Effects of a Single Dose of Methylprednisolone versus Three Doses of Rosiglitazone on Nerve Growth Factor Levels after Spinal Cord Injury

Acute spinal cord lesions result in dramatic changes in neuronal function. Studies have shown that the peroxisome proliferator-activated receptor-γ agonist, rosiglitazone, has neuroprotective properties. The effect of rosiglitazone after acute spinal cord injury was examined in the present study. Rats were subjected to laminectomy only; laminectomy with spinal cord contusion injury; laminectomy with contusion injury plus 30 mg/kg body weight methylprednisolone administered 5 min after surgery; or laminectomy with contusion injury plus 2 mg/kg body weight rosiglitazone administered intra-peritoneally 5 min, 6 h and 24 h after surgery. Both drugs increased neurotrophin gene and protein expression 24 h after injury compared with injured rats without drug treatment. Rosiglitazone increased neurotrophin expression at 7 days to a greater extent than methylprednisolone. Early functional recovery was observed in rats treated with rosiglitazone. The greater increase in rosiglitazone-induced nerve growth factor expression soon after injury could explain, at least in part, the improved recovery of motor function compared with methylprednisolone or saline.