肽YY3-36对饮食诱导肥胖大鼠食欲调节的研究

目的:探讨高脂饲料诱导肥胖抵抗大鼠热能摄入量减少的机制。方法:雌性SD大鼠36只,按体重随机分为高脂实验组和基础对照组,分别给予高脂饲料和基础饲料13w。13w末根据体重将高脂饲料组再分为饮食诱导肥胖(dietaryinducedobesity,DIO)和饮食诱导肥胖抵抗(dietaryinducedobesityresistant,DIO-R)组,比较各组大鼠能量摄入水平,血浆PYY3-36、NPY浓度,下丘脑匀浆NPY含量及下丘脑Y2-RmRNA表达水平的差异。结果:DIO-R大鼠累积热能摄入量低于DIO大鼠(P<0.01),与对照组相比无显著性差异(P>0.05);DIO-R大鼠血浆PYY3-36浓度显著高于DIO和对照组大鼠,下丘脑匀浆NPY含量显著低于DIO大鼠(P<0.01);DIO-R大鼠下丘脑Y2-RmRNA表达水平低于DIO和对照组大鼠(P<0.01)。结论:高脂饲料喂养下,SD大鼠表现为明显的肥胖易感性差异,这种差异与PYY3-36和NPY的食欲调节密切相关,血浆PYY3-36水平的升高与下丘脑NPY水平的下降减少了能量的摄入,从而抑制了体重的过度增加。

EFFECTS OF PEPTIDE YY3-36 ON APPETITE REGULATION TO DIETARY INDUCED OBESITY RESISTANT RATS

Objective: To explore the cause of decreasing energy intake of high-fat diet induced obesity resistant rats. Method:Thirty-six female SD rats were randomly divided into high-fat diet group (n=27) and control group (n=9), and given either high-fat diet or chow for 13w. Then the high-fat diet group was subdivided into dietary induced obesity (DIO) and dietary induced obesity resistant (DIO-R) groups according to the final body weight. Weight gain, energy intake, and the plasma concentration of PYY3-36, NPY, the hypothalamic NPY levels and Y2-R mRNA were measured and compared. Results: The total energy intake was lower significantly in DIO-R rats than that in DIO rats (P<0.01), while no significant difference was found between DIO-R and control group(P>0.05). The concentration of plasma PYY3-36 was significantly higher in DIO-R rats than that in DIO and control group (P<0.01), while the concentration of hypothalamic NPY was lower significantly in DIO-R than that in DIO group (P<0.01). The expression level of Y2-R mRNA was higher significantly in DIO-R group than that in DIO and control group in hypothalamus (P<0.01). Conclusion:On the high-fat diet , SD rats showed different susceptibility to obesity and energy intake, DIO-R rats decreased energy intake by increasing the level of circulating PYY3-36 and reducing the level of hypothalamic NPY .