五苓散对糖尿病视网膜病变大鼠血-视网膜屏障的保护作用

目的：探讨五苓散对糖尿病视网膜病变(DR)大鼠血-视网膜屏障的保护作用及其机制。

方法：SD雄性大鼠50只随机分为空白组、模型组、高剂量组、低剂量组、阳性对照组，每组10只，采用高脂高糖饮食联合腹腔注射链脲佐菌素诱导糖尿病大鼠模型。高剂量组和低剂量组大鼠采用五苓散水煎液灌胃，模型组和空白组大鼠采用等量生理盐水灌胃，阳性对照组大鼠右眼球内注射康柏西普。给药12wk后，采用酶联免疫吸附法(ELISA)检测大鼠血清C反应蛋白(CRP)和可溶性细胞间黏附分子1(sICAM-1)表达水平，HE染色观察视网膜组织结构，伊文思蓝(EB)渗漏试验观察大鼠血-视网膜屏障通透性，免疫组织化学法检测血管内皮生长因子(VEGF)在视网膜中的表达。

结果：模型组大鼠空腹血糖水平和视网膜组织EB渗透量、CRP和sICAM-1表达均较空白组明显升高，高剂量组大鼠视网膜组织EB渗透量、CRP和sICAM-1表达均低于低剂量组和阳性对照组(均P<0.05)。模型组大鼠视网膜神经节细胞层结构紊乱，视网膜水肿，VEGF表达明显升高； 与低剂量组和阳性对照组比较，高剂量组大鼠视网膜组织神经节细胞排列较清晰，水肿减轻。

结论：五苓散能有效降低糖尿病大鼠血清炎症因子水平，降低视网膜组织中VEGF的表达，减轻水肿，保护血-视网膜屏障。

Wu Ling San' protective effect on blood retinal barrier in diabetic rats

AIM: To investigate the therapeutic effects and mechanisms of Wu Ling San on retinopathy in diabetic rats.

METHODS: The rats with hyperglycemia were divided into five groups: model group, Wu Ling San high dose group, low dose group, positive control group and normal groups each group of ten. After oral administration for 12wk, the expression of ICAM-1 and CRP in the serum of rats were measured by ELISA. After HE staining, retinal structure was observed under the light microscope. Blood retinal vascular barrier permeability was measured by Evans blue. The vascular endothelial growth factor(VEGF)expression of retinal tissue were observed by immunohistochemistry

RESULTS: Compared with the normal group, the expression of CRP, ICAM-1 and the EB content in diabetic group were increased. The contents of CRP and ICAM-1 and EB permeability in Wu Ling San high dose group were lower than low dose group and positive control group(all P<0.05). There are retinal ganglion cell layer disorder, retinal edema, and positive VEGF immunohistochemistry expression in the diabetic group. Wu Ling San high dose group can improve retinal structure and reduce retinal edema.

CONCLUSION: Wu Ling San can effectively reduce the expression of inflammatory cytokine, VEGF and retina edema in diabetic retinopathy rats, and also can improve the retinal microvascular in order to protect diabetic retinopathy.