不同日龄视网膜变性大鼠眼底组织结构学观察

目的 探究转基因视网膜退行性变性S334ter-line-3大鼠在出生后不同日龄视网膜组织结构学变化.方法 选择出生后1,9,11,18,30,59 d的S334ter-line-3大鼠,断颈或腹腔注射过量麻药后处死大鼠,摘除双眼球,置入眼球混合固定液及福尔马林液中,左眼行常规石腊包埋,右眼行Histocryl plastic包埋,HE染色,光学显微镜下观察不同时点视网膜组织学结构.结果 出生后第1天,S334ter-line-3大鼠视网膜是一种未发育完善的胚胎型组织,仅有RPE细胞层、祖细胞层,短的内丛状层和神经节细胞层;第9天时其视网膜发育才较完善.第11天时视网膜感光细胞层即开始发生退行性变性,其外核层内可见深染皱缩的凋亡细胞核;第18天时感光细胞层内外节几乎完全消失,外核层变薄,胞核数仅为正常1/2;第30天时,S334ter-line-3大鼠视网膜外层退行性变性已基本完成,仅残留1排感光细胞核层,其外接RPE细胞层,内接视网膜内核层;第59天视网膜结构与第30天基本相同.结论 S334ter-line-3大鼠在出生后随年龄的增长,视网膜外层逐渐发生退行性变性,至出生后第30 d时这种退行性变性基本完成,故出生后30 d的大鼠适合作为视网膜移植中的移植受体.

Histological changes of retina in rats of retinal degeneration at different postnatal days

Objective To observe the histological changes of retina in S334ter-line-3 rats at different postnatal days.Methods Rats were injected over-dose sodium barbiturate or cut neck at postnatal days 1,9,11,18,30 and 59.The eyes were taken off and placed to eye mixed fixation first,and then moved to 10% formarlin.The samples were embedded after 24 h with paraffin or histocryl plastic,and then were stained with HE.Histological structures of retina with different day-age were observed under the light microscope.Results There were multi-layers ganglion cell layers(GCL),short inner plexiform layer(IPL)and the mostly undifferentiated neuroblastic outer layer(NBL)in retinas of S334ter-line-3 rats at postnatal day 1.Retinas had not developed well until at postnatal day 9.There were many degenerating rod photoreceptors with deeper and smaller nuclei at outer nuclear layer(ONL)inretinas at postnatal day 11.At postnatal day 18,there were only 5-6 layers of ONL of S334ter-3 rats remained,significantly thinner than that of normal rat,and outer and inner segment of photoreceptors nearly disappe ared completely,only 2-3 rows left.At postnatal day 30,only one row of photoreceptors remained,ONL and OPL completely lost and partial INL directly covered with the RPE in many areas.The morphology of retinas at postnatal day 59 was the same as at day 30.Conclusion Retinal outer segments of S334ter-line-3 rats progressively loss with the postnatal days,and complete at postnatal day 30.Therefore,S334ter-line-3 rat of postnatal day 30 can be used as receptors of retinal transplantation.