食源性肥胖大鼠下丘脑弓状核NPY表达上调

Up-regulation of neuropeptide Y expression in the arcuate nucleus of the diet-induced obese rats

目的:通过观察食源性肥胖(diet-induced obese,DIO)大鼠的摄食量、体重变化和下丘脑弓状核神经肽Y(neuropeptide Y,NPY)的表达,探讨NPY在大鼠发展为D IO中的作用。方法:SD大鼠给予高能饲料喂养14周后,根据体重筛选出D IO组和肥胖抵抗(diet-resistant,DR)组,记录体重和摄食量,利用免疫组织化学方法半定量分析下丘脑弓状核NPY的表达。结果:约50%的SD大鼠发展为DIO,DIO大鼠的摄食量明显增加,下丘脑弓状核N PY的表达上调,明显高于DR组(P<0.001)和对照组(P<0.05),具有显著性差异。结论:在长期高能饲料喂养下,D IO大鼠下丘脑弓状核N PY的表达上调可能是导致其摄食量和体重增加的重要原因之一。

Objective: In order to assess the role of neuropeptide Y (NPY) in the rat of diet-induced obesity (DIO), the change of the expression of NPY in the arcuate nucleus (ARC) of hypothalamus was observed, in association with the diet composition and individual sensitivity to the weight promoting action of the high fat (HIF) diet. Methods: (a) After fed HIF diet for 14 weeks, rats showing higher body weight and lower body weight were assigned as DIO and diet resistant (DR) group, respectively. Food intake was measured daily, for 4 weeks. (b) NPY expression was detected in ARC of the hypothalamus via immunohistochemistry. Results: (a) About 50% rats developed DIO on an HIF diet. (b) DIO rats were accompanied by a marked higher energy intake and up-regulation of NPY expression in ARC. Conclusion: Up-regulation of NPY expression in the hypothalamic ARC of the DIO rats in response to an HIF diet is associated with increased weight gain and obesity.