The Expression Of HSP70 After Cerclage-induced Spinal Cord Injury In MP Rats

[Objective]:The SD rats randomly selected are cerclaged to make models of spinal cord injury. To study the changes of expression of HSP70 with MP after making cerclage spinal cord injury model,and to discuss the initial treatment of spinal cord injury. The model is to further study spinal cord injury as a solid theoretical basis.[Methods]: The preliminary work of our group has established a personalized and repeatable cerclage spinal cord injury model. The method has a high repeatability,and it is simple and steady,which is suitable to study this topic.Sixty adult SD rats selected randomly were divided into three groups,the age is 13 weeks on average.N=20 Group A:Blank test group, only the laminectomy and dural sac circumference measurements but don’t cerclage spinal cord. N=20 Group B: Controlled trial group.6h decompression after cerclage postoperative. N=20. Group C: Test treatment group.1h after intravenous injection given to high doses of MP treatment and 6h decompression after cerclage postoperative. The key of cerclage technique was fully to expose the spinal cord studied.In the manufacturing cerclage spinal cord injury model process, T11 laminectomy to reveal dural, to measure the circumference of the dural sac(C1) with double-stranded 5/0 white absorption lines, to measure the length accurately, and take out the lines,then to obtain the length C2 by the algebraic formula(C2=C1* 7.0), the dural saccross-sectional area was 70% of the original area. After that each group was executed at 1d, 3d, 7d, 14 d and 21 d in post operation. The spinal cord was examinated by HE staining, Immunohistochemistry and terminal dexynucleotidyl transferase(Td T)-mediated d UTP nick end labeling( TUNEL). Neuromotor function test was used BBB score, and inclined plane score. The results were analyzed in each group, and to make correlation. with P<0.05 for visible variances.[Results]: Blank group(group A) with neuromotor function BBB scores, inclined plane score, HE staining revealed no evident unusual condition; HSP70-positive cells in rat spinal cord tissue rare expression. Compared with the blank group(group A), neuromotor function BBB score, inclined plane score are lower, the HSP70-positive cells in spinal cord tissue began to increase on the first postoperative day, after the first three days to reach the peak, the difference had a meaning in statistics.(record contrast between the groups P <0.05). Take the control group(group B) and the experimental treatment group by contrast,the latter had more scores in neuromotor function BBB rating, inclined plane and was remarkly higher in the spinal cord HSP70-positive cells added distinctly, HSP70-positive cells peaked in the first three days after surgery, the distinction was obvious in statistics(each group contrast between the data P <0.05).[Conclusion]: 1.Cerclage method is through absorbable lines to make acute spinal cord injury of rats model,it can take the continuous static compression to the spinal cord. The induced animal model of spinal cord injury in rats with good repeatability, quantitative and some clinical relevance, the model is an reliable method for modeling of spinal cord injury.2.Comparing the experimental treatment and the control groups, neuromotor function BBB scores, inclined plane scores and HSP70-positive cells were significant differences exist, it can be inferred to increase the expression of HSP70 in spinal cord injury after intravenous injection given to MP treatment. The mechanism of action of HSP70 is to improve the imbalance of calcium ion after acute spinal cord injury, and inhibit the lipidperoxidation, and avoid the damage of free radicals, it also can increase the synthesis of prostaglandins, and improve blood supply situation after the injury of the spinal cord,then it can strengthen the repair of spinal cord tissue, and reduce the occurrence of the secondary injury after spinal cord injury, what gave a maior push to protect nerve. 3. The expression of HSP70 in the body has added under the effect of external factors after spinal cord injury,and the study found that it can protect the body the effect of spinal nerves, thus avoid further injury of the spinal cord as a protective protein,it has certain effect to the recovery of spinal cord function in the later period.