| Objective To observe the effect of FTY720 on the expression of Bcl-2 and Bax protein in the rats after T10 acute spinal cord injury and to explore whether FTY720 is neuroprotective effect on neuron of rats after acute spinal cord injury.Methods A total of 150 Sprague-Dawley(SD)rats were divided randomly into 3 groups including the test group (a):60 rats treated with FTY720;the injured group (b):60 rats treated with physiological saline(N.S)and the control group (c):30 rats with no treatment after the laminectomy.All rats in group a,b were received 40 gcf impact to form T10 spinal cord injury (SCI) by Allen method after T9 -T11 laminectomy before they were received treatment. while rats in group c were just received the operation of laminectomy in T9 -T11 without any other treatment.There was five different time points including 6 hours,12 hours,24hours, 3 days, 7 days after administered or operation.On eath time point,12 rats from group a,12 rats from group b and 6 rats from group c were killed, and the spinal cord injured sections were taken out eihter for reverse transcription polymerase chain reaction(RT -PCR) analysis to detect the mRNA expression level of Bax and Bcl-2 or for immunohistochemical examination to show the protein expression level of Bax and Bcl-2 and for histomorphological observation by hematoxylin and eosin (HE)staining .Results (1) The histomorphological observation of HE staining: In 24 hours,the injury area in each group was surrounded by splinter hemorrhage and serious inflammation, a great deal cytoplasm of neuron show blebbing and condensation in the gray matter of spinal cord.In 3 days,the damaged zone with more inflammatory cells infiltration and was surrounded by atrophic neurons, reactive hyperplastic gliacytes and spinal cord cavities.In7 days,more apoptosis body can be seen in either gray matter or white matter. Compare to group b, more neuron survive and the structural damage is less serious in group a. (2) The result of immunohistochemical staining: Both the expression of Bcl-2 and Bax in group a and group b were higher than group c through all the time points we choosed(P<0.01).In 12h,24h,3d,7d the Bax protein expression level of group a was lower than group b; meanwhile the Bcl-2 protein expression level of group a was higher than group b. There was significantly statistical difference among each group (P<0.05). (3) RT-PCR results: Both the expression of Bcl-2 and Bax in group a and group b were higher than group c through all the time points we choosed(P<0.01).In 12h,24h,3d,7d the Bax mRNA expression level of group a was lower than group b; meanwhile the Bcl-2 mRNA expression level of group a was higher than group b.There was significantly statistical difference among each group (P<0.05) .Conclusions Early administration of FTY720(0.5mg/kg)can alleviate the structural damage and inhibit neuron apoptosis in spinal cord by increasing the mRNA and protein expression of Bcl-2 and reducing that of Bax.
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