Benificial Effect Of Perfusion Of Chondroitinase ABC Combined With Dexamethasone On Nerve Regeneration And Functional Recovery After Spinal Cord Injury In Rats

The incidence of spinal cord injury has been a sharp rise in recent years. The spinal cord injury leads to a high rate of mutilation and influences the quality of patients’lives seriously. Due to the limited self-repair ability of spinal cord, the repairing of spinal cord injury has not been solved finely today. In recent years, chondroitinase ABC was reported that could promote the regeneration of spinal cord after spinal cord injury and has become a new treatment pathway of spinal cord injury.Studies showed that after the primary injury of spinal cord, the inflammatory cytokines such as Tumor necrosis factor-α, Interleukins, cell adhesion molecules and nuclear factor-κB filled with the injury area, promoted the secretion of inflammatory mediators from neuroglia cells and up regulated the expression of adhesion molecules on the endothelial cells. These inflammatory mediators lead to the second injury of spinal cord such as endothelial injury of microcirculation, vasospasm or vascular occlusion and spinal cord edema. The second injury of spinal cord aggravates ischemic necrosis and neuronophagia. The spinal cord injury treated with dexamethasone could obtain good effect, however, systemic application of dexamethasone produce lots of side effects. Because of the least dosage to the best concentration of drug in local and the fewer side effects to the maximum extent, local application is more reasonable than systemic application.Astrocytes and oligodendrocytes can secrete chondroitin sulfate proteoglycan after spinal cord injury. Chondroitin sulfate proteoglycan could inhibit the regeneration of nerve and axon. When the regeneration of nerve and axon is blocked, astrocytes will be translated into structure of astrocytes. The structure of astrocytes inhibits the regeneration of axon. Chondroitinase ABC can decompose Chondroitin sulfate proteoglycan and promote the regeneration of nerve and axon. Combined chondroitinase ABC with dexamethasone on nerve regeneration and functional recovery after spinal cord injury may be a better treatment pathway.In our research, healthy adult female rats were used to make the model of SCI in T10 with the instrument of Impactor ModelⅡ. The tube was placed into subarachnoid space. The scores of BBB at different time points in each group showed that the effect of functional recovery in the DEX-ChABC group was better than that in control group. HE staining showed that the formation of cavity was observed in each group at 28 days after injury. The maximal transverse diameter and gross area of necrosis decreased significantly in the DEX-ChABC group than that in control group. The immunofluorescence staining suggested that the expression of GFAP and CS56 in the DEX-ChABC group were more weaker than that in control group. There was more significant NF160 crossing through the injury zone in the DEX-ChABC group than that in other groups.In summary, the effect of combined application of ChABC with DEX is significantly better than any single one application.