Objective: To observe the effect of electroacupuncture (EA) on Leptin and Leptin receptor (OB-Rb) of insulin resistant obese (OIR) rats, so as to explore its possible mechanism for obesity.
Methods: Twenty-four Wistar rats were randomly divided into normal, model and EA groups, with 8 rats in each group. The OIR model was established by feeding the rats with high-fat diet for 8 weeks. EA (2 Hz, 1 mA) was applied to "Zhongwan" (CV12), "Guanyuan" (CV4), "Zusanli" (ST36) and "Fenglong" (ST40) for 30 min, once every other day for 8 weeks. At the 6th week of intervention, glucose contents of intraperitoneal glucose tolerance test (IPGTT) and intraperitoneal insulin tolerance test (IPITT) were measured. After 8 weeks' intervention, the body weight and food intake were recorded. Serum total cholesterol (TC) and total triglyceride (TG) were assayed by using an automatic biochemical analyzer. The expression levels of Leptin and OB-Rb proteins in the small intestine and hypothalamus were detected by Western blot.
Results: Following modeling, the body weight, food intake, IPGTT, IPITT, the contents of serum TC and TG, and the expressions of Leptin protein in small intestine and hypothalamus were significantly up-regulated (P<0.01, P<0.05), and the expressions of OB-Rb protein in small intestine and hypothalamus were significantly down-regulated (P<0.05) in the model group compared with the normal group. After EA treatment, all the indexes mentioned above were completely reversed in the EA group relevant to the model group (P<0.05, P<0.01).
Conclusion: EA can improve insulin resis-tance by up-regulating the OB-Rb protein expression and enhancing the binding force of Leptin and OB-Rb.
目的：观察“标本配穴”电针对胰岛素抵抗肥胖大鼠能量调控信号瘦素(Leptin)及瘦素受体(OB-Rb)的影响，探究电针治疗肥胖可能存在的机制。方法：24只SPF级雄性Wistar大鼠随机分为正常组、模型组、电针组，每组8只。以高脂饮食建立胰岛素抵抗肥胖大鼠模型。电针组于“中脘”“关元”“足三里”“丰隆”给予电针治疗，每次30 min，隔日1次，持续8周。比较各组大鼠体质量、进食量、腹腔糖耐量(IPGTT)、腹腔胰岛素耐量(IPITT)、血清胆固醇(TC)和甘油三酯(TG)含量的变化，用Western blot法检测小肠和下丘脑中Leptin及OB-Rb蛋白的表达水平。结果：与正常组比较，模型组大鼠体质量、进食量、IPGTT、IPITT AUC及血清TC、TG含量均明显升高(P<0.01，P<0.05)，小肠和下丘脑Leptin蛋白含量明显升高(P<0.05)，小肠和下丘脑OB-Rb蛋白含量明显下降(P<0.05)；与模型组比较，电针组大鼠体质量、进食量、IPGTT、IPITT及血清TC、TG含量均明显降低(P<0.05，P<0.01)，小肠和下丘脑Leptin蛋白含量明显降低(P<0.05)，小肠和下丘脑OB-Rb蛋白含量明显升高(P<0.01，P<0.05)。结论：电针可以通过上调OB-Rb的蛋白表达和增强Leptin与OB-Rb的结合力而改善Leptin抵抗，达到控制食欲、减轻体质量、降低血脂、改善胰岛素抵抗和维持能量平衡的目的。.
Keywords: Electroacupuncture; Energy balance; Insulin resistance; Leptin resistance; Obesity.