【摘要】 目的:探讨胰岛素控制血糖对糖尿病早期大鼠视网膜血管形态改变和血管内皮细胞生长因子(Vascular endothelial growth factor,VEGF)表达的影响。方法:实验动物Wistar大鼠分正常对照组、糖尿病组、糖尿病血糖严格控制组和糖尿病血糖非严格控制组。链尿佐菌素(Streptozotocin,STZ)诱导糖尿病动物模型,动物成模3周后糖尿病血糖严格控制组及血糖非严格控制组大鼠予胰岛素治疗,20d后处死,行Fluorescein isothiocyanate-dextran(FITC-Dextran)灌注视网膜血管铺片观察大鼠视网膜血管形态变化,并行VEGF免疫荧光染色观察大鼠视网膜VEGF的表达改变。结果:FITC-Dextran灌注示糖尿病血糖非严格控制组大鼠视网膜浅层血管多处荧光素聚集,不均匀分布,深层毛细血管局部扩张、迂曲;血糖严格控制组视网膜血管管径较均匀一致,无局部扩张或狭窄。糖尿病血糖非严格控制组VEGF高表达,血糖严格控制组较糖尿病组、血糖非严格控制组视网膜VEGF表达下降,统计学比较具有显著性差异(P<0.05)。结论:胰岛素治疗严格控制血糖至正常水平可以降低糖尿病早期大鼠视网膜VEGF的表达、减轻视网膜血管损害;血糖波动会加重糖尿病视网膜病变的发展。眼科学报2007;23:205-211.更多还原

【Abstract】 Objective: To observe the role of blood glucose control on morpholo gy changes of retinal vessels and retinal vascular endothelial growth factor (VE GF) expression in early diabetic rats. Methods: Diabetes was induced in 8-week-old male wistar rats by a single intraperitoneal injection of Streptozotocin (STZ). After 3 weeks, the ani mals were randomly divided into four groups: 1) normal rats group, 2) diabetic r ats group, 3) diabetic rats with glucose controlled group, received intensive in sulin therapy for 20 days, and 4) diabetic rats with uncontrolled blood glucose group, received unregular insulin therapy, which caused the abrupt fluctuation o f glucose. After the treatment period, the animals were perfused with 30mg/ml Fl uorescein isothiocyanate-dextran (FITC-Dextran). The eyes were enucleated and fixed in 4% paraformaldehyde immediately. Retinal flat mounts and paraffin secti ons were prepared. Morphology of impaired retinal vessels and retinal VEGF expre ssion were assessed by immunofluorescence stain and image analysis. Results:The flat-mounted retinas showed more FITC-Dextran aggrega ted locally at vessels and capillary meandered or dilated in STZ-diabetic rats with uncontrolled blood glucose than in STZ-diabetic rats with controlled blood glucose. Retinal VEGF expression decreased in group 3 compared with group 2 or with group 4. The statistical difference was significant (P<0.05). Conclusion: Strict control of blood glucose by insulin could decrea se VEGF expression in retina and protect retinal vessels from impairing in early STZ-diabetic rats.更多还原