Zhang Tianlong, Gao Jiazi, Fang Juan, Gong He
Department of Engineering Mechanics, Jilin University, Changchun, 130022, People's Republic of China.
J Bone Miner Metab. 2018 Mar;36(2):157-169. doi: 10.1007/s00774-017-0827-6. Epub 2017 Mar 14.
This study aimed to explore the effects of additional weight bearing in combination with low-magnitude high-frequency vibration (LMHFV; 45 Hz, 0.3 g) on bone quality. One hundred twenty rats were randomly divided into ten groups; namely, sedentary (SED), additional weight bearing in which the rat wears a backpack whose weight is x% of the body weight (WBx; x = 5, 12, 19, 26), basic vibration (V), and additional weight bearing in combination with LMHFV in which the rat wears a backpack whose weight is x% of the body weight (Vx; x = 5, 12, 19, 26). The experiment was conducted for 12 weeks, 7 days per week, and 15 min per day. A three-point bending mechanical test, micro computed tomography, and a nanoindentation test were used. Serum samples were analyzed chemically. Failure load in V19 rats was significantly lower than that in SED rats (P < 0.05). Vx (x = 5, 12, 19, 26) rats showed poor microarchitectures. The content of tartrate-resistant acid phosphatase 5b was significantly higher in Vx (x = 5, 12, 19, 26) rats than that in SED rats (P < 0.05). V26 rats demonstrated comparatively better nanomechanical properties of materials than the other vibrational groups. Additional weight bearing in combination with LMHFV negatively affected the macromechanical properties and microarchitecture of bone. Heavy additional weight bearing, such as 26% of body weight, in combination with LMHFV was able to improve the nanomechanical properties of growing bone material compared with LMHFV. A combined mechanical stimulation was used, which may provide useful information to understand the mechanism of this mechanical stimulation on bone.
本研究旨在探讨额外负重联合低强度高频振动（LMHFV；45赫兹，0.3克）对骨质量的影响。120只大鼠被随机分为十组；即，静息组（SED）、大鼠佩戴重量为体重x%的背包的额外负重组（WBx；x = 5、12、19、26）、基础振动组（V）以及大鼠佩戴重量为体重x%的背包的额外负重联合LMHFV组（Vx；x = 5、12、19、26）。实验持续12周，每周7天，每天15分钟。采用三点弯曲力学试验、显微计算机断层扫描和纳米压痕试验。对血清样本进行化学分析。V19组大鼠的破坏载荷显著低于SED组大鼠（P < 0.05）。Vx（x = 5、12、19、26）组大鼠的微观结构较差。Vx（x = 5、12、19、26）组大鼠中抗酒石酸酸性磷酸酶5b的含量显著高于SED组大鼠（P < 0.05）。V26组大鼠的材料纳米力学性能相较于其他振动组表现出相对较好的情况。额外负重联合LMHFV对骨的宏观力学性能和微观结构有负面影响。与LMHFV相比，如体重26%的重度额外负重联合LMHFV能够改善生长中骨材料的纳米力学性能。采用了联合机械刺激，这可能为理解这种机械刺激对骨的作用机制提供有用信息。
