Effect of Cyclosporin A in a Rat Spinal Cord Injury Model

ABSTRACT

The effect and mechanism of drugs for the recovery of motor function after acute spinal cord injury has not yet been fully elucidated. This study was aimed to examine the effect of cyclosporin(CsA) on the recovery of motor function and its accompanying histopathological changes in the spinal cord injury model. A certain range of spinal cord injury was made with NYU weight-drop impactor. Injured rats were divided into 3 groups; control(castor oil) group(group A), two CsA treated groups(40mg/kg, i.p.) at 10min(group B) or 4hour(group C) after cord injury. Locomon test was done using BBB(Basso, Beattie, and Bresnahan) locomotion rating scale. After the locomotion test which has been done for 14 days after cord injury, group B,C showed improved motor function compared to group A. Especally, remarkable motor function recovery was noted in group C. Immunohistochemical stain was made to examine histological change after cord injury. Spinal cord injury produced by NYU impactor was quite reproducible in parameters of the magnitude of trauma, the extent of tissue damage, and neural dysfunction measured in this study. In the immunohistochemical study, moreover, increased number of neurofilament and decreased number of macrophage were found in the group of CsA treated 4 hours after cord injury. These results indicate that CsA improves motor function after cord injury, and suggest that some actions of CsA on calcineurin, expression of surface markers or macrophage may contribute to these effects.