目的：观察地塞米松（Dex ）对SD大鼠股骨头组织成脂与成骨分化相关基因表达及形态学改变的影响，探讨醋酸棉酚（GAA）能否通过11β-羟基类固醇脱氢酶（11β-HSD1）调节以上改变及可能机制。方法作成年SD大鼠腹腔内注射Dex 10 mg/kg ，12周及20周后观察股骨头形态学改变，11β-羟基类固醇脱氢酶1（11β-HSD1）、过氧化物酶体增殖物激活受体γ（PPARγ）、CCAAT区/增强子结合蛋白α（C/EBPα）、Run相关转录因子2（Runx2）的表达改变；以及应用GAA后上述指标的表达特点。结果应用Dex股骨头松质骨表现为骨小梁稀疏，骨小梁的面积比值下降，骨髓脂肪组织增多，面积比值增大，改变随Dex应用时间累积加重，GAA组表现为类似改变；成骨细胞的阳性染色比例数下降，脂肪细胞比例上升，并伴随相同趋势面积改变；成脂分化基因表达上调，成骨分化性基因则下降，11β-HSD1表达增加，GAA组11β-HSD1、PPARγ、Runx2、C/EBPα基因表达增强。结论 Dex所导致的骨质改变与股骨头坏死病理特征相符，推测可能与Dex抑制了成骨分化基因表达及成脂分化基因表达上调有关，其变化与11β-HSD1表达关联密切，但GAA不能有效改变这种病理改变与基因表达异常，推测可能存在其他调节途径。%Objective To explore the effects of gossypol acetate on the morphological features and the gene expression in the femoral head of Sprague-Dawley rat in vivo after treated with dexamethasone .Methods Dexamethasone(Dex) was injected into the abdominal cavity of SD rats at an dose of 10 mg/kg ,twice a week ,and feed gossypol acetate 5 mg · kg -1 · d-1 .The controls re-ceived saline 2 mL injection .The treatment lasted for 12 and 20 weeks .The slices of the femoral head were made for HE and immu-nohistochemical study .The total mRNA was extracted for RT-PCR assessment .Results The cancellous bone trabecular became sparse ,trabecular bone area ratio decreased ,bone marrow fat tissue increased .These changes were fitted for pathological character of bone necrosis .The gossypol acetate could not affect the pathological changes .The proportion of the positive stained osteoblasts increased ,adipocytes decreased .PPARγ,C/EBPα,11β-HSD1 expression enhanced ,Runx2 down regulated in the treatment groups and GAA group .Conclusion Dex can induce evident pathological changes conform to the characters of femoral head necrosis .They may have closed correlation between 11β-HSD1 and the gene expression .But GAA could not affected the pathological changes and abnormality of the gene expression .
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