血管内皮生长因子在糖尿病大鼠视网膜中的表达

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 en-dothelial growth factor,VEGF)的表达情况 ,探讨 VEGF在糖尿病视网膜病变 ( diabetic retinopa-thy,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 m RNA的表达情况。结果 :1正常对照组 ( M)、血糖恢复组及糖尿病 1个月组 ( M1)大鼠视网膜均无 VEGF蛋白质及 m RNA的阳性表达 ;2糖尿病 3个月组 ( M3 )未见 VEGF m RNA表达 ,而在内核层及节细胞层有 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 ;3糖尿病 5个月组 ( M5) VEGF m RNA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 during Retinopathy of Diabetic Rats

Objective:In order to understand the role of VEGF in diabetic retinopathy and go further into the mechanism, the expression of the VEGF during the angiogenesis in the formation of the diabetic retinopathy was examined in the study.Methods:Use STZ to get diabetic rat models, used immunohistochemistry and in situ hybridization to test the expression of VEGFmRNA and VEGF protein in retinal paraffin slide during different periods of DR. Results:①In control group (M), recovered blood sugar group and 1 month diabetic group (M 1), the morphology of retinal paraffin slides were normal and there was not expression of VEGF protein and mRNA. ②In 2 months diabetic group (M 3),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. ③In 5 months diatetic group (M 5), the expression rate of VEGF mRNA was 67%. Its expression appeared in every layer of retina, and the expression of VEGF mRNA in inner limiting membrane was similar to expression of GFAP. There was eighty nine percent of sample showed strong positive expression of VEGF protein in M 5 group. The expression mainly located in cells of inner nuclear layer, ganglionic layer and vessel, which was also similar to the expression of GFAP. Conclusion:There is expression of VEGF during the development of DR in STZ rats and the expression in retina are produced by autocrine and paracrine.