大鼠外伤性视神经损伤模型的建立

Establishment of traumatic optic nerve injury models in rats

目的建立大鼠定量视神经损伤模型,为研究视神经损伤的发病机制及治疗效果奠定基础。方法健康Sprague-Dawley大鼠27只,随机分为3组,分别为A组(损伤组)12只、B组(假损伤对照组)12只、C组(正常对照组)3只。A组暴露视神经,应用40g力的视神经夹在大鼠眼球后2mm处夹视神经30s,B组仅暴露视神经,C组不做任何处理。A、B组按损伤后不同时间分为3d组、7d组、14d组、28d组,采用双上丘注射50g.L-1荧光金标记双眼视网膜神经节细胞(retinal ganglion cells RGCs)。视网膜铺片荧光照相,计算RGCs计数,RGCs标识率及RGCs丧失率。结果 C组与B组RGCs计数及RGCs标识率比较,无明显差异;A组与B组各时间点RGCs计数及RGCs标识率比较,均有明显差异;A组视神经损伤后不同时间RCCs计数逐渐下降(3d:152.26±25.12,7d:111.19±20.32,14d:101.23±17.19,28d:94.86±18.26),14d组与28d组比较无统计学意义,其他时间点比较有统计学意义,视神经损伤后RGCs标识率随时间延长渐进性降低(3d:79.35%±8.29%,7d:59.76%±7.79%,14d:53.26%±7.26%,28d:51.29%±3.26%),而RGCs丧失率随时间延长渐进性增加(3d:20.65%±3.15%,7d:40.24%±5.63%,14d:46.74%±4.37%,28d:48.71%±5.12%)。结论应用40g力视神经夹在大鼠眼球后2mm处夹视神经30s能成功建立定量视神经损伤动物模型。

Objective To establish traumatic optic nerve injury models in rats for researching mechanisms of injury and treatment of optic nerve injury.Methods Twenty-seven healthy Sprague-Dawley（SD） rats were randomly divided into 3 groups,which were group A（partial optic nerve crush injury group） for 12 rats,group B（pseudo-injury control group） for 12 rats,group C（normal control group） for 3 rats.In group A,optic nerve was exposed and clipped for thirty seconds by a special designed optic nerve clip with 40-gram holding force at optic nerve with 2 mm behind the eyeball.In group B,optic nerve was only exposed.According to the sacrificing date of the rats,four subgroups in group A and B were further divided for three,seven,fourteen and twenty-eight days later.About 50 g·L-1 fluorogold was injected into both superior colliculi bilaterally to each subgroup.Flat mounts of the retina from both eyes were prepared on a slide and observed under a fluorescence microscope.The labeled retinal ganglion cells（RGCs） photos,the labeled RGCs rate and the lost RGCs rate were counted.Results There was no significant difference in RGCs and the labeled RGCs rate between group C and group B.There were significant differences in RGCs and the labeled RGCs rate between group A and group B.In group A,the retinal ganglion cells showed a tendency to decline gradually along with increases of the time in model of partial optic nerve crush injury（3 d：152.26±25.12;7 d：111.19±20.32;14 d：101.23±17.19;28 d：94.86±18.26）.There was no significant difference between 14 days group and 28 days group.There was a same tendency along with increase of the time in the labeled RGCs rate after optic nerve injury（3 d：79.35%±8.29%;7 d：59.76%±7.79%;14 d：53.26%±7.26%;28 d：51.29%±3.26%）.But the lost RGCs rate was increasing（3 d：20.65%±3.15%;7 d：40.24%±5.63%;14 d：46.74%±4.37%;28 d：48.71%±5.12%）.Conclusion Using a special designed clip with 40-gram holding force constantly pressed for thirty seconds can create an optic nerve crush injury model in rats.