肥胖大鼠棕色脂肪线粒体氧化损伤情况动态观察

DYNAMICAL OBSERVATION ON OXIDATIVE DAMAGE OF MITOCHONDRIA IN BROWN ADIPOSE TISSUE IN DIET-INDUCED OBESE RATS

目的研究高脂饮食诱导肥胖对大鼠棕色脂肪组织线粒体功能的影响。方法雄性Wistar大鼠160只,随机选40只为基础组(CN),其余120只建饮食诱导肥胖大鼠模型,选体质量增加上下1/3各40只做为饮食诱导肥胖(DIO)和饮食诱导肥胖抵抗(DR)大鼠,其余剔除。喂养10w,每2w每组选8只动物处死,留取棕色脂肪组织,测定活性氧簇(ROS),线粒体膜电位(MMP)水平及线粒体呼吸链复合体(Complex)Ⅰ、Ⅱ、Ⅲ、Ⅳ水平。结果 DIO组大鼠棕色脂肪组织中ROS水平在第8,10w时显著高于DR组和CN组(P<0.05)。DIO组MMP在第8,10w时显著低于CN组,DR组MMP水平在第4、8、10w时均显著低于CN组(P<0.05)。线粒体ComplexⅠ活性在第4、6w时代偿性升高,ComplexⅢ活性在第8、10w显著降低,ComplexⅣ活性在第4、6w时代偿性升高,但在第10w时失代偿性,DIO组显著低于CN组(P<0.05)。结论高脂饮食诱导肥胖引起棕色脂肪组织线粒体功能损伤。

Objective To investigate the effects of diet-induced obesity on the oxidative damage of mitochondria in rat brown adipose tissue. Methods Adult male Wistar rats （n=160） were selected randomly as the control group （CN,n=40） and diet-induced obesity model group （n=120）. After 2-week feeding of high-fat diet （week 2）, the higher weight gains in the upper 1/3 were designated as the diet-induced obesity rats （DIO,n=40）, the lower weight gains were diet-induced obesity resistance rats （DR,n=40） and the rests were excluded from the experiment. Rats were fed for 10 weeks, and every 2 weeks brown adipose tissues were taken from eight rats from CN, DIO, and DR groups. The level of ROS, MMP and the activities of mitochondria complex I, II ,III,IV were measured. Results At weeks 8 and 10, the level of ROS in DIO group was higher than DR and CN group （P〈0.05）. At weeks 8,10 and 4, 8, 10, the activities of MMP in DIO and DR groups were lower than CN group （P〈0.05） respectively. Complex I activity increased compensatively at weeks 4 and 6, the activity of complex III decreased significantly at weeks 8 and 10, complex IV activity compensatively increased at weeks 4 and 6, but at week 10 it was decompensated, and the DIO became significantly lower than CN group （P〈0.05）. Conclusion High-fat diet induces oxidative damage in brown adipose mitochondria.