EFFECTS OF AEROBIC EXERCISE TRAINING ON OXIDATIVE STRESS IN THE SKELETAL MUSCLES OF OBESE RATS

ABSTRACT Introduction Obesity is a complex and multifactorial metabolic disorder characterized by the accumulation of body fat; physical exercise increases energy expenditure and promotes a reparative effect through modulation of endogenous antioxidant defenses. Objective To evaluate the effects of the high-fat diet (HFD) on oxidative stress parameters in skeletal muscles of rats using aerobic exercise training protocols (AETP), moderate-intensity continuous training (MICT) and high-intensity interval training (HIIT). Methods The study was quantitative and experimental. Animals received 8 weeks of HFD or normal diet (ND), followed by 9 weeks of HFD or ND and the two AETPs. Results HFD did not alter the formation of thiobarbituric acid reactive substances (TBA-RS), total sulfhydryl and protein carbonyl content in the soleus and plantaris muscles; in contrast, the protocols caused a decrease in TBA-RS levels in the plantaris muscle and increased the sulfhydryl content in the soleus muscle, while MICT increased the sulfhydryl content in the plantaris muscle and reduced protein carbonyl content in both muscles. HFD reduced SOD activity in the plantaris muscle while the MICT protocol enhanced SOD in the soleus muscle and both protocols reversed the decrease in SOD in the plantaris muscle. HFD increased CAT activity in the soleus muscle, the HIIT protocol prevented this alteration and both protocols increased CAT in the plantaris muscle. HFD reduced GSH-Px activity in both muscles, and the MICT protocol prevented this reduction in the soleus muscle, while the HIIT protocol partially prevented this decrease. The MICT protocol did not prevent the reduction of GSH-Px and the HIIT protocol partially prevented this decrease in the plantaris muscle. Conclusions HFD elicited oxidative stress in the skeletal muscle of rats, and both protocols were able to prevent most of the alterations in oxidative stress parameters caused by the HFD. Level of evidence IV; Investigation of treatment outcomes.

摘要 引言 肥胖是一种复杂的多因素代谢紊乱性疾病，以体内脂肪堆积为核心特征；体育运动可提升能量消耗，并通过调控内源性抗氧化防御系统发挥修复作用。研究目的 本研究旨在探讨高脂饮食（high-fat diet, HFD）结合两类有氧运动训练方案（aerobic exercise training protocols, AETP）——中等强度持续训练（moderate-intensity continuous training, MICT）与高强度间歇训练（high-intensity interval training, HIIT）——对大鼠骨骼肌氧化应激相关参数的影响。研究方法 本研究为定量实验性研究。实验动物先接受8周高脂饮食或正常饮食（normal diet, ND），随后再进行9周高脂饮食或正常饮食干预，并辅以两种有氧运动训练方案。研究结果 高脂饮食未改变比目鱼肌与跖肌中硫代巴比妥酸反应物质（thiobarbituric acid reactive substances, TBA-RS）、总巯基及蛋白质羰基的含量；与之相对，两种训练方案均可降低跖肌的TBA-RS水平，并提升比目鱼肌的巯基含量；其中中等强度持续训练（MICT）可升高跖肌的巯基含量，同时降低两种骨骼肌的蛋白质羰基水平。高脂饮食会降低跖肌中超氧化物歧化酶（superoxide dismutase, SOD）活性，而中等强度持续训练（MICT）可提升比目鱼肌的SOD活性，且两类训练方案均能逆转高脂饮食诱导的跖肌SOD活性下降。高脂饮食可升高比目鱼肌内过氧化氢酶（catalase, CAT）活性，高强度间歇训练（HIIT）可阻断这一变化，且两种训练方案均能提升跖肌的CAT活性。高脂饮食会降低两种骨骼肌的谷胱甘肽过氧化物酶（glutathione peroxidase, GSH-Px）活性：中等强度持续训练（MICT）可阻止比目鱼肌中该酶活性的下降，而高强度间歇训练（HIIT）可部分逆转该降低；对于跖肌，中等强度持续训练（MICT）未能阻断GSH-Px活性的下降，高强度间歇训练（HIIT）则可部分抑制该指标的降低。研究结论 高脂饮食可诱导大鼠骨骼肌产生氧化应激，两类有氧运动训练方案均能改善高脂饮食引发的多数氧化应激相关参数异常。证据等级为IV级；属于治疗结局探究类研究。