Strain gradients correlate with sites of exercise-induced bone-forming surfaces in the adult skeleton
Strain gradients correlate with sites of exercise-induced bone-forming surfaces in the adult skeleton
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DOI：
10.1359/jbmr.1997.12.10.1737
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发表时间：
1997-10-01
影响因子：
6.2
通讯作者：
Zernicke, RF
中科院分区：
文献类型：
--
作者：
Judex, S;Gross, TS;Zernicke, RF
体力活动能够增加成年人的骨量，然而，机械刺激的特定成骨成分是未知的。使用外源性载荷模型，最近有报道称，纵向法向应变的周向梯度与骨膜骨形成的特定部位密切相关。本研究采用高速跑的方法，在骨骼适应性运动模型中，对6只成年公鸡（>1岁）在高速跑过程中跗跖部中段的应变环境进行了测定，第二组公鸡进行了高速跑，（1500个负荷循环/天）持续3周，8只动物中有5只的骨膜表面被激活，力学参数以及骨膜活化（通过掺入的荧光标记物测量）在细分中间骨干部分的12个30度扇区中进行位点特异性定量。每个扇区的骨膜矿化表面的量与诱导的峰值周向应变梯度强烈相关（R-2 = 0.63）。相反，峰值应变大小和峰值应变率与骨膜激活部位仅存在弱相关性。本研究的独特之处在于，特定的机械刺激（峰值周向应变梯度）成功地与非侵入性骨适应模型中诱导的特定骨膜骨激活部位相关。该力学参数的知识可帮助设计能够在最需要增加结构强度的部位存款骨的锻炼方案。
Physical activity is capable of increasing adult bone mass, The specific osteogenic component of the mechanical stimulus is, however, unknown. Using an exogenous loading model, it was recently reported that circumferential gradients of longitudinal normal strain are strongly associated with the specific sites of periosteal bone formation. Here, we used high-speed running to test this proposed relation in an exercise model of bone adaptation, The strain environment generated during running in a mid-diaphyseal tarsometatarsal section was determined from triple-rosette strain gages in six adult roosters (>1 year), A second group of roosters was run at a high speed (1500 loading cycles/day) on a treadmill for 3 weeks, Periosteal surfaces were activated in five out of eight animals, Mechanical parameters as well as periosteal activation (as measured by incorporated fluorescent labels) were quantified site-specifically in 12 30 degrees sectors subdividing a mid-diaphyseal section. The amount of periosteal mineralizing surface per sector correlated strongly (R-2 = 0.63) with the induced peak circumferential strain gradients. Conversely, peak strain magnitude and peak strain rate were only weakly associated with the sites of periosteal activation, The unique feature of this study is that a specific mechanical stimulus (peak circumferential strain gradients) was successfully correlated with specific sites of periosteal bone activation induced in a noninvasive bone adaptation model. The knowledge of this mechanical parameter may help to design exercise regimens that are able to deposit bone at sites where increased structural strength is most needed.