Wealthall Rosamund J, Herring Susan W
Department of Biology, University of Washington, Seattle, Washington 98195, USA.
Anat Rec A Discov Mol Cell Evol Biol. 2006 Nov;288(11):1163-72. doi: 10.1002/ar.a.20385.
Endochondral ossification at the caudal junctions of the cartilaginous nasal septum, in combination with interstitial expansion of the septum, is thought to displace the facial skeleton away from the neurocranium. However, the rate of endochondral ossification has not been measured or related to rates of septal enlargement. This study examined endochondral ossification at these junctions in mice from postnatal days 0-15, in the context of known cranial growth sites, the synchondroses. BrdU labeling was used to compare cell division at the septoethmoidal and septopresphenoidal junctions with cell division at the synchondroses, and double-fluorochrome labeling was used to measure mineralization rate. The results showed that the septoethmoidal and septopresphenoidal junctions develop the characteristic morphology of growth plates postnatally, and that the pattern of cell division is similar to that of synchondroses. Mineralization at these junctions occurred at rates that were not statistically different from those of the synchondroses. However, the cartilaginous septum increased in length much more rapidly than could be explained by caudal growth, implying that interstitial expansion is the more important contributor to septal growth.
鼻中隔软骨尾端连接处的软骨内成骨，结合鼻中隔的间质扩张，被认为会使面部骨骼远离神经颅。然而，软骨内成骨的速率尚未被测量，也未与鼻中隔增大的速率相关联。本研究在已知的颅骨生长部位——软骨结合的背景下，检查了出生后0至15天小鼠这些连接处的软骨内成骨情况。使用BrdU标记来比较筛骨鼻中隔和蝶骨前鼻中隔连接处的细胞分裂与软骨结合处的细胞分裂，并使用双荧光染料标记来测量矿化速率。结果表明，筛骨鼻中隔和蝶骨前鼻中隔连接处出生后发育出了生长板的特征形态，并且细胞分裂模式与软骨结合处相似。这些连接处的矿化速率与软骨结合处相比无统计学差异。然而，软骨性鼻中隔长度的增加比尾端生长所能解释的要快得多，这意味着间质扩张是鼻中隔生长的更重要因素。
