n-3多不饱和脂肪酸对高脂诱导胰岛素抵抗大鼠肝脏和骨骼肌胰岛素受体及葡萄糖转运蛋白4的作用

目的探讨n-3脂肪酸对饱和脂肪酸诱导的大鼠胰岛素抵抗(IR)肝脏和骨骼肌胰岛素受体(InsR)及葡萄糖转运蛋白4(GluT-4)的作用。方法45只雄性Wistar大鼠分为对照组、高脂组和n-3脂肪酸组。各组饲养11周后测定有关指标。结果(1)与对照组比较，高脂组大鼠体内脂肪相对含量、空腹血糖(FBG)、血清胰岛素(Ins)、甘油三酯(TG)、胆固醇(TC)、胰岛素抵抗指数(IRI)、肝脏TC和TG含量、肌肉中TG含量均显著升高；而肌肉组织中TC含量无显著改变，高脂组肝脏和肌肉InsR含量、肌肉Glut-4蛋白的相对含量均明显下降。(2)n-3脂肪酸组体内脂肪相对含量、FBG、Ins、TG、TC、IRI、肝脏TC和TG含量、肌肉组织中TG含量较高脂组均明显降低，肝脏InsR含量和肌肉GluT-4较高脂组明显升高。结论适量n-3脂肪酸代替饱和脂肪酸的一部分热量后，可增加IR大鼠肝脏InsR含量和肌肉GluT-4蛋白表达。

Effects of n-3 polyunsaturated free fatty acids on liver and muscle insulin receptor and GluT-4 in the insulin resistance rats induced by high fat-feeding

Objective To investigate the effects of n-3 polyunsaturated free fatty acids(PUFAs) on liver and muscle insulin receptor and GluT-4 in the insulin resistance rats induced by high fat-~feeding. Methods Fourty-five male rats were divided into 3 groups: control, high fat-feed and n-3 PUFAs treatment group. The control rats were fed with common diet.The high fat-fed group were fed with high fat diet containing 59% saturated free fatty acids. The rat feeds of n-3 fatty acids group was high-fat diet with 20% of saturated fatty acid replaced by EPA-E and DHA-E. The items were detected after each group was fed for 11 weeks. Results (1) In high fat-fed group, the relative contents of visceral fat,fasting glucose, serum levels of insulin, cholesterol and triglyceride, insulin resistance index, cholesterol and triglyceride in liver and muscle were significantly higher than those in the control, but the cholesterol in muscle was not obviously changed.The relative contents of liver and muscle insulin receptor and muscle GluT-4 were decreased compared with those in control. (2) In n-3 PUFAs treatment group, the relative contents of visceral fat,fasting glucose,serum levels of insulin, cholesterol and triglyceride, insulin resistance index, cholesterol and triglyceride in liver, and triglyceride in muscle were significantly decreased.The relative contents of insulin receptor in liver and GluT-4 in muscle were increased as compared with those in fat-fed group. The relative content of insulin receptor in muscle in high fat-fed group was not obviously changed. Conclusions High fat feeding induces ~insulin resistance, and the replacement of 20% saturated fatty acid by n-3 fatty acids can markedly ~increase the relative content of insulin receptor in liver and expression level of GluT-4 protein in muscle.