Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Japan.
Department of Sports and Life Science, National Institute of Fitness and Sports in Kanoya, Japan.
Int J Med Sci. 2019 Jun 2;16(6):822-830. doi: 10.7150/ijms.32590. eCollection 2019.
Electrical stimulation (ES)-induced muscle contraction has multiple effects; however, mechano-responsiveness of bone tissue declines with age. Here, we investigated whether daily low-frequency ES-induced muscle contraction treatment reduces muscle and bone loss and ameliorates bone fragility in early-stage disuse musculoskeletal atrophy in aged rats. Twenty-seven-month-old male rats were assigned to age-matched groups comprising the control (CON), sciatic nerve denervation (DN), or DN with direct low-frequency ES (DN+ES) groups. The structural and mechanical properties of the trabecular and cortical bone of the tibiae, and the morphological and functional properties of the tibialis anterior (TA) muscles were assessed one week after DN. ES-induced muscle contraction force mitigated denervation-induced muscle and trabecular bone loss and deterioration of the mechanical properties of the tibia mid-diaphysis, such as the stiffness, but not the maximal load, in aged rats. The TA muscle in the DN+ES group showed significant improvement in the myofiber cross-sectional area and muscle force relative to the DN group. These results suggest that low-frequency ES-induced muscle contraction treatment retards trabecular bone and muscle loss in aged rats in early-stage disuse musculoskeletal atrophy, and has beneficial effects on the functional properties of denervated skeletal muscle.
电刺激（ES）诱导的肌肉收缩具有多种作用；然而，随着年龄的增长，骨组织的机械响应能力会下降。在这里，我们研究了低频 ES 诱导的肌肉收缩治疗是否可以减少肌肉和骨量的损失，并改善老年大鼠早期失用性肌骨骼萎缩中的骨脆性。将 27 月龄的雄性大鼠分为对照组（CON）、坐骨神经切断组（DN）或坐骨神经切断加直接低频 ES 组（DN+ES）。在 DN 后一周评估胫骨的小梁和皮质骨的结构和力学特性，以及胫骨前肌（TA）的形态和功能特性。ES 诱导的肌肉收缩力减轻了失神经诱导的肌肉和小梁骨丢失以及胫骨中轴机械性能的恶化，例如刚度，但不是最大负荷，在老年大鼠中。与 DN 组相比，DN+ES 组的 TA 肌肉的肌纤维横截面积和肌肉力量均有显著改善。这些结果表明，低频 ES 诱导的肌肉收缩治疗可延缓老年大鼠早期失用性肌骨骼萎缩中的小梁骨和肌肉丢失，并对去神经骨骼肌肉的功能特性产生有益影响。
