Yang Nianhong, Wang Chongjian, Xu Mingjia, Mao Limei, Liu Liegang, Sun Xiufa
Department of Nutrition and Food hygiene, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
J Huazhong Univ Sci Technolog Med Sci. 2005;25(3):243-6. doi: 10.1007/BF02828131.
The interaction of high-fat diet and the peptide YY (PYY) gene expression in diet-induced obesity and the mechanisms which predisposed some individuals to become obese on high-fat diet were explored. Thirty-six male SD rats were randomly divided into high-fat diet group (n=27) and chow fed control group (n=9). After 15 weeks of either a high-fat diet or chew fed diet, the high-fat diet group was subdivided into dietary induced obesity (DIO) and dietary induced obesity resistant (DIR) group according to the final body weight. Then the DIO rats were subdivided into two groups for a 8-week secondary dietary intervention. One of the group was switched to chew fed diet, whereas the other DIO and DIR rats continued on the initial high-fat diet. Weight gain and food intake were measured, food efficiency was calculated, and the concentrations of plasma neuropeptide Y (NPY) and PYY were assayed. Hypothalamic NPY mRNA expression and PYY mRNA expression in ileum and colon was detected by RT-PCR. The results showed that at the end of 15th week, the levels of body weight and caloric intake were significantly higher in DIO group than in DIR or control group (P<0. 01), while no significant difference was found between DIR and control group (P>0.05). The concentration of plasma PYY was significantly higher in DIR group than in DIO and CF group, while no significant difference was found between DIO and CF group (P <0.01). After switching the DIO rats to chow fed diet, their body weight gains were significantly lower than that of the DIO-HF group. The expression of PYY mRNA was increased in DIO-HF/ CF rats than in DIO-HF rats, and the expression of hypothalamic NPY mRNA was decreased in DIO-HF/CF rats than in DIO-HF group. It was concluded that both dietary composition and PYY gene expression could potently alter the hypothalamic NPY expression and result in different susceptibility to obese and overeating. The decreased PYY was associated with the increased NPY expression and their predisposal to obese and overeating in rats.
研究了高脂饮食与肽YY（PYY）基因表达在饮食诱导肥胖中的相互作用，以及一些个体在高脂饮食下易肥胖的机制。36只雄性SD大鼠随机分为高脂饮食组（n = 27）和普通饮食对照组（n = 9）。在高脂饮食或普通饮食15周后，根据最终体重将高脂饮食组再分为饮食诱导肥胖（DIO）组和饮食诱导肥胖抵抗（DIR）组。然后将DIO大鼠再分为两组进行为期8周的二次饮食干预。其中一组改为普通饮食，而其他DIO和DIR大鼠继续最初的高脂饮食。测量体重增加和食物摄入量，计算食物效率，并检测血浆神经肽Y（NPY）和PYY的浓度。通过RT-PCR检测下丘脑NPY mRNA表达以及回肠和结肠中PYY mRNA表达。结果显示，在第15周结束时，DIO组的体重和热量摄入水平显著高于DIR组或对照组（P<0.01），而DIR组和对照组之间无显著差异（P>0.05）。DIR组血浆PYY浓度显著高于DIO组和CF组，而DIO组和CF组之间无显著差异（P<0.01）。将DIO大鼠改为普通饮食后，其体重增加显著低于DIO-HF组。DIO-HF/CF大鼠中PYY mRNA的表达高于DIO-HF大鼠，且DIO-HF/CF大鼠下丘脑NPY mRNA的表达低于DIO-HF组。得出结论，饮食组成和PYY基因表达均可有效改变下丘脑NPY表达，并导致对肥胖和暴饮暴食的易感性不同。PYY降低与大鼠NPY表达增加及其对肥胖和暴饮暴食的易感性有关。
