Peng Z, Tuukkanen J, Zhang H, Väänänen H K
Department of Anatomy, University of Turku, Finland.
J Bone Miner Res. 1999 Apr;14(4):616-23. doi: 10.1359/jbmr.1999.14.4.616.
The structural and mechanical properties of bone in the femoral neck and various other sites were investigated in intact (INT), sham-operated (Sham), and ovariectomized (OVX) rats. Six weeks after operation, the maximal load and energy absorption of the femoral neck were significantly lower in the OVX than in the INT or Sham groups, being 73.2 +/- 1.4 (SE) N, 86.3 +/- 4.1 N, and 87.1 +/- 3.2 N, respectively (p < 0.01) for load. The total cross-sectional area of the femoral neck did not change after OVX, but the marrow cavity area was enlarged, leading to a reduced bone area (including both cortical and trabecular bone) (p < 0.01). Histomorphometric analysis showed that new bone formation could not be detected at the periosteum of the femoral neck below the femoral head, but at the endocortical surfaces the double tetracycline labeling revealed an increased mineral apposition rate (MAR) and bone formation rate (BFR) in OVX animals (p < 0.001). In contrast, MAR and BFR were significantly increased in both periosteal and endocortical surfaces of the tibia, humerus, and femoral shaft, thus preventing a decrease in cortical bone area. The maximal bending loads of the tibia and humerus were not different in the various groups of animals. The correlation coefficient between maximal load and bone area revealed positive relationships in the femoral neck (r = 0.54, p < 0.01), tibia (r = 0.46, p < 0.01), and humerus (r = 0.51, p < 0.01). Ovariectomy resulted in a decreased trabecular bone volume of lumbar vertebra VI (L6) decreased compressive loads of lumbar vertebrae I, III, and IV. These lumbar bone loads were positively related to their L6 bone area (L4/L6: r = 0.66, p < 0.001). Element analyses (energy dispersion spectrometer) from trabecular and cortical areas of bone showed some changes related to aging but not to OVX. These results indicate that ovariectomy influences the biomechanical properties of rat bone by changing structural properties rather than material ones.
在完整（INT）、假手术（Sham）和去卵巢（OVX）大鼠中，研究了股骨颈及其他不同部位骨骼的结构和力学性能。术后六周，OVX组股骨颈的最大负荷和能量吸收显著低于INT组或Sham组，负荷分别为73.2±1.4（SE）N、86.3±4.1 N和87.1±3.2 N（p<0.01）。OVX后股骨颈的总横截面积未发生变化，但骨髓腔面积增大，导致骨面积（包括皮质骨和小梁骨）减小（p<0.01）。组织形态计量学分析显示，在股骨头下方股骨颈的骨膜处未检测到新骨形成，但在内皮质表面，双四环素标记显示OVX动物的矿物质沉积率（MAR）和骨形成率（BFR）增加（p<0.001）。相反，在胫骨、肱骨和股骨干的骨膜和内皮质表面，MAR和BFR均显著增加，从而防止了皮质骨面积的减少。不同组动物的胫骨和肱骨的最大弯曲负荷无差异。最大负荷与骨面积之间的相关系数在股骨颈（r = 0.54，p<0.01）、胫骨（r = 0.46，p<0.01）和肱骨（r = 0.51，p<0.01）中呈正相关。去卵巢导致第六腰椎（L6）的小梁骨体积减少，第一、三、四腰椎的压缩负荷降低。这些腰椎骨负荷与其L6骨面积呈正相关（L4/L6：r = 0.66，p<0.001）。对骨小梁和皮质区域进行元素分析（能量色散光谱仪）显示，有一些与衰老相关而非与去卵巢相关的变化。这些结果表明，去卵巢通过改变结构特性而非材料特性来影响大鼠骨骼的生物力学性能。
