电针对肥胖大鼠下丘脑POMC、AgRP蛋白和基因表达的影响

目的观测电针对肥胖大鼠下丘脑前阿黑皮素(POMC))和刺鼠相关肽(AgRP)蛋白、基因表达的影响,探讨针刺治疗肥胖的可能机制。方法雄性Wistar大鼠随机分为正常组、模型组、电针组,每组10只。高脂饮食喂养造肥胖模型,造模成功后给予电针组动物足三里、丰隆、关元和中脘电针10 min,3次/周,总疗程为8周。每2周记录大鼠体质量和进食量;用Western Blot法检测大鼠下丘脑POMC、AgRP蛋白表达水平,用real-time PCR法检测大鼠下丘脑POMC、AgRP基因表达。结果与正常组大鼠相比,模型组大鼠的体质量从干预前到干预结束后均升高(P<0.05);进食量始终较高(P<0.01);下丘脑POMC蛋白、基因表达显著降低(P<0.01);下丘脑AgRP蛋白、基因表达显著升高(P<0.01);与模型组相比,干预4周后,电针组大鼠进食量显著低于模型组(P<0.01),且该差异一直持续至干预8周后;干预6周后,电针组大鼠体质量开始低于模型组(P<0.05);干预8周后,电针组大鼠体质量均显著低于模型组(P<0.01);电针组大鼠下丘脑POMC蛋白、基因表达显著升高(P<0.01);电针组大鼠下丘脑AgRP蛋白表达低于模型组(P<0.05),基因表达显著降低(P<0.01)。结论电针能够改善肥胖大鼠下丘脑食欲肽的蛋白和基因表达,上调下丘脑抑食欲肽POMC的蛋白表达和基因表达、下调下丘脑促食欲肽AgRP的蛋白表达和基因表达,明显降低肥胖大鼠的进食欲望,减少其进食量,控制体质量增长、改善肥胖状态,这可能是针刺改善肥胖能量代谢的中枢机制之一。

Effect of Electro-acupuncture on POMC,AgRP Protein and Gene Expressions in Hypothalamus of Obese Rats

Objective To observe the effect of electropuncture(EA)on pro-opiomelanocortin(POMC)and agouti-related peptide(AgRP)protein and gene expressions in the hypothalamus of obese ratsand explore the possibility of acupuncture treatment of obesity.Methods Male Wistar rats were randomly divided into normal,model and EA groups(n=8).The obesity model was established by feeding the rats with high fat diet.For EA group,EA(2 Hz,1 mA)was applied to bilateral"Zusanli(ST36)""Fenglong(ST40)""Guanyuan(RN4)"and"Zhongwan(RN12)"for 10 min,3 times per week for a total of 8 weeks.During EA treatment,body weight and food intake of all rats were measured once every two weeks.The expression levels of POMC and AgRP in the hypothalamus were detected by Western blot and real-time PCR.Results Compared with the normal group,the body weight of the model group was higher during the 8 weeks intervention(P<0.05).The food intake was always higher(P<0.01).The hypothalamic POMC protein and gene expression in the hypothalamus were significantly decreased(P<0.01).AgRP protein and gene expression in the hypothalamus were significantly increased(P<0.01).Compared with the model group,after 4 weeks intervention,the food intake in the EA group was significantly lower than that in the model group(P<0.01).The difference continued until after 8 weeks intervention.After 6 weeks intervention,the body weight of the EA group began to be lower than that of the model group(P<0.05).After 8 weeks intervention,the weight of the EA group was significantly lower than that of the model group(P<0.01).The expressions of POMC protein and gene in the hypothalamus of the EA group were significantly increased(P<0.01).The expression of AgRP protein in the hypothalamus of the EA group was lower than that of the model group(P<0.05)and the gene expression was significantly reduced(P<0.01).Conclusion EA can regulate the protein and gene expressions of orexigenic neuropeptide,up-regulate the protein and gene expressions of POMC and down-regulate protein and gene expressions of AgRP in the hypothalamus and can significantly reduce obesity rats’desire to eat,their food intake,control weight gainand improve obesity,which may be one of the central mechanisms for acupuncture to improve obesity energy metabolism.