The Changes On The Expression Of Neurotrophic Factors And Apoptosis Genes Following HSCI

[Objective] : To explore the changes in the expression of NTFs(NGF, BDNF, NT3, bFGF, GDNF) and apoptosis genes(Bax, Bcl-2, Fas) after hemisection spinal cord injury.(Method] : The SD rats were divided into sham-operational group, 3d , 7d and 21d groups (the spinal cord between T9-T10 was hemisected, animal surviving for 3 , 7 and 21 days after operation respectively). 6 rats were used in every group. Spinal cord of every group were taken out and fixed 4% polymerisatum for 12 hours and then into 20% cane suger PBS over night. The samples were made into frozen sections 20 μ m on the thickness respectively .The sections were stained under the same condition using NGF, BDNF, NT-3, bFGF, GDNF,Bax, Bcl-2, Fas antibody by ABC method. The distribution and the number of NGF, BDNF, NT-3, bFGF, GDNF, Bax, Bcl, Fas positive neurons in ventral horn neurons of the spinal cord were observed and counted. Data were analyzed by one-way anova and q test.[Results] : 1. NGF, BDNF, NT, bFGF, GDNF immunoreactivity can be observed in motoneurons of the ventral horn in the sham-operational group. After hSCI, the number of NGF ,BDNF, NT-3,FGF, GDNF positive neurons in the ventralhorn in 3d, 7d and 21d groups were significantly higher than the sham-operational group. The number of BDNF-, NT-3-, bFGF positive neurons reached a peak at 3d after injury. There was a trend of decrease with time following hSCI. Comparetively, the number of NGF GDNF positive neurons reached a peak at 7d after injury. There is no statistical significance in number of NGF- GDNF positive neurons between the 3d and 2 Id group. 2. Bax Bcl-2 Fas immunoreactivity can also be seen in neurons of the ventral hom in the sham-operational group. After hSCI, the number of Bax% Bcl-2 Fas positive neurons apparently increased in the 3d group,7group and 21 group when compared to that of the sham-operational group. The Bax Fas positive neurons reached a peak at 3d after injury. There was a trend of decrease with time following hSCI. Bcl-2 positive neurons reached a peak at 7d after injury. There is no difference in the number of Bcl-2 positive neurons between 3d and 21d groups.[ Conclusion 1: 1. The number of NGF, BDNF NT-3 bFGF, GDNF positive neurons is increased in the spinal cord ventral horns following hSCI, which indicates the increased endogenous NGFBDNF NT- bFGFx GDNF may play an important role in early repairment of nerve injury after hSCI. 2. There exist high expression of apoptosis genes (Bax Bcl-2 N Fas) after hSCI, it undelies the basis for neuronal cell apoptosis.