Faugere M C, Friedler R M, Fanti P, Malluche H H
Department of Medicine, University of Kentucky Medical Center, Lexington.
J Bone Miner Res. 1990 Mar;5(3):263-72. doi: 10.1002/jbmr.5650050310.
The beagle dog model has been established by our laboratory as a useful animal model to study bone loss after cessation of ovarian function. Previously we demonstrated bone loss associated with an osteoblastic insufficiency at 4 months after ovariohysterectomy (OHX). This study was designed to evaluate by four sequential monthly bone biopsies the development and course of the histologic bone abnormalities after OHX. We found cancellous bone volume, trabecular density, and wall thickness to be decreased (p less than 0.05) and trabecular separation increased (p less than 0.05) as early as 1 month after OHX. After 2 months, there was a decrease in mineralizing surface and mineral apposition rate (p less than 0.05). Volume and surface of osteoid were increased after 3 months (p less than 0.05), and there was an increase in the number of osteoblasts (p less than 0.01). No histologic signs of increased resorption were observed during the experiment. However, the findings of low bone volume with decreased trabecular density and increased separation without a change in trabecular plate thickness 4 weeks after OHX suggest that a dramatic increase in resorption must have taken place soon after OHX. These results point to an early phase of initiation of bone loss related to hyperresorption followed by a maintenance phase of low bone mass ascriblastic insufficiency. The events that stimulate the early initiating phase after cessation of ovarian function, the factors contributing to it, and the direct demonstration of hyperresorption await further studies.
我们实验室已建立比格犬模型，作为研究卵巢功能停止后骨质流失的有用动物模型。此前我们证明，卵巢子宫切除术后（OHX）4个月时，骨质流失与成骨细胞功能不全有关。本研究旨在通过连续四个月每月进行一次骨活检，评估OHX后组织学骨异常的发展和过程。我们发现，早在OHX后1个月，松质骨体积、小梁密度和骨壁厚度就降低了（p<0.05），小梁间距增加了（p<0.05）。2个月后，矿化表面和矿化沉积率降低（p<0.05）。3个月后，类骨质的体积和表面积增加（p<0.05），成骨细胞数量增加（p<0.01）。实验期间未观察到吸收增加的组织学迹象。然而，OHX后4周骨体积低、小梁密度降低、间距增加且小梁板厚度无变化的结果表明，OHX后不久吸收必定急剧增加。这些结果表明，骨质流失的早期阶段与过度吸收有关，随后是低骨量的维持阶段，这归因于成骨细胞功能不全。刺激卵巢功能停止后早期起始阶段的事件、促成该阶段的因素以及过度吸收的直接证据有待进一步研究。
