Study of correlation between neural cell apoptosis and caspase-3 expression after rat cerclage-induced spinal cord injury model by different timing of early decompression

[Objective] To study the apoptosis of neural cells and the changes of caspase-3 expression on early operative decompression after acute spinal cord injury(ASCI)in rats. [Method]The model of spinal cord injury were established by cerclage-induced.Eighty-four SD rats were prospectively randomized to the control group(A) and experimental groups(B、C、D),namely,group A were laminectomy only.Groups B,C were decompressed for 8 hours、72 hours after cerclage-induced.Group D had no decompression.After surgery,BBB score,inclined plane score were observed with recovery of nerve function.HE and the expression of caspase-3 was detected by immunohistochemistry study at 1,3,7,21 days,the level of the neuronal cell was deleted by the terminal deoxynucleotidyl transferase-mediated DUTP nick end labeling(TUNEL)methods.[Result] BBB score and inclined plane score were statistically different compared in each group(P0.05).Experimental group,caspase-3,tunel positive cells were increased in 1 day,peaked in 3 days,decreased in 7 days and visibled in 21 days.At different time points in experimental group,caspase-3,tunel positive cells were statistically different,both positively correlated(r= 0.69-0.98,P0.05). [Conclusion]Spinal cord injury of cerclage-induced animal model in rats is an ideal way of modeling.Early decompression of spinal cord injury may prevent or reduce apoptosis of spinal cord nerve cells.