摘要
目的观察地塞米松(Dex)不同作用时间对大鼠骨量、骨组织维生素D受体(VDR)和血清25羟维生素D3(25(OH)D3)的影响。方法 40只3.5月龄的sprague-dawley(SD)雌性大鼠,随机分为Dex组和对照组,每组20只,分别干预4周和9周。Dex组肌肉注射Dex 2.5 mg/kg,每周2次,对照组注射等量生理盐水。干预4周和9周分别用双能X线骨密度仪测骨密度,逆转录聚合酶链反应和免疫组化法检测骨组织VDR mRNA和蛋白的表达水平,用ELISA法检测血清25(OH)D3的含量。结果干预4周,Dex组大鼠体重下降(56.67±24.43)g,9周下降(85.83±26.35)g(P<0.05);Dex组体重低于对照组(P<0.01)。干预9周,Dex组骨密度低于对照组(P<0.05)。干预4周,Dex组大鼠骨组织VDR mRNA表达高于对照组(1.48±0.32 vs 1.15±0.19)(P<0.05);9周,Dex组大鼠骨组织VDR mRNA表达低于对照组(1.07±0.35 vs 1.38±0.29)(P<0.05)。Dex组大鼠骨组织VDR蛋白表达在4周和9周与对照组均无差异(P>0.05)。干预4周,Dex组血清25(OH)D3含量与对照组无差异(P>0.05);9周,Dex组血清25(OH)D3含量低于对照组(P<0.05)。结论 SD大鼠肌肉注射Dex2.5mg/kg,每周2次,9周能成功建立糖皮质激素性骨质疏松模型。Dex可能通过减少VDR的转录和25(OH)D3的含量来引起骨密度下降,导致骨质疏松的发生。
Objective To investigate the effect of dexamethasone（ Dex） on bone mass,vitamin D receptor（ VDR）,and 25（ OH） D3 in rats at different time. Methods Forty 3. 5-month-old Sprague Dawley（ SD） rats were randomly assigned to Dex group and control group,with 20 rats in each group. The rats in Dex group were intramuscularly injected 2. 5 mg / kg Dex twice a week,while rats in control group were injected equivalent normal saline intramuscularly. BMD was measured using dual energy Xray absorptiometry. The expression of VDR mRNA and protein in bone tissue was measured with reverse transcription-polymerase chain reaction（ RT-PCR） and immunohistochemistry. 25-hydroxyvitamin D（ 25（ OH） D3） was detected with ELISA. Results The weight of rats decreased 56. 67 ± 24. 43 g in 4 weeks after intervention,and decreased 85. 83 ± 26. 35 g in 9 weeks. The weight of rats in Dex group was lower than that in control group（ P〈0. 01）. At 4 weeks,the expression of VDR mRNA in Dex group was higher than that in control group（ 1. 48 ± 0. 32 vs 1. 15 ± 0. 19,P〈0. 05）,but it was lower at 9 weeks（ 1. 07 ± 0. 35 vs 1. 38 ±0. 29,P〈0. 05）. The expression of VDR protein in Dex group was not different comparing to that in control group at 4 and 9weeks. The serum level of 25（ OH） D3 in Dex group had no change at 4 weeks,but decreased significantly at 9 weeks（ P〈0. 05）.Conclusion GIOP animal model can be successfully established by injecting 2. 5mg / kg Dex twice a week intramuscularly for 9weeks in SD rats. Dex may decrease BMD resulting in osteoporosis by decreasing VDR transcription and 25（ OH） D3 level.
出处
《中国骨质疏松杂志》
CAS
CSCD
北大核心
2015年第7期769-773,共5页
Chinese Journal of Osteoporosis
基金
国家自然科学基金(81260142)
广西自然科学基金(2013GXNSFAA019174)
