动物造模,年龄相关性黄斑变性模型 z-bio 2021-08-12 666

　　Objective: To establish a model of age-related macular degeneration in mice induced by chronic light combined with hydroquinone feeding, to observe its pathological characteristics, changes in ultra-fine structure and retinal function, and the pathogenesis of AMD, and to provide us with a new Research methods.

　　Method: Twenty 4-month-old C57BL/6 mice were randomly divided into model group and normal group, with 10 mice in each group. The mice in the model group were fed with a basic purity synthetic feed containing 8g/(kg?bw) hydroquinone, and 2500lx light for 12 hours a day. The mice in the normal group were fed the same prescription diet without hydroquinone under normal light for 3.5 months. Using electroretinogram (ERG), optical microscope and electron microscope, we observed the changes in the function and structure of the retina of the two groups of mice. The TUNEL method was used to observe the apoptosis of retinal cells and immunofluorescence was used. Detection of retinal and choroidal vascular endothelial growth factor (VEGF) and CD31, expression and distribution.

　　Result: The ERG test showed that the retinal function of the model group was lower than that of the normal group. The retinal pigment epithelium atrophy in the model group under light microscope, the number of photoreceptor cells in the Bruch membrane structure model group was (164.67±34.37), and the normal group was (243.33±15.23). ...The number of photoreceptor cells in the model group was significantly different from that in the normal group (t=-9.77, Pu003c0.05). Transmission electron microscopy showed that the retinal photoreceptor cell membrane disc structure in the model group was loosely deformed and partially broken. Some retinal pigment epithelial cells are shortened, Bruch's membrane is irregularly thickened, and the outer collagen layer can be deposited in layers, and endothelial cells protrude into Bruch's membrane. TUNEL results showed that there were few apoptotic cells in the normal group, and a large number of apoptotic cells appeared in the retinal pigment epithelium (RPE) and photoreceptor layer of the model group. The photoreceptor apoptotic rate was (43±2.73). )? And the difference between the two groups is statistically significant. Meaning (Pu003c0.01). The result of fluorescent antibody method showed that the normal group had weak positive expression of VEGF in the outer plexiform layer and nerve fiber layer. In addition to the above cells in the model group, strong positive staining was also seen in the RPE cell layer. There was no obvious CD31 positive staining in the cells of each layer of the retina in the normal group, and the strong expression of CD31 in the RPE cell layer of the model group, suggesting that there is angiogenesis in the RPE layer.

　　Conclusion: The mice with long-term light combined with hydroquinone diet are very close to the pathogenesis and characteristics of human AMD, which can provide a reliable animal model for further research on the pathogenesis and prevention of AMD.