不同剂量地塞米松对大鼠骨质量的作用  

Effects of Different Doses of Dexamethasone on Bone Qualities in Rats

作　　者：刘衍志[1] 陈艳 赵华[1] 仲利萍[1] 吴玲芝[1] 崔燎[1,2] 

机构地区：[1]广东医学院药理教研室,湛江524023 [2]广东天然药物研究与开发实验室,湛江524023

出　　处：《生物医学工程学杂志》2011年第4期737-743,747,共8页Journal of Biomedical Engineering

基　　金：国家自然科学基金资助项目(30973574)

摘　　要：观察不同剂量地塞米松(Dex)对大鼠骨质量的影响并探讨其作用机制。31只3月龄SPF级雌性SD大鼠随机分为4组:对照组(saline 7只)、Dex-L组(1 mg/kg 8只)、Dex-M组(2.5 mg/kg 8只)、Dex-H组(5 mg/kg 8只);尾静脉注射Dex,2次/周,8周后处死。取胫骨上段制作不脱钙骨切片进行骨形态计量学分析,取左侧尺骨用于测定钙、磷和羟脯氨酸含量,股骨进行骨密度(BMD)和生物力学检测。结果表明:与对照组相比,Dex各组体重均显著下降;胫骨荧光周长百分率、矿化沉积率、骨形成率等显著降低,骨小梁面积百分数,骨小梁数目显著增加,骨小梁分离度显著减少;Dex-L BMD和Dex-M羟脯氨酸含量明显下降,Dex各组力学参数显著降低。提示:Dex显著抑制骨形成,降低骨转换,随着剂量增加,骨小梁面积百分数增加,BMD和骨生物力学性能下降,同时骨内有机质合成降低,非矿化骨形成增加,骨质量降低。以1 mg/kg的Dex对骨的质量影响最明显,该剂量略增加骨小梁面积百分数,但骨形成、骨生物力学性能、骨内有机质含量明显下降。不同剂量的Dex对骨质量的影响不同,剂量与骨质量之间无比例依赖关系。This study was aimed to investigate the effects of different doses of dexamethasone（Dex） on bone quality in rats.Thirty-one SD rats were randomly divided into 4 groups,Control（7 with saline）,Dex-L（8 with 1mg Dex./kg）,Dex-M（8 with Dex.2.5mg/kg）,Dex-H（8 with Dex.5mg/kg）,with tail injection,twice per week for 8 weeks.All the rats were killed then.Their proximal tibia were processed into undecalcified sections and measured for bone histomorphometry.The content of Ca2＋ and hydroxyproline in their left ulnars were tested.Bone mineral density（BMD） and biomechanical property of the thigh bone were tested to observe the qualities of bone.Compared to the control group,the bodyweights of the rats in different Dex treatment Groups decreased remarkably.Percent labeled perimeter（%L.Pm）,Mineral apposition rate（MAR）,Bone formation rate（BFR/BV）and so on reduced significantly.Percent trabecular area（%Tb.Ar）and Trabecular number（Tb.N）were obviously higher while Trabecular separation（Tb.sp） was remarkablely lower than those of the control group.BMD in Dex-L and the content of hydroxyproline in Dex-M reduced notablely.Biomechanical property of Dex groups decreased significantly.Dex suppressed bone formation and reduced bone turnover significantly.As the increase doses of Dex,%Tb.Ar increased,and,on the contrary,BMD and biomechanical property decreased with the reduced matrix in bone at the same time.It suggested that non-mineralized bone formation increased and biomechanical property deceased.The doses of 1mg/kg Dex had the most obvious effect on bone quality.This dose slightly increased %Tb.Ar,however,bone formation,bone biomechanical property and matrix in bone decreased obviously.Diffferent doses of Dex have different effects on bone qualities.However the dose has no direct influcing ratio to the bone qualities.

关 键 词：地塞米松 骨形态计量学 生物力学性能 骨密度 骨质量 

分 类 号：R965[医药卫生—药理学]