University Clinic of Pediatrics and Adolescent Medicine, Medical University of Vienna, Währinger Gürtel 18-20 1090, Vienna, Austria.
Institute of Anatomy, Histology and Embryology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210 Vienna, Austria.
Spine J. 2017 Nov;17(11):1674-1684. doi: 10.1016/j.spinee.2017.06.001. Epub 2017 Jun 20.
The process of linear growth is driven by axial elongation of both long bones and vertebral bodies and is accomplished by enchondral ossification. Differences in regulation between the two skeletal sites are mirrored clinically by the age course in body proportions. Whereas long bone growth plates (GPs) can easily be discriminated, vertebral GPs are part of the cartilaginous end plate, which typically shows important species differences.
The objective of this study was to describe and compare histologic, histomorphometric, and regulatory characteristics in the GPs of the spine and the long bones in a porcine model.
Two- and six-week-old piglet GPs of three vertebral segments (cervical, thoracic, and lumbar) and eight long bones (proximal and distal radius, humerus, tibia, and femur) were analyzed morphometrically. Further, estrogen receptors, proliferation markers, and growth factor expressions were examined by immunohistochemistry.
Individual vertebral GPs were smaller in width and contained fewer chondrocytes than long bone GPs, although their proliferation activity was similar. Whereas the expression pattern of growth hormone-associated factors such as insulin-like growth factor (IGF)-1 and IGF-1 receptor (IGF-1R) was similar, estrogen receptor (ER)-ß and IGF-2 were distinctly expressed in the vertebral samples.
Vertebral GPs display differential growth, with measurements similar to the slowest-growing GPs of long bones. Further investigation is needed to decipher the molecular basis of the differential growth of the spine and the long bones. Knowledge on the distinct mechanism will ultimately improve the assessment of clinically essential characteristics of spinal growth, such as vertebral elongation potential and GP fusion.
线性生长过程是由长骨和椎体的轴向伸长驱动的，通过软骨内成骨完成。两个骨骼部位之间的调节差异在身体比例的年龄进程中反映在临床中。虽然长骨生长板（GP）很容易被区分，但椎体 GP 是软骨终板的一部分，软骨终板通常具有重要的物种差异。
本研究的目的是描述和比较猪模型中脊柱和长骨 GP 的组织学、组织形态计量学和调节特征。
对三个脊椎节段（颈椎、胸椎和腰椎）和八个长骨（近端和远端桡骨、肱骨、胫骨和股骨）的 2 周和 6 周龄小猪 GP 进行形态计量学分析。此外，通过免疫组织化学检查雌激素受体、增殖标志物和生长因子表达。
尽管单个椎体 GP 的增殖活性相似，但它们的宽度和所含软骨细胞数量均小于长骨 GP。生长激素相关因子（如胰岛素样生长因子 [IGF]-1 和 IGF-1 受体 [IGF-1R]）的表达模式相似，而雌激素受体（ER）-β和 IGF-2 在椎体样本中明显表达。
椎体 GP 表现出不同的生长方式，其测量值与长骨中生长最慢的 GP 相似。需要进一步研究以阐明脊柱和长骨生长差异的分子基础。对不同机制的了解最终将改善对脊柱生长的临床重要特征（如椎体伸长潜力和 GP 融合）的评估。
