Acute molecular responses of skeletal muscle to resistance exercise in able-bodied and spinal cord-injured subjects
Acute molecular responses of skeletal muscle to resistance exercise in able-bodied and spinal cord-injured subjects
复制标题
DOI：
10.1152/japplphysiol.00014.2003
复制
发表时间：
2003-06-01
影响因子：
3.3
通讯作者：
Dudley, GA
中科院分区：
文献类型：
--
作者：
Bickel, CS;Slade, JM;Dudley, GA
脊髓损伤（SCI）导致肌肉萎缩，这有助于许多健康问题，如心血管失调，代谢紊乱和骨质疏松症。肌电刺激（EMS）有望改善SCI相关的肌肉萎缩，从而改善整体健康状况。到目前为止，长期SCI受试者的EMS训练导致了一些肌肉肥大，但没有达到正常的肌肉质量。本研究的目的是比较股外侧肌从健全（AB）和SCI受试者急性发作EMS诱导的阻力运动后的分子反应，以确定是否SCI肌肉显示一些损伤的反应。分析包括已知对啮齿动物肌肉中增加的负荷有反应的mRNA标记物。AB和SCI受试者的肌肉进行EMS刺激的运动在两个30分钟的回合，由48小时的休息分开。在第二次运动后24小时获得穿刺活检样品。在AB和SCI肌肉中，胰岛素样生长因子结合蛋白4和5、细胞周期蛋白依赖性激酶抑制剂p21和肌细胞生成素mRNA水平均发生显著变化。在AB受试者中，机械生长因子的mRNA也增加。运动前SCI组肌肉总RNA含量低于AB组，运动后无显著差异。这项研究的结果表明，急性抗阻运动刺激AB和SCI受试者的骨骼肌分子反应。在SCI肌肉中看到的反应表明，即使在长时间的肌肉卸载之后，调节这些分子反应的系统也是完整的。
Spinal cord injury (SCI) results in muscle atrophy, which contributes to a number of health problems, such as cardiovascular deconditioning, metabolic derangement, and osteoporosis. Electromyostimulation ( EMS) holds the promise of ameliorating SCI-related muscle atrophy and, therefore, improving general health. To date, EMS training of long-term SCI subjects has resulted in some muscle hypertrophy but has fallen short of normalizing muscle mass. The aim of this study was to compare the molecular responses of vastus lateralis muscles from able-bodied ( AB) and SCI subjects after acute bouts of EMS-induced resistance exercise to determine whether SCI muscles displayed some impairment in response. Analysis included mRNA markers known to be responsive to increased loading in rodent muscles. Muscles of AB and SCI subjects were subjected to EMS-stimulated exercise in two 30-min bouts, separated by a 48-h rest. Needle biopsy samples were obtained 24 h after the second exercise bout. In both the AB and SCI muscles, significant changes were seen in insulin-like growth factor binding proteins 4 and 5, cyclin-dependent kinase inhibitor p21, and myogenin mRNA levels. In AB subjects, the mRNA for mechano-growth factor was also increased. Before exercise, the total RNA concentration of the SCI muscles was less than that of the AB subjects but not different postexercise. The results of this study indicate that acute bouts of resistance exercise stimulate molecular responses in the skeletal muscles of both AB and SCI subjects. The responses seen in the SCI muscles indicate that the systems that regulate these molecular responses are intact, even after extended periods of muscle unloading.