Kim Jisu, Lim Kiwon
Department of health and exercise science, Korea National Sport University, Seoul Republic of Korea.
Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul Republic of Korea.
J Exerc Nutrition Biochem. 2016 Dec 31;20(4):48-52. doi: 10.20463/jenb.2016.0057.
We investigated the effects of endurance training on the expression of long-chain fatty acid transport proteins in the skeletal muscle and whole-body fat oxidation during endurance exercise.
Seven-week-old male ICR mice (n = 12) were divided into 2 groups, namely, Sed (sedentary; non-trained) and Tr (endurance-trained) groups. The Tr group was adapted to treadmill training at a fixed intensity (15 m/min, 8° slope) for 3 days. Next, the exercise intensity was increased while maintaining the 8° slope. In the last week of training, the exercise intensity was set at 25 m/min for 50 min (about 70-75% maximal oxygen uptake for 4 weeks). After the protocol ended, the mice were sacrificed, and tissues were collected for western blot analysis.
Four weeks of endurance training resulted in a significant increase in the protein levels of FAT/CD36 and CPTІ. The FAT/ CD36 protein level in the Tr group was about 1.3-fold greater than that in the Sed group (p < 0.01). Furthermore, the increased CPTІ indicated higher activity (19% upregulation) in the Tr group compared to the Sed group (p < 0.05). The FAT/CD36 protein level and the estimated whole-body fat oxidation rate during 1-h exercise were found to be significantly correlated (r = 0.765, p < 0.01).
We suggest that the increase in FAT/CD36 protein in skeletal muscle by endurance training might be positively associated with whole-body fat oxidation, which might enhance endurance exercise capacity.
我们研究了耐力训练对耐力运动期间骨骼肌中长链脂肪酸转运蛋白表达及全身脂肪氧化的影响。
将7周龄雄性ICR小鼠（n = 12）分为2组，即Sed（久坐不动；未训练）组和Tr（耐力训练）组。Tr组在固定强度（15米/分钟，8°坡度）下进行跑步机训练3天。接下来，在保持8°坡度的同时增加运动强度。在训练的最后一周，运动强度设定为25米/分钟，持续50分钟（约为最大摄氧量的70 - 75%，持续4周）。实验方案结束后，处死小鼠并收集组织进行蛋白质印迹分析。
四周的耐力训练导致FAT/CD36和CPTІ的蛋白质水平显著增加。Tr组的FAT/CD36蛋白质水平比Sed组高约1.3倍（p < 0.01）。此外，与Sed组相比，Tr组中CPTІ的增加表明其活性更高（上调19%）（p < 0.05）。发现1小时运动期间的FAT/CD36蛋白质水平与估计的全身脂肪氧化率显著相关（r = 0.765，p < 0.01）。
我们认为，耐力训练使骨骼肌中FAT/CD36蛋白质增加可能与全身脂肪氧化呈正相关，这可能会增强耐力运动能力。
