大鼠视网膜光损伤与视细胞凋亡关系的研究

目的：研究细胞凋亡与视网膜光损伤的相互关系，以探讨视网膜光损伤的发生发展机制。方法：所有SD大鼠经循环光环境适应7天，实验前暗适应36小时，分别于光照3、6、9、12、15、18小时，灌流固定，摘除眼球。光镜标本在常规脱水、透明、石蜡包埋切片后，行HE、TUNEL法染色，光镜观察；电镜标本在树脂包埋、超薄切片、醋酸－柠檬酸铅双重染色后，透射电镜观察；应用CLAS－1000图像分析系统定量检测外核层面积和视细胞凋亡指数，所得数据作统计学分析。结果：视网膜只见视细胞出现光损伤和细胞凋亡，随着光照时间的延长，视网膜光损伤逐渐加重，视细胞凋亡逐渐增多。在外核层，透射电镜观察及核染色质浓集，而无炎性反应。外核层面积和视细胞凋亡指数作相关性分析有显著意义。结论：视细胞凋亡是视网膜光损伤的重要机制。光损伤启动了视细胞凋亡的发生，外核层细胞核的丢失是视细胞凋亡的结果：视网膜光损伤与视细胞凋亡有着密不可分的联系。

A Study on the Relationship of Optic Cell Apoptosis and Experimental Photic Injury in Rats

Obiective To explore the relationship between retinal photic injury and optic cell apoptosis,so as to probe into the generation mechanism of optic cell apoptosis.Methods All Sprague-Dawley rats were maintained under cyclic light environment for 7 days,the rats were kept in darkness for 36 hours before experiment.The rats were killed after 3,6,9,12,15 and 18 hours continuous intense white light exposure.The sample for light microscopy were enucleated and fixed after irrigation,then processed and embedded in paraffin by routine procedures.All sections were made for HE and TUNEL,examined by light microscopy.The sample for electronic microscopy were embedded in colophony,then made into ultrathin sections and dyed by acetate-citric lead and then it was exa mined by transmition electronic microscopy.The area of out nuclear layer and cell apoptosis index was quantitated by CIAS-1000 cell photo analyze system.The data obtained were assessed by statistially.Results Photic injury and optic cell apoptosis was found in Retina.The Photic injury in retina became worse and worse and optic cell apoptosis became more and more with the light exposure time increasing.The condensation of the chromatin come out without inflamatory response under electron microscope.The OA(out nuclear layer area)and AI(apoptosis index)were compared in relative analysis.The above comparisons were statistically significant.Conclusion Apoptosis is an important mechanism in light-induced retinal damage.It is the light damage that triggers the apoptosis of photoreceptor cells.The loss of cell in ONL is the result of apoptosis. Photic injury and optic cell apoptosis had impartible relationship.