中文摘要：

目的 研究高脂饮食诱导肥胖（DIO）及肥胖抵抗（DIO-R）大鼠血浆PYY3-36含量及回结肠PYYmRNA的表达情况，探讨PYY3-36与高脂饮食诱导肥胖抵抗的关系。方法 36只雌性SD大鼠，按体重随机分为高脂实验组（n=27）和基础对照组（n=9），分别给予高脂饲料和基础饲料喂养13周。据13周末体重将高脂饲料组再分为饮食诱导肥胖和饮食诱导肥胖抵抗组，比较各组大鼠能量撮入水平、血浆PYY3-36含量厦回结肠PYYmRNA表达水平的差异。结果 DIO-R大鼠热能摄入量显著低于DIO大鼠（P〈0．01），与对照组大鼠相比无显著性差异（P〉0．05）；DIO．R大鼠血浆PYY3．36含量及回结肠PYYmRNA表达水平显著高于DIO和对照组大鼠（P〈0．01）；DIO与对照组相比，除回肠PYYmRNA表达水平升高外，其余指标均无显著性差异（P〉0．05）。结论 高脂饮食条件下，SD大鼠表现为明显的肥胖易感性差异，这种差异可能与PYY3-36的食欲调节密切相关，血浆PYY3-36含量和回结肠PYYmRNA表达水平的升高可能是导致DIO-R大鼠热能摄入下降的内在机制之一。

英文摘要：

Objective To study the plasma concentration of peptide YY3 - 36（PYY3-36） and the expression levels of PYY mRNA of ileum and colon in dietary induced obesity （DIO） and dietary induced obesity resistant （DIO-R） rats and the relation between PYY3-36 and DIO-R rats. Methods Thirty-six female SD rats were randomly divided into high-fat diet group （ n = 27） and chow fed control group （ n = 9）, after 13 weeks of either a high-fat diet or chew fed diet, the high-fat diet group was sutMivided into DIO and DIO-R group according to the final body weight. Weight gain, caloric intake, the concentration of PYY3-36 and the expression levels of PYY mRNA were measured and compared. Results The total caloric intake of DIO-R rats was lower than DIO rats （ P 〈 0.01 ）, while no significant difference was found between DIO-R and control rats （ P 〉 0.05）. The concentration of PYY3-36 and the expressions of PYY mRNA of ileum and colon in DIO-R rats were higher significantly than that of the DIO and contrel rats （ P 〈 0.01 ）, while no significant difference was found between DIO and control group （ P 〉 0.05 ）, except that PYY mRNA of ileum was advanced in DIO group （ P 〈 0.01 ）. Conclusion On the High-fat diet, SD rats showed different susceptibility to obese and energy intake, increased levels of PYY3-36 and PYY mRNA might be related to dietary induced obesity resistant.