Abstract:Objective: To explore the neuroprotective mechanism of ischemic preconditioning in spinal core ischemia. Methods:Fifty adults rats were randomly assigned to 4 groups: the sham group receiving anesthesia and surgical preparation(group A, n=5),the ischemia/reperfusion (I/R)group adminstrated to 0.5 h ischemia followed by 3,6,12,or 24 h reperfusion (group B, n=20),the IPC group receiving three cycles of 5 min ischemia followed by 5 min of reperfusion (group C, n=5),and the IPC+Ⅰ/R group (group D, n=20). HE and immunohistochemical staining were used to evaluate the spinal neuron. Autophagic activity was investigated by electron microscopy and immunohistochemistry. The autophagosome marker LC3-Ⅱ and the autophagy-associated protein Beclin-1 were detected by Western blot. Results: In the Ⅰ/R group,LC3-Ⅱ was significantly elevated after 3 h of reperfusion,but declined significantly by 24 h. At 24 h,rats in the I/R group exhibited extensive spinal damage and decreased neuronal survival. In the IPC+Ⅰ/R group, neuronal death was reduced and expression of LC3-Ⅱ sustained throughout the 24 h reperfusion period. Conclusion:Ischemic preconditioning can sustain the beneficial effects of autophagic lysosomal degradation during Ⅰ/R by inhibiting autophagic cell death.