针刺对肥胖模型大鼠下丘脑瘦素受体mRNA的表达与针刺的影响： SYBR Green实时定量聚合酶链反应检测

背景：脂肪细胞合成的瘦素作用于下丘脑，引起食欲降低，能量消耗增加，导致降低体质量，减少体脂。但单纯性肥胖病患者由于瘦素抵抗导致肥胖。 目的：观察针刺对肥胖大鼠血清瘦素含量和下丘脑瘦素受体OB-Ra和OB-Rb表达的影响，探讨针灸减肥的机制。 设计、时间及地点：随机对照动物实验,于2006-10/2007-01在南京中医药大学动物实验中心完成。 材料：刚断乳的健康清洁级雄性SD大鼠90只,体质量50~70ｇ。实验过程中对动物处置符合2006年科学技术部发布的《关于善待实验动物的指导性意见》。 方法：随机挑选10只普通饲料喂养为正常组。另一组80只高脂致肥饲料喂养，将造模成功的肥胖大鼠30只随机分为肥胖模型组和针刺组，每组各15只。采用实时定量聚合酶链反应技术测定瘦素受体(OB-Ra，OB-Rb) 基因表达水平, 酶联免疫测定法测定血清中瘦素的含量。 主要观察指标：针刺治疗前后肥胖大鼠体质量、血清中瘦素的含量以及下丘脑OB-Ra与OB-Rb基因表达的变化。 结果：肥胖模型组大鼠体质量、血清瘦素水平均显著高于正常大鼠，而下丘脑OB-Rb基因表达水平均明显低于正常大鼠。针刺治疗取得良好减肥疗效的同时，针刺组大鼠血清瘦素明显回降，而下丘脑OB-Rb基因表达水平却明显升高。OB-Ra表达量3组差异无显著性意义。 结论: 针刺可改善肥胖大鼠瘦素抵抗状态以及促进下丘脑OB-Rb 基因表达可能是针刺减肥的细胞分子重要机制。

Effect of acupuncture on the expression of leptin receptor in hypothalamus in obesity rats: Determination by SYBR Green real-time quantitative polymerase chain reaction

BACKGROUND: The leptin synthesized from adipose tissue in the hypothalamus may reduce appetite and increase energy consumption, which lead to lower weight and reduced body fat. But simple obese patients cause the obesity because of leptin resistance. OBJECTIVE: To observe the effect of acupuncture on serum leptin contents and the expression of leptin receptor (OB-Ra and OB-Rb) in the hypothalamus of obesity rats, and to explore the underlying mechanism of acupuncture in reducing weight. DESIGN, TIME AND SETTING: Randomized control animal trials were performed between October 2006 and January 2007 in the Experimental Animals Center of Nanjing University of Traditional Chinese Medicine. MATERIALS: Ninety SD rats, male, healthy and weaned, body weight was 50-70 g, were used in this study. The experimental procedures were performed in accordance with the animal care guidelines of the State Ministry of Science and Technology in 2006. METHODS: Randomly selected 10 rats fed with ordinary forage were used as normal control group; Another group of 80 rats fed with high fat forage. Successfully established experimental model rats (n=30) were randomly divided into two groups: obese model group (n=15) and acupuncture group (n=15). Serum leptin contents were measured by Elisa, and leptin receptor (OB-Ra and OB-Rb) mRNA was detected with SYBR Green quantitative real-time polymerase chain reaction. MAIN OUTCOME MEASURES: The changes of body weight, contents of serum leptin as well as expression of hypothalamic OB-Ra and OB-Rb gene in the obese rats were observed before and after acupuncture. RESULTS: The body weight and levels of serum leptin in the obese rats were significantly higher than those in the normal rats, but the expression of hypothalamic OB-Rb gene in the obese rats were all lower than those in the normal rats. After acupuncture treatment, the marked weight lose was achieved and the levels of serum leptin were obviously decreased, while the expression of hypothalamic OB-Rb gene significantly increased in the obese rats. There was no significant difference in the expression of OB-Ra among groups. CONCLUSION: Acupuncture can ameliorate leptin resistance and promote the expression of hypothalamic OB-Rb gene in the obesity rats. These are possibly important cellular and molecular mechanisms in the anti-obesity of acupuncture.