抗性淀粉对饮食诱导肥胖大鼠减肥效果及其机制的研究

发布时间：2019-05-24 15:21

【摘要】：目的探讨抗性淀粉(Resistant starch,RS)控制体重的分子机制、相关路径及其作用的靶位点,为开发RS相关保健食品提供科学依据。方法选择SD大鼠70只,体重(100±10)g,每组10只,雌雄各半,随机分为7组。1组用普通饲料喂养,作为正常对照组,其余6组用高脂饲料喂养7周,体重增加且大于等于正常组体重均值加1.4倍标准差者为饮食诱导肥胖(Diet-induced obesity,DIO)大鼠,体重小于等于正常组体重均值加l倍标准差、总能量摄入大于正常组总能量摄入均值者为饮食诱导肥胖抵抗(Diet-induced obesity resistance,DIO-R)大鼠。将DIO大鼠分为5组,1组为高脂对照组,用高脂饲料继续喂养,其余各组分别用含5%、10%、15%RS及10%RS+丁酸抑制剂组的高脂饲料喂养5周后,检测各组实验动物血液中短链脂肪酸(乙酸、丙酸、丁酸)的产生情况及肠道面积和PH值的变化,用聚合酶链反应法(Polymerase Chain Reaction, PCA)测定抗性淀粉对解偶联蛋白2(uncoupling protein2,UCP2)表达的影响。结果 1.建立动物模型：初始体重无差异的大鼠,用高脂饲料喂养7周后,45只大鼠体重大于正常对照组体重均值的1.4倍标准差,为DIO大鼠。7只体重小于等于正常对照组体重均值加1倍标准差,与正常对照组比较差异均有统计学意义(P0.01) 2.RS对实验动物体重的影响：用含5%、10%、15%RS的饲料分别喂养DIO大鼠5周后,实验动物体重呈现下降趋势,和高脂对照组比较,有统计学意义(P0.05),且RS添加量与实验组大鼠体重呈负相关(r=-0.862),其中以15%RS组效果最明显。而丁酸抑制剂组虽然体重有下降,但与高脂对照组及5%RS组体重变化无统计学差异。 3.RS干预组大鼠的肾脏、心脏、肝脏、胸腺、脾脏等脏器系数均无明显影响,与高脂对照组及DIO-R组无差异。(P0.05)。 4.大鼠肠道面积随RS剂量增多有增大趋势,5%、10%、15%RS组盲肠面积分别为18.735±2.884、18.901±3.380、22.605±6.258,其中15%RS组与高脂对照组有显著差异(P0.05)。 5.RS可降低大鼠盲肠内容物的pH值,5%、10%、15%RS组分别为6.808±0.124、6.782±0.101、6.764±0.105,差异有统计学意义(P0.05),降低效果随RS摄入量增加而增大。但添加了丁酸抑制剂后则稍有上升,为6.923±0.174,和高脂对照组无差异。 6.RS对血液短链脂肪酸的影响：随着饲料中RS添加量的增加,血液中乙酸、丙酸、丁酸含量均升高,与高脂对照组有显著性差异(P0.01)。 7.RS对UCP2基因的影响：随RS添加量的增加,5%、10%、15%组UCP2基因表达水平分别为1.065±0.046、1.088±0.041、1.094±0.114,其中10%、15%组与对照组相比,有统计学意义,表明随着RS添加量的增加UCP2的表达水平提高,且UCP2的表达水平与体重负相关(r=-0.514)。添加丁酸抑制后,UCP2表达和高脂对照组水平一致,未见差异。结论本研究结果显示,RS对肥胖大鼠有一定的减肥效果。其机制可能与RS可缩短食物在肠道的转运时间,减少食物及残渣在肠道中停留时间,在一定程度上减少了能量在肠道中的吸收,同时RS可增加血液中短链脂肪酸的含量,进而增强UCP2基因表达有关。 UCP2表达上调,使能量以热能的形式释放,从而减少了过多能量以脂肪形式储存而发生肥胖。其具体机制及达到最佳减肥效果的RS剂量还有待进一步的研究。
[Abstract]:Objective To study the molecular mechanism, related pathway and the target site of resistance starch (RS) to control body weight, and to provide scientific basis for developing RS-related health-care food. Methods 70 SD rats were randomly divided into 7 groups. week, weight gain and greater than or equal to the normal group body weight plus 1.4 times the standard deviation as the diet-induced obesity (DIO) rat with a body weight of less than or equal to the normal group body weight average plus l-fold standard The difference is that the total energy intake is greater than that of the normal group, and the average energy intake is greater than that of the diet-induced obesity resistance (DIO-R). Rats were divided into 5 groups, one group was a high-fat control group and fed with high-fat feed, and the other groups were fed with high-fat feed containing 5%,10%,15% RS and 10% RS + butyric acid inhibitor group for 5 weeks, and the short-chain fatty acid (acetic acid, propylene) in the blood of each group was detected. The effects of resistant starch on the expression of uncoupling protein 2 (UCP2) were determined by polymerase chain reaction (PCA) in the presence of acid and butyric acid and the changes of intestinal area and pH. In response. Results 1. Animal model: The rats with no difference in initial body weight were fed with high-fat diet for 7 weeks, and the body weight of 45 rats was higher than that of the normal control group. The 1-fold standard deviation, compared with the normal control group, was statistically significant ( (P0.01)2. The effect of RS on the body weight of the experimental animals: The body weight of the experimental animals decreased with 5%,10% and 15% RS, respectively. (P0.05), and the amount of RS was negatively correlated with the weight of the experimental group (r =-0.862), of which 15% R The effect of the S group was the most obvious. While the weight of the inhibitor group was decreased, the body weight of the group with high-fat control group and 5% RS group was changed. 3. There was no significant difference in the organ coefficients of the kidney, heart, liver, thymus, spleen and other organs in the RS intervention group, and it was compared with the high-fat control group and the control group. No difference in DIO-R group The intestinal tract area of rats increased with the increase of RS dose,5%,10% and 15% RS, and the area of cecum was 18.735, 2.884, 18.901, 3.380, 22.605 and 6.258, respectively. 5%,10% and 15% RS group were 6.808, 0.124, 6.782, 0.101, 6.764 and 0.105, respectively. The effect increased with the increase of RS intake. However, after the addition of the inhibitor of butyric acid, it was slightly raised to 6.923-0. The effect of RS on the short-chain fatty acid in blood: the content of acetic acid, propionic acid and butyric acid in the blood was increased with the increase of the amount of RS in the feed, and the content of acetic acid, propionic acid and butyric acid in the blood was increased with the increase of the amount of RS in the feed. The expression level of UCP2 gene was 1.065, 0.046, 1.088, 0.041, 1.094, 0.114,10% and 15%, respectively, which indicated that with RS, the expression of UCP2 gene was 1.065, 0.046, 1.088, 0.041, 1.094 and 0.114, respectively. The addition amount increases the expression level of the UCP2, and the expression water of the UCP2 negatively correlated with weight (r =-0.514). After inhibition of butyric acid, UCP2 The level of expression and high-fat control group was consistent and no difference was found. Conclusion This study The results show that the RS can reduce the transit time of the food in the intestinal tract, reduce the residence time of the food and the residue in the intestinal tract, and reduce the absorption of the energy in the intestinal tract to a certain extent, while the RS can increase the short-chain fat in the blood. The content of the acid, in turn, enhances the expression of the UCP2 gene. The UCP2 expression is up-regulated so that the energy is released in the form of thermal energy, has reduced excessive energy to store in the form of fat and obesity. Its specific mechanism and reach the most
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R151

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