高山红景天组方对糖尿病鼠视网膜中VEGF表达的影响

Effect of compound rhodiola cretinii on VEGF expression in retina of rats with diabetes mellitus

目的观察中药高山红景天组方对糖尿病大鼠糖尿病视网膜病变(DR)早期血管内皮生长因子(VEGF)表达的影响。方法采用腹腔注射链脲佐菌素(STZ)的方法建立糖尿病大鼠模型。随机分为糖尿病模型治疗组、糖尿病模型未治疗组、正常给药组、正常对照组。造模成功4个月后糖尿病模型治疗组及正常给药组给予高山红景天3g/kg、川芎3g/kg、丹参3g/kg、甘草3g/kg,水煎灌胃,每日1次,正常对照组及糖尿病模型未治疗组均给予凉开水灌胃,每日1次,共1个月。处死大鼠,摘除眼球行VEGF免疫组织化学染色和逆转录-聚合酶链反应(RT-PCR)半定量分析VEGFmRNA的表达。结果糖尿病模型未治疗组与正常对照组间大鼠体重、血糖比较差异均有统计学意义(P<0.01),糖尿病模型治疗组与正常对照组间大鼠体重、血糖差异均有统计学意义(P<0.01)。VEGF免疫组织化学染色结果显示,糖尿病模型未治疗组、糖尿病模型治疗组、正常对照组及正常给药组视网膜组织VEGF的蛋白表达积分光密度(IOD)值分别为0.316±0.046、0.149±0.038、0.126±0.028、0.130±0.038;各组面密度(AD)值分别为0.463±0.185、0.121±0.015、0.122±0.007、0.121±0.011。糖尿病模型治疗组与糖尿病模型未治疗组相比、正常对照组与糖尿病模型未治疗组相比IOD值及AL值差异均有统计学意义(P<0.01)。正常给药组及正常对照组组间比较差异无统计学意义(P>0.05)。RT-PCR检测VEGFmRNA表达显示,糖尿病模型治疗组对目的基因有表达,表达水平较低,糖尿病模型未治疗组对目的基因有表达,表达水平较高;糖尿病模型治疗组与未治疗组比较差异有统计学意义(P<0.01);正常对照组对目的基因几乎无表达。结论高山红景天组方口服可使糖尿病鼠视网膜VEGF的表达减少,为DR的治疗提供新方法 。

BackgroundRetinal microvascular disease is a primary mechanism of diabetic retinopathy（DR）.Vascular endothelial growth factor（VEGF）is determined to involve in the pathogenesis of DR.ObjectiveThe aim of this study was to observe whether the traditional Chinese herbs could decrease the expression of vascular endothelial growth factor（VEGF）in the retina of rats with early DR.MethodsDiabetes models were established in 20 Wistar rats by the injection of streptozotocinum（STZ）60mg/kg to elevate the blood glucose to 16mmol/L on the third day.In 4 months after injection,compound rhodiola sachalinensis 2mL was administered by gastric perfusion once a day for 1 month in 10 model rats and 10 healthy Wistar rats respectively.Cool boiled water（2mL）was used in 10 model rats and 10 matched healthy rats respectively at the same method as model group and normal control group.The rats were sacrificed and the eyeballs were enucleated in 5 months after injection of STZ.The expression of VEGF mRNA in retina was detected by reverse transcription-polymerase chain reaction（RT-PCR）.The expression of VEGF protein in retina was detected by immunochemistry.ResultsThe body weight was significant decreased and the blood glucose levels were considerably increased in model group and model＋drug group in comparison with normal group and normal＋drug group（P0.01）.The immunochemistry revealed that the integral optical density（IOD）and area density（AD）of VEGF protein in retina in normal group,normal＋drug group and model＋drug group were significantly lower than that of model group（P0.01）.VEGF protein was positively expressed mainly in retinal ganglion cell layer,inner nuclear layer,outer plexform layer and photoreceptor layer.The intensity of expression of VEGF protein was higher in model group than the normal group,normal＋drug group and model＋drug group（P0.05）.RT-PCR showed that the expression of VEGF mRNA in retina was 1.0±0.4（gray scale）in model＋drug group,indicating a significant decline in comparison with model group（1.4±0.6）（t=3.838,P0.01）.ConclusionCompound rhodiola sachalinensis inhibits the expression of VEGF in the retina of rats with diabetes mellitus.It offers a new method for the treatment of DR.