Background and Objective: Because of the critical role of cell death in the pathology of neurodegenerative diseases, its prevention is regarded as one of the most salient ends in neuroprotective strategies. Concerning the bulk of reports about the putative neuroprotective effects of erythropoietin (Epo), in the present study following axotomy, the effects of different doses of Epo  on spinal motoneurons in neonates was investigated.

Materials and Methods: Following transection of  the right sciatic nerve of 20 two-day-old neonate rats and induction of apoptotic cell death in related motoneurons, the animals were subdivided into three experimental and one control groups. The experimental groups received different doses of 2500, 5000, 10000U/kg recombinant human Erythropoietin (rhEpo), and the control group was treated with equal volume of normal saline, intraperitoneally for 5 successive days. 24 hours following the last injection, histologic sections from the neonate spinal cords were prepared for counting of spinal motoneurons. In all samples, the intact side was regarded as the internal control.

Results: The difference between motoneuron means of intact and axotomy sides was significant in all groups, which advocates the efficacy of axotomy in cell death induction. Comparison of axotomized side of different groups indicated significant differences between both 5000 and 10000U/kg groups with control, and also between 10000 and 2500 groups, but no significant differences could be seen between other groups. Thus, 5000U/kg of rhEpo can be considered as the neuroprotective dose which can prevent cell death of axotomized motoneurons.

Conclusion: rhEpo has dose-dependent neuroprotective effects on axotomized spinal motoneurons.