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

用免疫组织化学方法观察了大鼠根尖周围病变中炎症细胞、马拉塞兹上皮组织（ERM）和神经纤维的分布。在根尖牙周组织中，炎症细胞浸润，神经纤维密度随时间增加。然而，在颈部和分叉牙周组织中，未观察到严重的炎症反应，神经纤维密度在所有实验期间与对照组相比似乎正常。组织学上未发现ERM与神经纤维间的交叉关系。在这种情况下，没有认识到汇率机制的扩散。而意外牙髓底穿孔的大鼠牙周组织在术后6周出现了严重的炎症反应和ERM肿大。这一发现表明炎症因子可能对ERM的增殖有反应。在宫颈和分岔牙周组织中，ERM和成骨细胞对TrkA有免疫反应。随着手术后时间的推移，ERM和成骨细胞的免疫反应性均下降。特别有趣的是，分布在ERM相反部位的成骨细胞表现出弱或负TrkA免疫反应性，数量减少，也表现出弱或负TrkA免疫反应性。据报道，磨牙分岔区是牙槽骨和牙周韧带被积极重建的区域。结果表明，成纤维细胞衍生的NGF受成牙细胞受体介导的内化影响，可能调节成牙细胞。考虑到这些发现，trka阳性ERM可能在调节颈椎和分叉牙周组织骨重塑中发挥重要作用。

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.