Effect of High Dose Methylprednisolone on Expression of iNOS and Apoptosis after Spinal Cord Injury in Rats

Objective: To investigate the effect of high dose methylprednisolone on expression of iNOS and apoptosis after spinal cord injury(SCI) in rats.Methods:Adult SD rats were divided at random into two groups:with Allen's weight drop to cause spinal cord injury and use high dose methylprednisolone group(group A),and use normal saline group(group B).After operation the rats were observed Tarlov's scores on neurofunction recovery of bilateral hind limbs at 4h,8h,1d,3d,7d,14d and 21d after surgery,and were sacrificed,then the tissue sections were stained with hematoxylin and eosin(HE),immunohistochemistry and terminal deoxynucleotidyl transferase-mediated dUTP nick end lebeling(TUNEL) method,and the injured spinal cord tissue was evaluated.Results:The histopathology changes in spinal cord tissue observed with HE staining microscopic examination in group B was worse than that in group A.Expression of iNOS and apoptotic cells were observed in two groups,and the apoptotic index and expression of iNOS in group B is higher than that in group A( P0.01 ).Conclusion:This study demonstrated that high dose methylprednisolone could inhibit expression of iNOS and apoptosis after SCI in rats.