不同剂量地塞米松对大鼠松质骨代谢的影响  

Effects of different doses of dexamethasone on trabecular bone metabolism in rat

作　　者：陈艳[1] 黄连芳[1] 刘衍志[1] 陈文双[1] 朱觉新[1] 崔燎[1] 

机构地区：[1]广东医学院天然药物研究与开发实验室,广东湛江524023

出　　处：《中国药理学通报》2012年第9期1311-1314,共4页Chinese Pharmacological Bulletin

基　　金：国家自然科学基金资助项目(No 30973574)

摘　　要：目的观察不同剂量地塞米松对大鼠松质骨骨代谢的影响。方法 31只SPF级3月龄SD♀大鼠,随机分为正常对照组、地塞米松(1、2.5及5 mg.kg-1)4个组,每周尾静脉注射给药2次,共8周。采用不脱钙骨切片和骨组织形态计量学方法观察和测量胫骨近端和第4腰椎的骨代谢参数。结果与正常组相比,地塞米松2.5及5 mg组胫骨上段骨小梁面积百分率增加;3个用药组的荧光周长百分率,骨形成率以及破骨细胞周长百分率都明显下降;而成骨细胞周长百分率只在5 mg组明显降低。腰椎骨小梁面积百分率增加差异没有显著性;但荧光周长百分率、骨形成率、破骨细胞和成骨细胞周长百分率降低差异都有显著性。结论地塞米松应用初期可能对骨代谢有促进作用而使胫骨上段骨量增加,但8周后对骨形成已经表现出明显抑制作用,并且有剂量依赖性,骨吸收也受到抑制,胫骨上段和腰椎的松质骨代谢都受到影响。Aim To investigate and study the effects of different doses of dexamethasone on trabecular bone metabolism of rat. Methods Thirty-one SPF SD rats were randomly divided into normal control group, dexamethasone 1 mg · kg^-1, 2.5 mg· kg^-1, and 5 mg · kg^-1 groups. They were intravenously injected with dexamethasone twice per week. 8 weeks later, all rats were killed and their proximal tibia metaphysis （PTM） and the fourth lumbars were processed with undecalcifled sections for bone histomorphometry analysis. Resuits Compared with normal group, percent trabecular bone area of PTM increased in 2. 5 mg and 5 mg groups. But percent labeled perimeter, bone formation rate and percentage of osteoclast perimeter of three dexamethasone groups decreased remarkably. And thepercentage of osteoblast perimeter decreased in 5mg groups only. Histomorphometric static data of lumbar vertebra displayed that there was no statistic difference in percent trabecular bone area in all dexamethasone groups, but the four dynamic parameters% L. Pm, BFR, % Ob. Pm and % Oc. Pm significantly reduced in these groups. Conclusions Dexamethasone maybe have a positive effect on bone metabolism in the begin- ning and increase the bone mass of PTM. But it soon inhibits the bone formation dose-dependently and inhibits the bone resorption as well after 8 weeks. Dexamethasone inhibits trabecular bone metabolism in both PTM and lumbar.

关 键 词：糖皮质激素 地塞米松 松质骨 骨代谢 骨组织形态计量学 大鼠 

分 类 号：R332[医药卫生—人体生理学] R322.71[医药卫生—基础医学]