电针对饮食诱导单纯性肥胖大鼠的抗肥胖作用及其机制

Anti-obesity effects of electroacupuncture on rats with diet-induced obesity and its mechanism

目的观察电针对饮食诱导的单纯性肥胖(DIO)大鼠的体质量、脂肪细胞形态学改变、胰岛素抵抗(IR)及下丘脑蛋白酪氨酸磷酸酶1B(PTP1B)和胰岛素受体底物1(IRS1)蛋白表达等的影响,探讨电针治疗肥胖症的机制。方法 50只SD雄性大鼠随机分为低脂组(10只)和高脂组(40只),分别以低脂饲料及高脂饲料喂养,高脂组大鼠造模成功后,随机分为模型组、电针组、西药组,每组10只。电针组电针"后三里"和"曲池"穴,每日1次,每次20 min,连续治疗28 d;西药组每天予以奥利司他(32.4 mg/kg)灌胃;低脂组和模型组不做治疗。28 d后,取血用生化和放射免疫方法分别检测空腹血糖(FPG)、空腹胰岛素(FINS)。取下丘脑用Western Blot法检测PTP1B和IRS1蛋白表达水平,并用病理切片HE染色观察脂肪组织形态学改变。结果电针组和西药组大鼠体质量、FPG、FINS、胰岛素抵抗指数(HOMA-IR)、PTP1B蛋白表达及脂肪细胞直径均低于模型组(P<0.05),电针组和西药组IRS1蛋白表达与模型组对比无显著差异(P>0.05)。西药组大鼠大便溏稀不成形,活动减少,精神萎靡,毛色枯黄,而电针组大鼠大便正常,毛色有光泽。结论电针可通过降低PTP1B蛋白的表达,改善DIO大鼠的IR情况,抑制大鼠体质量的增长,同时改变脂肪细胞大小,这可能是电针减肥的重要作用机理之一。相比西药组大鼠表现出来的副作用,电针是一种具有明显优势的抗肥胖治疗方法。

Objective To observe the effects of electroacupuncture（ EA） on body weight,insulin resistance（ IR）,hypothalamic protein tyrosine phosphatase 1B（ PTP1B） and insulin receptor substrate 1（ IRS1） in diet-induced obesity（ DIO） rats,as well as its mechanism. Methods 50 SD male rats were randomly divided into low-fat diet（ LFD） group（ n = 10） and high-fat diet（ HFD） group（ n = 40）. When the DIO model was successfully established in HFD group,DIO rats were randomly divided into model group,EA group,and Orlistat（ OLST） group（ n = 10 in each group）. EA was applied to Zusanli（ ST36） and Quchi（ LI11） and the stimulation was retained for 20 minutes each time for 28 consecutive days in the EA group. Rats in OLST group was orally administered with Orlistat by daily intragastricgavage（ 32. 4 mg / kg）. No intervention was offered to rats in LFD and HFD groups. After 4 weeks,all rats were sacrificed to measure the levels of fasting plasma glucose（ FPG） using biochemistry technique,fasting insulin（ FINS） using radioimmunoassay,PTP1 B and IRS1 using Western blotting assay and morphological changes of adipocytes using HE staining. Results Body weights,levels of FPG,FINS,HOMA-IR and diameter of adipocyte in rats of EA and OLST groups were all significantly lower than those in HFD group（ P〈0. 05）. But there were no significant difference between EA,OLST and HFD groups in IRS1（ P〈0. 05）. Rats in OLST group showed watery stools,decreased activity,mental fatigue and withered fur,while those in EA group had regular stools and lustrous fur. Conclusion EA exhibits an anti- obesity effect,probably by inhibiting the expression of PTP1 B,relieving IR,reducing the weight and shrinking adipocyte,which may be the mechanism for losing weight. EA seems to be superior to Orlistat as anti-obesity therapy with less side effects.