感光细胞缺失对视网膜节细胞melanopsin表达的影响

目的：研究感光细胞缺失对视网膜节细胞 melanopsin 表达的影响。方法：SD 大鼠腹腔注射60 mg/kg N- 甲基-N-亚硝基脲建立感光细胞变性缺失的动物模型,用免疫荧光方法观察视网膜铺片及切片中 melanopsin 阳性细胞的分布及特征。结果：在药物注射12 h 后动物视网膜感光细胞层开始凋亡,细胞数目随时相减少,13 d 后完全消失。在正视网膜节细胞表达 melanopsin,呈串珠样分布在胞体及突起的胞膜上,其树突穿过节细胞层, 在内网层的两侧分叉形成网状结构。在感光细胞缺失动物模型组,12 h 时,节细胞表达 melanopsin 更广泛；而后突起上的 melanopsin 表达随时减少。28 d 时,melanopsin 的表达主要局限于节细胞的胞体。结论：感光细胞缺失影响节细胞突起 melanopsin 的表达。

Effects of photoreceptor degeneration on expression of melanopsin in retinal ganglion cells

Objective:To investigate the effects of photoreceptor degeneration on the expression of melanopsin. Methods:Photoreceptor degenerative model was made by i.p injection of N-methyl-N-nitrosourea at a dose of 60 mg/kg.Mclanopsin positive cells were observed by fluorescent immunohistochemistry on whole-mount and eye sections.Results:Apoptosis of photoreceptors appeared 12 h after injection;photoreceptors decreased as time went by,and disappeared on 13 d.Melanopsin expressed on ganglion cells.The stained processes had a beaded appearance;dendrites bifurcated at the outermost and innermost of inner plexiform layer(ipl),forming reticular network.Mclanopsin was extensively expressed 12 h after injection,then melanopsin expression in dendrites de- creased gradually;on 28 d melanopsin expression was confined to cell bodies.Conclusion:Photoreceptor degener- ation affects melanopsin expression on ganglion cells dendrites.