高脂饮食对大鼠胰岛素抵抗及氧化损伤指标的影响及意义

Effect of high fat diet on insulin resistance and oxidative damage markers in rats

目的建立胰岛素抵抗(IK)大鼠模型并观察氧化应激指标的变化。方法将SD大鼠随机分为正常对照组(NC)及高脂饮食组(HFD),分别予普通饮食及高脂饮食6周,用高胰岛素正常血糖钳夹技术评价胰岛素敏感性;检测总抗氧化能力(TAOC)、超氧化物歧化酶(SOD)、丙二醛(MDA)等氧化应激指标,同时检测血总胆固醇(TC)、甘油三酯(TG)、游离脂肪酸(FFA)及胰岛素(Ins)水平。结果与NC组相比,HFD组的大鼠体重、血压、血糖、胰岛素水平明显高于NC组(P<0.05),而钳夹试验的结果显示IR组的葡萄糖输注率(GIR)低于NC组;HFD组出现明显的血脂代谢异常,TC、TG及FFA均高于NC组;HFD组MDA高于NC组,但TAOC和SOD却低于NC组。结论持续6周高脂饮食可成功复制胰岛素抵抗大鼠模型,IR状况下机体存在明显的氧化损伤。

Objective To establish the insulin resistance （IR） model and to observe the change of oxidative damage markers. Methods The Sprague-Dawley （SD） rats were randomly divided into normal control group （NC） and high fat diet group（HFD）, which were respectively treated as the standard chow diet and the high-fat diet for 6 weeks. Insulin sensitivity was estimated by hyperinsulinemic-englycemic clamp. The oxidative damage markers such as total antioxidant capacity （TAOC）, superoxide dismutase （SOD）, and rnalondialdehyde （MDA） were measured. At the samc time, the levels of total cholesterol （TC）, triglyceride （TG）, free fatty acid （FFA）, and insulin were measured. Result Compared with NC group, the body weight, blood pressure,blood glucose and the level of insulin of FIFD group were significantly increased （P〈0.05） ,and the glucose infusion rates （GIR） in HFD group as shown by hyperinsulinemicenglycemic clamp was lower than that of NC group. The HFD group demonstrated abnormal metabolism of blood fat, with increased levels of TC, TG and FFA as compared with NC group. Compared with NC group, the level of MDA was higher and the levels of TAOC ane SOD were lower in HFD group. Conclusion IR model could be successfully established by feeding with FIFD for 6 weeks. The obvious oxidative damage was presented in IR states.