Objectives: To observe the effects on the glucose-lipid metabolism and the expression of zinc-α2-glycoprotein (ZAG) and glucose transporter 4 (GLUT4) in the femoral quadriceps and adipose tissue after electroacupuncture (EA) at "Pishu" (BL 20), "Weiwanxiashu" (EX-B 3), "Zusanli" (ST 36) and "Sanyinjiao" (SP 6) in the rats with diabetes mellitus type 2 (T2DM), so as to explore the effect mechanism of EA in treatment of T2DM.
Methods: Twelve ZDF male rats were fed with high-sugar and high-fat fodder, Purina #5008 for 4 weeks to induce T2DM model. After successfully modeled, the rats were randomly divided into a model group and an EA group, with 6 rats in each one. Additionally, 6 ZL male rats of the same months age were collected as the blank group. The rats in the EA group were treated with EA at bilateral "Pishu" (BL 20), "Weiwanxiashu" (EX-B 3), "Zusanli" (ST 36) and "Sanyinjiao" (SP 6), with continuous wave, 15 Hz in frequency, and 2 mA in intensity. The electric stimulation lasted 20 min each time. EA was delivered once daily, 6 times a week for 4 weeks. Separately, the levels of fasting blood glucose (FBG) was measured before modeling, before and after intervention, and the body mass of each rat was weighted before and after intervention. After intervention, the levels of the total cholesterol (TC), triacylglycerol (TG) and free fatty acid (FFA) in serum were detected using enzyme colorimetric method; and the levels of the serum insulin (INS) and ZAG were detected by ELISA. Besides, the insulin sensitivity index (HOMA-ISI) was calculated. With Western blot technique adopted, the protein expressions of ZAG and GLUT4 in the femoral quadriceps and adipose tissue were determined.
Results: After intervention, compared with the blank group, the levels of FBG and body mass, and the levels of serum TC, TG, FFA and INS increased (P<0.01), while HOMA-ISI decreased (P<0.01); the level of ZAG in the serum and the protein expressions of ZAG and GLUT4 in the femoral quadriceps and adipose tissue dropped (P<0.01) in the model group. In the EA group, compared with the model group, the levels of FBG and body mass, and the levels of serum TC, TG, FFA and INS were reduced (P<0.01), and HOMA-ISI increased (P<0.01); the level of ZAG in the serum and the protein expressions of ZAG and GLUT4 in the femoral quadriceps and adipose tissue increased (P<0.01, P<0.05).
Conclusions: Electroacupuncture can effectively regulate glucose-lipid metabolism, improve insulin resistance and sensitivity in the rats with T2DM, which is associated with the modulation of ZAG and GLUT4 expression in the skeletal muscle and adipose tissue.
目的: 观察电针“脾俞”“胃脘下俞”“足三里”“三阴交”对2型糖尿病（T2DM）模型大鼠糖脂代谢及股四头肌和脂肪组织锌α2糖蛋白（ZAG）、葡萄糖转运体4（GLUT4）蛋白表达的影响，探讨电针治疗T2DM的作用机制。方法: 12只雄性ZDF大鼠采用Purina #5008高糖高脂饲料喂养4周诱导T2DM模型，造模成功后随机分为模型组和电针组，每组6只；另选取6只同月龄雄性ZL大鼠作为空白组。对电针组大鼠行电针干预，穴取双侧“脾俞”“胃脘下俞”“足三里”“三阴交”，连续波，频率15 Hz，电流强度2 mA，每次20 min，每日1次，每周连续6次，共4周。于造模前、干预前后测量各组大鼠空腹血糖（FBG），干预前后测量大鼠体质量。干预后，采用酶比色法检测血清总胆固醇（TC）、三酰甘油（TG）、游离脂肪酸（FFA）含量；ELISA法检测血清胰岛素（INS）、ZAG含量，计算胰岛素敏感指数（HOMA-ISI）；采用Western blot法检测股四头肌和脂肪组织ZAG、GLUT4蛋白表达。结果: 干预后，与空白组比较，模型组大鼠FBG、体质量及血清TC、TG、FFA、INS含量升高（P<0.01），HOMA-ISI降低（P<0.01）；血清ZAG含量，股四头肌和脂肪组织ZAG、GLUT4蛋白表达减少（P<0.01）。与模型组比较，电针组大鼠FBG、体质量及血清TC、TG、FFA、INS含量降低（P<0.01），HOMA-ISI升高（P<0.01）；血清ZAG含量，股四头肌和脂肪组织ZAG、GLUT4蛋白表达增加（P<0.01，P<0.05）。结论: 电针可调节T2DM模型大鼠糖脂代谢，改善胰岛素抵抗，提高胰岛素敏感性，其作用机制与调控骨骼肌与脂肪组织ZAG、GLUT4蛋白表达有关。.
Keywords: electroacupuncture; glucose and lipid metabolism; glucose transporter 4; type 2 diabetes mellitus; zinc-α2-glycoprotein.