高脂膳食诱导的甲状腺激素改变对肥胖易感性的影响  

CHANGES OF THYROID HORMONE INDUCED BY HIGH-FAT DIET AFFECT OBESITY PROPENSITY IN MICE

作　　者：段晓梅[1,2] 郝立月 李丽婷[1,2] 夏淑芳[1,2] 乐国伟[1,2] 施用晖[1,2] 

机构地区：[1]江南大学食品科学与技术国家重点实验室,无锡214000 [2]江南大学江南大学食品学院,营养与功能因子研究中心,无锡214000

出　　处：《营养学报》2016年第1期41-47,共7页Acta Nutrimenta Sinica

基　　金：国家十二五科技支撑计划项目(No.2012BAD33B05)

摘　　要：目的通过饲喂高脂膳食建立肥胖易感和肥胖抵抗表型,探究高脂膳食诱导的甲状腺激素改变对肥胖易感和肥胖抵抗表型产生的影响。方法 40只C57BL/6雄性小鼠分为正常组(脂肪含量4.6%,n=10)和高脂组(脂肪含量22.9%,n=30)。17w时用综合实验动物监测系统(CLAMS)测定小鼠的能量代谢后处死,测定血清中甲状腺激素水平和血脂水平,并采用荧光定量PCR(q RT-PCR)测定肝脏中Ⅰ型脱碘酶(DIO1)和甲状腺激素受体β(TRβ)以及脂代谢相关基因脂肪酸合成酶(FAS)、肉毒碱棕榈酸转移酶1α(CPT1α)、过氧化物酶增殖体激活受体辅激动子1α(PGC1α)和胆固醇7α羟化酶(CYP7A1)的表达。结果肥胖易感组的平均体重显著高于肥胖抵抗组(P<0.05)。肥胖抵抗组小鼠的能量摄入量显著低于肥胖易感组而产热量显著高于肥胖易感组(P<0.05),且肥胖抵抗组的呼吸交换率(RER值)更接近0.7。q RT-PCR结果表明与肥胖易感组相比,肥胖抵抗组小鼠肝脏中DIO1、TRβ、CPT1α、PGC1α和CYP7A1的表达显著上调(P<0.05),而FAS的表达显著下调。结论高脂膳食可能通过抑制肥胖易感组小鼠肝脏DIO1和TRβ的表达使得能量消耗降低,摄入的过多能量以脂肪形式储存在体内,最终导致肥胖抵抗和肥胖易感的表型差异。Objective To investigate the effects of thyroid hormone on the development of obesity resistant（OR） and prone phenotypes（OP） induced by high-fat diet in mice. Methods A total of forty male C57BL/6 mice were randomly divided into control group（n=10） and high-fat diet group（n=30）. The metabolism was measured by comprehensive laboratory animal monitoring system（CLAMS） in 17 th week, and then the mice were sacrificed. The serum levels of thyroid hormone and lipids were detected. Meanwhile, the m RNA levels of hepatic（deiodinase 1） DIO1, thyroid hormone receptor β（TRβ） and lipid metabolism related genes（fatty acid synthetase（FAS）, carnitine palmitoyltransferase 1α（CPT1α）, perxisome proliferator- activited receptor-γ coactivitor-1α（PGC1α） and cytochrome P450 family 7 subfamily A polypeptide 1（CYP7A1）） were determined by quantitative reverse transcription-polymerase chain reaction（q RT-PCR）. Results The average body weight of OP group was significantly higher than that of OR group（P0.05）. Energy intake of OP group was significantly higher than that of OR group, while the energy expenditure was significantly lower than that of OR group（P0.05）. Compared to OP group, respiratory exchange ratio（RER） of OR group was close to 0.7. q RT-PCR results showed that the expression of hepatic DIO1, TRβ, CPT1α, PGC1α and CYP7A1 were significantly higher in OR group than those in OP group（P0.05）. Meanwhile, the expression of FAS was significantly lower in OR group than OP group（P0.05）. Conclusion High-fat diet may decrease energy expenditure in OP group by inhibiting the expression of hepatic DIO1 and TRβ. Hence, excess energy was stored as fat in the boby. As a consequence, the high-fat diet causes the difference in OR and OP.

关 键 词：肥胖抵抗 肥胖易感 Ⅰ型脱碘酶 甲状腺激素受体β 能量平衡 脂质代谢 

分 类 号：R589.2[医药卫生—内分泌]