Simske S J, Guerra K M, Greenberg A R, Luttges M W
BioServe Space Technologies, University of Colorado, Boulder 80309-0429.
J Biomech. 1992 May;25(5):489-99. doi: 10.1016/0021-9290(92)90089-j.
The present investigation addresses the extent of tail-suspension effects on the long bones of mice. The effects are explored in both sexes, in both forelimb and hindlimb bones, and in both diaphyseal and metaphyseal/epiphyseal bones. Two weeks of suspension provided unloading of the femora and tibiae and an altered loading of the humeri. Whole-bone effects included lower mass (approximately 10%) and length (approximately 4%) in the bones of suspended mice compared to controls. The geometric and material properties of the femora were considered along the entire length of the diaphysis and in the metaphysis/epiphysis portions as a unit. Geometric effects included lower cross-sectional cortical area (16%), cortical thickness (25%) and moment of inertia (21%) in the femora of suspended mice; these differences were observed in both distal and proximal portions of the femur diaphysis. The relative amount of bone comprising the middle 8 mm of the diaphysis was greater (3%) in the control mice than in the suspended mice. Significant mass differences between the group in the metaphysis/epiphysis were not observed. Material effects included lower %ash (approximately 2%) in the femora and tibiae as well as in the humeri of suspended mice compared to controls. With respect to the measured physical and material properties, suspension produced similar bone responses in male and female mice. The effects of suspension are manifested largely through geometric rather than through material changes.
本研究探讨尾部悬吊对小鼠长骨的影响程度。在雄性和雌性小鼠中，在前肢骨和后肢骨中，以及在骨干和干骺端/骨骺端骨中均对这些影响进行了探究。两周的悬吊导致股骨和胫骨卸载，并改变了肱骨的负荷。与对照组相比，悬吊小鼠骨骼的整体影响包括质量降低（约10%）和长度缩短（约4%）。将股骨的几何和材料特性作为一个整体，沿着骨干的整个长度以及干骺端/骨骺端部分进行考量。几何影响包括悬吊小鼠股骨的横截面皮质面积降低（16%）、皮质厚度降低（25%）和惯性矩降低（21%）；在股骨干骺端的远端和近端均观察到了这些差异。对照小鼠骨干中间8毫米的骨相对量比悬吊小鼠更大（3%）。未观察到两组在干骺端/骨骺端的质量存在显著差异。材料影响包括与对照组相比，悬吊小鼠的股骨、胫骨以及肱骨的灰分百分比降低（约2%）。就所测量的物理和材料特性而言，悬吊在雄性和雌性小鼠中产生了相似的骨骼反应。悬吊的影响主要通过几何变化而非材料变化体现出来。
