糖尿病视网膜病变早期血管内皮生长因子作用机制的研究

目的:通过链脲佐菌素(streptozocin,STZ)糖尿病大鼠视网膜的石蜡切片及血管铺片,研究糖尿病大鼠视网膜病变时血管内皮生长因子(vascularendothelialgrowthfactor,VEGF)作用的分子病理机制。方法:建立糖尿病大鼠模型,随机分为正常对照组(C),糖尿病1月组(M₁)、3月组(M₃)、5月组(M₅)。分别在视网膜石蜡切片及血管铺片上行VEGF原位杂交和免疫组化。结果:①石蜡切片:原位杂交仅M₅表达为67%;免疫组化M₃表达为34%,M₅表达为89%。②视网膜血管铺片:原位杂交仅M₅表达为34%;免疫组化仅M₅表达为56%。结论:①除内皮细胞外,周细胞及Müller细胞也可产生VEGF;②糖尿病视网膜病变早期VEGF可能是来源于旁分泌途径。

Mechanisms of vascular endothelial growth factor in diabetic rat retinopathy

AIM: To study the molecular mechanism of vascular endothelial growth factor (VEGF) in pathogenesis of diabetes in rats. METHODS: The diabetic rat model was established by using streptozocin. The animals were divided into normal control (C group), diabetic for one month (M₁ group), for three months (M₃ group) and for five months (M₅ group). In situ hybridization and immunohistochemistry were conduced to observe the expression of VEGF on retinal digest preparation and paraffin section. RESULTS: 1. On paraffin section: the positive rate of VEGF expression in M₅ group was 67% by in situ hybridization and 89% by immunohistochemistry. There was only 34% positive expression of VEGF in M₃ group by immunohistochemistry. 2. On retinal digest preparation: the VEGF positive expression rate in M₅ group was 34% by in situ hybridization and 56% by immunohistochemistry. CONCLUSION: Both endothelial cells and Mural cells and Müller cells express VEGF. The source of VEGF may be from the paracrine pathway in early stage of diabetic retinopathy.