A rehabilitation exercise program induces severe bone mineral deficits in estrogen-deficient rats after extended disuse.
A rehabilitation exercise program induces severe bone mineral deficits in estrogen-deficient rats after extended disuse.
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长期停用后，康复锻炼计划会导致缺乏雌激素的大鼠出现严重的骨矿物质缺乏。
DOI：
10.1097/gme.0b013e318255657f
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
Brown,Marybeth
中科院分区：
文献类型：
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作者：
Yarrow,JoshuaF;McCoy,SeanC;Ferreira,JAndries;Pingel,JenniferE;Conrad,BryanP;Wronski,ThomasJ;Williams,AlyssaA;Borst,StephenE;Brown,Marybeth
雌激素和机械负荷都调节骨的维持。然而，机械超载似乎在提高雌激素缺乏的妇女骨密度（BMD）的有效性较低。本研究的目的是确定雌二醇（E2）是否影响早期骨适应性reamblood（REAMB）和/或康复锻炼后后肢卸载（HLU）的卵巢切除rates.Methods81 5个月龄雌性SD大鼠随机分为以下组：（1）完整对照，（2）卵巢切除术（OVX），（3）OVX+ E2，（4）OVX+ 4周HLU，（5）OVX+ E2 + HLU，（6）OVX+ HLU+ 2周四足REAMB，（7）OVX+ E2 + HLU+ REAMB，（8）OVX+ HLU+ REAMB+补充攀爬、跳跃，（9）OVX+ E2 + HLU+ REAMB+ EX。串行双能X射线吸收扫描进行跟踪全身骨特性在整个研究中，和周边定量计算机断层扫描被用来确定远端股骨干骺端骨矿物质的characteristics.ResultsTotal身体骨密度增加了4%至8%的所有动物接受补充E 2，而骨密度没有改变在动物中没有E 2。OVX降低了股骨干骺端骨小梁BMD，HLU加剧了这种损失，同时也降低了皮质BMD。E2对OVX+ HLU诱导的股骨干骺端骨丢失具有保护作用。相反，无论雌激素状态如何，REAMB都不会改变BMD。在缺乏E2的情况下，REAMB+ EX导致OVX+ HLU后严重的骨丢失，骨小梁BMD和皮质BMD测量值分别比对照组低91%和7%（P≤ 0.001）。然而，在E2的存在下，REAMB+ EX并没有负面影响骨矿物质characteristics.ConclusionsE2保护对骨丢失造成的联合OVX+ HLU的啮齿类动物。在没有雌激素的情况下，运动诱导不利的早期阶段骨适应后，长期废用。
ObjectiveBoth estrogen and mechanical loading regulate bone maintenance. However, mechanical overload seems less effective in enhancing bone mineral density (BMD) in estrogen-deficient women. The aim of this study was to determine whether estradiol (E 2) influences early-phase bone adaptations to reambulation (REAMB) and/or rehabilitation exercises after hindlimb unloading (HLU) of ovariectomized rats.MethodsEighty-one 5-month-old female Sprague-Dawley rats were randomized into the following groups:(1) intact controls,(2) ovariectomy (OVX),(3) OVX+ E 2,(4) OVX+ 4 weeks of HLU,(5) OVX+ E 2+ HLU,(6) OVX+ HLU+ 2 weeks of quadrupedal REAMB,(7) OVX+ E 2+ HLU+ REAMB,(8) OVX+ HLU+ REAMB+ supplemental climbing, jumping, and balance exercises (EX), or (9) OVX+ E 2+ HLU+ REAMB+ EX. Serial dual-energy x-ray absorptiometry scans were performed to track total body bone characteristics throughout the study, and peripheral quantitative computerized tomography was used to determine distal femoral metaphyseal bone mineral characteristics.ResultsTotal body BMD increased by 4% to 8% in all animals receiving supplemental E 2, whereas BMD did not change in animals without E 2. OVX reduced trabecular BMD at the femoral metaphysis, and HLU exacerbated this loss while also reducing cortical BMD. E 2 protected against OVX+ HLU–induced bone loss at the femoral metaphysis. Conversely, REAMB did not alter BMD, regardless of estrogen status. In the absence of E 2, REAMB+ EX resulted in severe bone loss after OVX+ HLU, with trabecular BMD and cortical BMD measurements that were 91% and 7% below those of controls, respectively (P≤ 0.001). However, in the presence of E 2, REAMB+ EX did not negatively influence bone mineral characteristics.ConclusionsE 2 protects against bone loss resulting from combined OVX+ HLU of rodents. In the absence of estrogen, exercise induces disadvantageous early-phase bone adaptations after extended disuse.