Physical exercise improves body weight gain and liver function in malnourished rats without disturbing the redox balance

ABSTRACT Objective To study the relationship between exercise and malnourishment because recent evidence suggests that exercise can cause the beneficial adaptation of antioxidant systems, whereas malnourishment can cause harmful adaptation of these systems. Methods Thirty-two female Fischer rats were equally divided into Sedentary Control, Trained Control, Sedentary Malnourished and Trained Malnourished groups. The training protocol consisted of swimming for 30 minutes continuously for 5 days/week for 8 weeks. Results It was demonstrated that aspartate aminotransferase and alanine aminotransferase activities increased in malnourished rats, but physical training reversed these effects by lowering the raised levels. The glutathione level was diminished by malnourishment whereas physical training increased the levels of liver carbonyl protein and increased the levels of thiobarbituric acid reactive substances that were diminished by malnourishment. In addition, Trained Malnourished rats had a higher average body weight than Sedentary Malnourished ones (62.77g vs. 55.08g, respectively). Conclusion The data show that exercise was able to reverse or reduce damage caused by malnourishment, such as weight loss and liver dysfunction by a pathway independent of the participation of enzymes involved in antioxidant defense and that there is no interaction between exercise and malnutrition.

摘要
研究目的：旨在探究运动与营养不良的关联——现有研究证据表明，运动可促使抗氧化系统产生有益适应性改变，而营养不良则会引发该系统的有害适应性变化。
方法：将32只雌性费舍尔（Fischer）大鼠平均分为久坐对照组、运动对照组、久坐营养不良组及运动营养不良组4组。本研究的运动方案为每周5天、每日连续游泳30分钟，持续8周。
结果：研究显示，营养不良大鼠的天冬氨酸氨基转移酶（aspartate aminotransferase, AST）与丙氨酸氨基转移酶（alanine aminotransferase, ALT）活性均升高，而运动训练可通过降低上述升高的酶活性逆转该变化。营养不良会降低谷胱甘肽水平；运动训练则可升高肝脏羰基蛋白水平，并提升此前因营养不良而降低的硫代巴比妥酸反应物质（thiobarbituric acid reactive substances, TBARS）水平。此外，运动营养不良组大鼠的平均体重大于久坐营养不良组大鼠（分别为62.77g与55.08g）。
结论：本研究数据表明，运动可通过不依赖抗氧化防御相关酶参与的通路，逆转或减轻营养不良所致的体重下降、肝功能损伤等损害；且运动与营养不良之间不存在交互作用。