Katz M L, Eldred G E, Robison W G
Mech Ageing Dev. 1987 Jun;39(1):81-90. doi: 10.1016/0047-6374(87)90088-1.
A lipofuscin-like autofluorescence develops in the degenerating photoreceptor cells of the RCS rat, a strain with inherited retinal dystrophy. In animals with normal retinas, age-related lipofuscin accumulation in the eye is restricted to the retinal pigment epithelium (RPE). Previous investigations have established that RPE lipofuscin accumulation in the normal rat retina can be reduced by dietary vitamin A deficiency. In order to determine whether the photoreceptor-derived fluorescence in the RCS rat retina is related to RPE lipofuscin fluorescence, the influence of dietary vitamin A on the fluorophore content of the RCS rat retina was studied. Vitamin A deficiency substantially reduced the autofluorescence associated with degenerating photoreceptor cells of the RCS rat retina. A specific vitamin A-dependent fluorophore was isolated from these retinas using thin-layer chromatography (TLC). The mobility of this fluorophore on TLC differs from that of the major age-dependent fluorophore isolated from the RPE of normal rats. Thus, if the vitamin A-dependent fluorophores of the photoreceptors and RPE are related, it appears that the fluorophore generated in the photoreceptor cells must undergo chemical modification once it has been taken up by the RPE. The fact that both the RPE- and photoreceptor-associated fluorophores are vitamin A-dependent suggests that such a relationship between them is likely. These experiments indicate that the RPE is somewhat different from other lipofuscin-accumulating tissues in that a major precursor of RPE lipofuscin fluorophores originates in another cell type and enters the RPE via phagocytosis.
在患有遗传性视网膜营养不良的RCS大鼠退化的光感受器细胞中会出现一种类似脂褐素的自发荧光。在视网膜正常的动物中，眼睛中与年龄相关的脂褐素积累仅限于视网膜色素上皮（RPE）。先前的研究表明，正常大鼠视网膜中RPE脂褐素的积累可通过饮食中维生素A缺乏来减少。为了确定RCS大鼠视网膜中源自光感受器的荧光是否与RPE脂褐素荧光有关，研究了饮食中维生素A对RCS大鼠视网膜荧光团含量的影响。维生素A缺乏显著降低了与RCS大鼠视网膜退化光感受器细胞相关的自发荧光。使用薄层色谱法（TLC）从这些视网膜中分离出一种特定的维生素A依赖性荧光团。这种荧光团在TLC上的迁移率与从正常大鼠RPE中分离出的主要年龄依赖性荧光团不同。因此，如果光感受器和RPE的维生素A依赖性荧光团相关，那么看来光感受器细胞中产生的荧光团一旦被RPE摄取，就必须经历化学修饰。RPE和光感受器相关荧光团均为维生素A依赖性这一事实表明它们之间可能存在这种关系。这些实验表明，RPE与其他积累脂褐素的组织有所不同，因为RPE脂褐素荧光团的主要前体起源于另一种细胞类型，并通过吞噬作用进入RPE。
