胰岛素抵抗和肥胖不同易感性的关系研究

目的研究高脂饲料饮食诱导肥胖不同易感性大鼠在形成胰岛素抵抗中的差异。方法健康雄性SD大鼠采用高脂饲料1(脂肪供能占45%)喂养3w后,按体重由高到低排序后分为三组:位于体重中间1/3的大鼠为对照组,改为喂饲基础饲料(脂肪供能占10%);位于体重上1/3的大鼠进入肥胖组,位于体重下1/3的大鼠进入肥胖抵抗组,此两组喂饲高脂饲料2(脂肪供能占60%)。分别于实验的3、6、8、10、11w末各组随机处死5只大鼠,动态监测各组大鼠体重、体脂含量、血脂、血糖、胰岛素和瘦素的变化趋势。结果肥胖组在能量摄入、体脂含量、血糖、血脂、血清胰岛素、胰岛素敏感指数和瘦素水平上都与肥胖抵抗组和对照组有显著性差异。结论在同样的高脂饲料诱导下,肥胖大鼠比肥胖抵抗大鼠更易形成胰岛素抵抗。     

不同肥胖易感性大鼠模型的建立及其能量代谢的研究

目的建立不同肥胖易感性大鼠动物模型,并探讨其能量代谢的特点。方法雄性SD大鼠60只,给予高脂饲料喂养3 w后,按体重增加量排序,上1/3(18只)作为肥胖易感(OP)组,下1/3(18只)作为肥胖抵抗(OR)组,中间1/3作为对照组。继续喂养12w后,每组随机挑选一半动物,每日给予半量饲料进行限食饲喂,另一半继续自由采食,持续2 w后,测量肥胖易感(OP)、肥胖抵抗(OR)及对照组大鼠不同状态下能量摄入量、基础代谢率(BMR)、静息代谢率(RMR)、基础能量消耗(BEE)等代谢指标。结果 OP大鼠体重、Lee’s指数、BMI指数、能量利用率均显著高于OR组和对照组,OR组与对照组之间无显著差异。在自由采食状态下,OP、OR和对照组间能量摄入水平无显著差异,OR组BMR、RMR及BEE水平显著高于对照组和OP组。在半量限食状态下,各组代谢水平较自由采食状态均有所降低,OR组BMR、RMR及BEE水平较自由采食状态降低幅度最大。结论 OP和OR大鼠在基础代谢方面存在差异,且OR较OP具有更为灵敏的能量平衡调节系统。     

高脂和限食对不同肥胖易感性大鼠能量代谢的影响

目的探讨不同肥胖易感性大鼠在高脂饲料及半量限食状态下能量代谢的差异。方法健康雄性SD大鼠60只,高脂饲料喂养3周,按体重增加量排序筛选出肥胖易感(obesity-prone,OP)、肥胖抵抗(obesity-resistant,OR)和对照组,继续喂养12周;由各组随机挑选一半动物进行半量限食饲喂,另一半继续自由采食,持续2周。间接测热法测量大鼠基础代谢率(BMR)、静息代谢率(RMR)等代谢指标;处死动物,分离肾周、睾周和大网膜脂肪,计算体脂百分比。结果在高脂饲料状态下,OR大鼠BMR、RMR显著高于OP组和对照组;在半量限食状态下,OR大鼠BMR、RMR显著低于OP组和对照组。在限食状态下OP、OR及对照组大鼠BMR、RMR较自由采食状态均有所降低,OR组降幅最大;经过2周限食后,OP组体脂百分比下降显著,而OR组基本无变化。结论 OP、OR大鼠在高脂饲料或半量限食状态下代谢水平均存在显著差异,OR较OP对能量摄入水平的变化反应更为灵敏。     

饮食诱导肥胖和肥胖抵抗大鼠胃肠动力学研究

目的探讨高脂饮食诱导肥胖易感（OP）大鼠和肥胖抵抗（OR）大鼠胃肠动力和营养素吸收差异,从胃肠的角度揭示肥胖和肥胖抵抗发生的原因。方法高脂饲料喂饲健康雄性SD大鼠8周,筛选出OP大鼠和OR大鼠。实验结束后,连续进行3 d代谢实验,并收集大鼠的粪便和尿液,分别测定其营养素含量,并计算出肥胖和肥胖抵抗大鼠的营养素消化吸收量。采用酚红灌胃法测定各组大鼠胃排空率,采用墨汁推进方法测定小肠推进功能。结果OP大鼠蛋白质和脂肪的摄入量与吸收量显著高于OR大鼠。OP大鼠和OR大鼠胃排空率比较差异无统计学意义,OP大鼠小肠推进率显著高于OR大鼠。结论在高脂饮食诱导下,胃肠动力差异以及营养素摄入和吸收的差异可能是导致肥胖和肥胖抵抗的原因之一。     

肥胖大鼠胰岛素抵抗和leptin抵抗的关系研究

目的：探讨在肥胖形成的过程中Leptin抵抗和胰岛素抵抗何时出现及其因果关系。方法：选取雄性Wistar大鼠20按体重随机分为基础对照和肥胖2组,喂养5周,每周末称重,采尾血测定血糖、胰岛素和Leptin。结果：肥胖组体重、血糖、胰岛素和Leptin均高于基础对照组。在肥胖形成的过程中Leptin抵抗的发生先于胰岛素抵抗。肥胖组Leptin抵抗首先出现在第2周末而胰岛素抵抗出现在第3周末,推测Leptin抵抗是胰岛素抵抗的原因。结论：肥胖是糖尿病重要的危险因素。     

饮食诱导肥胖和肥胖抵抗大鼠脂联素水平研究

目的探讨高脂饲料对大鼠内脏脂肪中脂联素表达和血清中脂联素水平的影响及大鼠肥胖易感性差异的机制。方法 80只雄性SD大鼠,按体重随机分为两组:对照组(n=10),基础饲料喂养20w;高脂组(n=70),高脂饲料喂养12w。第12w末,根据体重将高脂组分为饮食诱导肥胖(DIO)和肥胖抵抗(DIO-R)组,继续喂养8w,观察各组大鼠体重、内脏脂肪湿重、体脂比、热能摄入量及能量利用率的差异;用Real Time PCR法测定内脏脂肪脂联素mRNA的表达水平;ELISA法测定血清脂联素水平。结果 DIO组体重、内脏脂肪湿重、体脂比、能量利用率显著高于对照组和DIO-R,而DIO-R除能量的摄入量显著低于对照组外,其他与对照组相比未见显著性差异;DIO大鼠内脏脂肪脂联素mRNA的表达水平显著低于对照组和DIO-R;DIO大鼠血清脂联素水平显著低于DIO-R。结论高脂饲料诱导下,不同肥胖易感性大鼠体内脂联素水平有明显差异性,脂联素可能在肥胖形成过程中扮演重要角色。     

饮食诱导肥胖抵抗和饮食诱导肥胖大鼠的对比研究

目的 探讨饮食诱导肥胖抵抗(DIO—R)大鼠和饮食诱导肥胖(DIO)大鼠的肥胖相关指标的变化。方法 采用50只健康雄性别大鼠，随机分为对照组和高脂组，分别用基础饲料和高脂饲料喂养13周，然后根据体重筛选出DIO—R和DIO组，观察能量摄入和体脂含量的变化；试纸法测定血糖；应用酶法测定大鼠总胆固醇(CHO)、甘油三脂(TG)、高密度胆固醇(HDL—C)；放免法测血清瘦素(1eptin)含量。结果 在前5周时，DIO—R大鼠与DIO大鼠摄入的总能量无显性差异；在实验终期，DIO—R大鼠明显低于DIO大鼠(P＜0．05)。DIO—R大鼠体脂含员、血糖、TG、CHO均明显低于DIO大鼠(P＜0．05)，DIO—R和DIO大鼠的HDL—C无明显差别。高脂饲料使大鼠血清(1eptin)水平明显增加(P＜0．05)，但DIO—R与DIO大鼠间无明显差别。结论 高脂饲料能够诱导别大鼠发生肥胖和肥胖抵抗，血清leptin水平增加在大鼠肥胖抵抗的发生中起部分作用。     

肥胖和肥胖抵抗大鼠神经肽Y及其受体基因表达的研究

目的:探讨高脂饲料对大鼠下丘脑神经肽Y(NPY)及其受体Y1、Y2、Y5基因表达的影响及大鼠肥胖易感性差异的机制。方法:36只雌性SD大鼠,按体重随机分为高脂组和对照组,分别给予高脂饲料和基础饲料13w。实验结束时,根据体重将高脂组分为饮食诱导肥胖(DIO)和肥胖抵抗(DIO-R)大鼠,观察各组大鼠体重、内脏脂肪湿重、脂体比、热能摄入量及能量利用率的差异;RT-PCR法测定下丘脑NPY及其受体Y1、Y2、Y5mRNA的表达水平。结果:DIO大鼠体重、内脏脂肪湿重、脂体比、热能摄入量及能量利用率显著高于对照组和DIO-R大鼠,而DIO-R大鼠与对照组相比未见显著性差异;DIO大鼠下丘脑NPY及其受体Y1、Y2、Y5mRNA的表达水平显著高于对照组和DIO-R大鼠,而DIO-R大鼠与对照组相比,除Y2受体mRNA的表达水平显著下降外,其余指标均无显著性差异。结论:高脂饲料诱导下,SD大鼠表现为明显的肥胖易感性差异,下丘脑NPY及其受体的高水平表达可能是导致DIO大鼠热能摄入过多的内在机制之一。     

饮食诱导肥胖与肥胖抵抗大鼠抵抗素的表达及与胰岛素抵抗的关系

【目的】研究高脂饮食诱导肥胖及肥胖抵抗大鼠脂肪组织抵抗素表达及其与胰岛素抵抗的关系。【方法】采用幼年SD大鼠,随机分为对照组和高脂组,分别以基础饲料和高脂饲料喂养8周,根据体重筛选出肥胖大鼠和肥胖抵抗大鼠。分别于高脂饲养8周和16周时检测肥胖、肥胖抵抗大鼠抵抗素表达,血清抵抗素、胰岛素、胰岛素敏感指数等指标。【结果】肥胖抵抗大鼠抵抗素表达及胰岛素抵抗程度均显著低于肥胖大鼠。随高脂喂养时间延长,差异更加显著。【结论】肥胖抵抗与肥胖的发生和抵抗素不同程度的表达相关。     

边缘性锌缺乏对大鼠肥胖的影响

目的观察边缘性锌缺乏对大鼠肥胖的影响。方法 SPF级成年雄性SD大鼠32只,随机分为4组,低锌组喂饲含6 mg/kg锌的边缘性锌缺乏饲料,中锌组喂饲含10 mg/kg锌的边缘性锌缺乏饲料,低锌对饲组和对照组喂饲正常锌含量的AIN-93M饲料。喂养6周后,处死动物。测血锌、血脂、血清瘦素含量,肝脏总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)、丙二醛(MDA)水平。结果低锌组大鼠第5周起血锌含量明显低于低锌对饲组和对照组(P0.05),成功建立边缘性缺锌模型。第6周时,低锌组大鼠脂体比明显高于低锌对饲组和对照组(P0.05);低锌组和中锌组大鼠肝脏MDA含量明显高于对照组(P0.05);低锌组和中锌组大鼠肝脏TAOC、SOD水平明显低于对照组(P0.05)。结论边缘性锌缺乏可增加肥胖发生的风险,缺锌组大鼠体内氧化应激升高可能是边缘性锌缺乏增加肥胖风险的主要原因。     

营养性肥胖大鼠氧应激水平的改变

目的观察营养性肥胖大鼠氧应激、抗氧化能力的改变。方法20只断乳的SD雄性大鼠(75~80g)随机分两组,每组10只。膳食诱导肥胖组(DIO组)喂饲高脂饲料,对照组喂饲基础饲料,10周后取血及睾周、肾周脂肪组织。用ELISA法检测血浆8-表氧-前列腺素2α(8-epi-PGF2α)、二硫代双硝基苯甲酸法测血浆抗氧化酶GPX(谷胱甘肽过氧化物酶)活性、黄嘌呤氧化酶法测血浆SOD(超氧化物歧化酶)活性,HPLC(高效液相色谱仪)测血浆维生素E并经血脂校正。同时测血浆空腹血糖、胰岛素、三酰甘油(TG)、总胆固醇(TCHL)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)等糖脂代谢指标。结果高脂喂养10周后,DIO组的各项肥胖指标(体重、腹部脂肪/体重、Lee’s指数)均高于对照组(P<0.01);血浆8-epi-PGF2α增高,SOD和GPX活性、经血脂校正后的血浆维生素E水平显著降低(P<0.05)。另有脂代谢紊乱,空腹血糖与胰岛素也显著高于对照组。结论高脂喂养肥胖大鼠模型显示血脂升高并伴有胰岛素抵抗;氧应激水平增高而抗氧化能力下降。     

Dietary total antioxidant capacity and obesity in children and adolescents

Background Dietary antioxidant intake has been suggested to protect against oxidative damage and related clinical complications. The aim of the present study was to assess the potential relationships between the dietary total antioxidant capacity (TAC) and obesity-related features in children and adolescents.

Materials and methods Anthropometric variables from 369 children and adolescents were measured (184 obese and 185 control). A validated food-frequency questionnaire was used to calculate the TAC and the daily nutrient and energy intake.

Results Dietary TAC showed positive associations with fiber, folic acid, magnesium, and vitamins A, C and E. The body mass index, standard deviation score of body mass index and total body fat were inversely associated with dietary TAC only in obese subjects.

Conclusion These data suggest that dietary TAC may be a potential indicator of the risk to develop obesity-related features and could be considered a useful method in assessing antioxidant intake.     

儿童肥胖脂肪因子与血管内皮功能、氧化应激的关系研究

目的 探讨儿童肥胖脂肪因子与血管内皮功能和氧化应激的关系.方法 将2009年12月至2012年12月在东阳妇女儿童医院诊断的肥胖症患儿160例纳入肥胖组,随机抽取同期体检的健康儿童50例纳入对照组.采用ELISA法分别对两组儿童血清瘦素(LP)、内脂素(VFT)和肿瘤坏死因子-α(TNF-α)脂肪因子进行检测,采用高分辨率超声检测肱动脉扩张力,评估两组儿童血管内皮功能,采用相应的方法检测丙二醛(MDA)、维生素E、低密度脂蛋白胆固醇(LDL-C).结果 肥胖组儿童血清中LP、VFT和TNF-α表达水平均高于对照组,差异均有统计学意义(t值分别为0.043、0.039和0.042,均P＜0.05).肥胖组儿童肱动脉反应性充血后及含服硝酸甘油(GTN)后相对于静息状态的扩张百分率均低于对照组,差异均有统计学意义(t值分别为0.049和0.047,均P＜0.05).血清LP、VFT、TNF-α指标表达水平与肱动脉扩张百分率均呈负相关(rLP=-0.407、rVFT=-0.397、rTNF-α=-0.420,均P＜0.05).与对照组相比,肥胖组的LDL-C和MDA较高(t值分别为0.037和0.039,均P＜0.05),血浆维生素E水平较低(t =0.031,P＜0.05).结论 肥胖儿童血清LP、VFT、TNF-α脂肪因子表达水平与血管内皮功能呈负相关,肥胖儿童体内存在氧化应激.     

Impact of fish intake on oxidative stress when included into a moderate energy-restricted program to treat obesity

Background The role of some nutritional factors and hypocaloric diets on oxidative balance is a matter of debate, especially related to the prevention and treatment of obesity and co-morbidities. Aim of the study The aim was to investigate the antioxidant capacity of different energy restricted diets in the treatment of obesity, paying emphasis to the effect of incorporating omega-3 fatty acids with or without other seafood components. Methods The study was a randomized 8-weeks parallel intervention trial prescribed to lose weight, which was implemented in 276 subjects aged 31.4 ± 5.4 y.o. following four different balanced hypocaloric diets (TEE-30%): fish-restricted (control), cod and salmon based diets and DHA+EPA supplemented administration. At baseline (day 0) and at the end of the trial (day 56), anthropometry, dietary intake, erythrocyte membrane fatty acid content, circulating malondialdehyde (MDA) and plasma antioxidant status (AOP) were determined. Results Overall, percent weight loss was −5.8 ± 3.2% (P < 0.001) and the AOP statistically increased after the energy restriction period (P = 0.015), basically due to the seafood-based diets. In contrast, MDA statistically only decreased (P = 0.026) after the cod-based diet intake with no changes after the other nutritional treatments. In fact, the cod-based intervention statistically decreased oxidative stress when expressed as the MDA/AOP ratio (P = 0.006). Conclusions A moderate calorie-restricted cod-based diet was found as a useful strategy to lose weight, which was accompanied by a specific improvement on oxidative stress markers. The low saturated fat content and the seafood protein source of this diet may be important factors involved in these findings.     

氧化作用与子宫内膜异位症

子宫内膜异位症是育龄妇女的常见疾病 ,近年来其发病率有上升趋势 ,研究认为EM发生发展与腹腔氧化作用有关。氧化作用是一种炎症反应 ,EM中巨噬细胞释放的氧化活性物 ,腹腔液中氧化低密度脂蛋白及其产物的增加 ,子宫内膜细胞氧化酶与抗氧化酶的异常表达 ,腹腔液中VitE的消耗 ,均说明EM与腹腔氧化作用有关。本文综述有关研究结果为用抗氧化剂和抗炎症制剂预防EM发生提供新的研究途径     

Study of the Association between Thiols and Oxidative Stress Markers in Children with Obesity

Obesity has reached epidemic proportions, and the World Health Organization defined childhood overweight and obesity as a noncommunicable disease that represents the most serious public health challenges of the twenty-first century. Oxidative stress, defined as an imbalance between oxidants and antioxidants causing an impairment of the redox signals, is linked to the development of metabolic diseases. In addition, reactive oxygen species generated during metabolic disorder could increase inflammation, causing the development of insulin resistance, diabetes, and cardiovascular disease. We analyze serum levels of cysteine (Cys), cysteinyl-glycine (Cys-Gly), homocysteine (Hcy), and glutathione (GSH), and other markers of oxidative stress, such as thiobarbituric acid reactive substances (T-BARS), 8-isoprostane, and protein carbonyl in our children with obesity. Total antioxidant status was also determined. We found lower GSH and Cys-Gly levels, and higher Hcy and oxidative stress markers levels. We also found a positive correlation between Body Mass Index (BMI), Cys, GSH, and Hcy levels, between insulin and Cys levels, and between BMI and the homeostasis model assessment-estimated insulin resistance (HOMA-IR) with 8-isoprostane levels. Finally, we found a correlation between age and GSH and Cys levels. The deficiency of GSH could be restored by dietary supplementation with GSH precursors, supplying an inexpensive approach to oppose oxidative stress, thus avoiding obesity complications.     

高脂饮食诱导肥胖与肥胖抵抗动物模型建立

目的建立高脂饮食诱导肥胖易感（OP）大鼠和肥胖抵抗（OR）大鼠动物模型。方法高脂饲料喂饲健康雄性SD大鼠8周后,筛选出OP大鼠和OR大鼠。实验结束后,处死动物,测量体脂肪含量,并收集血清,以检测血糖与血脂水平。结果OP大鼠肾周脂肪、睾周脂肪、网膜脂肪、体脂肪含量均显著高于OR大鼠,OP大鼠血糖、甘油三酯水平显著高于OR大鼠,而高密度脂蛋白水平显著低于OR大鼠。结论使用高脂饲料建立饮食诱导肥胖与肥胖抵抗动物模型,方法可靠,模型成功。