目的:探讨链脲佐菌素(streptozotocin,STZ)诱导的糖尿病视网膜黏附连接VE-cadherin和β-catenin的表达。方法:SD大鼠50只,随机分为正常对照组(Con)、糖尿病组(DM)。腹腔注射STZ建立DM模型,2,5,8wk处死动物。用伊凡思蓝方法检测视网膜的渗透性;用免疫组织化学和Western blot方法检测各组大鼠视网膜VE-cadherin和β-catenin的表达情况。结果:造模后2,5,8wk大鼠视网膜血管渗透性增加。免疫组化分析证实DM大鼠视网膜VE-cadherin主要表达在视网膜血管上,β-catetin主要表达在视网膜外界膜、外核层、外网状层、内网状层和内界膜。Western blot分析证明随着DM视网膜病变的发生发展,视网膜VE-cadherin表达量显著减少,2,5,8wk组与Con组两两比较均有差异(P<0.05);而β-catetin表达量显著增加,2,5,8wk组与Con组两两比较差异有统计学意义(P<0.05)。结论:STZ诱导的DM大鼠VE-cadherin表达量减少而β-catetin表达量显著增加,两者成反比。

AIM:To study the expression of VE-cadherin and pcatenin in adherens junction in streptozotocin(STZ)-induced diabetic rat retina. METHODS:Fifty healthy adult male SD rats were chosen and randomly divided into normal control(Con), and diabetic mellitus(DM) groups.Diabetic model was established by intraperitoneal injection of STZ.After 2,5 and 8 weeks,retinas were separated and vascular permeability was quantified by albumin leakage from blood vessels into the retina using the Evans blue method.VE-cadherin andβ-catenin expression was measured in rat retinas using immunohistochemistry and Western blot analysis. RESULTS:Retinal vascular permeability was increased in the 2-,5- and 8-week diabetic retina respectively, compared with that in the controls(P<0.05).The localization of the expression of VE-cadherin was observed in retinal vessels of diabetic rats by immunohistochemistry. The allocation of the expresson ofβ-catenin was observed in external limiting membrane,outer nuclear layer,outer plexiform layer,inner plexiform layer,internal limiting membrane and microvessel of rat retinas.The expression of VE-cadherin was significantly decreased in STZ-induced diabetic rat retinas with the progression of diabetes.The expression ofβ-catenin was significantly increased in STZ-induced diabetic rat retinas with the progression of diabetes. CONCLUSION:The expression of VE-cadherin is decreased and that ofβ-catenin is increased in DM.