Effects of nerve growth factor on neuronal nitric oxide production after spinal cord injury in rats

摘要

Objective: To explore the protective effects of nerve growth factor (NGF) on injured spinal cord. Methods: The spinal cord injury (SCI) model of Wistar rats was established by a 10 g x 2.5 cm impact force on the T_8 spinal cord. NGF (60 μg/20 μl) was given to the rats of the treatment group immediately and at 2, 4, 8, 12, 24 hours after SCI. The level of neuronal constitutive nitric oxide synthase ( ncNOS) and the expression of ncNOS mRNA in the spinal cord were detected by the immunohistochemistry assay and in situ hybridization method. Results: Abnormal expression of ncNOS was detected in the spinal ventral horn motorneuron in injured rats. The levels of ncNOS protein in the NGF group were significantly lower than those in the normal saline group ( P < 0.05 ). The ncNOS mRNA expression was found in the spinal ventral horn motorneuron in injured rats and the expression in the NGF group was significantly decreased compared with that in the normal saline group (P < 0.01). Conclusions: NGF can protect the injured tissue of the spinal cord by prohibiting abnormal expression of nitric oxide synthase and the neurotoxicity of nitric oxide.