尼尔雌醇对去卵巢大鼠胫骨骨重建的影响

目的　探讨尼尔雌醇防治绝经后骨质疏松 (PMO)的作用机制。方法　雌性Wistar大鼠30只 ,随机分成假手术组、去卵巢组和尼尔雌醇治疗 (N)组。假手术组进行假手术 ,其余 2组切除卵巢制备PMO模型 ,N组使用尼尔雌醇治疗 3个月。各组动物处死后 ,取一侧胫骨提取总RNA ,逆转录 聚合酶链反应 (RT PCR)检测白细胞介素 (IL 6 )mRNA表达情况。另一侧用骨形态计量学方法研究去卵巢大鼠胫骨干骺端对尼尔雌醇的治疗反应 ,包括静力学参数 :(1)骨小梁体积 (TBV)占全部骨组织体积 (TTV)的百分比 (TBV/TTV) ;(2 )骨小梁表面与其体积之比 (S/V) ;(3)TBV占海绵骨 (SBV)体积的百分比 (TBV/SBV) ;(4 )平均骨小梁板厚度 (MTPT) ;(5 )平均骨小梁板密度 (MTPD) ;(6 )平均骨小梁板间隙 (MTPS) ;(7)平均骨皮质厚度 (MCW)。动力学参数 :(1)骨小梁类骨质表面占骨小梁表面的百分比 (TOS) ;(2 )平均类骨质宽度 (MOSW) ;(3)四环素单标记线占骨小梁表面的百分比 [Sfract(s) ];(4 )四环素双标记线占骨小梁表面的百分比 [Sfract(d) ];(5 )四环素单标记线的 1/ 2和双标记线之和占骨小梁表面的百分比 [Sfract(s/ 2 d) ];(6 )四环素双标记线间的平均距离 (DDL) ;(7)矿化沉积率 (MiAR) ;(8)矿化延迟时间 (MLT) ;(9)组织水平的骨形成率 (Svf) ;

Effect of nylestriol on bone remodeling in ovariectomized rats

Objective To clarify the effects of nylestriol on microarchitecture and interleukin-6(IL-6) mRNA expression in tibial bone in ovariectomized rats. Methods 30 female rats were randomly allocated into 3 groups: sham, OVX and nylestriol-treated group. Nylestriol-treated group were ovariectomized, then fed with nylestriol for 3 months and the bone mineral density (BMD) was measured in lumbar vertebra by dual energy x-ray absorptiometry. After sacrifice of the animal, bone histomorphometric parameters were measured to study the changes in bone microarchitecture, and RT-PCR was performed to detect the expression of IL-6 mRNA in bone tissue. Results BMD was significantly reduced, while IL-6 mRNA level elevated in the OVX group compared with the sham group. Static histomorphometric data showed that the trabecular bone volume, mean trabecular plate thickness and density were reduced while the mean trabecular plate space elevated remarkably in the OVX group in comparison with that in the sham group. As for dynamic parameters, trabecular osteoid surface, tetracyclin labeled surface and bone turnover rate were increased while osteoid maturation rate decreased significantly in the OVX group compared with the sham group. BMD, IL-6 mRNA expression and bone histomorphometric parameters were improved in nylestriol-treated rats. Conclusion Nylestriol plays an important role in maintaining bone volume and improving bone microarchitecture by markedly inhibiting bone turnover and bone resorption, which might be to some degree attributed to reduced IL-6 expression.