Abstract: Objective To explore the effect of α-phenyl-N-tert-butylinitrone (PBN) on expression of nerve growth factor (NGF) in serum and spinal cord tissue in rats after spinal cord injury (SCI). Methods 174 female Sprague-Dawley rats were randomly assigned to following groups: normal control group (n=54), normal saline control group (NS group, n=60, intrathecally injected normal saline 15 μl), and PBN group (n=60, intrathecally injected PBN, 3 mg, 15 μl). The model was established with New York University blow device (150 kDyne, 1 s dwell time). PBN was intrathecally injected into the damaged areas 30 min after operation, then once a day for 7 days. The Basso-Beattie-Bresnahan (BBB) Locomotor Rating Scale was used to assess the rats 3 days and 1 day before, and 1 day, 5 days, 10 days, 15 days, 20 days,25 days, 30 days and 35 days after SCI. NGF in the injured spinal cord tissue and serum was measured 1 h, 12 h, 24 h, 48 h, 3 days, 7 days,14 days and 21 days after SCI. Results NGF increased in serum but not in spinal cord. The ratio of NGF/total protein in serum rose and peaked 48 h after SCI, and the ratio was higher in NS group (0.92%±0.02%) than in PBN group (0.77%±0.05%) (P=0.021). BBB scores increased from the 9th day, and PBN group improved better than NS group (P<0.01). Conclusion PBN could reduce the expression of NGF in the SCI rats, and promote the recovery of neurol function.

Key words: spinal cord injury, free radical, α-phenyl-N-tert-butylinitrone, nerve growth factor, rats