有氧运动及膳食干预对肥胖大鼠减脂效果及Irisin调控的研究

Effects of Aerobic Exercise and Dietary Intervention on Fat Loss in Obese Rats and the Regulation of Irisin

目的:观察4周高脂膳食与普通膳食结合有氧运动对肥胖大鼠骨骼肌FNDC5蛋白和白色脂肪中棕色化相关蛋白的表达及减肥效果。方法:65只雄性SD大鼠通过高脂饲料喂养建立肥胖大鼠模型,造模成功后筛选40只大鼠随机分为高脂膳食对照组(H)、高脂膳食+运动组(HE)、普通膳食对照组(C)、普通膳食+运动组(E),每组10只。运动组大鼠进行4周的60%V O2max跑台运动。4周干预结束次日将大鼠麻醉后进行体脂检测,随后将动物处死取血样及分离双侧比目鱼肌及附睾处白色脂肪,免疫荧光法检测大鼠骨骼肌纤维横截面积,ELISA法检测各组大鼠血清Irisin的水平,Western blot法检测骨骼肌FNDC5、AMPK、PGC1-α及白色脂肪中p38MAPK、UCP1等相关蛋白的表达。结果:4周干预后,普通膳食+运动组大鼠体重及体脂含量显著低于高脂膳食对照组(P<0.01),比目鱼肌纤维横截面积低于高脂膳食对照组(P<0.01),但比目鱼肌湿重无明显差异(P>0.05),普通膳食+运动组大鼠血清中Irisin水平显著高于高脂膳食对照组(P<0.01),比目鱼肌中FNDC5、AMPK、PGC1-α均显著高于高脂膳食对照组(P<0.01),白色脂肪组织中p38 MAPK及UCP1表达水平均高于高脂膳食对照组,结果具有非常显著差异性(P<0.01)。结论:4周运动结合饮食调控可以明显降低体脂水平,具有控制体重的作用,可激活p38 MAPK-UCP1通路促进白色脂肪组织棕色化,增加机体能量消耗。

Objective:To observe the expression of FNDC5 protein in skeletal muscle and browning-related protein in white fat of obese rats and the effect of weight loss after 4-week high-fat diet and normal diet combined with aerobic exercise.Method:Sixty-five male Sprague-Dawley rats were fed on high-fat diet to establish an obese rat model.After successful modeling,40 rats were randomly divided into high-fat diet control group(H),high-fat diet exercise group(HE),and normal diet control Group(C),Exercise group(E),each of 10.The rats in the exercise group were given 4 weeks of treadmill exercise with 60%O2max max.The diets were fed with a high-fat meal and a normal meal according to the group.The body weight of both groups was recorded weekly.After 4 weeks of intervention,the rats were anesthetized and tested for body fat,and then the rats were then sacrificed for blood sampling,the bilateral soleus and epididymal white adipose tissue was separated to record the wet weight and measure the cross-sectional area of the soleus fibers by testing laminin with immunofluorescence confocal laser scanning microscope.Serum Irisin levels were detected by ELISA.The expression of FNDC5,AMPK,PGC1-αand p38 MAPK,UCP1 were measured using Western blotting.Result:After 4 weeks intervention,the weight and fat mass of C group were significantly lower than those of H group(P<0.01),the cross-sectional area of soleus of C group were significantly lower than those of H group(P<0.01),but there were no significant differences between them in wet weight of soleus(P>0.05).Compared with H group,the level of Irisin in serum of C group was increased significantly(P<0.01).FNDC5,AMPK and PGC1-αin soleus muscle were significantly higher than H group(P<0.01).Compared with H group,the expression of p38 MAPK and UCP1 in white adipose tissue was increased significantly.Conclusion:4 weeks of exercise combined with diet regulation can significantly reduce body fat levels and have a role in weight control,and it can activate the p38MAPK-UCP1 pathway to promote browning of white adipose tissue and increase body energy expenditure.