Fritzen Andreas Mæchel, Thøgersen Frank D, Qadri Khaled Abdul Nasser, Krag Thomas, Sveen Marie-Louise, Vissing John, Jeppesen Tina D
Department of Neurology, Copenhagen Neuromuscular Center, Rigshospitalet, DK-2100 Copenhagen, Denmark.
Molecular Physiology Group, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, DK-2100 Copenhagen, Denmark.
J Clin Med. 2020 Jul 10;9(7):2188. doi: 10.3390/jcm9072188.
Aging is related to an inevitable loss of muscle mass and strength. The mechanisms behind age-related loss of muscle tissue are not fully understood but may, among other things, be induced by age-related differences in myogenic regulatory factors. Resistance exercise training and deconditioning offers a model to investigate differences in myogenic regulatory factors that may be important for age-related loss of muscle mass and strength. Nine elderly (82 ± 7 years old) and nine young, healthy persons (22 ± 2 years old) participated in the study. Exercise consisted of six weeks of resistance training of the quadriceps muscle followed by eight weeks of deconditioning. Muscle biopsy samples before and after training and during the deconditioning period were analyzed for MyoD, myogenin, insulin-like growth-factor I receptor, activin receptor IIB, smad2, porin, and citrate synthase. Muscle strength improved with resistance training by 78% (95.0 ± 22.0 kg) in the elderly to a similar extent as in the young participants (83.5%; 178.2 ± 44.2 kg) and returned to baseline in both groups after eight weeks of deconditioning. No difference was seen in expression of muscle regulatory factors between elderly and young in response to exercise training and deconditioning. In conclusion, the capacity to gain muscle strength with resistance exercise training in elderly was not impaired, highlighting this as a potent tool to combat age-related loss of muscle function, possibly due to preserved regulation of myogenic factors in elderly compared with young muscle.
衰老与肌肉质量和力量的不可避免丧失有关。与年龄相关的肌肉组织丧失背后的机制尚未完全了解，但除其他因素外，可能由生肌调节因子的年龄相关差异所诱发。抗阻运动训练和去适应提供了一个模型，用于研究生肌调节因子的差异，这些差异可能对与年龄相关的肌肉质量和力量丧失很重要。九名老年人（82±7岁）和九名年轻健康人（22±2岁）参与了这项研究。运动包括对股四头肌进行六周的抗阻训练，随后进行八周的去适应。在训练前后以及去适应期间采集肌肉活检样本，分析其中的肌分化抗原（MyoD）、肌细胞生成素、胰岛素样生长因子I受体、激活素受体IIB、smad2、孔蛋白和柠檬酸合酶。老年人通过抗阻训练肌肉力量提高了78%（从95.0±22.0千克），提高幅度与年轻参与者相似（83.5%；从178.2±44.2千克），并且在八周的去适应后两组均恢复到基线水平。在运动训练和去适应后，老年人和年轻人在肌肉调节因子的表达上没有差异。总之，老年人通过抗阻运动训练增加肌肉力量的能力并未受损，这突出表明抗阻运动训练是对抗与年龄相关的肌肉功能丧失的有效工具，这可能是由于与年轻肌肉相比，老年人的生肌因子调节得以保留。
