大强度间歇运动对高脂喂养大鼠代谢表征和骨骼肌脂代谢基因表达的影响

The Effects of High-intensity Interval Training on Metabolic Profiles and Gene Expression of Muscle Lipid Metabolism in High-fat Diet Rat

研究目的:探讨大强度间歇运动对高脂诱导大鼠肥胖症的预防作用及骨骼肌脂代谢调控机制,为肥胖症的预防提供理论和实践依据。研究方法:37只雄性SD大鼠分为对照安静组(CS组)、高脂安静组(HS组)、高脂持续运动组(HE组)和高脂间歇运动组(HI组)。HE组和HI组分别进行低强度持续运动和大强度间歇运动训练,每周5天,共10周。定期测量摄食量和体重,采用全自动生化分析技术检测血脂、血糖含量,Elisa试剂盒检测血清胰岛素含量,H&E染色法观察脂肪细胞大小,Real-time PCR技术检测骨骼肌脂代谢调控基因Rev-erbα、SCD1、CPT1和FAT/CD36mRNA相对表达量,Western blot技术检测各调控基因的蛋白表达量。结果:HS组体重、血脂和血糖、脂肪细胞大小显著增加,QUICKI指数下降。HI组体重、血脂、血糖和脂肪细胞大小明显降低,QUICKI指数升高;且效果明显优于低强度持续运动方式。HS组FAT/CD36和SCD1mRNA与蛋白表达量明显高于CS组;HI组Reverbα、FAT/CD36和CPT1mRNA表达量显著高于HS组;HE组与HS组无统计学差异。结论:高脂饮食诱导大鼠代谢表征和骨骼肌脂代谢异常。分子生物学机制分析表明,大强度间歇运动促进脂肪酸跨膜转运、胞内合成和参与β氧化,有效预防高脂饮食诱导的代谢表征异常和骨骼肌脂质代谢紊乱,其效果明显优于低强度持续运动方式。大强度间歇运动刺激Rev-erbα表达上调,增加对脂代谢调节因子的调控,可能是维持骨骼肌脂质稳态适应的新机制。

Objective：To explore the efficacy of high-intensity interval training on preventing high-fat diet-induced obesity,and the molecular mechanism of regulating lipid metabolism in skeletal muscle.Methods：Thirty-seven Sprague-Dawley male rats were divided into four groups,control diet/sedentary group（CS）,high-fat diet/sedentary（HS）,high-fat diet/mildintensity endurance exercise（HE）,and high-fat diet/high-intensity interval exercise（HI）.After acclimation,all exercise groups were made to exercise for 10 weeks on a motor-driven rodent treadmill according to exercise protocols,with matched running distances.Body weight,fat content,blood metabolites,quantitative insulin sensitivity check index（QUICKI）,and adipocyte size were assessed using measurement,automatic biochemical analyzer,and histochemical method,respectively.The expressions of gene and protein regulating fatty acid metabolism were quantified by real-time PCR and western blotting,including nuclear receptor subfamily 1,group D,member 1（Rev-erbα）,stearoyl-CoA desaturase-1（SCD1）,carnitine palmitoyltransferase 1（CPT1）,and fatty acid translocase（FAT/CD36）.Results：Body weight,TG,TC,LDL-C,and GLU in HS group was increased,while QUICKI was reduced.The size of adiposity cell in HS group was expanded.Body weight,serum lipid and GLU in HI group were lower than those in HS group,while insulin sensitivity was significantly improved in HI group.Adipocyte size in HI group was less than that in HS and HE group.The difference between HE group and HS group was not significant.The expression of FAT/CD36,and CPT1 was elevated in the HI group,which also had the highest level of Rev-erbαexpression.The expression of FAT/CD36,and SCD1 was up-regulated in HS,with no statistic change in Rev-erbαexpression.Conclusions：High-fat diet led to disorder of metabolic characterization and lipid metabolism in rat skeletal muscle.The HI-induced increase in fatty acid transport across the cell membrane,intracellular synthesis and ？-oxidation,which could effectively prevent the disorder of metabolic profiles and lipid imbalance.The effect of high-intensity interval training was more time-effective than that of mild-intensity durance training.The HI-induced up-regulation of Rev-erbαmight be newly developed mechanism in interaction with regulatory of lipid metabolism,and further to maintain lipid homeostasis in skeletal muscle.