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Comparative study on the formation of biominerals in enamel and enameloid

牙釉质和釉质中生物矿物质形成的比较研究

基本信息

批准号：
16591844
负责人：
SASAGAWA Ichiro
金额：
$ 2.24万
依托单位：
The Nippon Dental University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2006
项目状态：
已结题

项目摘要

The enameloid covering the surface of the teeth in bony fishes exhibits a very high degree of mineralization, and seems to have functions similar to the enamel in mammals. The dental epithelial cells constituting enamel organs during the enameloid formation stages in rayfinned fishes were observed by transmission electron microscopy and enzyme cytochemistry, which detects hydrolytic enzyme activities. During the mineralization and maturation stages, infoldings of the distal plasma membrane in the inner dental epithelial (IDE) cells were marked, and many mitochondria and acid phosphatase positive lysosomes were present in the cytoplasm. The activities of non-specific alkaline phosphatase, calcium-dependent adenosine triphosphatase and potassium-dependent p-nitrophenylphosphatase were usually detected at the plasma membrane of the IDE cells during the mineralization and maturation stages. These results suggest that the dental epithelial cells are mainly involved in the degeneration and r … More emoval of enameloid matrix and in material transportation during the enameloid mineralization and maturation stages, and that these functions are very important to make large crystals in enameloid.Collar enamel, as well as cap enameloid, is found in the jaw teeth of Lepi sosteus and Polypterus. This means that we can observe amelogenesis following cap enameloid formation during tooth development. In this study, light and electron microscopic immunohistochemistry using antibodies specific to the C-terminal, central and N-terminal regions, respectively, of porcine amelogenin was performed to examine the collar enamel matrices. The enamel matrices showed intense immunoreactions to the C-terminal and central region-specific antibodies. The data suggest that the enamel matrix in bony fishes contains a domain that closely resembles the C-terminal and central regions of porcine amelogenin. The size of crystals in collar enamel was not so large in comparison with that in enameloid. Less absorptive function of the dental epithelial cells on the collar enamel might cause the difference between enamel and enameloid. Less

覆盖在硬骨鱼牙齿表面的釉质具有非常高的矿化度，似乎具有与哺乳动物的釉质相似的功能。用透射电子显微镜和酶细胞化学方法观察了构成釉质形成阶段的釉质器官的牙齿上皮细胞，并检测了水解酶的活性。在矿化和成熟期，内牙上皮(IDE)细胞的远端质膜明显内折，胞浆内可见大量线粒体和酸性磷酸酶阳性的溶酶体。非特异性碱性磷酸酶、钙依赖性三磷酸腺苷酶和钾依赖性对硝基苯基磷酸酶活性通常在IDE细胞矿化和成熟期的质膜上检测到。提示牙上皮细胞主要参与退变和r-…。在釉质矿化和成熟期，釉质基质有更多的迁移和物质运输，这些功能对于形成大的釉质晶体是非常重要的。领釉质和帽釉质体存在于Lepi sosteus和Polypterus的颌齿中。这意味着我们可以在牙齿发育过程中观察到牙帽釉质形成后的釉质形成。在这项研究中，分别使用针对猪釉原蛋白C末端、中央和N末端区域的抗体进行了光镜和电子显微镜免疫组织化学染色，以检测项圈釉质基质。釉质基质对C末端和中央区域特异性抗体表现出强烈的免疫反应。这些数据表明，多骨鱼类的釉质基质含有一个与猪釉原蛋白的C末端和中心区域非常相似的结构域。与牙釉质相比，领釉质中的晶体尺寸较小。牙釉质与牙釉质之间的差异可能是由于牙釉质上皮细胞对牙釉质的吸收功能减弱所致。较少