Examination on the role and the proliferation mechanism of the epithelial rests of Malassez.

马拉色上皮残基的作用及增殖机制的探讨。

• 批准号: 17591995
• 负责人: HASHIGUCHI Isamu
• 金额: $ 2.24万
• 依托单位: KYUSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17591995/
• 关键词: epithelial rests of Malassez; rat; induced periapical lesion; TrkA

We examined immunohistochemically the distribution of inflammatory cells, epithelial rests of Malassez (ERM) and nerve fibers in induced rat periapical lesion. In the apical periodontium, inflammatory cells infiltrated and nerve fibers increased in density in a time dependent fashion. In the cervical and bifurcational periodontium, however, severe inflammatory reactions were not observed and the density of nerve fibers seemed to be normal as compared to the findings of control rats among the all experimental periods. Cross relationships between ERM and nerve fibers were not found histologically. In this situation, the proliferation of ERM was not recognized. In the periodontium of rats with accidentally perforated pulp floor, however, severe inflammatory responses took placed and the enlarged mass of ERM were observed at 6 weeks after the operation. This finding indicated that inflammatory factors might be responsive to the proliferation of ERM. In the cervical and bifurcational periodontium, ERM and osteoblasts were immunoreactive to TrkA. As time passed after the surgery, the immunoreactivity of both ERM and osteoblasts decreased. It was of particular interest that osteoblasts distributed on opposite site to ERM showing weak or negative TrkA immunoreactivity decreased in number and also showed weak or negative TrkA immunoreactivity. It was reported that the furcation area of molars was area at which the alveolar bone and periodontal ligament was remodeled actively. It was suggested that fibroblast-derived NGF, which was subject to receptor-mediated internalization by odontoblasts, might regulate odontoblasts. Taking these findings into consideration, TrkA-positive ERM might play important role in regulation of bone remodeling in the cervical and bifurcational periodontium.

用免疫组织化学方法观察了大鼠根尖周病变组织中炎性细胞、上皮细胞和神经纤维的分布。根尖周炎性细胞浸润，神经纤维密度增加，呈时间依赖性。然而，在颈部和分叉牙周组织中，没有观察到严重的炎症反应，神经纤维的密度似乎是正常的，与对照组大鼠的结果相比，在所有实验期间。组织学上未发现ERM与神经纤维的交叉关系。在这种情况下，机构风险管理的扩散没有得到承认。而髓室底穿孔大鼠牙周组织中，术后6周出现严重的炎症反应，并可见大量的ERM。这一发现表明，炎症因子可能是响应于ERM的增殖。在颈部和分叉牙周组织中，ERM和成骨细胞对TrkA呈免疫反应性。随着手术后时间的推移，ERM和成骨细胞的免疫反应性下降。特别值得注意的是，分布在ERM相反部位的成骨细胞显示弱或阴性TrkA免疫反应，数量减少，也显示弱或阴性TrkA免疫反应。磨牙根分叉区是牙槽骨和牙周膜改建活跃的区域。这表明，成纤维细胞来源的神经生长因子，这是受成牙本质细胞的受体介导的内化，可能会调节成牙本质细胞。因此，TrkA阳性的ERM可能在调节颈分叉牙周组织的骨重建中发挥重要作用。