The Effects of Moderate-Intensity Aerobic Exercise on Lipid Metabolism, Inflammatory Responses, and Muscle Metabolism in an Obesity-Induced Rat Model

다국어 초록 (Multilingual Abstract)

Purpose : Previous studies have reported the beneficial effects of aerobic exercise on obesity-related metabolic dysfunction. However, limited studies have comprehensively investigated the effects of moderate-intensity aerobic exercise on both blood metabolic characteristics and muscle metabolism in obesity-induced rat models. This study aimed to investigate the effects of moderate-intensity aerobic exercise on blood metabolic characteristics and muscle metabolism in a rat model of obesity.
Methods : Twenty-four male Sprague-Dawley rats (4 weeks old) were randomly assigned to normal, obese, and obese-exercise groups. Obesity was induced by feeding a 60 % high-fat diet for four weeks. The obese-exercise group performed moderate-intensity treadmill exercise (5 ° incline, 18 m/min) for 20~30 minutes per day, five days per week, for four weeks. After the intervention, body weight, blood biochemical parameters, histological changes, and protein expression in the liver and soleus muscle were analyzed. One-way analysis of variance (ANOVA) was used to identify significant differences among groups, followed by the least significant difference (LSD) post hoc test.
Results : The obese-exercise group showed significantly lower body weight and adipocyte size compared with the obese group (p<.05). Serum triglyceride (TG), total cholesterol (TC), leptin, inflammatory cytokines (TNF-α, IL-1β), and reactive oxygen species (ROS) levels were significantly reduced (p<.05). Conversely, adiponectin and muscle synthesis-related proteins (PGC-1α, IGF-1, p-PI3K, p-mTOR) were significantly increased (p<.05). In the liver, the expression of lipid synthesis-related proteins (SREBP-1, SREBP-2, ACC, HMGCR) was decreased (p<.05), while muscle degradation-related proteins (Atrogin-1, MuRF-1) were downregulated in the soleus muscle (p<.05).
Conclusion : These findings suggest that moderate-intensity aerobic exercise improves lipid metabolism, regulates muscle protein balance, and alleviates metabolic dysfunction associated with obesity. Therefore, these findings suggest that moderate-intensity aerobic exercise may contribute to the improvement of obesity-related metabolic dysfunction. However, caution is needed when extrapolating these findings to humans, and further clinical studies are warranted.