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| 糖皮质激素对成年大鼠骨量的影响 |
| Effect of glucocorticoid on bone mass in adult rats |
| 投稿时间：2013-04-01 |
| DOI： |
| 中文关键词: 双能X线吸收测量法 大鼠 糖皮质激素 骨密度 |
| 英文关键词:DXA Rats Glucocorticoids Bone mineral density |
| 基金项目:中央高校基本科研业务费专项资金（2012QNZT150）；湖南省科学技术厅科技计划（2012WK3039） |
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| 中文摘要: |
| 目的：利用双能X线吸收法（DXA）探讨成年大鼠接受糖皮质激素后骨量变化的规律。方法21只44周龄SD雌性大鼠分别假性去卵巢＋未注射糖皮质激素（SHAM组）、摘除双侧卵巢（OVX组）或注射甲基强的松龙[2.5mg/（kg·d）]（PRED组），应用扇形束DXA（QDR-4500A）每4周测定一次全身骨密度（BMD）、骨矿含量（BMC）、骨骼面积（AREA）；术后12周处死，测定离体腰椎、股骨、胫骨及其兴趣区的BMD、BMC、AREA。压缩试验测定第二腰椎最大载荷和弹性模量。结果（1）术后8周开始OVX组体重显著重于同龄SHAM组（8周时，P＜0.05，12周时P＜0.01），术后4周开始PRED组体重显著轻于同龄SHAM组（P＜0.05）；（2）术后12周OVX组整体BMC显著高于SHAM组（P＜0.05），术后8、12周OVX组整体BMC显著高于PRED组（P＜0.05）；（3）术后12周OVX组离体第5、6腰椎BMD及第6腰椎BMC显著低于SHAM组和PRED组（P＜0.05），PRED组离体各腰椎BMD、BMC、AREA与SHAM组无明显差异；（4）术后12周与SHAM组比较，OVX组离体股骨（-7.42％）、股骨远端（-10.85％）和近端（-6.92％）、胫骨近端（-11.40％）BMD显著降低（P＜0.05），其中股骨、股骨远端、胫骨近端BMC也显著降低（P＜0.05）；（5）术后12周与SHAM组比较，PRED组离体股骨及各区BMD、BMC、AREA无显著性差异，整体胫骨及各区BMD无显著性差异；（6）术后12周与SHAM组比较，OVX组及PRED组胫骨中远端骨量增加；（7）与SHAM组比较，OVX组最大载荷和弹性模量显著降低，PRED组最大载荷显著降低。结论成熟期大鼠接受甲基强的松龙后，皮质骨和松质骨骨量没有显著变化，DXA检查难以发现其骨丢失情况；力学性能改变提示糖皮质激素更多的是引起骨质量的改变而导致了力学性能的下降及骨折的发生。 |
| 英文摘要: |
| Objective To investigate the effect of glucocorticoid on bone mass in mature rats using dual X-ray absorptiometry (DXA).Methods Twenty-one 44-week female Sprague-Dawley rats were randomized into sham operation group (SHAM), ovariectomy group ( OVX) , and prednisolone group ( PRED) .Rats in PRED were injected with methylprednisolone at the dose of 2.5mg· kg-1· d-1.Bone mineral density (BMD), bone mineral content (BMC), and bone area (AREA) of the whole skeleton were measured using DXA (QDR-4500A, Hologic) every 4 weeks in vivo.At the 12th week after the operation, all the rats were executed.And then BMD, BMC, and AREA of the lumbar vertebrae, the femur, and the tibia were mesasured.The compression test was performed to test the maximum loading and elastic modulus of the L2 vertebrae.Results The body weight in OVX group increased significantly compared with that in SHAM group from the 8th week after the operation (the 8th week, P<0.05; the 12th week, P<0.01).The body weight in PRED group was significantly lower than that in SHAM group from the 4th week after the operation (P<0.05).BMC of the whole body in OVX group was significantly higher than that in SHAM group at the 12th week after the operation (P<0.05), and the results in OVX group at the 8th and the 12th week were significantly higher than those in PRED group (P<0.05).BMD of L5 and L6 and the BMC of L6 in OVX at the 12th week after the operation was significantly lower than that in SHAM or PRED group ( P<0.05 ) .No significant difference of BMD, BMC, and bone area of the lumbar vertebrae ( L4, L5, and L6) between PRED group and SHAM group was observed in vitro.Compared with that in SHAM group, a significant lower BMD of the femur ( -7.42%) , the distal femur ( -10.85%) , the proximal femur ( -6.92%) , and the proximal tibia (-11.40%) in OVX group at the 12 th week after the operation was observed in vitro.And a significantly lower BMC of the femur, the distal femur, and the proximal tibia was also observed (P<0.05).At the 12th week after the operation, no significant difference of BMD, BMC, and bone area of the whole femur and all regions of interest of the femur, and BMD of whole tibia and all regions of interest of the tibia was observed between SHAM and PRED group.Compared with that in SHAM group, a significant increase of the bone mass of the distal tibia in OVX group and PRED group was observed.And the maximum loading and elastic modulus in OVX group were significantly lower than those in SHAM group, and the maximum loading in PRED group also decreased significantly.Conclusion After the injection of methylprednisolone in mature rats, no significant change in cortical and cancellous bone mass is observed.It is difficult to detect the bone mass loss using DXA.The changes of biomechanical properties indicate that glucocorticoid induces the change of bone mass, thus resulting in the decrease of biomechanical properties and the occurrence of fractures. |
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