Cancellous bone turnover in growing rats: time-dependent changes in association between calcein label and osteoblasts.
Cancellous bone turnover in growing rats: time-dependent changes in association between calcein label and osteoblasts.
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生长大鼠的松质骨转换：钙黄绿素标记与成骨细胞之间关联的时间依赖性变化。
DOI：
10.1002/jbmr.5650090913
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Turner,RT
中科院分区：
文献类型：
--
作者：
Turner,RT
将钙黄绿素给予正在生长的雄性大鼠以标记骨矿化，并在 6 小时至 12 天后处死各组动物。荧光染料标记的周长和成骨细胞周长是在近端胫骨干骺端的次级海绵体内的生长调整采样点测定的。钙黄绿素标记的周长和成骨细胞衬里的周长之间的最佳对应发生在标签施用后的最初 24 小时内。此后这种关联逐渐减少，因为（1）荧光染料标记表面上的骨形成停止和（2）新的骨形成灶的开始。具有邻近钙黄绿素标记的成骨细胞衬里小梁的时间依赖性下降超过了非荧光染料标记小梁上成骨细胞周长的增加，表明成骨细胞数量出现净下降。由于骨吸收，荧光染料标记的周长和骨面积在标记后随时间平行减少。有趣的是，松质骨的减少完全是由小梁数量的减少引起的。小梁厚度没有变化。研究结果表明，成骨细胞数量减少和进行性骨吸收导致生长板最远端的小梁完全侵蚀。由于小梁的生长和破坏几乎相等，松质干骺端的长度不随时间变化。结论是，生长中的大鼠的松质骨转换代表了与成人的骨转换根本不同的成熟过程。
Calcein was given to growing male rats to label mineralizing bone, and groups of animals were sacrificed from 6 h to 12 days later. Fluorochrome‐labeled perimeter and osteoblast perimeter were determined in a growth‐adjusted sampling site in the secondary spongiosa of the proximal tibial metaphysis. The best correspondence between calcein‐labeled perimeter and osteoblast‐lined perimeter was during the initial 24 h following administration of the label. This association decreased progressively thereafter because of (1) cessation of bone formation on fluorochrome‐labeled surfaces and (2) initiation of new foci of bone formation. The time‐dependent decline in osteoblast‐lined trabeculae with adjacent calcein label exceeded the increase in osteoblast perimeter on nonfluorochrome‐labeled trabeculae, indicating that there was a net decrease in osteoblast number. Fluorochrome‐labeled perimeter and bone area showed parallel decreases with time after labeling, as a result of bone resorption. Interestingly, the decrease in cancellous bone was caused exclusively by a reduction in trabecular number. There was no change in trabecular thickness. The findings suggest that the decreased osteoblast number and progressive bone resorption resulted in complete erosion of trabeculae most distal to the growth plate. As a result of the nearly equal growth and destruction of trabeculae, there was no change in the length of the cancellous metaphysis with time. It is concluded that cancellous bone turnover in growing rats represents a maturation process that differs fundamentally from bone turnover in adults.