Non-invasive axial loading of mouse tibiae increases cortical bone fori-nation and modifies trabecular organization: A new model to study cortical and cancellous compartments in a single loaded element
Non-invasive axial loading of mouse tibiae increases cortical bone fori-nation and modifies trabecular organization: A new model to study cortical and cancellous compartments in a single loaded element
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DOI：
10.1016/j.bone.2005.07.022
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发表时间：
2005-12-01
期刊：
影响因子：
4.1
通讯作者：
Pitsillides, AA
中科院分区：
文献类型：
--
作者：
De Souza, RL;Matsuura, M;Pitsillides, AA
系统研究骨骼对负荷的反应需要在适当的实验动物中建立简单的非侵入性模型，其中施加的负荷是可控的，骨骼的变化是可量化的。在这里，我们验证了一个模型，用于施加轴向负荷，非侵入性的小鼠胫骨。这使得松质骨和皮质骨中的机械载荷的影响可以在单个骨内确定，其中遗传、神经元和功能影响也可以容易地操纵。使用雌性C57 B1/J6小鼠，在行走（< 300 μ m张力）和跳跃（< 600 μ m压缩）期间，用连接到骨的外侧面和内侧面的单个纵向取向的应变计测量胫骨中轴处的峰值应变。为了校准，还使用相同定位的量规来确定屈曲膝关节和踝关节之间的体外压缩胫骨载荷所产生的应变。施加5至13 N之间的载荷在侧表面上产生1150-2000 pc的应变，并且在体内隔日重复这些载荷2周，在皮质骨形成中产生与载荷大小相关的显著增加，这在8、12和20周龄的小鼠中是相似的。Micro-CT扫描显示，负荷显著增加8周龄小鼠的骨小梁体积，但改变了12和20周龄小鼠的骨小梁体积减少的骨小梁组织。这种胫骨加载模型与其他方法相比具有几个优点，包括在正常、突变和转基因小鼠的单个骨中废用或用骨促性剂治疗的背景下，研究松质骨和皮质骨中加载的影响的范围。(c)2005年爱思唯尔公司All rights reserved.
Systematic study of bones' responses to loading requires simple non-invasive models in appropriate experimental animals where the applied load is controllable and the changes in bone quantifiable. Herein, we validate a model for applying axial loads, non-invasively to murine tibiae. This allows the effects of mechanical loading in both cancellous and cortical bone to be determined within a single bone in which genetic, neuronal and functional influences can also be readily manipulated. Using female C57B1/J6 mice, peak strains at the tibial mid-shaft were measured during walking (< 300 mu epsilon tension) and jumping (< 600 mu epsilon compression) with single longitudinally oriented strain gauges attached to the bone's lateral and medial surfaces. Identically positioned gauges were also used to determine, for calibration, the strains engendered by external applied compressive tibial loading between the flexed knee and ankle ex vivo. Applied loads between 5 and 13 N produced strains of 1150-2000 pc on the lateral surface, and in vivo repetitions of these loads on alternate days for 2 weeks produced significant load magnitude-related increases in cortical bone formation that were similar in mice at 8, 12 and 20 weeks of age. Micro-CT scans showed that loading significantly increases trabecular bone volume in 8 week old mice, but modifies trabecular organization with decreases in trabecular bone volume in 12 and 20 week old mice. This model for loading the tibia has several advantages over other approaches, including scope to study the effects of loading in cancellous as well as cortical bone, against a background of either disuse or of treatment with osteotropic agents within a single bone in normal, mutant and transgenic mice. (c) 2005 Elsevier Inc. All rights reserved.