Greatly increased cancellous bone formation with rapid improvements in bone structure in the rat maternal skeleton after lactation
Greatly increased cancellous bone formation with rapid improvements in bone structure in the rat maternal skeleton after lactation
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DOI：
10.1359/jbmr.2002.17.11.1954
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发表时间：
2002-11-01
影响因子：
6.2
通讯作者：
Miller, SC
中科院分区：
文献类型：
--
作者：
Bowman, BM;Siska, CC;Miller, SC
哺乳期间松质骨质量和强度会下降，但这些在哺乳期后会部分或完全重建。本研究的目的是确定哺乳后，在建立育种大鼠松质骨结构和形成的变化。为此，在第二次妊娠（Preg-2）和第二次哺乳（Lac-2）结束时以及断奶后2、4和6周时采集大鼠。包括未产（NP）组进行比较。骨结构测量采用形态学方法和骨动力学组织形态计量学。正如预期，胫骨干骺端松质骨在第一个生殖周期丢失，并在Lac-2期间再次耗尽。与第二次妊娠结束时或未经产动物相比，Lac-2结束时骨形成指数升高。在第二次断奶后2周内，与Lac-2结束时测量的已经升高的骨形成相比，双标记表面（dLS）的量增加了约800%，矿化表面（MS）增加了>400%，骨形成率（BFR）增加了约400%。哺乳后2 - 4周，松质骨质量和结构指数相应增加，与Preg-2结束时测量的松质骨体积和结构相比，松质骨体积和结构基本完全恢复。结果表明，哺乳后大鼠骨形成迅速而实质性增加，松质骨质量和结构重建。哺乳期后骨骼的变化可能有助于为随后的生殖周期准备和保护母体骨骼。
There is a decrease in cancellous bone mass and strength during lactation but these are partially or completely reconstituted in the postlactational period. The purpose of this study was to determine changes in cancellous bone structure and formation after lactation in established breeder rats. For this, rats were taken at the end of the second pregnancy (Preg-2) and second lactation (Lac-2) and 2, 4, and 6 weeks after weaning. Nulliparous (NP) groups were included for comparisons. Bone structure was measured using morphometric methods and bone dynamics by histomorphometry. Tibial metaphyseal cancellous bone was lost during the first reproductive cycle, as expected, and again depleted during the Lac-2. Bone formation indices were elevated at the end of Lac-2, compared with those at the end of the second pregnancy or in the nulliparous animals. Within 2 weeks after the second weaning, the amount of double-labeled surface (dLS) increased similar to800%, the mineralizing surface (MS) increased >400% with similar increases in bone formation rates (BFRs), compared with already elevated bone formation measured at the end of Lac-2. From 2 to 4 weeks after lactation, there were commensurate increases in cancellous bone mass and structural indices with essentially complete restoration of cancellous bone volume and structure compared with that measured at the end of Preg-2. The results show rapid and substantial increases in bone formation with reconstitution of cancellous bone mass and structure after lactation in rats. The skeletal changes that occur during the postlactational period may serve to prepare and protect the maternal skeleton for subsequent reproductive cycles.