Effect of methylprednisolone on expression of heat shock protein 70 following injury of spinal cord in rats

Objective To study the effect ofmethylprednisolone (MP) on the expression of heatshock protein 70 (HSP70) following the injury of spinal cord (SC1) in rats. Methods 125 SD rots wererandomly divided into 5 groups: the simple operation group (n=30), the MP control group (n=30), theinjury group (n=30), the MP treatment group (n=30) and the normal control group (n=5). Specimen of thespinal cord were collected at 2, 6, 12, 24, 48, 72 h after SCI, respectively. Their pathomorphology wasobserved and HSP70 expression was detected by immunohistochemistry. Results After treatment ofMP, the secondary injury was lightened, according to the HE staining of the specimen.lmmunohistochemistry revealed that there were no HSP70 expression in the normal control group and theMP control group, that there was a little HSP70 in the simple operation group, and that there was a lot ofHSP70 in the injury group 2 h after injury, and the expression peaked at 24 h and maintained to 72 h afterinjury. The expression was significantly increased and the peak of expression was in advance in the MPtreatment group as compared with injury group, and it was also found in neuropil of white substance ofspinal cord. Conclusion High-dose NIP can obviously increase the expression of HSP70 in injuredspinal cord, and has the peak time of expression in advance, and enlarge the scope of expression. It maybe one of the mechanism to protect the spinal cord that MP guide myeloid tissue to overexpress HSP70after spinal cord injury. Key words: Methylprednisolone; Injury of spinal cord; Heat shock protein 70