Li Shuang, Fang Jia-Hua, Jiang Fa-Gang
Department of Ophthalmology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province, China.
Int J Ophthalmol. 2010;3(4):311-5. doi: 10.3980/j.issn.2222-3959.2010.04.08. Epub 2010 Dec 18.
To explore the injury of retinal ganglion cells (RGCs) and optic nerves in acute ocular hypertension (OHT) rats.
We retrogradely labeled RGCs and optic nerves of Sprague-Dawley rats by injecting 20g/L fluorogold (FG) into bilateral superior colliculi. Twenty-four hours after the injection, the right eyes were performed physiological saline anterior chamber perfusion with intraocular pressure maintained at 100mmHg for 60 minutes, while the contralateral eyes were performed sham procedure as control group without elevation of the saline bottle. Retinal hematoxylin and eosin (HE) sections, retinal whole mounts and frozen sections were made 14 days later to observe the morphology and survival of RGCs. Frozen sections and transmission electron microscopy were utilized to investigate the histological manifestations of optic nerves at the same time.
A larger number of RGCs presented in control group. It had an average density of 1995±125/mm(2) and distributed uniformly, while RGCs in OHT eyes reduced significantly to 1505±43/mm(2) compared with control group (P<0.05). The optic nerves in control group showed stronger and more uniform fluorescence on the frozen sections, and the auxiliary fibers as well as myelin sheaths were in even and intact organization by transmission electron microscopy. However, exiguous fluorescence signals, vesicular dissociation and disintegration of myelin sheaths were found in OHT group.
The present study suggested that fluorogold retrograde tracing is a feasible, convenient method for quantitative and qualitative study of neuronal populations and axonal injury in acute ocular hypertension rats.
探讨急性高眼压（OHT）大鼠视网膜神经节细胞（RGCs）和视神经的损伤情况。
通过向Sprague-Dawley大鼠双侧上丘注射20g/L荧光金（FG）对RGCs和视神经进行逆行标记。注射后24小时，右眼进行生理盐水前房灌注，眼压维持在100mmHg持续60分钟，而对侧眼进行假手术作为对照组，不抬高盐水瓶。14天后制作视网膜苏木精-伊红（HE）切片、视网膜整体铺片和冰冻切片，观察RGCs的形态和存活情况。同时利用冰冻切片和透射电子显微镜研究视神经的组织学表现。
对照组RGCs数量较多。其平均密度为1995±125/mm²，分布均匀，而高眼压组RGCs与对照组相比显著减少至1505±43/mm²（P<0.05）。对照组视神经在冰冻切片上显示更强且更均匀的荧光，透射电子显微镜下辅助纤维和髓鞘组织均匀且完整。然而，高眼压组发现荧光信号稀少、髓鞘泡状解离和崩解。
本研究表明荧光金逆行追踪是一种用于急性高眼压大鼠神经元群体和轴突损伤定量和定性研究的可行、便捷方法。
