遗传性视网膜变性rd小鼠及其感光细胞凋亡研究

目的 研究遗传性视网膜变性rd小鼠感光细胞层的发育变化及细胞凋亡。方法 对出生后5d到40d的rd小鼠及对照小鼠视网膜感光细胞层进行光镜及超微结构观察、TUNEL法检测及形态计量学分析。结果 与同龄对照鼠相比，rd小鼠出生后第10d视网膜开始变性，尔后1周内感光细胞迅速减少，第18d时只残留一层视椎细胞。rd小鼠出生后第10d感光细胞层开始出现TUNEL染色阳性细胞，第14d及16d达到高峰。电镜下变性高峰期rd小鼠视网膜感光细胞层可见大量浓缩核、染色质边聚及凋亡小体。结论 rd小鼠视网膜感光细胞在发育过程中变性，并通过凋亡的方式死亡。

HEREDITARY RETINAL DYSTROPHY OF rd MICE AND PHOTORECEPTORS APOPTOSIS

Objective To study the development of hereditary dystrophic retina of rd mice and photoreceptors apoptosis. Methods Retinal sections of rd mice and their controls at different ages ranging from postnatal days 5 to 40 were examined by morphological(light and electronic microscope), morphometric and TUNEL analysis. Results Compared with age-matched control mice, the retinal dystrophy of rd mice began at postnatal days 10, resulting in rapid loss of photoreceptors and reaching a peak at postnatal days 18. TUNEL postitive nucleus of photoreceptor cells emerged from postnatal days 10 and reached a peak at postnatal days 14 and 16. Ultrastructure of photoreceptor cell layer showed marked nuclear pyknotosis and chromatin margination. Apoptotic bodies of photoreceptor cells were observed.Conclusion Rd mice retina degenerated during the process of maturity. Photoreceptor cell death occurred through apoptosis.