Pretreatment with erythropoietin attenuates the neurological injury after spinal cord ischemia

Study design: Experimental study. Objectives: To investigate the effect of erythropoietin (EPO) pretreatment on spinal cord ischemic injury. Setting: Experimental Research Center at Seoul National University Bundang Hospital, Korea. Methods: Rats were treated with either 1000 IUkg(-1) of EPO (EPO group, n=8) or saline (control group, n=8) 24 h before ischemia. Spinal cord ischemia was induced using a balloon-tipped catheter placed on the proximal descending aorta in the control group and the EPO group, but not in the sham group (n=8). Neurological function was assessed using the motor deficit index (MDI; 0=normal, 6=complete paralysis) until 7 days after reperfusion, and histological examination of spinal cord was performed. Results: At the first day after reperfusion, the EPO group demonstrated a significantly lower MDI compared with the control group (2.0 (0.3-2.0) vs 4.0 (3.0-4.8), median (interquartile range); EPO group vs control group, respectively; P=0.002). This trend was sustained until 7 days after reperfusion (1.0 (1.0-1.8) vs 4.5 (3.3-5.0); EPO group vs control group, respectively; P=0.001), and more normal motor neurons (29.9 +/- 3.1 vs 21.4 +/- 3.4, mean +/- s.d.; EPO group vs control group, respectively; P < 0.001) were observed. However, compared with the sham group, the EPO group displayed a significantly higher MDI (0.0, sham group) and fewer intact motor neurons (37.8 +/- 5.5, sham group; P < 0.001, sham vs control group). Conclusion: Pretreatment with EPO significantly attenuates neurological injury following spinal cord ischemia, although it cannot completely abolish the ischemic injury. Spinal Cord (2012) 50, 208-212; doi:10.1038/sc.2011.136; published online 29 November 2011