雌激素缺乏对牙周炎大鼠牙槽骨骨保护素表达的影响

目的 研究雌激素缺乏对牙周炎大鼠牙槽骨中骨保护素(OPG)表达的影响,探讨雌激素调节牙槽骨改建的机制.方法 采用切除双侧卵巢及牙周结扎的方法建立雌激素缺乏的大鼠牙周炎动物模型,观察大鼠牙周组织病理改变,应用免疫组织化学技术观察OPG在牙槽骨的表达,比较卵巢切除(OVX,n=18)、假手术(Sham,n=17)及雌二醇治疗(OVX+E2,n=18)3组大鼠牙槽骨OPG表达吸光度(A)值的差异.结果 各组大鼠组织学观察均显示牙槽骨骨小梁稀疏,牙槽骨表面可见破骨细胞及骨吸收陷窝,OVX组更为显著.Sham组、OVX组及OVX+E2组的牙槽骨OPG阳性表达A值分别为38 799±6228、27 854±5246和37 146±6394,OVX组吸光度低于Sham组和OVX+E2组(均P＜0.05),而Sham组和OVX+E2组之间差异无统计学意义(P＞0.05).结论 雌激素缺乏降低牙槽骨中骨保护素的表达,促进实验性牙周炎大鼠牙槽骨的吸收.

Effect of estrogen-deficiency on expression of osteoprotegerin in alveolar bone: experiment with rats with periodontitis

Objective To investigate the effects of estrogen-deficiency upon the expression of osteoprotegerin(OPG)in alveolar bone so as to clarify the role of estrogen in alveolaf bone metabolism．Methods Fifty-three SD rats were randomly divided into 3 groups:OVX group(n=18)undergoing bilateral ovariectomy,OVX+E2 group(n=18),undergoing bilateral ovariectomy and subcutaneous injection of estradiol once 3 days since day 2 after the operation,and sham operation group(n=17)undergoing sham operation.Four weeks after the operation periodontal ligature was conducted and hish-sugar diet was fed to establish periodontitis models.Four weeks later the rats were killed.The morphological changes and expression of OPG in alveolar bone were observed by light microscopy and immunohistochemistry.Results All the rats showed sparseness of bone trabeculae in alveolar bone and osteoclasts and lacuna at the surface of alveolar bone.Especially the rats of the group OVX.The A values(absorption of the OPG expression)in the alveolar bone of the OVX groups was 27 854±5246,significantly lower than those of the sham operation group and OVX+E,group(38 799±6228 and 37 146±6394 respectively,both P<0.05)without significant difference between the sham operation group and OVX+E2 group(P>0.05).Conclusion Estrogen deficiency decreases the expression of OPG in alveolar bone,and enhances the absorption of alveolar bone.