仿生脉冲电磁场对0VX-0P大鼠骨密度与生物力学相关关系的影响

目的骨密度与骨的生物力学性能存在相关性，但某些治疗方法对骨密度及骨折发生率的影响并不一致，表明不同治疗方法可能对骨密度与骨的生物力学性能间的相关关系存在不同的影响。为此，本研究观察了仿生脉冲电磁场对去卵巢骨质疏松大鼠骨密度与生物力学关系的影响，并与雌激素进行了比较。方法6月龄雌性未孕Wistar大鼠160只，按体质量随机抽取分为以下4组：去卵巢组（OVX），去卵巢＋苯甲酸雌二醇组（E），假手术组（Sham），电磁场治疗组（EM）。OVX、EM、E组行双侧卵巢切除术，Sham组行假手术。术后第9W开始治疗：E组苯甲酸雌二醇肌肉注射，0．5mg／kg，1次，2W。EM组大鼠暴露于仿生脉冲电磁场治疗，1h／1次／d，OVX、Sham组不予以任何处理，作为对照组。开始治疗后6W、8W、10W、12W等时间点分别在麻醉下处死实验动物，腰6椎体、右侧股骨应用DEXA测定骨密度，并进行腰6椎体、右侧股骨生物力学指标的测定。结果股骨BMD（bone mineral densityBMD）与最大载荷、腰6椎体BMD与最大载荷之间均存在一种正向的线性关系。在股骨中，OVX较组相关曲线较Sham组相关曲线向右下方平移，E组则平移不明显，EM组则有左上方平移。在腰6椎体中，OVX、E组相关曲线向右下方平移不明显，EM组有左上方平移。结论仿生脉冲电磁场不但具有提高OVX-OP大鼠的BMD，同时改善了骨密度与生物力学性能的相关关系。

Impact of bionics pulsed electromagnetic fields in relation to BMD and biomechanics of ovariectomy osteoporosis rats

Objective The relation between BMD (bone mineral density BMD)and biomechanics was proved by other scholars, but the impacts of some treatments to BMD and fracture does not parallel.So the study aims at linear correlation between BMD and biomechanics in ovariectomy osteoporosis rats exposed to bionics electromagnetic fields. Methods One handred and sixty 6-month old female Wistar rats were randomly divided into four different groups by body mass radomly: ovariectomy group(OVX),sham operation group (Sham), E group (Estrogen+ OVX) and EM group(BEMF+OVX). All rats were subjected to bilateral ovariectomy except sham operation group. After 8 weeks operation, E group rats were given estrogen 0.5 mg/kg/1,1/2 W. EM group rats were exposed to bionics electromagnetic fields, 1 h/d. OVX and Sham group rats were given nothing. After the treatments,the rat's femurs and sixth lubers were apart abstracted and measured BMD by DEXA in 6weeks,8 weeks,10 weeks,12 weeks.Then the maximum load were measured by material testing machine. Results There were positive line relation between femurs and sixth lumber's BMD and mechanic load. In the femurs,the line in OVX group moved to down-right comparing with Sham group, the line in E group does not change, the line in EM group moved to up-left. In the sixth lumbers, the line in OVX group and E group moved to down-right comparing with Sham group, the line in EM group moved to up-left. Conclusions BEMF not makes BMD increase but also may facilitating linear correlation between BMD and biomechanics in ovariectomy osteoporosis rats.