Effects Of Methylprednisolone Of Different Doses On Cell Apoptosis And Bax Express After Chronic Compressive Spinal Cord Injury In Rat

Objective: To explore the preventive effects of different dose methylprednisolone(MP) on neural cell apoptosis,Bax express,and neurological function in rats after chronic spinal cord injury(CCSCI).Methods: Sixty-four SD rats underwent the chronic progressive compressive spinal cord injury mode so as to establish compressed spinal cord animal models.After fifty days,reach about 60%～75% oppress degree ,then remove the pressure installation ,and then Sixty-four SD rats were randomly divided into four equal groups: small dose MP group(A;)moderate dose MP group(B) ;high dose MP group(C);and only remove the pressure installation group(D). To compare the effects of different dose MP on neural cell apoptosis,Bax express by deoxynucleotidal ransferase-mediated DUTP-biotinnick end labeling(TUNEL) method and ABC method and measure neurological function in 1.3.7.and 14 days post-operatively.Result:Positive expression of apoptotic cell and Bax appeared in every group. The expresion of positive cell was paralleled by the degree of cell apoptotic and was paralleled by the significant improvement in neurological function . The expresion degree is comaratively highly in d1 and d3, and it decreases by degrees from d7, comes down most obvious in dl4.The positive expression of apoptotic cell and Bax in Group C at 7d and 14d after injury was obvious less than that in Group D (d7:P<0.05,d14:P<0.01), and there were significant statistic difference remained between Group B and Group D at 14d after injury(p<0.05). High dose MP improved very significant the neurological function,and there were significant statistic difference remained between Group C and Group D in neurological function evaluated by open-field and inclined plane test at 14d after injury.Conclusion:Chronic compressive spinal cord injury can induced apoptosis. high dose MP and moderate dose MP can inhibit the cell apoptosis and improve neurological function by inhibit Bax express. The effect of high dose of MP in treatment of chronic spinal cord injury is better than those of moderate dose of MP.