcomes in juvenile rats after neonatal hypoxia-ischemia. Pediatr Res 58: 297-301. Brain injury as a result of hypoxia-ischemia remains a common cause of morbidity and mortality in neonates. No effective therapy is currently available. The hematopoietic cytokine erythropoietin (Epo) provides neuroprotection in many adult models of brain injury and is currently being investigated as a therapeutic agent for human stroke and spinal cord injury. We tested the hypothesis that recombinant Epo (rEpo) would improve neurobehavioral outcomes after neonatal hypoxic-ischemic brain injury. Postnatal day 7 rats underwent right common carotid artery occlusion followed by a 90-min exposure to 8% oxygen. Rats were subsequently treated with rEpo or placebo. Sensory neglect and apomorphine-induced rotation were measured at P27 and P28. Rats were killed at P30, blood was drawn, and the brains were perfusion-fixed for histology and immunohistochemistry. No differences in gross brain injury between rEpo and placebo-treated rats were found. Neonatal rEpo treatment protected dopamine neurons as indicated by the preservation of tyrosine hydroxylase-positive cells in the substantia nigra pars compacta and ventral tegmental area. rEpo treatment also improved functional outcomes by reducing sensory neglect and preventing the rotational asymmetry seen in control animals. No differences in hematocrit, white blood cell counts, neutrophil counts, or platelet counts were measured. We observed that rEpo treatment protected mesencephalic dopamine neurons and reduced the degree of behavioral asymmetries at 4 wk of life. On the basis of these findings, we conclude that further studies investigating the safety and efficacy of high-dose rEpo as a neuroprotective strategy are indicated in neonatal models of hypoxic-ischemic brain injury. Department of Pediatrics, University of Washington, Seattle, Washington 98195, USA. http://www.ncbi.nlm.nih.gov/entrez/q..._uids=16055937