运动预处理部分抵抗小鼠长期高脂饮食喂养引起的脂代谢紊乱

Exercise preconditioning attenuates the lipid metabolic disorder induced by chronic high fat diet feeding in mice

已有研究表明运动具有广泛的健康效应,其能够通过改善机体代谢等机制防治慢性疾病。新近研究表明运动预处理(即在疾病发生、发展之前给予运动干预)具有一定的心脏保护效应,但其能否抵抗高脂饮食诱导的肥胖和代谢紊乱尚不清楚。本研究旨在明确运动预处理对长期高脂饮食喂养小鼠的体重和代谢的影响,并探讨其可能机制。C57BL/6小鼠(4周龄)在经过3个月的游泳训练或安静对照后,给予正常饮食(normal diet, ND)或高脂饮食(high fat diet, HFD)喂养4个月。结果显示:3个月的游泳训练能够显著降低小鼠血糖、提高葡萄糖耐量和增加抓力。运动预处理不能改善由于HFD喂养引起的体重增加,但能够改善由于HFD喂养引起的糖耐量异常。运动预处理对ND和HFD喂养小鼠的运动能力和运动节律均无明显影响。HFD喂养后小鼠血清总胆固醇、低密度脂蛋白水平增加,皮下脂肪和附睾脂肪含量增加。运动预处理能够显著降低ND喂养小鼠循环游离脂肪酸和低密度脂蛋白水平。运动预处理能够增加HFD喂养小鼠的循环高密度脂蛋白水平,降低循环低密度脂蛋白水平,但不影响皮下脂肪和附睾脂肪的重量。HFD喂养增加肝脏重量,提高肝脏总胆固醇水平,引起小鼠肝脏线粒体功能相关分子表达异常,而运动预处理能够部分逆转由于HFD喂养引起的肝脏线粒体功能相关分子表达异常。以上结果提示,运动预处理能够部分逆转由于HFD喂养引起的脂代谢紊乱,且运动对机体脂代谢的改善作用能够在运动停止后持续一段时间。

Mounting evidence has shown that exercise exerts extensive beneficial effects, including preventing and protecting against chronic diseases, through improving metabolism and other mechanisms. Recent studies have shown that exercise preconditioning affords significant cardioprotective effects. However, whether exercise preconditioning improves high fat diet(HFD)-induced obesity and lipid metabolic disorder remains unknown. The study was aimed to explore the effects of exercise preconditioning on HFDinduced obesity and lipid metabolic disorder in mice. 4-week-old C57BL/6 mice were subjected to swimming or sedentary control for 3 months, and then were fed with normal diet(ND) or HFD for 4 more months. The results showed that the blood glucose was decreased, and the glucose tolerance and grip strength were increased in exercised mice after training. Exercise preconditioning failed to improve HFD-induced body weight gain, but improved HFD-induced glucose intolerance. Exercise preconditioning showed no significant effects on both exercise capacity and physical activity in ND-and HFD-fed mice. HFD feeding increased total cholesterol and low density lipoprotein(LDL) levels in circulation, promoted subcutaneous fat and epididymal fat accumulation in mice. Exercise preconditioning increased circulating high density lipoprotein(HDL) and decreased circulating LDL, without affecting the subcutaneous fat and epididymal fat in HFD-fed mice. HFD feeding increased liver weight and hepatic total cholesterol contents, and dysregulated the expressions of several mitochondria function-related proteins in mice. These abnormalities were partially reversed by exercise preconditioning. Together, these results suggest that exercise preconditioning can partially reverse the HFD-induced lipid metabolic disorder and hepatic dysfunction, and these beneficial effects of exercise sustain for a period of time, even after exercise is discontinued.