摘要
目的 研究卵巢切除大鼠皮质骨的几何学改变和力学性能改变 ,探讨雌激素缺乏时皮质骨改变的发生机理。方法 选雌性SD大鼠 5 6只 ,分为Sham组和OVX组 ,动物分别在 4、12、2 0和 2 8周时处死 7只 ,取其胫骨备用。左侧于近 3 5和远 2 5交界部切断 ,在电镜下摄片 ,计测截面总面积、皮质骨面积、骨外径周长、骨髓腔面积和骨内径周长。右侧以近 3 5与远 2 5交界点为加载点进行三点弯曲力学实验。结果 Sham组术后 4周至 2 8周胫骨截面总面积和骨外径周长逐渐增加。 (P <0 0 0 5 ) ,而髓腔面积和内径周长变化不明显。OVX组截面总面积和外径周长也有逐渐增加趋势 ,但差异无显著性。而内径周长和髓腔面积都明显增加 ,在相同时期显著大于Sham组 (P <0 0 0 5 ) ,而皮质骨面积却与Sham组差异无显著性。三点弯曲试验结果表明 ,从 4～ 2 8周实验对照两组抗弯强度和刚度均逐渐增加 ,但两组间差异无显著性。在各时期骨组织材料力学性能也无显著性差异。结论 卵巢切除对皮质骨的影响主要表现在使骨髓腔扩大 ,对骨外膜的影响较小 ,在短期内对皮质骨的力学性能无明显影响。
Objective\ With the aim of studying the changes in geometry,morphology and mechanical properties of cortical bone in ovariectomized rats,the authors tried to find out the mechanism of changes in cortical bone due to estrogenic hormone deficiency. Methods\ Fifty\|six female SD rats,three months old,weighing 240 g,were randomly divided into sham\|operated group(sham),and ovariectomined group(OVX).Seven rats each time were killed at the end of the 4 th,12 th,20 th and 28 th week,and tibias were taken out for experiment.The left tibia was excised at the junction of proximal 3/5 and distal 2/5,and was photographed under electron microscope.The total tissue area,cortical area,periosteal perimeter,area of marrow cavity and perimeter of endosteum were measured.For the right tibia,the continuous loading point was chosen at proximal 3/5 and distal 2/5 as place to make three\|point bending tests. Results\ In the sham group,the total tissue area and periosteal perimeter gradually increased from 4 th to 28 th week while there was no distinct change in the area of marrow cavity and perimeter of endosteum.In OVX group the total tissue area and periosteal perimeter also showed a tendency to increase,but there was no significant difference between the two groups.The perimeter of endosteum and area of marrow cavity were significantly larger than those in the sham group,but no distinct difference was found in the cortical area of tibia between the two groups at the same stage of experiment.The three\|point bending test showed that from 4 th to 28 th week,the structure strain and stiffness of tibia increased gradually in both groups, but there was no significant difference between the two groups.Neither was in the mechanical properties of tibial cortical bone between the two groups at every stage of experiment. Conclusion\ The effect of ovariectomy on corticat bone mainly consists of expanded area of marrow cavity while periosteum was little affected and no remarkable change in mechanical properties ensues.\;
出处
《中国骨质疏松杂志》
CAS
CSCD
2001年第1期22-24,共3页
Chinese Journal of Osteoporosis
