Spatial periodicity in growth plate shear mechanical properties is disrupted by vitamin D deficiency.
Spatial periodicity in growth plate shear mechanical properties is disrupted by vitamin D deficiency.
复制标题
维生素 D 缺乏会破坏生长板剪切力学特性的空间周期性。
DOI：
10.1016/j.jbiomech.2013.04.023
复制
发表时间：
2013
影响因子：
2.4
通讯作者：
Bonassar,LawrenceJ
中科院分区：
文献类型：
--
作者：
Sevenler,Derin;Buckley,MarkR;Kim,Grace;vanderMeulen,MarjoleinCH;Cohen,Itai;Bonassar,LawrenceJ
生长板是生长中儿童长骨中一段高度组织化的软骨，容易受到维生素D缺乏引起的机械故障和结构和功能的破坏。我们测量了正常和维生素D和缺钙饲料饲养的大鼠胫骨近端生长板的剪切力学性能。在垂直于生长方向的小的生长板试件上施加正弦振动剪切载荷，同时用快速共聚焦显微镜实时成像。局部变形和剪切应变采用图像相关法进行量化。生长板的增殖区承载了大部分的剪切应变，静息区、肥大区和钙化区变形较小。令人惊讶的是，我们经常在两组患者的增殖区观察到不连续的变形，类似于细胞柱在生长方向上相互滑动。这些不连续性表现为纵向剪切应变集中的区域。此外，这些剪切应变浓度在增殖区均匀分布，它们之间的间距在生长板区域和对照试件之间是相似的。与健康对照组相比，维生素D缺乏的生长板在增殖区和肥大区的细胞柱的大小和方向上显示出更大的差异。柱间观察到很高的应变，与对照组很相似。然而，剪切应变浓度的规则间隔没有被保留，这与结构组织减少的观察结果相呼应。
The growth plate is a highly organized section of cartilage in the long bones of growing children that is susceptible to mechanical failure as well as structural and functional disruption caused by a dietary deficiency of vitamin D. The shear mechanical properties of the proximal tibial growth plate of rats raised either on normal or vitamin D and calcium deficient diets were measured. A sinusoidal oscillating shear load was applied to small excised growth plate specimens perpendicular to the direction of growth while imaging the deformation in real time with a fast confocal microscope. Local deformations and shear strains were quantified using image correlation. The proliferative zone of the growth plate bores the majority of the shear strain and the resting, hypertrophic and calcification zones deformed less. Surprisingly, we regularly observed discontinuous deformations in the proliferative zone in both groups that resembled cell columns sliding past one another in the direction of growth. These discontinuities manifested as regions of concentrated longitudinal shear strain. Furthermore, these shear strain concentrations were spaced evenly in the proliferative zone and the spacing between them was similar across growth plate regions and across control specimens. In contrast to the healthy controls, the vitamin D deficient growth plate exhibited larger variations in the size and orientation of cellular columns in the proliferative and hypertrophic zones. High strains were observed between columns, much as they were in the controls. However, the regular spacing of shear strain concentrations was not preserved, echoing the observation of decreased structural organization.