糖尿病大鼠视网膜中血管内皮生长因子的表达

目的 利用糖尿病大鼠动物模型，通过大鼠视网膜中血管内皮生长因子(vascular endothellal growth fac—tor，VEGF)的表达情况，探讨VEGF在糖尿病视网膜病变(Diabetlc Retinopathy，DR)发展过程中作用机理。方法 复制链脲佐菌素(Streptozocin，STZ)糖尿病大鼠动物模型，取不同组、不同时期大鼠视网膜，利用免疫组织化学及原位杂交方法，检测VEGF蛋白质及mRNA的表达情况。结果 正常对照组(H)、血糖恢复组及糖尿病1月组(H1)大鼠视网膜均无VEGF蛋白质及mRNA的阳性表达。糖尿病3月组(M3)未见VEGF mRNA表达，而在内核层及节细胞层VEGF蛋白表达阳性(34％)，此表达与胶质纤维酸性蛋白(GFAP)染色阳性细胞相同。糖尿病5月组(M5)VEGFmRNA表达阳性率为67％，表达位于视网膜各层，内界膜中的表达与GFAP免疫组化阳性分布相同，VEGF蛋白质表达强阳性(89％)，主要位于内核层、节细胞层的细胞及血管上。结论 VEGF在STZ大鼠视网膜中的表达与病程相关，而且VEGF的产生存在着自分泌和旁分泌多种途径。

Expression of vascular endothelial growth factor in retinopathy of diabetic rats

Aim In order to study the role of VEGF and to estimate the mechanism during the development of diabetic retinopathy, the expression of the VEGF in diabetic rat retina was examined. Methods Using streptozocin (STZ) to obtain diabetic rat models, the expression of VEGF mRNA and VEGF protein was tested in retinal paraffin slide during different periods of OR with immunohistochem-istry and in situ hybridization. Results In control group (M), recovered blood sugar group and 1 month diabetic group ( M1), the morphology of retinal paraffin slides was normal and there was no expression of VEGF protein and mRNA. In 3 months diabetic group (M3), there was no expression of VEGF mRNA. But VEGF protein (34%) mainly expressed in inner nuclear layer and ganglion cell layer, where GFAP expressed also. In 5 months diabetic group (M5), the expression rate of VEGF mRNA was 67%. Its expression appeared in every layer of retina and in inner limiting membrane the expression was similar to GFAP. Eighty-nine percent of sample showed strong positive expression of VEGF protein in M5 group. It mainly located in cells of inner nuclear layer, ganglionic layer and vessel, which was also similar to GFAP. Conclusion There is expression of VEGF during the development of DR in STZ rats and the expression in retina is produced by autocrine and paracrine.