OVX大鼠正畸牙齿移动牙周组织TNFβ的表达

Expression of TNFβ in periodontal tissues susfaining orthodontic tooth movement in ovariectomized Rats

目的通过免疫组织化学方法，观察大鼠卵巢切除术（ＯＶＸ）后正畸牙周组织内ＴＮＦβ的表达，了解雌激素缺乏时正畸牙周组织的改建情况。方法将ＯＶＸ及对照组ＳＤ大鼠按术后的天数随机分为０、７、２１、４２ｄ组，分别施以相同的矫治装置，加力２周，力值４０ｇ，牵引大鼠第１磨牙向近中移动。实验结束后处死动物，取上颌正畸牙及其牙周组织作免疫组化染色。结果ＯＶＸ组大鼠正畸牙周组织内ＴＮＦβ呈强阳性表达，而对照组大鼠的相同部位ＴＮＦβ则呈阴性表达，主要阳性表达细胞为牙周成纤维细胞、破骨细胞；随着ＯＶＸ术后时间的延长，实验组大鼠牙周组织内ＴＮＦβ的含量逐渐增加，两组切片染色的灰度值差异有非常显著意义（Ｐ＜００１）。结论雌激素缺乏时正畸牙周组织改建有其特殊性，ＴＮＦβ在ＯＶＸ大鼠正畸牙周组织的改建中有重要作用，其机制尚需进一步研究。

Objective To observe the expression of TNFβ in periodontal tissues sustaining orthodontic tooth movement in OVX rats,and investigate the relationship between estrogen and orthodontic tooth movement.Methods Sixteen rats were randomly divided into experimental and control groups.On days 0,7,21 and 42 post-ovariectomy,the rats were sub-grouped in to pairs of each.The same orthodontic appliance was placed to all rats,and the first molar was moved mesially with 40 gram forces for two weeks.All rats were killed by over-anesthesia during the designed period of time.The maxillas were prepared for laboratory evaluation.TNFβ was stained with immunohistochemical staining technique(ABC method).Results TNFβ staining was strongly positive,especially in the plasma of oestoclasts and fibroblasts in periodontal tissues in OVX rats,and was slightly positive or negative in the same places in the control group ( P <0 01).Conclsion There are some characteristics in periodontal tissue remodelling by orthodontic tooth movement in OVX rats.TNFβ may play an important role in local regulation of bone turnover,at least in ovariectomized rats.The mechanism desewes further study.