【作者】 汪军；

【导师】 王瑞元；

【作者基本信息】 北京体育大学 ， 运动人体科学， 2007， 博士

【摘要】 研究目的:一次性运动和长期运动对肥胖大鼠摄食以及血浆和下丘脑相关摄食内分泌指标的影响,初步探讨运动减肥的神经内分泌机制。研究方法:实验动物与分组:10周营养性肥胖建模成功SD大鼠。一次性运动实验分为即刻、1h、3h、12h、24h和对照组,长期运动实验分为长期运动组和长期对照组。实验动物运动方式:大鼠专用电动跑台,坡度5%,速度20m/min,运动时间40分钟。一次性运动实验在肥胖大鼠运动后不同时间段取材,长期运动实验肥胖大鼠运动8周,每周5次,在最后一次运动结束后24小时取材。样本测试:全自动生化分析仪测试肥胖大鼠血糖、甘油三酯、胆固醇、HDL、LDL;RIA方法测试血浆和下丘脑ghrelin、obestatin、NPY蛋白表达;RT-PCR方法测试下丘脑ghrelin受体GHSR-1a、obestatin受体GPR-39和NPY基因表达。研究结果:1、肥胖大鼠血浆ghrelin和Ghrelin/Obestatin比值有下降趋势,NPY显著升高;下丘脑ghrelin和obestatin显著下降,Ghrelin/Obestatin比值显著上升,而NPY有下降趋势。GHSR-1a基因表达显著下降,而NPY基因表达没有明显变化,GPR-39 mRNA在下丘脑没有表达;2、一次性运动后,肥胖大鼠摄食量显著下降,12h开始恢复;血糖等基础指标下降,在3h开始恢复;运动后不同时间段血浆ghrelin和obestatin没有变化,但可以降低NPY浓度;3、一次性运动后,肥胖大鼠下丘脑ghrelin和obestatin在12h之前降低,然后急剧升高,在24h恢复;NPY在运动后开始升高,在24h恢复;GHSR-1a和NPY基因表达没有影响,GPR-39基因没有表达;4、8周跑台运动后,肥胖大鼠血浆ghrelin和obestatin没有影响;下丘脑ghrelin和obestatin显著下降,NPY显著升高;GHSR-1a基因表达没有影响,NPY基因表达显著增加。结论:1、Ghrelin可能通过中枢机制影响摄食和能量代谢调节;2、Obestatin-GPR39通路在能量代谢调节中可能不起作用;3、下丘脑Ghrelin/Obestatin比值在大鼠肥胖发生中可能有一定的作用。更多还原

【Abstract】 Aims:Research the effects of food intake related endocrinological hormones on serum and hypothalamic of obese rats by acute and long time of exercise and discuss the neuroendocrinology mechanisms of weight loss by exercise.Methods:Diet induced obese rats go throuth two experimental models: acute exercise experiment and 8 weeks exercise experiment.The rats run at a speed of 20 m min-1,50 slope on the treadmeal for 40 min one times on the acute experimental model and every five days for 8 weeks on the chronic experimental model.On the day they were sacrificed,rats from the acute experimental exercise group were randomly divided into six subgroups,namely C,EO,E1,E3,E12 and E24,which respectively were named as the preexercise control group,0 min postexercise group,one hour postexercise group,three hour postexercise group,twele hour postexercise group and twenty hour postexercisegroup.On the chronic exercise experiment model,the rats are divided long exercise group and long control group and the rats had rest for 24 hours before they are sacrificed after the last day.We determined the concentrations of ghrelin,obestatin and NPY on serum and hypothalamic of obese rats at once,one hour,three hour,12 hour and 24 hour after acute exercise and the concentrations after eight weeks’ exercise by using RIA;we also determined the receptor GHSR-1a mRNA of ghrelin,GPR-39 mRNA of obestatin and NPY mRNA on the hypothalamic tissues by RT-PCR.Results:1) Compared with normal weight rats,the obese rats had distinct differences on body weight,BMI and serum preferences.The concentration of ghrelin and the ratio of Ghrelin/Obestatin had a decline tendency on serum,obestatin had an up tendency and NPY was higher than the normal weight rats distinctly.But on the hypothalamic tissues,the concentrations of ghrelin and obestatin decreased greatly,the ratio of Ghrelin/Obestatin increased,NPY had a decline tendency lightly.The ghrelin receptor GHSR-1a mRNA decreased distinctly,NPY mRNA had no change and we couldn’t find GPR-39 mRNA on hypothalamic.2) After acute exercise,appetite and food size decreased greatly on obese rats and recovered at the point of 12 hours;Glu and other preferences on plasma decreased and recovered at the point of 3 hours;on every time points,the serum concentrations of ghrelin and obestatin had no changes, but NPY decreased distinctly.3) After acute exercise,the concentrations of ghrelin and obestatin on hypothalamic decreased before the point of 12 hours,then they increased greatly and recovered to preexercise after 24 hours;NPY increased at once after exercise and recovered after 24 hours;The receptor GHSR-1a mRNA of ghrelin and NPY mRNA had no changes after exercise and we couldn’t find GPR-39 mRNA on hypothalamic too.4) After 8 weeks oxygen exercise,the obese rats expended a great deal energy with no food intake increased,on the contrast,their food size decreased greatly;Exercise alone had no effects on serum ghrelin and obestatin,but on hypothalamic,ghrelin and obestatin decreased distinctly,NPY increased greatly;The receptor GHSR-1a mRNA of ghrelin had no change,but NPY mRNA increased distinctly after exercise.Conclusions:1) Ghrelin mediated food intake and energy metabolism post exercise through hypothalamic centers.2) Obestatin- GPR-39 may be had no use on energy homeostasis.3) The ratio of Ghrelin/Obestatin must be very important on the etiology of obese rats.更多还原