McGlynn Mark L, Rosales Alejandro M, Collins Christopher W, Slivka Dustin R
School of Health and Kinesiology, University of Nebraska at Omaha, Omaha, NE, United States.
School of Integrative Physiology and Athletic Training, University of Montana, Missoula, MT, United States.
Front Physiol. 2024 Oct 21;15:1473241. doi: 10.3389/fphys.2024.1473241. eCollection 2024.
The development and maintenance of the skeletal muscle is crucial for the support of daily function. Heat, when applied locally, has shown substantial promise in the maintenance of the muscle. The purpose of this study was to determine the combined effects of local heat application and acute resistance exercise on gene expression associated with the human muscle growth program.
Participants (n = 12, 26 ± 7 years, 1.77 ± 0.07 m, 79.6 ± 15.4 kg, and 16.1 ± 11.6 %BF) completed an acute bilateral bout of resistance exercise consisting of leg press (11 ± 2 reps; 170 ± 37 kg) and leg extension (11 ± 1 reps; 58 ± 18 kg). Participants wore a thermal wrap containing circulating fluid (40°C, exercise + heat; EX + HT) during the entire experimental period and 4 h post-exercise, while the other leg served as an exercise-only (EX) control. Biopsies of the were collected (Pre, Post, and 4hPost) for gene expression analyses.
Intramuscular temperatures increased (Post, +2.2°C ± 0.7°C, and < 0.001; 4hPost, +2.5°C ± 0.6°C, and < 0.001) and were greater in the EX + HT leg post-exercise (+0.35°C ± 0.3°C, and = 0.005) and after 4hPost (+2.1°C ± 0.8°C and < 0.001). mRNA was greater in the EX + HT leg vs. the EX (fold change = 2.74 ± 0.42 vs. 1.70 ± 0.28, = 0.037). No other genes demonstrated temperature sensitivity when comparing both legs ( > 0.05). mRNA associated with the negative regulator, (), decreased post-exercise ( = 0.001) and after 4 h ( = 0.001). mRNA associated with proteolysis decreased post-exercise (, = 0.001; , = 0.001) and after 4 h ( = 0.001; , = 0.027).
The elevated transcription of the () after exercise in the heated condition may provide a mechanism by which muscle growth could be enhanced.
骨骼肌的发育和维持对于日常功能的支撑至关重要。局部施加热量在维持肌肉方面已显示出巨大潜力。本研究的目的是确定局部热应用与急性抗阻运动对与人类肌肉生长程序相关的基因表达的联合影响。
参与者（n = 12，年龄26±7岁，身高1.77±0.07米，体重79.6±15.4千克，体脂率16.1±11.6%）完成了一组急性双侧抗阻运动，包括腿举（11±2次重复；170±37千克）和腿屈伸（11±1次重复；58±18千克）。在整个实验期间以及运动后4小时，参与者的一条腿佩戴含有循环流体的热裹布（40°C，运动+热；EX + HT），而另一条腿作为仅运动（EX）对照。采集（运动前、运动后和运动后4小时）肌肉活检样本进行基因表达分析。
肌内温度升高（运动后，+2.2°C±0.7°C，P<0.001；运动后4小时，+2.5°C±0.6°C，P<0.001），且运动后EX + HT腿的温度更高（+0.35°C±0.3°C，P = 0.005），运动后4小时也更高（+2.1°C±0.8°C，P<0.001）。与EX腿相比，EX + HT腿中MyoD mRNA更高（倍数变化 = 2.74±0.42对1.70±0.28，P = 0.037）。比较双腿时，没有其他基因表现出温度敏感性（P>0.05）。与负调节因子atrogin-1（ATG1）相关的mRNA在运动后（P = 0.001）和4小时后（P = 0.001）降低。与蛋白水解相关的mRNA在运动后（P<0.001；P<0.001）和4小时后（P = 0.001；P = 0.027）降低。
在加热条件下运动后MyoD（Myogenic differentiation 1）转录升高可能提供了一种增强肌肉生长的机制。
