维生素E对2型糖尿病大鼠血糖及胰岛素抵抗的影响

THE EFFECTS OF VITAMIN E ON BLOOD GLUCOSE AND INSULIN RESISTANCE IN TYPE 2 DIABETIC RATS

目的了解不同剂量的维生素E（VE）对2型糖尿病大鼠血糖及胰岛素抵抗的影响。方法成年雄性Wistar大鼠60只,随机分为正常对照组（A组）、糖尿病对照组（B组）、500 mg/kg的VE饲料组（E1组）、2 500mg/kg的VE饲料组（E2组）。A组喂饲普通饲料;其余3组采用高脂饲料喂养4周联合小剂量链脲佐菌素腹腔注射的方法,制备2型糖尿病大鼠模型。造模成功后,A组大鼠给予普通饲料,B组大鼠给予高脂饲料,E1和E2组大鼠给予高脂饲料的基础上分别添加含500和2 500mg/kg VE的饲料进行干预,时间为8周。实验结束后,大鼠称体质量,腹主动脉取血,采用葡萄糖氧化酶法测定空腹血糖水平,放射免疫法测定空腹血清胰岛素水平,计算胰岛素抵抗指数。结果造模前各组大鼠体质量、空腹血糖水平差异均无显著性（P〉0.05）。干预后,B组大鼠体质量明显高于A组（F=6.54,q=2.92,P〈0.05）,E1组、E2组体质量与B组比较差异均无显著性（P〉0.05）;与B组比较,E1组和E2组大鼠空腹血糖水平无显著变化（P〉0.05）,而血清胰岛素水平和胰岛素抵抗指数则明显降低（F=4.64、7.26,q=3.59~3.95,P〈0.05）,E1组和E2组间各指标比较差异无显著性（P〉0.05）。结论补充含500mg/kg VE饲料可改善糖尿病大鼠的胰岛素抵抗,但对空腹血糖水平无改善作用。

Objective To study the effects of different doses of vitamin E （V-E） on blood sugar and insulin resistance in type 2 diabetic （T2DM） rats. Methods Sixty adult male Wistar rats were evenly randomized to four groups as group A （normal control group）, group B （diabetes model group）, group E1 （500 mg V-E/kg diet）, and group E2 （2 500 mg VE/kg diet）. The rats in group A were fed with common forage, those in the other three groups were fed with high fat forage plus intraperitoneal injection of small dose of Streptozotocin for four weeks to create a model of T2DM in rats. Upon completion of the model, the rats in group A were given common forage, those in group B were offered high-fat forage, those in groups E1 and E2 were added with 500 and 2 500 mg/kg of V-E in addition to high-fat forage for eight weeks. After the end of the experiments, the weight of the rats was measured, blood was taken from abdominal aorta for fasting blood sugar level using glucose oxidase method, fasting serum insulin level was detected with radioimmunoassay, and the index of insulin resistance was calculated. Results Before creation of the model, the differences in the weight and levels of fasting blood sugar among each group were not significant （P〉0.05）. After in tervention, the body weight of rats in group B was much higher than that in group A （F=6.54,q=2.92,P〈0.05）. But there was no significant differences in the body weight between groups E1, E2 and B （P〉0.05）. Compared with group B, the fasting blood glucose levels in groups E1 and E2 groups did not significantly decrease （P〉0.05）, but the serum insulin level and insulin resis tance index were significantly decreased （F = 4.64,7.26 ; q = 3.59 - 3.95 s P〈0.05）. There was no significant difference between E1 and E2 groups in fasting blood glucose and serum insulin level （P〉0.05）. Conclusion Supplement of forage containing vitamin E 500 mg/kg diet may improve insulin resistance in diabetic rats, but no effect on fasting blood glucose levels.