Cho M I, Lin W L, Garant P R
Department of Oral Biology, School of Dental Medicine, State University of New York, Buffalo 14214.
Anat Rec. 1991 Sep;231(1):14-24. doi: 10.1002/ar.1092310104.
Occurrence of epidermal growth factor (EGF)-binding sites during differentiation of cementoblasts and periodontal ligament (PDL) fibroblasts was investigated using radioautography after I. V. injection of 125I-EGF to 14-day-old rats. During differentiation of cementoblasts, a very low level of EGF-binding sites was present on the mesenchymal cells in dental follicle proper, precementoblasts, and cementoblasts. On the other hand, during differentiation of PDL fibroblasts, numerous EGF-binding sites were observed on the undifferentiated paravascular cells and on the perifollicular mesenchymes representing the major source of PDL fibroblast precursor cells. Also heavy labeling was observed throughout their differentiation to PDL fibroblasts, as well as during full synthetic activity as mature cells. Quantitative analysis of the light microscopic radioautographs revealed that these cells demonstrated approximately 4 grains per 100 microns 2 of cell area. These results suggest that EGF plays an important role in differentiation of PDL fibroblasts, but not in that of cementoblasts. Furthermore, the well-known in vivo effect of EGF in producing precocious eruption of teeth may be a consequence of a more extensive effect of EGF throughout differentiation of PDL fibroblasts as well as during full synthetic activity as mature cells.
通过给14日龄大鼠静脉注射125I-表皮生长因子（EGF）后进行放射自显影，研究了成牙骨质细胞和牙周膜（PDL）成纤维细胞分化过程中EGF结合位点的出现情况。在成牙骨质细胞分化过程中，牙囊固有间充质细胞、前成牙骨质细胞和成牙骨质细胞上存在非常低水平的EGF结合位点。另一方面，在PDL成纤维细胞分化过程中，在未分化的血管旁细胞和代表PDL成纤维细胞前体细胞主要来源的滤泡周围间充质上观察到大量EGF结合位点。在它们向PDL成纤维细胞分化的整个过程中，以及作为成熟细胞进行充分合成活动期间，也观察到大量标记。对光镜放射自显影片的定量分析表明，这些细胞每100平方微米细胞面积显示约4个银粒。这些结果表明，EGF在PDL成纤维细胞的分化中起重要作用，但在成牙骨质细胞的分化中不起作用。此外，EGF在体内使牙齿早萌的众所周知的作用可能是EGF在PDL成纤维细胞整个分化过程以及作为成熟细胞进行充分合成活动期间产生更广泛作用的结果。
