Novotny Susan A, Mader Tara L, Greising Angela G, Lin Angela S, Guldberg Robert E, Warren Gordon L, Lowe Dawn A
Program in Physical Therapy and Rehabilitation Sciences, University of Minnesota, Minneapolis, Minnesota, United States of America.
Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia, United States of America.
PLoS One. 2014 Aug 14;9(8):e104339. doi: 10.1371/journal.pone.0104339. eCollection 2014.
The objective of the study was to determine if low intensity, high frequency vibration training impacted the musculoskeletal system in a mouse model of Duchenne muscular dystrophy, relative to healthy mice. Three-week old wildtype (n = 26) and mdx mice (n = 22) were randomized to non-vibrated or vibrated (45 Hz and 0.6 g, 15 min/d, 5 d/wk) groups. In vivo and ex vivo contractile function of the anterior crural and extensor digitorum longus muscles, respectively, were assessed following 8 wks of vibration. Mdx mice were injected 5 and 1 days prior to sacrifice with Calcein and Xylenol, respectively. Muscles were prepared for histological and triglyceride analyses and subcutaneous and visceral fat pads were excised and weighed. Tibial bones were dissected and analyzed by micro-computed tomography for trabecular morphometry at the metaphysis, and cortical geometry and density at the mid-diaphysis. Three-point bending tests were used to assess cortical bone mechanical properties and a subset of tibiae was processed for dynamic histomorphometry. Vibration training for 8 wks did not alter trabecular morphometry, dynamic histomorphometry, cortical geometry, or mechanical properties (P ≥ 0.34). Vibration did not alter any measure of muscle contractile function (P ≥ 0.12); however the preservation of muscle function and morphology in mdx mice indicates vibration is not deleterious to muscle lacking dystrophin. Vibrated mice had smaller subcutaneous fat pads (P = 0.03) and higher intramuscular triglyceride concentrations (P = 0.03). These data suggest that vibration training at 45 Hz and 0.6 g did not significantly impact the tibial bone and the surrounding musculature, but may influence fat distribution in mice.
本研究的目的是确定相对于健康小鼠，低强度、高频振动训练是否会影响杜兴氏肌营养不良小鼠模型的肌肉骨骼系统。将三周龄的野生型小鼠（n = 26）和mdx小鼠（n = 22）随机分为非振动组或振动组（45Hz，0.6g，每天15分钟，每周5天）。振动8周后，分别评估胫前肌和趾长伸肌的体内和体外收缩功能。在处死前5天和1天，分别给mdx小鼠注射钙黄绿素和二甲苯酚。制备肌肉用于组织学和甘油三酯分析，并切除皮下和内脏脂肪垫并称重。解剖胫骨，通过微型计算机断层扫描分析干骺端的小梁形态、骨干中部的皮质几何形状和密度。采用三点弯曲试验评估皮质骨力学性能，并对一部分胫骨进行动态组织形态计量学分析。振动训练8周未改变小梁形态、动态组织形态计量学、皮质几何形状或力学性能（P≥0.34）。振动未改变任何肌肉收缩功能指标（P≥0.12）；然而，mdx小鼠肌肉功能和形态的保留表明振动对缺乏肌营养不良蛋白的肌肉无害。振动小鼠的皮下脂肪垫较小（P = 0.03），肌肉内甘油三酯浓度较高（P = 0.03）。这些数据表明，45Hz、0.6g的振动训练对胫骨和周围肌肉组织没有显著影响，但可能会影响小鼠的脂肪分布。
