【摘要】 应用micro-CT获得腰椎松质骨微结构的三维参数,分析卵巢切除术与雌二醇干预对大鼠松质骨微结构及整体骨生物力学性能的作用,初步讨论松质骨微结构的改变对生物力学性能的影响。6月龄未交配雌性SD大鼠30只,随机分成3组(每组10只):假手术对照组(Sham)、去卵巢组(OVX)和去卵巢+补充雌二醇组(EBT)。术后相同条件饲养5个月,取第3腰椎进行生物力学压缩试验,第4腰椎行micro-CT扫描。结果表明,与相应的Sham组比较,OVX组的BV/TV、Tb.N均明显下降,Tb.Sp和SMI明显增高。EBT组的BV/TV、Tb.N和Tb.Th均大于OVX组,Tb.Th和SMI明显小于OVX组。骨力学性能检测显示OVX组腰椎松质骨E、Fmax和σmax均明显降低,而EBT组上述骨生物力学参数均明显改善。通过micro-CT获得的骨微结构参数并结合骨力学性能检测能为合理评价骨质疏松及抗骨质疏松药物药效研究提供较好的实验依据。更多还原

【Abstract】 This study was aimed at observing the effects of ovariectomy and estradiol on the microarchitecture of cancellous bone and exploring the influence of microarchitectural change on the biomechanical properties.Thirty 6-month-old unmated female SD rats were randonmly divided into 3 groups(10 rat each): sham-operated control group (Sham), ovariectomized group (OVX)and Estradiol Benzoate treated group(EBT). All rats were housed in standard environmental conditions. Five months after operation, the rats were sacrificed. The biomechanical properties of the third lumbar vertebras(L3) were measured with compression testing in vitro. Micro-CT scanning was performed on the fourth lumbar vertebras(L4) in vitro. In comparison with the corresponding variables of Sham, the bone volume fraction(BV/TV) and the trabecular number (Tb.N) of OVX were reduced remarkably, and the trabecular separation (Tb.Sp) and the structural model index(SMI) of OVX were enhanced obviously. These facts implicated that the bone trabecular plate-like structure of OVX were decreased.BV/TV, Tb.N and the trabecular thickness (Tb.Th) of EBT were greater than those of OVX. Tb.Sp and SMI of EBT were much smaller than those of OVX. The results of mechanical test showed that the maximum forioe (Fmax)、the maximun stress(σmax) and the elastic modeulus(E) of the lumbar vertebral cancellous bone of OVX were declined sharply, while the aforesaid biomechanical index of EBT was improved distinctly. The performance of three-dimensional micro-CT and the mechanical testing to assess microarchitecture of cancellous bone are useful for evaluatding the state of osteoporosis and the antiosteoporotic effect of agents.更多还原