Abstract: Objective To observe the effects of myelotomy on autophagy activation after traumatic spinal cord injury (SCI) in rats. Methods 54 adult female Sprague-Dawley rats were randomly assigned to sham-operated group (SG, n=18), contusion group (CG, n=18) or myelotomy group (MTG, n=18). The T10 SCI model in rats was induced with a New York University (NYU) impactor and myelotomy was performed 24 hours after SCI. They were evaluated with the BBB score 1, 7, 14 days after injury. The expression of mRNA of Beclin-1 and Bcl-2 were detected with real-time quantitative reverse transcriptase polymerase chain reaction (RT-PCR). The formation of autophagosome was investigated under electronic microscope (EM) 3 days after injury. Results BBB score was more in the MTG than in the CG 7 and 14 days after injury (P<0.05), while the expression of Beclin-1 mRNA was less (P<0.05). The expression of Bcl-2 mRNA was more in the MTG than in the CG 3 and 7 days after injury (P<0.05). The expression of Beclin-1 mRNA was negatively correlated with BBB scores (P< 0.05). The formation of autophagosome was less in the MTG than in the CG. Conclusion Myelotomy can improve the recovery of motor function in rats after acute traumatic SCI, which may associate with neuroprotection mediated by inhibition of autophagy through the Bcl-2 signaling pathway.

Key words: spinal cord injury, autophagy, Beclin-1, Bcl-2, myelotomy