大鼠视神经压榨伤模型的建立

目的建立大鼠标定性视神经损伤模型.方法健康SD大鼠28只,7只为正常对照组,只进行双上丘注射3%快蓝逆行标记视网膜神经节细胞(retinal ganglion cells,RGCs),另21只为标定性视神经损伤组,依损伤后存活时间的不同再分为A组(4d组)、B组(14d组)及C组(21d组),每组7只.21只大鼠以夹持力为40 g的特制视神经夹,在大鼠眼球后2 mm处夹持视神经4s,制成大鼠标定性视神经压榨伤模型,于处死前3d采用双上丘直接注射3%快蓝(fast blue)法标记双眼RGCs,将全视网膜铺片置于荧光显微镜下,在距视乳头1 mm处的颞上、颞下、鼻下、鼻上4处作荧光摄影(400 ×),并输入计算机经图像分析仪计数RGCs,按RGCs标识率进行统计学比较.RGCs标识率=损伤眼(右眼)RGCs数/未损伤眼(左眼)RGCs数×100%.结果正常大鼠的RGCs标识率右眼RGCs数/左眼RGCs数为99.79%±13.05%,左眼RGCs数/右眼RGCs数为101.86%±13.91%,无论是用左眼的RGCs数比右眼的RGCs数,或用右眼的RGCs数比左眼的RGCs数,其结果无显著性差异(P＞0.5).视神经损伤组的RGCs标识率A组(4d组)RGCs标识率为77.79%±7.11%;B组(14d组)RGCs标识率为63.76%±3.79%;C组(21d组)RGCs标识率为54.66%±4.75%.以上显示,损伤各组的RGCs标识率明显低于正常对照组(P＜0.05),且随着时间的推移,损伤A、B、C组的RGCs标识率渐进性降低.结论用特制的夹持力为40 g的视神经夹,夹持正常大鼠视神经4s,可造成部分性RGCs丧失,随大鼠存活时间的推移,RGCs呈渐进性丧失.眼科学报2001;1799～102.

A Model of Calibrated Optic Nerve Crush Injury in Rats

OBJECTIVE: To establish a calibrated optic nerve crush injury model in rats. METHODS: Twenty-eight healthy Sprague-Dawley (SD) rats were randomly divided into two groups. Seven rats were in normal control group, i.e. group A. In group B, model of partial optic nerve crush injury group, partial optic nerve crush injury model was induced in the right eyes of another 21 rats by a special designed optic nerve clip with 40-gram holding force at optic nerve 2 mm behind the eyeball clipped for four seconds to partially block the optic nerve axoplasmic transport. The left eyes served as a control. According to the sacrificing date of the rats, three subgroups in group B were further divided. Therefore, seven rats were in each subgroup. One, eleven and eighteen days later, 3% fast blue was injected into both superior colliculi to each subgroup and group A. The eyes were enucleated another three days later, flat mounts of the retinal from both eyes were prepared on a slide and observed under a fluorescence microscope. Four photos with 400 x magnification were taken from quadrants of the retina 1 mm away from the optic disc. The labeled retinal ganglion cells (RGCs) photos were counted by a computerized image analyzer. The labeled RGCs rate, a comparison of the labeled RGCs from both eyes in a rat were used for statistical analyzing. (The labeled RGCs rate = RGCs from injured right eye/RGCs from uninjured left eye x 100%). RESULTS: In group A, the group of normal control group, the labeling rate from the ratio of RGCs counting of right eye to left eye was 99.79% +/- 13.05% and from the ratio of the RGCs of left eye to right eye was 101.86% +/- 13.91%. In group B, model of partial optic nerve crush injury group, the labeled RGCs rate were 77.79% +/- 7.11%, 63.76% +/- 3.79% and 54.66% +/- 4.75% in day 4, day 14 and 21 respectively. CONCLUSION: Using a special designed clip with 40-gram holding force constantly pressed for four seconds to create an optic nerve crush injury model in rats. As time past along, it is revealed that the labeled RGCs rate gradually reduced.