rhGDNF对大鼠脊髓损伤后Ntyr表达影响的研究

目的研究大鼠脊髓损伤（spinal cord injury，SCI）后应用人重组胶质细胞源性神经营养因子（recombinated human glial cell line derived neurotrophic factor，rhGDNF）对酪氨酸硝基化蛋白（nitrotyrosine，Ntyr）表达情况的影响。方法48只雄性SD大鼠随机分为正常组、假手术组、生理盐水对照组和rhGDNF实验组，改良Allen法致脊髓中等程度损伤，伤后1d、3d、7d、14d用免疫荧光染色法测定Ntyr的表达情况，同时评定下肢运动功能（Tarlov评分和改良Rivlin斜板）。结果伤后1d rhGDNF组Ntyr阳性神经元数量多于生理盐水对照组（P〈0．05），伤后3d、7d、14d时较同时程生理盐水对照组明显减少（P〈0．05）。2组的运动功能评分比较：伤后1d无明显差异，伤后3d、7d、14d时rhGDNF治疗组较生理盐水对照组明显提高（P〈0．05）。结论SCI后应用rhGDNF可减少大鼠脊髓Ntyr的表达，促进其运动功能恢复。

Influence of rhGDNF to Ntyr expression in rats' spinal cord after spinal cord injury

Objective To explore changes of nitrotyrosine （Ntyr） expression after spinal cord injury treated with recombinated human glial cell line-derived neurotrophic factor （rhGDNF） in rats. Methods Forty-eight healthy male SD rats weighed 220- 250 g were divided into 4 groups at random： normal group, sham-operated group, normal saline treated group and rhGDNF treated group. Saline and rhGDNF were given through lumbar intrathecal catheter at 1 d, 3 d, 7 d, 14 d after T9 segment of spinal cord Were injured by modified Allen contusion method. Immunofluorescence was used to investigate the expression of Ntyr at 1 d, 3 d, 7 d, 14 d. Animals were behaviorally tested by the Tarlov＇ s grading and Rivlin＇ s oblique plate test. Results The number of Ntyr positive-reaction neurons in rhGDNF treated group was more than normal saline treated group＇s at 1 d （P 〈 0.05）. At 3 d, 7 d, 14 d, the numbers of Ntyr positive-reaction neurons significantly decreased after rhGDNF treated and were less than those of normal saline treated group at the same time （ P 〈 0.05 ）. At 1 d, there was no difference between normal saline treated group and rhGDNF treated group in behavioral assessment. At 3 d, 7 d, 14 d the behavioral assessment scores significantly increased after rhGDNF treated and were better than those of normal saline treated group at the same time （P 〈 0.05 ）. Conclusion The results indicate that intratheeal infusion of exogenous rhGDNF after spinal cord injury may reduce Ntyr expression and enhance functional recovery.