针刺对Ⅱ型糖尿病大鼠弓状核神经细胞自发放电的影响

Effects of Acupuncture on the Spontaneous Firing of Neurons of Hypothalamic ARC in Rats with Type-Ⅱ Diabetes

目的 :观察Ⅱ型糖尿病 (NIDDM)大鼠模型下丘脑弓状核 (ARC)神经细胞自发放电和针刺对它的影响 ,探讨针刺治疗NIDDM的中枢机制。方法 :采用小剂量腹腔注射链脲霉素 (STZ)结合高热量饮食制造NIDDM大鼠模型 ,应用神经细胞微电极记录方法和脑立体定位技术观察NIDDM大鼠ARC神经细胞自发放电的变化 ,并观察针刺“足三里”、“内庭”、“胰俞”(治疗 4周 )对ARC神经细胞自发放电频率的影响。结果 :治疗前ARC神经细胞自发放电频率为 3 .9± 0 .8Hz(正常组为 1 1 .2± 2 .8Hz) ,治疗后为 1 3 .1± 3 .3Hz,治疗前后比较 ,P <0 .0 0 1。结论

Objective: To observe the effect of acupuncture on neuronal discharges of hypothalamic arcuate nuclei (ARC) in type Ⅱ diabetes rats for exploring the neural mechanism of acupuncture in treatment of diabetes. Methods: SD rats were randomly divided into control group (n=20), model group (n=22) and acupuncture group (n=21). Non insulin dependent diabetes mellitus (NIDDM, i.e. type Ⅱ diabetes) rat model was established by intraperitoneal injection of streptozotocin (STZ, 25 mg/kg/day) for two days, followed by immediately feeding high fat diet for 12 weeks. 'Zusanli'(ST 36) and 'Yishu'(EX 17) were punctured with filiform needles and stimulated with uniform reinforcing reducing manipulation for 1 min; and 'Neiting'(ST 44) was stimulated with twirling reducing method for 30 sec first, then these acupoints were stimulated with electroacupuncture therapeutic apparatus (10 Hz, 1.5 V, continuous waves) for 15 min. Acupuncture treatment was conducted once daily, continuously for 4 weeks. Blood sugar was measured before and after treatment. Neuronal discharges of hypothalamic ARC were recorded with glass microelectrodes (filled with 3 M KCl+ 2% pontamine sky blue) in other 18 rats, with 6 animals in each group. Results: Before and after acupuncture treatment, blood sugar values of control, model and acupuncture groups were 7.25±1.07 mmol/L, 7.67± 1.83 mmol/L; 16.41±5.30 mmol/L, 14.28±7.04 mmol/L; 16.39± 4.78 mmol/L, 11.18± 5.12 mmol/L, indicating that acupuncture could lower the increased PBG in NIDDM rats. In model group, the frequency of ARC neuronal discharges was 3.9±0.8 Hz (that of normal rats being 11.2± 2.8 Hz), while in acupuncture group, it was 13.1±3.3 Hz, being significantly higher than that of model group (P<0.001). Conclusion: Results of the present paper suggest that acupuncture can raise neuronal firing rate of ARC which may be related to the regulative effect of acupuncture on type Ⅱ diabetes.