LIGHT-INDUCED DEPOSITS IN BRUCHS MEMBRANE OF PROTOPORPHYRIC MICE
LIGHT-INDUCED DEPOSITS IN BRUCHS MEMBRANE OF PROTOPORPHYRIC MICE
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DOI：
10.1001/archopht.1993.01090010130039
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发表时间：
1993-01-01
影响因子：
--
通讯作者：
GREEN, WR
中科院分区：
文献类型：
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作者：
GOTTSCH, JD;BYNOE, LA;GREEN, WR
脉络膜毛细血管内皮细胞的光敏化与血液传播的光敏剂，如原卟啉IX，已被提出作为脉络膜毛细血管硬化和布鲁赫膜沉积在年龄相关性黄斑变性中看到的机制。利用原卟啉IX水平增加约10倍并暴露于蓝光（14 μ W/cm 2;带宽，390至430 nm）的原卟啉症小鼠模型，在7个月时通过透射电子显微镜可以证明脉络膜毛细血管和视网膜下色素上皮基底层样沉积物的时间和光依赖性增加。在暴露于蓝光13周的原卟啉小鼠中，首先注意到具有均匀电子致密材料的脉络膜毛细血管内皮基底膜增厚。在28周时，实验动物在脉络膜毛细血管基底膜水平上显示出均匀沉积物的厚带，沿布鲁赫膜内侧沿着有不同尺寸的电子致密纤维颗粒沉积物，纤维测量值高达16 nm，周期为13 nm。这些沉积物导致Bruch膜整体增厚，脉络膜毛细血管变窄。该动物模型的布鲁赫膜内的这些沉积物的形态学外观和定位类似于先前描述的在年龄相关性黄斑变性发展之前在老化布鲁赫膜中注意到的沉积物。
Photosensitization of choriocapillary endothelium with blood-borne photosensitizers, such as protoporphyrin IX, has been proposed as a mechanism for the choriocapillary sclerosis and Bruch's membrane deposits seen in age-related macular degeneration. Utilizing a mouse model of protoporphyria with approximately a 10-fold increase in protoporphyrin IX level and exposure to blue light (14 muW/cm2; bandwidth, 390 to 430 nm), a time- and light-dependent increase in choriocapillary and sub-retinal pigment epithelium basal laminar-like deposits could be demonstrated at 7 months by transmission electron microscopy. Thickening of the choriocapillary endothelial basement membrane with a homogeneous electron-dense material was first noted in protoporphyric mice exposed to blue light for 13 weeks. At 28 weeks the experimental animals exhibited a thick band of homogeneous deposits at the level of the choriocapillary basement membrane and electron-dense fibrillogranular deposits of varying sizes along the inner aspect of Bruch's membrane, with fibrils measuring up to 16 nm, with a periodicity of 13 nm. These deposits contributed to an overall thickening of Bruch's membrane with narrowing of the choriocapillaris. The morphologic appearance and localization of these deposits within Bruch's membrane of this animal model are similar to previously described deposits noted in the aging Bruch's membrane prior to the development of age-related macular degeneration.