多巴胺对糖尿病视网膜病变模型大鼠视网膜组织中氧化应激和VEGF表达的影响

Effects of dopamine on oxidative stress and VEGF expression in retinal tissues of rats with diabetic retinopathy model

目的探讨多巴胺对糖尿病视网膜病变(DR)模型大鼠视网膜组织中氧化应激和血管内皮生长因子(VEGF)表达的影响。方法随机将90只大鼠分为3组,分别为对照组、模型组和多巴胺组,每组各30只。通过连续4周高糖高脂饮食建立DR模型,对照组和模型组不给予药物干预,多巴胺组大鼠眼部玻璃体内注射50 mg/kg多巴胺溶液。光学显微镜下观察3组大鼠苏木精-伊红染色视网膜组织的情况,采用酶联免疫吸附试验检测3组大鼠视网膜组织中过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、丙二醛(MDA)、单核细胞趋化蛋白-1(MCP-1)、白细胞介素-6(IL-6)和VEGF水平,并通过Western Blot检测3组大鼠的VEGF表达。结果对照组大鼠视网膜内界膜平整,新生血管内皮细胞突入玻璃体较少,未见与内界膜相连的到达玻璃体内的新生血管。与对照组比较,模型组大鼠突破内界膜的血管内皮细胞较多,可见内界膜下的细胞增殖明显。与模型组比较,多巴胺组大鼠视网膜内界膜欠平整,新生血管内皮细胞突入玻璃体较少,可见内界膜下的细胞增殖减少。与对照组比较,模型组CAT和SOD水平均降低,MDA、MCP-1、IL-6和VEGF水平均升高,两组比较差异均有统计学意义(均P<0.05)。与模型组比较,多巴胺组CAT和SOD水平均升高,MDA、MCP-1、IL-6和VEGF水平均降低,两组比较差异均有统计学意义(均P<0.05)。结论多巴胺可以上调DR大鼠视网膜组织中CAT和SOD水平,下调MDA、MCP-1、IL-6水平和VEGF表达。

Objective To investigate the effect of dopamine on oxidative stress and vascular endothelial growth factor(VEGF)expression in the retinal tissue of diabetic retinopathy(DR)model rats.Methods Ninety rats were randomly divided into three groups:the control group,the model group,and the dopamine group,with 30 rats in each group.In the dopamine group,the DR model was established by a high-sugar and high-fat diet for four consecutive weeks,and no drug intervention was given to the control or model groups.The eyes of rats in the dopamine group were injected intravitreally with 50 mg/kg dopamine solution.The retinal tissues of the rats in the three groups were observed under a light microscope after hematoxylin-eosin staining.The levels of catalase(CAT),superoxide dismutase(SOD),malondialdehyde(MDA),monocyte chemotactic protein-1(MCP-1),interleukin-6(IL-6),and VEGF were detected by enzyme-linked immunosorbent assay(ELISA)in the retinal tissues of the rats in the three groups.Western blot was used to detect VEGF expression in the three groups of rats.Results In the control rats,the inner retinal border membrane was flat,with fewer neovascular endothelial cells protruding into the vitreous,and no neovascularization connected to the inner membrane reaching the intravitreous was observed.Compared with the control group,rats in the model group had more vascular endothelial cells breaking through the inner border membrane,and significant cellular proliferation was observed under the inner border membrane.Compared with the model group,rats in the dopamine group had a less flat inner retinal border membrane,fewer neovascularized endothelial cells protruding into the vitreous,and less cellular proliferation under the inner border membrane.Compared with the control group,CAT and SOD levels were decreased,while MDA,MCP-1,IL-6,and VEGF levels were increased in the model group,and the differences between the two groups were statistically significant(all P<0.05).Compared with the model group,CAT and SOD levels were increased in the dopamine group,while MDA,MCP-1,IL-6,and VEGF levels were decreased,and the differences between the two groups were statistically significant(all P<0.05).Conclusions Dopamine up-regulated CAT and SOD levels and down-regulated MDA,MCP-1,IL-6 levels,and VEGF expression in the retinal tissues of DR rats.