Kagayama M, Li H C, Zhu J, Sasano Y, Hatakeyama Y, Mizoguchi I
Department of Oral Anatomy, Tohoku University School of Dentistry, Sendai, Japan.
J Periodontal Res. 1997 Apr;32(3):273-8. doi: 10.1111/j.1600-0765.1997.tb00534.x.
To determine the phenotypic expression of cementoblasts responsible for acellular cementum, an immunohistochemical study was performed using a polyclonal antibody raised against the aminoterminal peptide of rat osteocalcin (OC). Maxillary first molars of Wistar male rats aged 2 and 3 wk were used for observations. Serial sections of decalcified paraffin embedded specimens were stained either with hematoxylin and eosin or with the anti-OC antibody. In 2-wk-old rats, apical roots were lined with the epithelial root sheath. A thin layer of acellular cementum was seen at most of the root surface, but was not seen near to root apex. In 3-wk-old rats, cellular cementum began to be formed at root apex, and acellular cementum became more thick than in 2-wk-old rats. Acellular and cellular cementum were lined with the fibroblast-like cells. Osteocalcin staining was detected in cells lining root surface in both 2- and 3-wk-old rats. Almost all cells lining cellular cementum were positive for OC. In contrast OC positive cells lining acellular cementum and root surface devoid of cementum appeared at a specific site of the root. The cells at the interradicular area of root surface were positive but the cells at the outer area (the opposite side of the interradicular area) were negative for OC. Osteoblasts and odontoblasts were positive with the antibody. The present results suggest that the OC expression of cementoblasts forming acellular cementum is similar to that of cells forming cellular cementum as well as osteoblasts and odontoblasts, and has a role for calcification of acellular cementum.
为了确定负责无细胞牙骨质形成的成牙骨质细胞的表型表达，我们使用针对大鼠骨钙素（OC）氨基末端肽产生的多克隆抗体进行了免疫组织化学研究。选用2周龄和3周龄的雄性Wistar大鼠的上颌第一磨牙进行观察。对脱钙石蜡包埋标本的连续切片进行苏木精和伊红染色或抗OC抗体染色。在2周龄的大鼠中，根尖由上皮根鞘衬里。在大多数牙根表面可见一薄层无细胞牙骨质，但在根尖附近未见。在3周龄的大鼠中，根尖开始形成细胞性牙骨质，且无细胞牙骨质比2周龄大鼠的更厚。无细胞和细胞性牙骨质均衬有类成纤维细胞。在2周龄和3周龄大鼠的牙根表面衬里细胞中均检测到骨钙素染色。几乎所有衬在细胞性牙骨质上的细胞OC均呈阳性。相比之下，衬在无细胞牙骨质和无牙骨质牙根表面的OC阳性细胞出现在牙根的特定部位。牙根表面根分叉区的细胞OC呈阳性，但外侧区域（根分叉区的对侧）的细胞OC呈阴性。成骨细胞和成牙本质细胞抗体呈阳性。目前的结果表明，形成无细胞牙骨质的成牙骨质细胞的OC表达与形成细胞性牙骨质的细胞以及成骨细胞和成牙本质细胞的OC表达相似，并且对无细胞牙骨质的钙化起作用。
