血管内皮生长因子及碱性成纤维细胞生长因子与糖尿病大鼠视网膜早期血管病变的关系

目的　观察糖尿病大鼠视网膜病变与血管内皮生长因子 (VEGF)及碱性成纤维细胞生长因子 (bFGF)作用的关系 ,在理论上指导临床工作。方法　将 55只大鼠建立糖尿病大鼠模型 ,随机分为正常对照组 (M ) 1 0只 ,糖尿病 1个月组 (M1 )、3个月组 (M3)、5个月组 (M5)各 1 5只。标本制成视网膜血管铺片 ,行bFGF、VEGF原位杂交、免疫组织化学 ,并分别对视网膜血管进行透射电镜观察。结果　 (1 )视网膜消化铺片 :见周细胞数量 :M1 组与M组相比差异无显著意义 (P >0 0 5) ,而M3组及M5组与M组相比明显减少 (均P <0 0 1 )。毛细血管形态以M5组病变最重 ,可见毛细血管栓塞 ,无细胞毛细血管。 (2 )VEGF原位杂交 :仅M5组表达为 34 %。 (3)VEGF免疫组织化学 :M5组有表达 ,为 56 %。bFGF原位杂交从M3组开始有表达 ,为 78% ;M5组增至 89% ,bFGF免疫组织化学也从M3组开始 ,为 56 % ;M5组增至 89%。 (4)血管的透射电镜观察 :M组未见异常改变 ,从M1 组开始出现异常改变 ,以M5最明显。表现为基底膜节段性增厚、断裂缺失 ,内皮细胞肿胀变形 ,向管腔内指状突起 ,异染色质浓集居边 ,周细胞核异染色质浓集居边 ,线粒体肿胀变性 ,甚至呈空泡状。结论　糖尿病大鼠视网膜病变时血管器质性改变在先 ,而生长因子表达在后 ,VEGF作用在bFGF

Effects of vascular endothelial growth factor and basic fibroblast growth factor in early stage diabetic retinopathy and their molecular pathological mechanism

Objective To study the effects of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in early stage diabetic retinopathy and their mechanisms, so as to guide the clinical work theoretically Methods Fifty five Wistar rats were randomly divided into four groups Ten rats were used as controls (M group) Streptozocin was injected intraperitoneally to induce diabetes for I month (M 1 group, n =15), 3 months (M 3 group, n =15), and 5 months (M 5 group, n =15) At the experimental ends of each group, the rats were over anesthetized and their eyeballs were extracted to make digest preparation In situ hybridization and immunohistochemistry were used to investigate the expression of bFGF and VEGF on retinal vascular Transmission electron microscopy was used to observe the histology of the retinal vessels Results There was no difference in the number of pericytes between M 1 group and M group ( P >0 05), but the number of pericytes was significantly lower in M 3 and M 5 groups than in the M and M 1 groups ( P <0 001) VEGF in situ hybridization showed an expression rate of 34% in the M 5 group VEGF immunohistochemistry showed an expression rate of 56% in M 5 group bFGF in situ hybridization showed an expression rate of 78% in M 3 group and an expression rate of 89% in M 5 group Transmission electron microscopy showed no change in M group However, it showed swelling of endothelial cells, finger like process into the capillary cavity, and uneven distribution of heterochromatin in pericytes in M 1 group Obvious fragmental thickening and splitting of basement membrane, swelling and deformation, finger like process to the capillary cavity, and concentration and margination of heterochromatin in endothelial cells and swelling and deformation of rough surfaced endoplasmic reticulum and mitochondrion in pericytes were seen in the M 3 and M 5 groups, especially the latter Conclusion During the course of diabetic retinopathy, morphologic changes of vessels occurs prior to the expression of growth factors, in which the expression of VEGF follows the expression of bFGF