有氧运动对C57BL/6小鼠骨骼肌PPARα及CPT-1的影响

Effects of Aerobic Exercise on PPARα and Its Related Factors in Skeletal Muscle of C57BL/6 Mice

目的:研究8周有氧运动对高脂饮食小鼠血脂及骨骼肌中脂质代谢相关因子的影响,探讨过氧化物酶体增殖物激活受体α(PPARα)与运动改善脂质代谢的关系。方法:雄性C57BL/6小鼠60只,随机分为正常饮食安静(NC)及运动组(NE)、高脂饮食安静(HC)及运动组(HE)。其中,HC与HE组均喂以高脂饲料;NE和HE组进行为期8周的无负重游泳训练。实验结束后,采用酶法和比色法分别检测血脂和游离脂肪酸(FFA)水平,并采用NorthernBlot、WesternBlot检测各组小鼠骨骼肌中PPARα、肉毒碱棕榈酰转移酶1(CPT-1)基因及蛋白表达。结果:高脂饮食条件下,运动组血清TG、TC、LDL及FFA比安静组显著降低,HDL显著升高;并且运动组骨骼肌PPARα及CPT-1的mRNA和蛋白表达均较安静组有所提高,尤其HE组表达量较HC组显著提高。结论:运动可有效促进脂肪酸的利用而改善血清脂质水平,并且可使骨骼肌PPARα、CPT-1表达量在转录和翻译水平上均有所提高,提示PPARα作为一个重要的脂质调节因子,在运动改善血脂中发挥着积极的作用。

Objective To study the changes in plasma lipid profile and lipid metabolic related genes in muscle after 8-week swimming, in order to understand the relation of peroxisome proliferator-aetivated receptors （PPARα） to the lipid metabolism. Methods Sixty 6 weeks old male C57BL/6 mice were randomly divided into normal diet control group （NC）, normal diet exercise group （NE）, high fat diet control group （HC）, and high fat diet exercise group （HE）. The HE and HC mice were fed with high fat diet, the NE and HE mice were forced to swim for 8 weeks. The plasma lipid and FFA in mice were detected by enzymic method and colorimetry. Detection of the expression of PPARα and CPT-1 mRNA and protein in mice muscle were detected by Northern blot and Western blot, respectively. Results Serum TG, TC, LDL-c and FFA levels significantly decreased, and HDL level significantly increased in HE group, as compared with that in HC group. The expression of PPARα mRNA and protein in muscle of both exercise groups, especially in HE group are significantly increased, as compared with that in both control groups. The expression of PPARα mRNA and protein in muscle of exercise groups are significantly increased as compared to its control group, especially in high fat diet exercise group. Conclusion Exercise could promote the utilization of FFA and improve the plasma lipid profile, while the expression of the PPARα and CPT-1 in muscle increased at the transcription and translation level, indicating that the PPARα played an important role as a lipid regulatory factor in improving dyslipidemia through exercise.