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Cytochemical Studies of Blood Retinal Barrier

血视网膜屏障的细胞化学研究

基本信息

批准号：
63480394
负责人：
YASUBUTI Yikio
金额：
$ 3.2万
依托单位：
Kyoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1990
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-63480394/
关键词：
Peroxidase Retinal pigment epithelium Choriocapillaries Bruch's membrane Frozen thin-section Cationized ferritin Sialic acid Charge barrier 網膜色素上皮細胞膜表面荷電フォドリンアクチニン tracer 脈絡膜血管網膜毛細血管 cationized ferritin anionized ferrit

项目摘要

In order to study the characteristics of blood retinal barrier, various peroxidase molecules were utilized as cytochemical tracers. We observed the tracers penetrated through choriocapillaries and basal portion of Retinal Pigment Epithelial (RPE) cells under an electron microscope. Interestingly, smaller tracers with anionic charges did not penetrate much faster than larger tracers with cationic charges. The characteristics of invasion of such tracer proteins were modified according to their electrical charges.The extracellular and intracellular distribution of anionic sites in RPE cells and choriocapillaries were examined by labeling ultra-thin frozen sections with cationized ferritin (CF). We demonstrated CF particles were distributed along the basal laminae of RPE cells and choriocapillaries. In RPE cell junctions, CF particles were evident on the surfaces of cell junctions except gap junctions. By labeling ultra-thin frozen sections with various lectin-ferritin, we showed these anionic site were mainly due to sialic acids.Essner et al. have reported that Bruch's membrane has anionic sites and may serve as a charge barrier against the movement of anionic molecules from the choriocapillaries to RPE cells and the outer neural retina. Our findings showing that basal infoldings of RPE cells and the Bruch's membrane are denely labeled with cationized ferritin suggest that not only the Bruch's membrane but also the basal infoldings of the pigment epithelium have anionic sites and play a role as charge barrier.

为了研究血视网膜屏障的特性，利用各种过氧化物酶分子作为细胞化学示踪剂。电镜下观察示踪剂穿透脉络膜和视网膜色素上皮（RPE）细胞的基底部。有趣的是，带阴离子电荷的较小示踪剂的渗透速度并不比带阳离子电荷的较大示踪剂快。用阳离子化的铁蛋白（CF）标记超薄冰冻切片，观察RPE细胞和脉络膜毛细血管中阴离子位点在细胞内外的分布。CF颗粒沿着RPE细胞和脉络膜帽的基底层分布。在RPE细胞连接中，除了缝隙连接外，细胞连接表面上的CF颗粒是明显的。通过用各种凝集素-铁蛋白标记超薄冰冻切片，我们发现这些阴离子位点主要是由于唾液酸，Bruch等报道了Bruch膜具有阴离子位点，并可能作为电荷屏障，阻止阴离子分子从脉络膜帽膜向RPE细胞和外神经视网膜移动。我们的研究结果表明，基础infoldings的RPE细胞和布鲁赫的膜denely标记阳离子化铁蛋白表明，不仅布鲁赫的膜，但也基础infoldings的色素上皮有阴离子网站，并发挥作用，作为电荷屏障。