Department of Sports Traumatology M51, Bispebjerg-Frederiksberg Hospital, Copenhagen, Denmark.
Department of Biomedical Sciences, Faculty of Health and Medical Sciences, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark.
Scand J Med Sci Sports. 2018 Aug;28(8):1859-1865. doi: 10.1111/sms.13196. Epub 2018 May 8.
The myotendinous junction (MTJ) is at high risk of strain injuries, due to high amounts of energy that is transferred through this structure. The risk of strain injury is significantly reduced by heavy resistance training (HRT), indicating a remodeling capacity of MTJ. We investigated the degree of remodeling of muscle fibers near the human MTJ. In 8 individuals, samples were taken from the semitendinosus and gracilis MTJ and they were stained immunohistochemically for myonuclei (DAPI), fibroblasts (TCF7L2), and satellite cells (CD56). A high portion of the muscle fibers adjacent to the MTJ contained a centrally located myonucleus (47 ± 8%, mean ± SD) and half of the muscle fibers were CD56 positive. The number of satellite cells and fibroblasts were not higher than what has previously been reported from muscle bellies. The immunohistochemical findings suggest that the rate of remodeling of muscle fibers near the MTJ is very high. The finding that there was no increased number of satellite cells and fibroblasts could be explained as a dynamic phenomenon. The effect of HRT should be evaluated in a randomized setting.
肌肌腱结合部（MTJ）由于大量能量在此结构中传递，因此容易发生应变损伤。高强度阻力训练（HRT）显著降低了应变损伤的风险，表明 MTJ 具有重塑能力。我们研究了人类 MTJ 附近肌肉纤维的重塑程度。在 8 个人中，从半腱肌和股薄肌 MTJ 取样，并对其进行核芯蛋白（DAPI）、成纤维细胞（TCF7L2）和卫星细胞（CD56）的免疫组织化学染色。接近 MTJ 的肌肉纤维中有很大一部分含有中央核芯蛋白（47±8%，平均值±标准差），并且一半的肌肉纤维呈 CD56 阳性。卫星细胞和成纤维细胞的数量并不高于以前从肌肉腹部报道的数量。免疫组织化学发现表明，MTJ 附近肌肉纤维的重塑速度非常高。没有增加卫星细胞和成纤维细胞数量的发现可以解释为一种动态现象。HRT 的效果应在随机环境中进行评估。
