High-resolution electron microscopic study of the initial stage of collagen mineralization.

胶原矿化初始阶段的高分辨率电子显微镜研究。

• 批准号: 06671830
• 负责人: MIAKE Yasuo
• 金额: $ 1.34万
• 依托单位: TOKYO DENTAL COLLEGE
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06671830/
• 关键词: Unusual collagen,; Hydroxiapatite,; Formative disturbance,; High-resolution TEM,; Crystal lattice

The purpose of this study is to investigate the initial mineralization mechanism of collagen.Specimens were selected from examples of dentin containing unusual collagen agregates. Initial crystals (about 2nm thick) on normal collagen assumed needle or thin-platelet shape. On the basis of crystal morphology, initial crystals were thought to be made up of hydroxiapatite or octacalcium phosphate.But, since it was impossible to view crystal lattices and micro-area electron diffraction patterns clearly, I was unable to determine crystal type.Mature crystals (about 4nm thick) were platelet-like in shape.Their crystal-lattice spacing (about 0.82nm) indicated hydroxiapatite.Similar results were produced from crystals on unusual collagen agregates.Because unusual collagen agregates form neither periodic striations nor hole zone, their mineralization occurs independent of both these phenomena.Since the direction of the crystal c-axis coincides with that collagen-molecule long axis, it seems that crystal commence depositing lengthwise along collagen molecules.In conclusion, this study suggests that the initial mineralization of collagen comprises three events : 1) initial precipitation of octacalcium phosphate between collagen molecules, 2) subsequent transformation of octacalcium phosphate into hydroxiapatite, and 3) crystal growth of this hydroxiapatite.

本研究的目的是探讨胶原的初始矿化机制。正常胶原上的初始晶体（约2nm厚）呈针状或薄血小板状。根据晶体形态，最初的晶体被认为是由羟基磷灰石或磷酸八钙组成的。但是，由于无法清楚地观察晶格和微区电子衍射图案，我无法确定晶体类型。成熟晶体（约4nm厚）为片状，其晶格间距在不寻常的胶原聚集体上的晶体也产生了类似的结果，因为不寻常的胶原聚集体既不形成周期性条纹，也不形成空穴区，它们的矿化独立于这两种现象而发生。由于晶体c轴的方向与胶原分子长轴一致，因此似乎晶体开始沿沿着胶原分子纵向沉积。总之，这项研究表明，胶原蛋白的初始矿化包括三个事件：1）胶原蛋白分子之间磷酸八钙的初始沉淀，2）磷酸八钙随后转化为羟磷灰石，以及3）这种羟磷灰石的晶体生长。

项目成果

木代 宏: "コルヒチン投与によるラット切歯象牙芽細胞と象牙質の超微構造的変化" 歯科学報. 96(印刷中). (1996)

Hiroshi Kishiro：“秋水仙碱诱导的大鼠门牙成牙本质细胞和牙本质的超微结构变化”《牙科杂志》96（出版中）。

木代宏: "コルヒチニ投与によるラット切歯象牙芽細胞と象牙質の超微構造的変化" 歯科学報. 96. 141-166 (1996)

Hiroshi Kishiro：“秋水仙碱给药诱导的大鼠门牙成牙本质细胞和牙本质的超微结构变化”《牙科杂志》96. 141-166 (1996)。

Hiroshi Kishiro: "Ultrastructural changes in rat-insisor odontoblasts and dentin caused by abministration of colchicine." Shikwa Gakuho. Vol.96 (2). 141-166 (1996)

Hiroshi Kishiro：“秋水仙碱引起的大鼠齿牙质细胞和牙本质的超微结构变化。”