蛇毒神经生长因子对鼠视网膜神经节细胞GAP-43表达的影响

Venom nerve growth factor on GAP-43 expression in rat retinal ganglion cells

目的通过对视网膜神经节细胞（retinal ganglion cell,RGC）生长相关蛋白-43（growth associated protein-43,GAP-43）的研究,观察蛇毒神经生长因子（venom nerve growthfactor,vNGF）在鼠视神经横断伤后对RGC的保护作用。方法将24只SD大鼠随机平均分为实验对照组、实验治疗组。各组右眼制作视神经横断伤模型,实验治疗组向玻璃体腔内注入0.8 g.L^-1vNGF 0.025 mL,实验对照组向玻璃体腔内注入0.025 mL平衡盐液。左眼未做任何处理,作为正常对照组。于损伤后7 d、14 d取材,应用病理图像分析计数RGC及观察大鼠视网膜神经纤维层厚度变化,进行GAP-43免疫组织化学染色分析。结果光镜下,伤后7-14 d,实验治疗组大鼠RGC数目明显高于实验对照组,有非常显著性统计学差异（P〈0.01）,2组均比正常对照组RGC数目下降,有非常显著性统计学差异（P〈0.01）。免疫组织化学结果：实验治疗组7 d时GAP-43表达明显,14 d时稍减弱;实验对照组7 d时有GAP-43表达,但较实验治疗组弱,到14 d时表达明显减弱。结论在视神经横断伤后,vNGF能增加并延长GAP-43的表达强度,提高RGC的存活数量,对RGC有明显的保护作用。

Objective To investigate the neuroprotective effects of venom nerve growth factor（vNGF） on retinal ganglion cells（RGC） after optic nerve transected in rat by studying RGC growth associated protein-43. Methods Twenty-four SD rats were randomly divided into experimental treatment group and experimental control group. The optic nerves of the right eyes were transected. And then 0.025 mL of 0.8 g · L^-1 vNGF was injected into the vitreous of experimental treatment group eyes, 0. 025 mL balance salt solution were injected into the vitreous of experimental control group eyes. The left eyes were not treated with anything as normal control group. The numbers of RGC were counted and the histological changes of retina were observed at 7 days and 14 days after transected by using image diagnosis system,and the expression of GAP43 was studied by immunohistochemical staiaing. Results Observed under light microseope from 7 days to 14 days,the numbers of RGC in the experimental treatment group were higher than those in the experimental control group, and there was significant difference （ P 〈 0.01 ）. The numbers of RGC in both the experimental treatment groups and experimental control groups were lower than those in normal control group（P 〈 0.01 ）. With the results of immunohistochemical staining, the expression of GAP43 in the experimental treatment groups were apparent at 7 days and decreased slightly at 14 days. There were also expression of GAP43 in the experimental control groups at 7 days but inferior to those of experiment treatment groups,and decreased obviously at 14 days. Conclusion After optic nerve transected,vNGF are effective in enhancing and prolonging the expression of GAP-43, increasing the survival rate of RGC, and has the protective effect on RGC.