针剌对肥胖大鼠脑弓状核作用的调整

背景弓状核功能异常可能是肥胖发病的重要因素之一,已知针灸减肥机制涉及神经及神经体液调节,针刺对弓状核功能调整作用如何?目的探讨针刺对肥胖大鼠弓状核功能的作用,进一步深化针刺减肥的中枢神经作用机制.设计以实验动物为研究对象的随机对照实验研究.单位一所中医药大学临床医学院的针灸研究所及一所人口管理学院.材料实验于2002-04/10在南京中医药大学第二临床医学院针灸研究所完成.选用1个月龄刚断乳SD雄性大鼠.方法以普通全价鼠饲料喂养的大鼠作为正常组,将造模成功的实验性肥胖大鼠随机分为对照组和针刺组,每组12只.针刺组大鼠给予针刺治疗14 d,正常组和对照组大鼠分别每天放入大鼠固定器中适应15 min,持续14 d.采用神经电生理及神经化学技术观察针刺治疗前后肥胖大鼠体质量、Lee's指数、体脂,中枢和外周瘦素和胰岛素水平以及下丘脑弓状核神经细胞自发放电频率的变化.主要观察指标①针刺对实验性肥胖大鼠肥胖指标及对心包、肾周和附睾脂肪量的影响.②针刺对各组大鼠下丘脑弓状核神经细胞自发放电的影响.③针刺对各组大鼠下丘脑和血清瘦素和胰岛素含量的影响.④下丘脑弓状核神经细胞自发放电与下丘脑瘦素和胰岛素水平的相关分析.结果肥胖大鼠体质量、Lee's指数、体脂量(517.74±29.35)g,(319.85±3.96),(13.88±1.32)g,P＜0.01]均显著高于正常大鼠水平;肥胖大鼠下丘脑弓状核神经细胞自发放电频率显著低于正常大鼠(3.12±1.92)Hz,(8.99±2.71)Hz,P＜0.01];大鼠下丘脑弓状核神经细胞自发放电频率与体质量、Lee's指数和体脂量均呈负相关(r=-0.592,-0.672,-0.521).针刺组较对照组肥胖大鼠下丘脑弓状核神经细胞自发放电频率明显增高(9.75±2.02)Hz,P＜0.01].结论针刺对肥胖机体下丘脑弓状核功能的良性作用可能是针灸减肥的作用机制之一.

Adjustment of acupuncture on arcuate nucleus of hypothalamus in obese rats

BACKGROUND: The abnormality of the function of arcuate nucleus may be an important factor of obesity. It has been known that the mechanisms of acupuncture in treating obesity are related to nervous and neurohumoral regulation. What is the regulating effect of acupuncture on the function of arcuate nucleus?OBJECTIVE: To study the effects of acupuncture on the function of arcuate nucleus of obese rats, and further investigate central nervous functional mechanism of reducing weight by acupuncture.DESIGN: Randomized controlled study based on the experimental animals.SETTING: Acupuncture institute in second clinical medical college of a university of traditional Chinese medicine, and a population management college.MATERIALS: This experiment was carried out in the Acupuncture Institute of Second Clinical Medical College, Nanjing University of Traditional Chinese Medicine between April and October 2002. One-month old male SD rats just in ablactation were selected.METHODS: Rats fed with ordinary wholesome rat-feed were in the normal group. The successfully established experimental obese rats models were randomly divided as control group and acupuncture group with 12 rats in each group. Rats in the acupuncture group were given acupuncture treatment for 14 days, and rats in the normal and control groups were put into rat fixation-machine for 15 minutes every day, lasting for 14 days. Body mass, Lee' s index, body lipid, level of central and peripheral leptin and insulin(INS) as well as the frequency of spontaneous discharge of nerve cell in the arcuate nucleus(ARC) of hypothalamus in obese rats were observed with nervous electrophysiological and nervous biochemical technology before and after acupuncture.MAIN OUTCOME MEASURES: ① Effect of acupuncture on obesity index, fat contents of pericardium, kidney and epididymis of experimental obese rats. ② Effect of acupuncture on the frequency of spontaneous discharge of ARC nerve cell of hypothalamus in obese rats. ③ Effect of acupuncture on the contents of hypothalamic and serum leptin and INS of rats in each groups. ④ Correlation of the frequency of spontaneous discharge of ARC nerve cell of hypothalamus with the level of hypothalamic leptin and INS.RESULTS: The body mass(517.74±29.35) g], Lee' s index (319.85 ± 3.96) and body fat content of obesity rats (13.88 ± 1.32) g] were all significantly higher than those in the normal rats, the differences were significant(P ＜ 0.01); the frequency of spontaneous discharge of nerve cell in ARC of hypothalamus in obese rats (3.12 ± 1.92) Hz] were all markedly lower than those of the normal rats (8.99 ± 2.71 ) Hz], the differences were significant (P ＜ 0.01 ); the frequency of spontaneous discharge of nerve cell in ARC was negatively correlated with body mass, Lee' s index and body lipid( r = -0. 592, -0. 672, -0. 521 ) . Acupuncture significantly increased the frequency of spontaneous discharge of nerve cell in ARC of hypothalamus in obese rats (9.75 ±2.02) Hz] as compared with the control group, the differences were significant( P ＜ 0. 01 ).CONCLUSION: The good regulating effect of acupuncture on the function of arcuate nucleus of hypothalamus might be one of mechanisms in the antiobesity of acupuncture.