绿茶多酚对胰岛素抵抗模型大鼠血脂与血压的效应及其机制

目的:利用胰岛素抵抗模型大鼠,探究绿茶多酚(greenteapolyphenols,GTP)调脂降压作用及其作用机制。方法:高脂、高糖和高盐饲料饲养大鼠,饲养6w时,给予GTP,1次/d,连续6w,并于处理前,处理6w和12w测定大鼠血压,以及各组大鼠空腹血糖、血脂、胰岛素水平及血中MDA、TNF-α、Renin、AngⅡ水平和SOD活性。结果:GTP可显著降低胰岛素抵抗模型大鼠血压和血脂,并提高胰岛素敏感指数;同时,降低血中AngⅡ、MDA、TNF-α水平,升高SOD活性。结论:GTP对胰岛素抵抗时发生的高血脂和高血压具有调脂和降压作用,其作用机制与其抗氧化,抑制AngⅡ和TNF-α因子生成有关。

EFFECTS OF GREEN TEA POLYPHENOLS ON BLOOD PRESSURE AND SERUM LIPID IN RATS WITH INSULIN RESISTANCE AND ITS MECHANISM

Objective: To study the effects of green tea polyphenols (GTP) on blood pressure (BP) , and serum lipid in the model rats of insulin resistance and its mechanism. Method: Adult healthy SD rats were maintained on high-fat-sugar-salt diet for 12 w, and GTP was administered to the rats for 6 w by oral feeding at the beginning of 7th week. BP was measured at the end of 0, 6th, 12th week. The levels of serum glucose, serum lipid, fasting serum insulin and the levels of MDA, TNF-α, plasma renin, angiotensinⅡ(AngⅡ) and the activity of SOD were measured and the insulin-sensitivity index (ISI) was calculated at the end of the experiment. Results: High dosage of GTP could significantly decrease BP, reduce the levels of serum lipid and Ang, and also increase ISI. The levels of MDA and TNFα were significantly decreased by GTP treatment, and the activity of SOD was increased significantly. Conclusion: GTP possesses the effects of decreasing blood pressure and serum lipid when insulin resistance occurs, and its mechanism may be related to antioxidation and inhibition of AngⅡand TNF-α formation.