| Objective:(1).To establish a new animal model of spinal cord compression.(2).Through the change trend of beclin-1 and other factors, the development process and regulation of autophagy after spinal cord compression were discussed;(3).To study the imaging and pathological changes after spinal cord compression.Methods:The C6-C7 epidural space of SD rat was implanted into the biological material with the volume expansion after absorbing water. Thus, the spinal cord of SD rats is compressed, but it does not cause motor dysfunction. To establish a new spinal cord compression animal model with no motor dysfunction with the spinal cord compression.Thirty 200g-250 g SD rats were randomly divided into the control group and the experimental group. First of all, the cervical vertebral lamina of SD rat was exposed by posterior approach.Then,the water absorbing expansion material was implanted into the epidural space of C6-C7. Control group SD rats underwent sham operation, without implantation the water absorbent materials. After the operation, the motor function of SD rats was observed. If the limbs spasm, weakness, limb movement coordination and motor dysfunction performance, it showes that the operation of the experimental animals caused acute injury. Then the experimental animals were eliminated and the samples were supplemented. 3 rats in each group were sacrificed on 1day、3day、7day、10day and14 day after the operation. The movement behavior(BBB score),MRI, HE,TUNEL staining and Beclin-1 immunohistochemical staining were tested. Observe the change trend of the above indexes in different periods. Statistical method: The measurement data was expressed by x ± s. With normal distribution measurement data using paired T test,SNK-q test was used in the experimental group and the control group, P<0.05 indicated that the difference was statistically significant.Results:MRI examination was performed at each time point after operation.The results showed that the water absorbent expanded material were implanted into the epidural space of C6-C7.Without prolapse and slip,spinal cord is compressed by this material. The experimental group and the control group did not appear motor dysfunction after the operation. HE staining showed that there was a marked pressure in the spinal cord of the experimental group, neuronal cell degeneration, vacuoloid change.TUNEL detection showed positive cells from 1 days after modeling. In the control group, there was no corresponding changes in the same segment of spinal cord. Beclin-1immunohistochemical staining showed that the Beclin1 positive cells in the control group were expressed in a small amount.In the experimental group,Beclin-1 positive cells began to increase first days after modeling. Reached a peak in the seventh day.There was no significant difference between the fourteenth days after modeling and the control group,(P>0.05).Conclusion:The spinal cord compression model can simulate the pathological and physiological changes after spinal cord compression,the operation process is simple,can be carried out a variety of detection,the results were reproducible. This model has high survival rate of the experimental animals.And it is a reliable animal model for the study of such diseases.The results of HE staining and TUNEL apoptotic cells showed that the model could simulate the pathological changes and apoptosis of spinal cord after chronic compression.The changes of beclin-1 positive cells at different time points after compression in the spinal cord showed that: Autophagy may play a role in the pathophysiology of chronic spinal cord injury.But the exact mechanism and function still need further research. |
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