Bone and hormonal changes induced by skeletal unloading in the mature male rat.
Bone and hormonal changes induced by skeletal unloading in the mature male rat.
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DOI：
10.1152/ajpendo.1999.276.1.e62
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
W. Dehority;B. Halloran;D. Bikle;T. Curren;P. Kostenuik;T. Wronski;Ying Shen;B. Rabkin;A. Bouraoui
中科院分区：
文献类型：
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作者：
W. Dehority;B. Halloran;D. Bikle;T. Curren;P. Kostenuik;T. Wronski;Ying Shen;B. Rabkin;A. Bouraoui
为了确定大鼠后肢抬高模型是否可用于研究航天飞行和重力负荷损失对成年动物骨骼的影响，并研究年龄对骨骼对机械负荷反应性的影响，我们研究了6个月大的大鼠后肢抬高长达5周。在成年人中，负重的丧失诱导了轻度高钙血症，血清1，25-二羟维生素D减少，椎骨骨量减少，并使与骨成熟相关的股骨质量的正常增加变钝。卸载减少成骨细胞数量，减少骨膜和松质骨形成，但对骨吸收没有影响。卸载过程中矿化表面、矿物质沉积率和骨形成率降低。我们的研究结果表明，成年大鼠后肢海拔模型的效用作为一种手段，模拟骨骼上的重力负荷的损失，他们表明，非负重的影响是长期的，并有一个更大的相对影响，在成年比在年轻的生长动物的骨形成。
To determine whether the rat hindlimb elevation model can be used to study the effects of spaceflight and loss of gravitational loading on bone in the adult animal, and to examine the effects of age on bone responsiveness to mechanical loading, we studied 6-mo-old rats subjected to hindlimb elevation for up to 5 wk. Loss of weight bearing in the adult induced a mild hypercalcemia, diminished serum 1,25-dihydroxyvitamin D, decreased vertebral bone mass, and blunted the otherwise normal increase in femoral mass associated with bone maturation. Unloading decreased osteoblast numbers and reduced periosteal and cancellous bone formation but had no effect on bone resorption. Mineralizing surface, mineral apposition rate, and bone formation rate decreased during unloading. Our results demonstrate the utility of the adult rat hindlimb elevation model as a means of simulating the loss of gravitational loading on the skeleton, and they show that the effects of nonweight bearing are prolonged and have a greater relative effect on bone formation in the adult than in the young growing animal.