The effect of methylprednisolone on caspase-3 activation after rat spinal cord transection

Purpose: Caspase-3 is known as a crucial effector for apoptotic cell death. Apoptosis has recently been recognized as an important cell death mechanism after spinal cord injury (SCI). This study attempts to define the effect of methylprednisolone (MP) on the activation of caspase-3 in the lesioned area following SCI. Methods: Forty-eight rats with a complete transection of the thoracic spinal cord received a placebo or MP (30 mg/kg, iv.) at 5 min, 2 and 4 h post-injury and were then sacrificed at 12, 24 h 3 or 7 days thereafter. Results: Caspase-3 positive cells in the lesioned area were immunocytochemically observed in both cord stumps and decreased in number with increasing distance from the lesion site. More caspase-3 positive cells were present in the MP-treated group than the control group at all time points, but the differences were not statistically significant. Conclusion: These results suggest that the MP-induced decrease of tissue loss following SCI may not involve a reduction of apoptotic cell death.