【作者】 罗雪婷；

【导师】 刘无逸；

【作者基本信息】 上海体育学院 ， 运动人体科学， 2010， 硕士

【摘要】 目的通过建立高脂饲料喂养的胰岛素抵抗大鼠模型,观察胰岛素抵抗大鼠经过有氧运动和/或恢复普通饲料干预后,骨骼肌肌内甘油三酯(IMTG)、骨骼肌脂蛋白酯酶(LPL)、超氧化物歧化酶(SOD)、丙二醛(MDA)及解偶联蛋白3(UCP3)蛋白表达水平的变化；探讨有氧运动和/或恢复普通饲料对胰岛素抵抗大鼠骨骼肌脂质代谢的影响及改善胰岛素敏感性的可能作用机制。方法7周龄雄性SD大鼠130只,普通饲料安静对照组10只,采用普通饲料喂养。高脂组大鼠采用高脂饲料喂养,共同喂养8周。选取高脂组体重上游的1/3大鼠40只,随机分为4组,即DIO高脂组、DIO运动干预组、DIO普通饲料组、DIO运动+普通饲料组,每组10只,检测大鼠空腹血糖(FBG)和血清胰岛素(FIN)浓度,行口服糖耐量试验(OGTT),计算胰岛素敏感指数(ISI),确定建模成功。普通饲料组采用基础饲料喂养,运动干预组进行中等强度的跑台有氧运动,共干预8周。最后一次运动结束后检测各组大鼠FBG、FIN浓度,行OGTT试验,试剂盒检测骨骼肌IMTG、MDA含量及LPL、SOD活性,应用Western blot检测骨骼肌UCP3蛋白表达的变化。结果1.8周高脂喂养后,高脂组大鼠体重明显高于对照组(P<0.01),ISI明显低于对照组(P<0.01)。2.继续8周高脂喂养后,高脂组大鼠体重、骨骼肌IMTG、MDA明显高于对照组(P<0.01),ISI、LPL、SOD和UCP3明显低于对照组(P<0.05或P<0.01)。3.运动或/和恢复普通饲料8周后,DIO普通饲料组、DIO运动+普通饲料组ISI与CON对照组相比差异无统计学意义(P>0.05)。DIO运动干预组、DIO普通饲料组、DIO运动+普通饲料组各组空腹血糖、空腹胰岛素与CON对照组差异无统计学意义(P>0.05)。4.单纯有氧运动干预8周后,DIO大鼠IMTG、MDA明显低于DIO高脂组(P<0.01),SOD、UCP3明显高于DIO高脂组(P<0.05或P<0.01),LPL与DIO高脂组相比,差异无统计学意义(P>0.05)。与CON对照组相比,MDA、SOD和UCP3差异无统计学意义(P>0.05)。5.单纯恢复普通饲料8周,DIO大鼠IMTG、MDA明显低于DIO高脂组(P<0.01),LPL和SOD活性、UCP。与DIO高脂组相比,差异无统计学意义(P>0.05)。与CON对照组相比,MDA、SOD、UCP3差异无统计学意义(P>0.05)。6.有氧运动+恢复普通饲料8周,DIO大鼠IMTG、MDA明显低于DIO高脂组(P<0.01),LPL、SOD和UCP3明显高于DIO高脂组(P<0.01)。与CON对照组相比,IMTG和LPL、MDA和SOD、UCP3差异均无统计学意义(P>0.05)。结论1.高脂饲料喂养8周可诱导大鼠IR的形成。继续高脂饲料喂养8周,大鼠骨骼肌脂质沉积、脂质过氧化及IR加重。2.有氧运动和/或恢复普通饲料均可改善IR及骨骼肌脂质代谢紊乱,大鼠骨骼肌脂质沉积减少、脂质氧化能力增强可能是运动和/或饮食改善IR状态的机制之一更多还原

【Abstract】 Obejective To observe the effect of aerobic exercise and/or standard diet on the expression level of intramyocellular triglyceride (IMTG) and lipoprotein lipase (LPL)、uncoupling protein 3 (UCP3)、superoxide dismutase (SOD) and Malondialdehyde (MDA) in keletal muscle of insulin resistant (IR) rats fed with high fat. And to discuss the effects of aerobic exercise and/or standard diet on skeletal muscle lipid metabolism and the development of insulin resistant of rats and its possible mechanism.Methods 40 male SD rats were modeled into IR rats by high fat diet for 8 weeks, while the 10 rats of control group were fed with standard diet. Then the 40 IR rats were randomly divided into 4 groups:DIO Group were given high fat diet for 8weeks; DIO-exercise Group and DIO-standard diet Group were respectively treated by aerobic exercise and standard diet; DIO-exercise&standard diet Group were treated by both aerobic exercise and standard diet.The groups were recorded at the beginning and the end of the treatment, including Fasting blood glucose (FBG)、Fasting insulin (FIN) and OGTT; and insulin sensitivity index(ISI) was calculated. Put rats to death after the completion of the 8-week training,and then detect the level of IMTG、LPL、SOD and MDA of skeletal muscles; Western blot was used to determine the expressions of UCP3.Results 1. The body weight was obviously higher (P<0.01) and ISI was obviously lower (P<0.01) in the DIO Group than the control group after feeding high fat diet for 8 weeks.2. The body weight, IMTG and MDA was obviously higher (P<0.01) and ISI, LPL, SOD and UCP3 was obviously lower (P<0.05 or P<0.01) in the DIO Group than the control group after feeding high fat diet for another 8 weeks.3. After aerobic exercise and/or standard diet treatment for 8 weeks, the difference of ISI was not statistically significant between DIO-standard diet Group, DIO-exercise&standard diet Group and control group (P>0.05). The difference of FBG、FIN was not statistically significant between DIO-exercise Group, DIO-standard diet Group, DIO-exercise & standard diet Group and control group (P>0.05).4. The IMTG, MDA was obviously lower (P<0.01) and SOD, UCP3 was obviously higher (P<0.01 or P<0.05) in the DIO-exercise Group than the DIO Group, but there is no significant difference between DIO-exercise and DIO Group (P>0.05). And there is no significant difference in the MDA, SOD and UCP3 contents between the DIO-exercise and the control group (P>0.05).5. The IMTG, MDA was obviously lower (P<0.01) in the DIO-standard diet Group than the DIO Group, but there is no significant difference in the LPL, SOD and UCP3 between DIO-standard diet Group and DIO Group (P>0.05). And there is no significant difference in the MDA, SOD and UCP3 content between the DIO-exercise and the control group (P>0.05).6. The IMTG, MDA was obviously lower (P<0.01) and LPL, SOD, UCP3 was obviously higher (P<0.01) in the DIO-exercise&standard diet Group than the DIO Group, but there is no significant difference between DIO-exercise&standard diet Group and DIO Group (P>0.05). And there is no significant difference in these indexes between the DIO-exercise&standard diet and the control group (P>0.05).Conclusions 1. The rat model of IR was successfully established by feeding the SD rats 8 weeks with high fat diet. After feeding high fat diet for another 8 weeks, the lipid deposition, lipid peroxidation in skeletal muscle and IR were even more serious.2. The aerobic exercise and/or standard diet treament can improve IR and the abnormal lipid metabolism of skeletal muscle. The reduction of lipid deposition and enhancement of capacity of lipid oxidation in Skeletal muscle may be one of mechanisms on aerobic exercise improving insulin resistance.更多还原