Objective
The mechanism of spinal cord injury has been thought to be related to the vulnerability of spinal motor neuron cells against ischemia. We have examined whether recombinant human erythropoietin (rhEPO), which is reported to have potent neuroprotective activity against a variety of potential brain injuries such as ischemia and reperfusion, can protect against ischemic spinal cord damage.
Methods
After induction of ischemia, rhEPO(800U/kg) or vehicle was injected intravenously. Cell damage was analyzed by counting the number of motor neurons. To investigate the mechanism by which rhEPO prevents ischemic spinal cord damage, we observed the immunoreactivity of brain-derived neurotrophic factor (BDNF), and its receptor trkB.
Results
rhEPO eased the functional deficits and increased the number of motor neurons, following ischemia. BDNF and trkB were induced at 8 hours of reperfusion following a 15-min ischemia in. vehicle treated group (Group I), and about 70% of motor neuron cells showed selective cell death after 7 days of reperfusion. On the other hand, large populations of the motor neuron cells survived at 7 days in rhEpo treated group (group E), and BDNF and trkB were induced persistently in motor neurons as compared with group I.
Conclusion
These results suggest that rhEPO may protect motor neurons from ischemic injury by increasing induction of BDNF and trkB. RhEPO could be a potent candidate for a use as a therapeutic agent in the treatment of ischemic spinal cord injury.