荧光金逆行标记评价视神经切断后视网膜节细胞存活率

Evaluating the survival rate of axotomized retinal ganglion cells by fluorogold retrograde labeling

目的:利用荧光金逆行标记评价视神经切断后视网膜节细胞(RGCs)的存活率。方法:将SD大鼠20只随机均分为4组,正常对照组和视神经切断后5 d、7 d和14 d组。用荧光金逆行标记和定量解剖学技术观察正常对照组和视神经切断后5 d、7 d和14 d组RGCs的密度。结果:正常对照组RGCs呈放射状分布,边界清晰,可见明显细胞突起,无渗漏现象;视神经切断组RGCs随时间延长而减少,细胞分布不均匀,并且可见吞噬死亡细胞碎片和从死亡细胞渗漏的荧光金的小胶质细胞。正常对照组左眼与右眼RGCs密度差异无统计学意义(P>0.05);视神经切断后RGCs进行性减少,切断后5 d、7 d和14 d组左眼RGCs密度均明显低于正常对照组(P<0.01),视神经切断后5 d、7 d和14 d存活率分别为53%、38%和13%。结论:荧光金逆行标记是评价视神经切断后RGCs存活率有效的方法。

Objective： To evaluate the survival rate of retinal ganglion cells（RGCs） after transsection of the optic nerve using the method of fiuorogold retrograde labeling. Methods ：Twenty SD rats were randomly divided into four groups：normal control group ,5 d, 7 d and 14 d after transsection of the optic nerve groups. The RGCs density of the normal control group and 5 d,7 d and 14 d after transsection of the optic nerve groups was observed by fluorogold retrograde labeling and quantitative anatomical technology. Results： In the normal control group, the RGCs labeled by the fluorescent gold presented radial distribution, clear boundary and obvious cell processes without any leak. In the optic nerve transsection groups, the number of RGCs decreased with time increasing and the cell distribution was not uniform; and the debris of dead cells and cell leakage from the dead FG microglial cells were observed. In the normal control group, the average density of RGCs of the left eye had no significant difference compared to that of the right eye （ P 〉 0.05）. In the 5 d,7 d and 14 d after transsection of the optic nerve groups, the number of RGCs was reduced progressively and the density of RGCs of the left eye was significantly lower than that in the normal control group （P 〈 0.01 ） ;the survival rates of RGCs in the groups of 5 d, 7 d and 14 d after optic nerve transsection were 53%, 38% and 13%, respectively. Conclusions： Fluorogold retrograde labeling is an effective method of evaluating the survival rate of axotomized retinal ganglion ceils.