Evolution of Mechanisms of Enamel Formation and its Biological Significance.

牙釉质形成机制的演变及其生物学意义。

• 批准号: 60440084
• 负责人: SUGA Shoichi
• 金额: $ 13.12万
• 依托单位: The Nippon Dental University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (A)
• 财政年份: 1985
• 资助国家: 日本
• 起止时间: 1985 至 1987
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-60440084/
• 关键词: Teeth; Evolution of teeth; Tooth enamel; Enameloid; Mineralization; Trace element; Fluoride; 系統発生; エナメロイド; 進化; ストロンチウム; 鉄; 石灰化組織; 魚

The purpose of present project was to verify the evolution of formation mechanisms of tooth enamel and enameloid, which are most highly mineralized in the tissues of vertebrate The project was consisted of following in vestigations.1).Progressive mineralization pattern of the developing enamel and enameloid of the various animals were investigated comparatively by means of microradiography and tetracycline labelling. The microradiograms were examined by the computer aided image processing.The process of enamel formation is composed of the matrix formation stage in which the organic matrix formed by the secretory ameloblasts is slightly mineralized immediately after it is laid down and the maturation stage which takes much longer period than the previous stage and in which the matrix is very heavily mineralized secondarily. During the latter stage, the gradient and the time of completion of mineralization and the final mineralization degree are different in the each layer of enamel and … More enameloid. These findings are consistently observed for tooth germs of various animals ranging from the fishes to the mammals. The results suggest that the enameloid of fish teeth is a primitive type of the enamel of amphibians, reptiles and mammals.2). The concentration and distribution pattern of the trace elements in the enamel and enameloid of the various animals were examined using the electron microprobe after the microradiographical investigation of their ground sections were made. The fishes may be divided into two groups in terms of fluoride concentration in the enameloid, the fishes whose enameloid contains fluoride higher than about 2.0% and those whose enameloid contains fluoride lower than about 0.2% Difference of fluoride concentration in the enameloid seems to be related to the phylogeny of fishes rather than to the fluoride concentration in the environmental water.In the animals of amphibians, reptiles and mammals examined, there is no enamel which contains so high fluoride as obsered in the enameloid of the first group of fishes. On the other hand, the chloride concentration which is very low in the enameloid of fishes and in the enamel of amphibians increase very highly in the narrow surface enamel of reptiles and in the entire enamel of the mammals ranging from insectivore to marsupials and shows very peculiar distribution pattern. It is considered that extent of chloride incorporation into the mineralizing enameloid and enamel is related to the evolution of their formation mechanisms. The iron concentration is considered to be also related to the evolution of formation mechanisms of enameloid and enamel. Less

本研究的目的是验证脊椎动物组织中矿化程度最高的牙釉质和釉质的形成机制的演变。本研究包括以下几个方面的研究：1)通过显微放射照相和四环素标记，比较研究了不同动物发育过程中牙釉质和釉质的矿化规律。牙釉质的形成过程包括基质形成阶段和成熟阶段，基质形成阶段是由分泌性成釉细胞形成的有机基质在放置后立即轻度矿化，成熟期比前一阶段需要更长的时间，其次是基质的高度矿化。在后期，牙釉质和…各层的矿化梯度、矿化完成时间和最终矿化程度不同更多的釉质。这些发现在从鱼类到哺乳动物的各种动物的牙胚中都得到了一致的观察。结果表明，鱼牙釉质是两栖类、爬行动物和哺乳动物牙釉质的原始类型。在对各种动物的釉质和釉质研磨切片进行显微放射照相后，用电子探针研究了它们的微量元素含量和分布规律。根据釉质中氟的含量可将鱼类分为两类，釉质含氟量高于2.0%的鱼类和含氟量低于0.2%左右的鱼类釉质含氟量的差异似乎与鱼类的系统发育有关，而与环境水中氟的浓度无关。在所研究的两栖、爬行动物和哺乳动物中，没有观察到像第一类鱼的釉质含氟量那样高的釉质。另一方面，在鱼类的釉质和两栖动物的釉质中，氯的浓度很低，在爬行动物的狭窄表面釉质和哺乳动物从昆虫到有袋动物的整个釉质中，氯的浓度增加得很高，并表现出非常特殊的分布规律。认为氯离子进入成矿牙釉质和釉质中的程度与其形成机制的演化有关。铁的浓度也被认为与牙釉质和牙釉质形成机制的演化有关。较少

项目成果

須賀 昭一: 大森昌衛,須賀昭一,後藤仁敏編 『海洋生物の石灰化と系統発生』東海大学出版会.

Shoichi Suga：Masae Omori、Shoichi Suga、Hitotoshi Goto（编辑）海洋生物的钙化和系统发育，东海大学出版社。

須藤 豊哉,須賀 昭一: 歯学. 75. 412-413 (1987)

须藤丰也，须贺翔一：牙科 75. 412-413 (1987)

Shoichi SUGA et al.: Eds Fluoride Research 1985.Studies in Environmental Science,Vol.27 1986 Elsevier Science Publishers B.V.,Amsterdam.285-297 (1986)

Shoichi SUGA 等人：氟化物研究编辑 1985。环境科学研究，第 27 卷 1986 Elsevier Science Publishers B.V.，阿姆斯特丹.285-297 (1986)

Shoichi SUGA et al.: J.Dent.Res.65(Sp Iss). 733 (1986)

Shoichi SUGA 等人：J.Dent.Res.65(Sp Iss)。

Suga, S., Taki, Y. and Wada, K.: "Fluoride Concentration in the Enameloid of the Lower Teleost Fishes." J Dent Res. 65(Abst). 733 (1986)

Suga, S.、Taki, Y. 和 Wada, K.：“低等硬骨鱼釉质中的氟化物浓度”。