Kagayama M, Sasano Y, Zhu J, Hirata M, Mizoguchi I, Kamakura S
Department of Anatomy, Tohoku University School of Dentistry, Sendai,
Acta Anat (Basel). 1998;163(1):1-9. doi: 10.1159/000046440.
Epithelial rests of Malassez and cementoblasts were examined in the rat molars during the early stages of root formation using an antilaminin antibody and/or peanut agglutinin (PNA), and an antiosteocalcin (OC) antibody, respectively. The roots of the first molars were used for study. The antilaminin antibody stained the basement membrane surrounding the epithelial root sheath and epithelial rests. The basement membrane of the epithelial root sheath was continuous, but that of the epithelial rests was discontinuous. The cells of epithelial rests and epithelial root sheath were positive for PNA. The structural characteristics of the epithelial rests were seen in the sections stained doubly with PNA and the antilaminin antibody. The cells of epithelial rests were fibroblast-like and formed a fine mesh in 2-week-old rats. In 3-week-old rats, the epithelial rests were also present at the coronal half of root surface, showing typical cell cords, but were not present at the apical part of the root surface where the cellular cementum covered the root dentin. At the root apex of 3-week-old rats, the cells of epithelial rests forming fine meshes were seen near the epithelial root sheath. The anti-OC antibody stained cementoblasts lining acellular and cellular cementum. The sections doubly stained with the anti-OC and the antilaminin antibodies or PNA further revealed the close relation between epithelial rests and cementoblasts. The OC-positive cells lining acellular cementum or dentin were localized very close to the epithelial rests. In contrast, the OC-positive cells lining cellular cementum did not show close association with the epithelial cells, except the cells located most apically where the basement membrane of the epithelial root sheath is disrupted and the initial cellular cementum begins to be formed. The present results suggest that the epithelial rests and/or the discontinuous basement membrane of them may have a role for the acellular cementum formation at least in the early stage of root formation.
在牙根形成早期，分别使用抗层粘连蛋白抗体和/或花生凝集素（PNA）以及抗骨钙素（OC）抗体，对大鼠磨牙中的马拉瑟上皮剩余和成牙骨质细胞进行了检查。研究使用了第一磨牙的牙根。抗层粘连蛋白抗体对围绕上皮根鞘和上皮剩余的基底膜进行了染色。上皮根鞘的基底膜是连续的，但上皮剩余的基底膜是不连续的。上皮剩余和上皮根鞘的细胞对PNA呈阳性。在用PNA和抗层粘连蛋白抗体双重染色的切片中可以看到上皮剩余的结构特征。在2周龄大鼠中，上皮剩余的细胞呈成纤维细胞样并形成精细的网状结构。在3周龄大鼠中，上皮剩余也存在于牙根表面的冠方一半，呈现典型的细胞索，但在牙根表面的根尖部分不存在，此处细胞性牙骨质覆盖着牙根牙本质。在3周龄大鼠的根尖处，在上皮根鞘附近可见形成精细网状结构的上皮剩余细胞。抗OC抗体对衬于无细胞和细胞性牙骨质的成牙骨质细胞进行了染色。用抗OC抗体和抗层粘连蛋白抗体或PNA双重染色的切片进一步揭示了上皮剩余和成牙骨质细胞之间的密切关系。衬于无细胞牙骨质或牙本质的OC阳性细胞定位非常靠近上皮剩余。相比之下，衬于细胞性牙骨质的OC阳性细胞与上皮细胞没有紧密关联，除了最根尖处的细胞，此处上皮根鞘的基底膜被破坏且开始形成初始细胞性牙骨质。目前的结果表明，上皮剩余和/或它们的不连续基底膜可能至少在牙根形成的早期阶段对无细胞牙骨质的形成起作用。
