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 mechanis m after spinal cord injury (SCI). This study attempts to define the effect of methylprednisolone (MP) on the activation of caspase-3 in the lesioned a rea following SCI. Methods: Forty-eight rats with a complete transection of the thoracic spina l cord received a placebo or MP (30 mg/kg, iv.) at 5 min, 2 and 4 h post-in jury and were then sacrificed at 12, 24 h 3 or 7 days thereafter. Results: Caspase-3 positive cells in the lesioned area were immunocytochemi cally observed in both cord stumps and decreased in number with increasing distance from the lesion site. More caspase-3 positive cells were present i n the MP-treated group than the control group at all time points, but the d ifferences were not statistically significant. Conclusion: These results suggest that the MP-induced decrease of tissue lo ss following SCI may not involve a reduction of apoptotic cell death.