中文摘要：

目的观察Rac1-siRNA重组载体对大鼠视网膜血管内皮细胞生长因子（VEGF）表达的抑制作用。方法将25只成年SD大鼠,采用光动力法诱导双眼视网膜静脉阻塞后,1只眼玻璃体腔转染Rac1-siRNA重组载体作为基因干预组,另1只眼注射空白载体作为空白对照组。25只正常SD大鼠单眼玻璃体腔内转染Rac1-siRNA重组载体作为空白干预组。免疫组织化学法和RT-PCR法检测各组大鼠视网膜VEGF的表达情况。结果VEGF在基因干预组和空白对照组中与空白干预组相比表达较强,空白对照组最强,差异有统计学意义（P〈0.05）。结论Rac1-siRNA重组载体能有效抑制视网膜内VEGF的表达。

英文摘要：

Objective Retinal neovascularization and hemorrhage,exudation and proliferation of new blood vessel are major pathologic process in many ocular diseases.Many factors are associated with angiogenesis.This paper was to observe the inhibitory effect of Rac1-siRNA on vascular endothelial growth factor（VEGF）in retina of rat model.Methods Retinal vein obstruction was induced by retinal photodynamic method in 25 SD rats.Rac1-siRNA vector was injected into vitreous in lateral eyes of model rats as gene intervention group.The blank vector was utilized in fellow eyes as blank contrast group.Rac1-siRNA vector was injected into vitreous in normal 25 SD rats as blank intervention group.Two weeks after transfection,the expression of VEGF was detected by immunohistochemistry and RT-PCR.Results Abnormal retinal vein was found after photocoagulation of retina in the model rats by FITC-dextran retinal angiography under the light microscope.The VEGF was expressed in the inner nuclear layer and retinal ganglion cell layer in various groups,showing the brown-yellow staining in cytoplasm.The mean optical density of VEGF was 82.964±11.382,45.042±7.347 and 15.936±5.602 in blank contrast group,gene intervention group and blank intervention group respectively,showing a significant difference among three groups（F=0.042 3,P=0.000）,and a considerable difference was seen between blank contrast group and gene intervention group（P=0.000）,blank intervention group and gene intervention group（P=0.000）or blank contrast group and blank intervention group（P=0.000）.The expression of VEGF in gene intervention group and blank contrast group is higher than blank intervention group.Conclusion The inhibitory effect of reconstructive vector Rac1-siRNA on retinal VEGF is identified.