基于PPAR-α/PGC-1α途径探讨低氧减重对肥胖大鼠能量代谢的影响

The Effect of Hypoxia Exercise on Energy Metabolism in Obese Rats Based on PPAR-α/PGC-1αPathway

目的:探讨低氧运动对肥胖大鼠能量代谢的影响及其作用机制。方法:80只雄性SD大鼠随机分为普通膳食对照组(10只)、高脂膳食模型组(70),模型组大鼠给予7周高脂膳食诱导,构建肥胖大鼠模型,取建模成功的肥胖大鼠60只,随机分为常氧安静组(A组)、常氧运动组(AE组)、16.3%低氧安静组(B组)、16.3%低氧运动组(BE组)、13.3%低氧安静组(C组)、13.3%低氧运动组(CE组),每组10只,继续进行高脂膳食饲养,运动组大鼠进行跑台耐力训练,测量大鼠体长、体重,计算Lee's指数;检测血糖(BG)和血脂四项(BG、TC、LDL-C、TG);采用大鼠代谢系统检测运动后耗氧量、能量消耗;检测骨骼肌组织中PPAR-α、PGC-1α蛋白表达。结果:7周高脂膳食饲养后,大鼠体重明显增加,且超过对照组大鼠体重的20%,血糖、TC、TG、LDL-C含量均明显增加(P<0.01,P<0.05),提示营养性肥胖大鼠模型建立成功。采用低氧、耐力运动干预后8周后,与A组比较,AE、BE、C、CE组大鼠的体重增长、TC、TG、LDL-C、血糖均明显下降(P<0.05,P<0.01),BE、CE组大鼠HDL-C明显升高(P<0.01);与AE组比较,BE、CE组大鼠体重增长、TC、TG、LDL-C、血糖明显降低(P<0.01),BE、CE组大鼠HDL-C明显升高(P<0.01);与A组相比,AE、B、BE、C、CE组大鼠运动即刻耗氧量、耗能量呈现增加趋势(P<0.01,P<0.05);与AE组相比,BE、CE组大鼠运动即刻耗氧量、耗能量呈现增加趋势(P<0.01或P<0.05);与A组相比,BE、C、CE组大鼠PPAR-α、PGC-1α蛋白表达明显升高(P<0.05,P<0.01);与AE组相比,BE、C、CE大鼠PPAR-α、PGC-1α蛋白表达明显增加(P<0.05,P<0.01)。结论:低氧运动可能增强骨骼肌PGC-1α、PPAR-α蛋白的表达,进而改善肥胖大鼠的能量代谢水平。

Objective:To study the mechanism of hypoxic exercise energy metabolism in obese rats.Methods:Eighty male SD rats were randomly divided into normal diet control group(10 rats)and high-fat diet model group(70 rats),and the model group rats were induced with high-fat diet for 7 weeks to construct an obese rat model.60 obese rats with successful modeling were randomly divided into normoxic quiet group(group A),normoxic exercise group(group AE),16.3%hypoxic quiet group(group B),16.3%hypoxic exercise group(group BE),13.3%hypoxic quiet group(group C),and 13.3%hypoxic exercise group(group CE).group,13.3%hypoxic quiet group(group C),13.3%hypoxic exercise group(group CE),10 rats in each group,continued to be fed with high-fat diet,and the rats in the exercise group were trained with running platform endurance,and body length and body weight were measured,and Lee's index was calculated.Blood glucose(BG)and lipid quadruple(BG,TC,LDL-C,TG)were detected;oxygen consumption and energy expenditure after exercise were detected using rat metabolic system;PPAR-αand PGC-1αprotein expression in skeletal muscle tissue were detected.Results:After 7 weeks of high-fat dietary feeding,the rats'body weight increased significantly and exceeded 20%of the body weight of the control rats,and blood glucose,TC,TG,and LDL-C contents increased significantly(P<0.01,P<0.05),suggesting that the nutritional obesity rat model was successfully established.After 8 weeks of intervention with hypoxia and endurance exercise,the body weight gain,TC,TG,LDL-C,and blood glucose of rats in AE,BE,C,and CE groups were significantly decreased(P<0.05,P<0.01),and HDL-C of rats in BE and CE groups were significantly increased(P<0.01)compared with group A.Compared with group AE,the body weight gain,TC,TG,LDL-C and blood glucose of rats in groups BE and CE were significantly lower(P<0.01),and the HDL-C of rats in groups BE and CE was significantly higher(P<0.01);compared with group A,the immediate oxygen consumption and energy consumption of rats in the AE,B,BE,C and CE groups showed an increasing trend(P<0.01,P<0.05);compared with group AE,groups BE and CE showed an increase in oxygen consumption and energy consumption immediately after exercise(P<0.05);compared with group A,the expression of PPAR-αand PGC-1αprotein in groups BE,C and CE was significantly increased(P<0.05,P<0.01);compared with group AE,the expression of PPAR-αand PGC-1αprotein in the BE,C and CE rats was significantly increased(P<0.05,P<0.01).Protein expression was significantly increased in BE,C and CE rats compared with group AE(P<0.05,P<0.01).Conclusion:Hypoxic exercise may enhance the expression of PGC-1αand PPAR-αproteins in skeletal muscle and thus improve the energy metabolism level in obese rats.