Effects of nerve growth factor on the neuronal apoptosis after spinal cord injury in rats

Objective To explore the protective mec hanisms of nerve growth factor (NGF) on spinal cord injury.Methods The spinal cord injury (SCI) of the Wistar rats was induced with Allen 's way by a 10g×2.5cm impact on the posterior T_8 spina l cord.NGF was given to the treatment group rats by subarachnoid space tube at o nce,2,4,8,12,24h after SCI.The expression levels of bax and bcl-2 protei n in rat spinal cord were detected by immunohistochemistry assay.The apoptosis m otor neurons in spinal cord were investigated by the methods of in situ terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labelin g of DNA fragments reaction.Results The strong expression of bax protein was found in rat spinal cord of the normal group animals.The levels of bax protein in the no rmal saline group were significantly increased as compared with those in the nor mal group.The levels of bax protein in the NGF group were significantly decrease d as compared with those in the normal saline group (P0.01).The strong expression of bcl-2 protein was found in rat spinal cord of the normal group animals.The levels of bcl-2 protein in the normal saline group were decreased as compared with those in the normal group.The levels of bcl-2 protein in the NGF group were significantly increased as compared with those in the normal sali ne group (P0.01).The neurons with apoptosis were reduced in spinal cord of the injured rats,as compared with that in the control group.The number of ap optosis neurons in the NGF group were significantly greater than in the normal s aline group (P 0.01).Conclusion NGF can protect spinal cord from injury in viv o.One of mechanisms is that NGF can inhibit apoptosis after spinal cord injury.