CALCIUM ION INTERACTIONS IN DEVELOPING DENTAL TISSUES

已知钙化组织的形成细胞负责 其有机成分的合成和分泌。相同的单元格 牵涉到矿化的某些方面，但几乎没有直接 解释其作用的证据。钙，除了参与了 矿化作用对许多代谢过程都有调节作用。 包括分泌物和酶的激活。分泌型成釉细胞是一种 两极细胞，其远端有离散的分泌活动区 形成新的釉质微晶的末端。光滑而褶皱的尾部 成熟的成釉细胞与矿化和蛋白质有关 从相邻的成熟牙釉质中去除。成釉细胞中的钙相互作用 将通过使用模型系统进行调查，在该模型系统中注入代理 这会不同程度地干扰牙釉质生理。一系列经纪人 将包括氟、钴、锶、四环素、秋水仙素和 长春花碱。通过应用特定的标准来评估 这些试剂、模型系统将被识别在哪些分泌物中，最初 晶体形成或整体矿化被选择性地抑制。这个 将详细分析这些制剂对成釉细胞功能的影响。 通过由1)能量色散X射线组成的多方法方法 光谱(EDS)微量分析和Ca45放射自显影 特定细胞层的钙水平，2)超微结构检查 细胞、釉质前体和形成釉质的形态变化 晶体，3)焦锑酸钾和酶细胞化学，EDS 微量分析、电子能量损失谱(EELS)和H3-色氨酸 放射自显影跟踪关键元素的分布和活动， 与成釉细胞及其功能相关的酶和前体。 后续时间和剂量研究将验证特定的关系 在不同的参数之间。我们的长期目标是推进我们的 对钙离子与硬组织形成细胞相互作用的认识 以及生物成矿作用的机制。这样的理解 对许多疾病的预防和治疗是必不可少的。

Formative cells of calcifying tissues are known to be responsible for synthesis and secretion of their organic components. The same cells are implicated in certain aspects of mineralization but with little direct evidence to explain their role. Calcium, in addition to being involved in mineralization, exerts regulatory influence on many metabolic processes including secretion and enzyme activation. The secretory ameloblast is a polarized cell with discrete regions of secretory activity at its distal extremity where new enamel crystallites form. Smooth and ruffle-ended maturative ameloblasts are associated with mineralization and protein removal from adjacent maturing enamel. Calcium interactions in ameloblasts will be investigated by using model systems in which agents are injected which disturb enamel physiology to varying degrees. The series of agents will include fluoride, cobalt, strontium, tetracycline, colchicine and vinblastine. By applying specific criteria for evaluating the effects of these agents, model systems will be indentified in which secretion, initial crystal formation or overall mineralization is selectively inhibited. The detailed effects of these agents on ameloblast functions will be analysed by a multimethod approach comprised of 1) energy dispersive x-ray spectroscopy (EDS) microanalysis and Ca45 autoradiography to determine calcium levels in specific cell layers, 2) ultrastructural examination for morphologic changes in cells, enamel precursors and forming enamel crystals, 3) potassium pyroantimonate and enzyme cytochemistry, EDS microanalysis, electron energy loss spectroscopy (EELS) and H3-Trytophan autoradiography to follow the distribution and activities of key elements, enzymes and precursors in relation to the ameloblasts and their functions. Follow-up time and dosage studies will verify specific relationships between the various parameters. The long-term objective is to advance our understanding of the interactions of calcium and hard tissue forming cells as well as the mechanisms of biological mineralization. Such understanding is essential for prevention and treatment of many diseases.