Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61822, USA.
J Appl Physiol (1985). 2013 Apr;114(7):923-33. doi: 10.1152/japplphysiol.00948.2011. Epub 2013 Jan 17.
Three-dimensional hierarchical structure of female Sprague-Dawley rat tibia cortical bone was characterized as a function of age (3, 12, 32, 42, 60, and 72 wk) using a high-resolution micro-computed tomography. At the whole bone level, 3-wk samples exhibited statistically significant differences in a mean total tissue volume, mean cortical bone volume, mean cortical bone volume density, mean periosteal perimeter, and mean cortical thickness (P < 0.05) compared with all other ages. At the tissue level, there was a statistically significant increase in a mean canal number density and a decrease in a mean canal volume and diameter between 3-wk and 12-wk samples. While no significant variations were found between mean canal lengths, there was a dependence of mean canal orientation on age. At the cell level, there were no statistically significant differences in a lacuna number density and a lacuna volume density, and all lacunae element-based parameters displayed no dependence on age across age. In addition, at the microstructural level, the cannular indexes were reported separately for anterior, posterior, medial, and lateral anatomic regions. From 3 to 32 wk of age, there existed significantly fewer canals per volume of bone in the medial region of the tibia vs. other cross-sectional quadrants. Although there were changes with age, there were no statistically significant differences in the mean canal volume, mean canal diameter, and mean canal length between the four anatomic regions.
采用高分辨率微计算机断层扫描技术，研究了年龄（3、12、32、42、60 和 72 周）对雌性 Sprague-Dawley 大鼠胫骨皮质骨三维分层结构的影响。在整个骨水平上，与其他所有年龄组相比，3 周龄样本的总组织体积、皮质骨体积、皮质骨体积密度、骨膜周长和皮质厚度的平均值均存在显著差异（P<0.05）。在组织水平上，3 周龄和 12 周龄样本之间，平均管腔数量密度呈统计学显著增加，平均管腔容积和直径呈统计学显著降低。虽然平均管腔长度没有显著变化，但平均管腔方向依赖于年龄。在细胞水平上，腔隙数量密度和腔隙体积密度没有统计学显著差异，所有腔隙元素参数在整个年龄范围内均与年龄无关。此外，在微观结构水平上，分别报告了前、后、内、外侧解剖区域的管腔指数。从 3 周到 32 周龄，胫骨内侧区域每单位体积骨的管腔数量明显少于其他四个横切象限。尽管存在年龄变化，但四个解剖区域之间的平均管腔容积、平均管腔直径和平均管腔长度均无统计学显著差异。
