University of Eastern Finland, Department of Medicine, Institute of Biomedicine, P.O. Box 1674, FI-70211, Kuopio, Finland.
Bone. 2011 Apr 1;48(4):878-84. doi: 10.1016/j.bone.2010.12.001. Epub 2010 Dec 10.
It has been established that almost 40% of postmenopausal women in the United States have osteopenia and models to study its prevention are thus urgently needed. Bears (Ursus spp.) displaying winter sleep were previously introduced as promising models to study the treatment of disuse-induced bone loss. The present study examined the potential of another analogous model species, the raccoon dog (Nyctereutes procyonoides), in bone research. Similar to bears, raccoon dogs display prolonged passivity and catabolism in winter, but they are of a moderate body mass, easy to handle and reared on farms. Wild specimens (n=51) were hunted in winter 2007-2008. The bone mineral density of femoral diaphysis and neck was examined with peripheral quantitative computed tomography, after which their mechanical properties were tested with the three-point bending and femoral neck loading tests. A subsample of the specimens was analyzed histologically. While the body mass of the raccoon dogs decreased from 7.0±0.3 to 4.5±0.2 kg (-36%) during winter, the bone mass and biomechanical properties remained unchanged despite of heavy wintertime catabolism similar to bears. Thus, the cortical mineral density remained at approximately 1400 mg/cm(3), the trabecular mineral density at 450 mg/cm(3) and the maximum load of the femoral neck at 700 N. However, in histological samples, the proportion of osteoid perimeter vs. mineralized bone perimeter decreased during wintering. A possible mechanism of bone mass preservation is the endocrine status of overwintering raccoon dogs, which could participate in preventing bone loss.
已经确定，美国近 40%的绝经后妇女患有骨质疏松症，因此迫切需要建立研究其预防方法的模型。熊（Ursus spp.）在冬眠期间表现出的特征，被认为是研究治疗因废用导致的骨丢失的有前途的模型。本研究检验了另一种类似的模式物种，即貉（Nyctereutes procyonoides），在骨研究中的潜力。与熊相似，貉在冬季表现出长时间的被动和分解代谢，但它们的体重适中，易于处理，并且可以在农场中饲养。2007-2008 年冬季，从野外捕获了 51 只貉。使用外周定量计算机断层扫描技术检测股骨骨干和颈部的骨矿物质密度，然后使用三点弯曲和股骨颈加载试验测试其机械性能。对标本的一部分进行了组织学分析。虽然貉的体重从 7.0±0.3 公斤减少到 4.5±0.2 公斤（-36%），但尽管冬季分解代谢严重，类似于熊，其骨量和生物力学特性仍然保持不变。因此，皮质矿物质密度保持在大约 1400 mg/cm(3)，小梁矿物质密度保持在 450 mg/cm(3)，股骨颈的最大负荷保持在 700 N。然而，在组织学样本中，在冬季期间，类骨质周长与矿化骨周长的比例减少。骨量保存的一种可能机制是越冬貉的内分泌状态，它可能参与预防骨丢失。
