Youn S H, Maeda T, Kurisu K, Wakisaka S
Department of Oral Anatomy and Developmental Biology, Osaka University Faculty of Dentistry, Japan.
Arch Histol Cytol. 1999 May;62(2):139-47. doi: 10.1679/aohc.62.139.
The present immunohistochemical study was designed to investigate changes in the distribution and expression level of calbindin D28k in the periodontal ligament during experimental tooth movement in the rat molar to clarify the physiological role of this protein in the ligament. In normal animals, calbindin D28k-like immunoreactivity appeared sparsely in spindle-shaped cells in the alveolar half of the periodontal ligament. Electron microscopic observations showed that these immunoreactive cells were characterized by well-developed rough-surfaced endoplasmic reticulum and phagosomes--which often contained collagen fibers--suggesting that these cells could be categorized as periodontal fibroblasts. Twelve hours following the onset of the experimental tooth movement, cells positive for calbindin D28k increased in number in the periodontal ligament, especially in the alveolar half of the pressured side. Immunoelectron microscopy showed that the calbindin D28k-immunopositive cells had morphological features similar to those of fibroblasts in the normal ligament, and that these cells occasionally made contact with immunonegative macrophage-like cells. Immunopositive cells gradually decreased in number, and the distribution of the cells and intensity of the immunoreactivity returned to normal levels by 14 days following the induction of the experimental tooth movement. The present results suggest that calbindin D28k plays an important role in the homeostasis and cyto-protection of fibroblasts in the periodontal ligament at the initial phase of experimental tooth movement.
本免疫组织化学研究旨在调查大鼠磨牙实验性牙齿移动过程中牙周膜中钙结合蛋白D28k的分布和表达水平变化，以阐明该蛋白在牙周膜中的生理作用。在正常动物中，钙结合蛋白D28k样免疫反应性稀疏地出现在牙周膜牙槽侧的梭形细胞中。电子显微镜观察显示，这些免疫反应性细胞的特征是粗面内质网和吞噬体发达，吞噬体中常含有胶原纤维，这表明这些细胞可归类为牙周成纤维细胞。实验性牙齿移动开始12小时后，牙周膜中钙结合蛋白D28k阳性细胞数量增加，尤其是在受压侧的牙槽侧。免疫电子显微镜显示，钙结合蛋白D28k免疫阳性细胞具有与正常牙周膜中成纤维细胞相似的形态特征，且这些细胞偶尔与免疫阴性的巨噬细胞样细胞接触。免疫阳性细胞数量逐渐减少，到实验性牙齿移动诱导后14天，细胞分布和免疫反应强度恢复到正常水平。目前的结果表明，钙结合蛋白D28k在实验性牙齿移动初始阶段对牙周膜成纤维细胞的稳态和细胞保护起重要作用。
