α-硫辛酸对糖尿病大鼠视网膜保护作用研究

Protective effect of α-lipoic acid on diabetic retinopathy in rats

目的:观察α-硫辛酸(α-lipoicacid,α-LA)对糖尿病大鼠视网膜保护作用及相关机制。方法:链脲佐菌素ip制备糖尿病大鼠模型,分为糖尿病组(DM组),α-LA治疗组,同时设立正常对照组(NC组)。治疗组ip给予α-LA100mg/kg,1次/d。12wk时测定血糖,以及各组大鼠血清丙二醛(MDA)含量、超氧化物歧化酶(SOD)的活性及还原型谷胱甘肽(GSH)含量,制备视网膜消化铺片,检测视网膜微血管形态改变,免疫组织化学方法检测视网膜NF-κB蛋白表达变化。结果:与NC组相比,糖尿病大鼠血清MDA含量明显升高,SOD活性、GSH含量降低(P<0.05),视网膜微血管周细胞、内皮细胞减少,无细胞毛细血管数目明显增多,视网膜NF-κB蛋白表达显著增强;与DM组相比,α-LA组大鼠MDA含量明显降低(P<0.05),SOD活性、GSH含量明显升高(P<0.05),视网膜微血管周细胞、内皮细胞数目增多,无细胞毛细血管数目减少,视网膜NF-κB蛋白表达明显减弱(P<0.01)。结论:α-LA可通过抑制氧化应激及视网膜NF-κB活化,对糖尿病视网膜病变起到一定保护作用。

AIM：To explore the mechanism of α-lipoic acid（α-LA）on the protection of diabetic retinopathy. METHODS：The streptozotocin（45mg/kg）was intrape-ritoneally injected to establish the diabetic model in 16 male SD rats as experimental group,model rats were divided into diabetes group and α-lipoic acid（α-LA） group,control group also was established. α-lipoic acid was given to treatment group at dose of 100mg/（kg·d） by gavage. At 12 weeks, the blood glucose, content of malondialdehyde （MDA） and reduced glutathione hormone （GSH）, the activity of superoxide dismutase（SOD） were assayed. Retinal capillary trypsin digestion were prepared to observe the changes of capillary vessel. The immunohistochemistry was used to assess the expression of NF-κB protein in retina. RESULTS：Compared with control group, the content of MDA, SOD and activity of GSH in diabetes group were significantly lower（P〈0.05） . The number of pericytes and epithlium cells decreased obviously and cell-free capillary increased（P〈0.05）.The expression of NF-κB enhanced. Compared with diabetes group, the content of MDA decreased obviously while the content of SOD and activity of GSH increased significantly（P〈0.05） in α-lipoic acid group. The number of pericytes and epithlium cells increased and cell-free capillary decreased obviously（P〈0.05）. The expression of NF-κB attenuated（P〈0.01）. CONCLUSION：The α-lipoic acid could inhibit the oxidative damage and activation of NF-κB and protect against diabetic retinopathy.