Histochemical studies on the distribution of calcium in the cells related to the formation of dental and periodontal hard tissues.

采用组织化学、电镜、x射线显微分析等方法观察钙在牙釉质器官、牙髓和牙周组织中的分布。所有标本均快速冷冻/冷冻替代并包埋在环氧树脂中以保存形态学和细胞钙。这种方法允许在光镜下组织化学证明细胞钙为弥漫性或离散的红色Ca-GBHA沉淀，并在电镜下检查相邻的超薄切片。我们的研究发现，在分泌和成熟成釉细胞的细胞质中存在强烈的钙反应，而在其他珐琅器官细胞中不存在钙反应。电镜和x射线微分析研究证实，在分泌性成釉细胞的管泡结构中存在含钙颗粒和结晶形态，暗示这些细胞器在钙的跨细胞易位中起作用。在牙髓中，分化成牙髓细胞中有Ca-GBHA反应，但在其他牙髓细胞中没有。在牙根形成阶段的磨牙胚中，位于无反应性上皮根鞘断裂部分的成水泥细胞和成水泥细胞中出现了Ca-GBHA反应。牙槽骨形成面和吸收面上的成骨细胞和破骨细胞在细胞质中也表现出强烈的Ca-GBHA反应。在本项目中，我们因此建立了一种既保留细胞形态又保留不稳定细胞钙的组织制备方法。建立组织化学钙染色法。通过这些方法，数据表明高浓度钙在与牙釉质、牙本质或骨的形成或吸收直接相关的细胞中只存在。目前研究结果的生理意义有待进一步研究。

The distribution of calcium in the enamel organ, pulp and periodontal tissues was examined by means of histochemical, electron microscopic and X-ray microanalytical methods. All specimens were rapidly frozen/freeze-substituted and embedded in epoxy resin for the preservation of morphology and cell calcium. This method allowed a histochemical demonstration of cell calcium as diffuse or discrete red Ca-GBHA precipitates under the light microscope, and an electron microscopic examination of adjacent ultrathin sections.Our study revealed intense calcium reactions in the cytoplasm of both secretory and maturation ameloblasts, and its absence in other enamel organ cells. Electron microscopy and X-ray microanalytical studies confirmed the presence of calcium-containing granules and crystalline figures in the tubulovesicular structures of secretory ameloblasts, implicating the contribution of such organelles in transcellular translocation of calcium. In the pulp, Ca-GBHA reactins were shown in differentiated odontoblasts but not in other pulp cells. In molar tooth germs at the stage of root formation, Ca-GBHA reactions appeared in cementoblasts and precementoblasts located at disrupted portions of unreactive epithelial root sheath. Osteoblasts and osteoclasts on the forming and absorbing surfaces of the alveolar bone also showed intense Ca-GBHA reactions in the cytoplasm.In this project, we thus established a tissue preparation method whereby both cell morphology and unstable cell calcium is preserved. A histochemical calcium staining method was also established. With these methods, data suggesting the exclusive localization of high concentrations of calcium in cells directly related to formation or absorption of enamel, dentin or bone were presented. The elucidation of the physiological significance of present findings awaits further studies.