Experiment Of Spinal Cord Ischemia Nerve Injury And Repair After Lumbar Artery Ligation

Objective: To investigate the change of caspase-3, TNF-α,NF-κB, NGF, GAP-43, BDNF expression after spinal cord ischemia injury in the SD rats by ligature lumbar arteries, for observe the process of self-repair after spinal cord ischemia injury in the SD rats form molecular biology level.Method: 48 SD rats divide into ischemia group and sham operation group randomly.6 in the sham operation group and 42 in the ischemia group, the SD rats are divided into 1h, 2h, 4h, 6h, 8h, 12 h and 24 h after ischemia randomly among ischemia group. BMS score is adopted to assess the change of behavior, the expression of Fas, caspase-3, TNF-α, NF-κB, NGF, GAP-43 and BDNF was detected by immunohistochemistry. The model of spinal cord ischemia injury is set up by separate and coagulation lumbar arteries through laparotomy. Separate lumbar arteries only in sham operation group.Result: In ischemia group, BMS score was obvious decrease immediately after ischemia injury and return to normal level(8.33±0.61) 24 h after ischemia injury, there was no significant difference compared with control group(P > 0.05). Immunohistochemical study showed obvious increase were found in Fas 、caspase-3、TNF-α、NF-κB activity in ischemia group, which had statistically difference compared with control group(P<0.05),whereas return to normal level 24 h after ischemia injury no significant difference compared with control group(P>0.05) except Fas. GAP-43 positive cell number continue to increased after ischemia injury and had statistically difference compared with control group in each group(P<0.05). The number of NGF positive cell were increase 8h after ischemia injury and in 8h、12h、24h after ischemia injury there had statistically difference compared with control group. A transient decrease was found in BDNF activity cell number after ischemia injury and then gradually increased, compared with control group there were significant difference(P<0.05) at 4h、6h、8h、12h、24h after ischemia injury.Conclusion: Completely severed SD rat lumbar artery can be a reliable model of spinal cord ischemia injury. Ischemia injury in spinal cord would repair 24 h after ischemia in SD rats which were ligated all lumbar arteries. The mechanism of self-repair may be related to the decreased of Fas、caspase-3、TNF-α、NF-κB expression and the increased of NGF、GAP-43、BDNF expression.