黄芪多糖对高脂喂养肥胖大鼠胰岛素敏感性的影响

Effects of astragalus polysaccharides on insulin sensitivity in obesity rats fed with high-fat diet

目的建立肥胖胰岛素抵抗(IR)大鼠模型,观察黄芪多糖(APS)对肥胖大鼠胰岛素抵抗的影响。方法选用健康雄性Sprague-Dawley大鼠50只,随机分为正常对照组(n=10)和肥胖组(n=40)。分别给予普通饲料和高脂饲料喂养。5周后再将肥胖组大鼠随机分为4组:模型对照组、低剂量APS组[200 mg/(kg.d)]、中剂量APS组[400 mg/(kg.d)]和高剂量APS组[800 mg/(kg.d)],每组10只。正常对照组、模型对照组采用生理盐水灌胃,各APS组给予不同剂量APS灌胃2周。采用高胰岛素-正葡萄糖钳夹实验测定葡萄糖输注率(GIR),同时检测血糖、血脂和胰岛素水平。结果①肥胖组大鼠体重较正常对照组体重明显增加,差异有统计学意义(P<0.05)。②与正常对照组比较,模型对照组大鼠血浆甘油三酯、总胆固醇、血糖及胰岛素水平显著增高(P<0.05);与模型对照组比较,低、中剂量APS组相关指标显著改善,差异有统计学意义(P<0.05)。③高胰岛素-正葡萄糖钳夹显示,各肥胖组大鼠GIR较正常对照组显著降低(P<0.05);与模型对照组比较,中剂量APS组可显著提高肥胖大鼠的GIR(P<0.05),低剂量和高剂量APS组GIR也增高,但无统计学意义(P>0.05)。结论①5周的高脂膳食使大鼠体重明显增加,高胰岛素-正葡萄糖钳夹实验证实高脂膳食诱导的SD大鼠IR模型成立;②APS可改善肥胖大鼠胰岛素敏感性,增加IR大鼠GIR。

Objective To establish obesity model of rats and study the effect of astragalus polysaccharides （APS） on insulin resistance in vivo. Methods Fifty male Sprague-Dawley rats were randomly divided into two groups： the normal control group （n= 10） and the obesity group （n = 40）. Rats in the normal control group were fed with ordinary diet while those in the obesity group were fed with high-fat diet for five weeks. Then the rats in the obesity group were randomly divided into four groups： the model control group, the low-APS group, the medium-APS group and the high-APS group, with 10 rats in each. APS of different dosages [200, 400, or 800 mg/ （kg · d）] or normal saline was intragastrically administered for two weeks. Glucose infusion rate （GIR） of the rats in each group was detected by hyperinsulinemic-englucemic clamp technique （GCT）. The levels of plasma glucose, insulin and lipidemia were also measured. Results O The weight of rats increased more obviously in the obesity group than in the normal control group （P 〈 0. 05）. （2） The levels of plasma total triglyceride （TG）, total cholesterol （TC）, glucose and insulin of rats were significantly higher in the model control group than in the normal control group （P〈0.05）. Compared with those in the model control group, the above-mentioned indexes in low- and medium-APS groups were improved significantly （P〈0.05）. （2） GCT showed that GIR in all the obesity groups decreased compared with that in the normal control group （P〈0.05）. Compared with that in the model control group, GIR in the medium-APS group increased significantly （P（0.05）, but GIR in the low- and high-APS group did not significantly increase （P〈0.05）. Oonclusion （1） The obesity IR rat model was established after five weeks＇ high-fat diet feeding. GCT demonstrates that the IR rat model is successfully established. （2） APS can improve insulin sensitivity of obesity rats and increase GIR of IR rats.