遗传性视网膜变性动物模型感光细胞节段早期变化的形态学研究

目的：了解遗传性视网膜变性的感光细胞节段在出生后早期发生的形态学变化，为临床诊治提供参考信息。方法：取出生后不同时间的retinal degeneration(rd)、retinaldegenerationslow(rds)小鼠及正常对照小鼠视网膜，经光镜、扫描电镜和透射电镜观察感光细胞节段的形态发生发育和结构变化过程，比较其在各型的动态变化和各型间的形态学差异。结果：rd鼠节段变性发生早，生后1周时开始出出节段变短，线粒体变性改变多见；2周时节段层变薄，内节段结构不完整，外节膜盘变形、排列紊乱；3周时节段层近消失。rds鼠外节段不发育，变性发生晚，2周时内节段变短；3周时明显变短；4周时细胞器减少、内节段变形。结论：感光细胞节段的变性改变与其基因型相关，不同遗传背景的视网膜变性有着不同的表型。

Investigation of the early morphological changes of photorecepter segment in animal model of hereditary retinal degeneration

Objective:To investigate the morphological changes of photorecepter segment during the early postnatal period of hereditary retinal degeneration.Methods:Retinas of retinal degeneration(rd),retinal degeneration slow(rds) mice and control animals were observed at different postnatal periods.Microscopic structure and ultrastructure of retinal photoreceptor segment were observed with light microscopy,scanning electron microscopy and transmission electron microscopy.Changes were compared among different groups.Results:In rd mice,the degeneration of photorecepter segment begins early.The segments become shorter at Plw(postnatal 1 week),and mitochondria degeneration is often seen.At P2w,segment layer becomes thinner and integrity of inner segments destructed.At P3w,segment layer almost disappears.In rds mice,outer segment never develops within P4w and the degeneration begins late.Inner segments become thinner at P2w and obviously shorter at P3w,and at P4w,they deform and their organelles reduce in number.Conclusions:Degeneration of the segment is related to the genotype.Different hereditary background leads to different phenotype.