大鼠切牙生长发育的组织学和免疫组织化学研究

Histological and immunohistochemical studies on development of rat incisor

目的 :探讨釉质发育中釉器细胞的形态分化与其功能分化的关系 ,研究成熟期成釉细胞的 SA部与 RA部的形态在功能上的意义。方法 :采用大鼠进行心脏灌流固定、Epon、GMA树脂包埋 ,半薄切片技术 ,后进行甲苯氨蓝和组织化学染色 ,观察大鼠切牙发育组织形态学变化以及牙釉质蛋白的分布规律。结果 :大鼠的牙胚发育分为增殖期、分化期、成熟期。在成熟期成釉细胞呈特异的周期性变化 ,即 SA部和 RA部交替出现。组织化学研究结果显示在釉质形成期 ,釉质蛋白大部分留在釉基质层 ,也有一部分向牙本质内扩散到牙本质、牙本质小管以及造牙本质细胞层内。结论 :1大鼠切牙釉器发育的增殖期、分化期、成熟期分别与人牙的蕾状期、帽状期、钟状期相似。成熟期成釉细胞的 RA部与无机质的注入有关系 ,SA部与水和蛋白质的脱去有关系。 2关于牙釉质蛋白向牙本质侧的扩散 。

? Objective:The study discussed the relationship between the cell differentiation and its function differentiation of enamel organ during the development of enamel,explained the meaning of shape and function of SA and RA in the mature enameloblasts.Methods:The rats were fixed with pouring hearts,embed with Epon and GMA resin,made semithin slice,stained with toluidine blue and histochemistry,then we observed the changes of histomorphology and the law of distribution of enamel.Results:The developmemt of tooth germ of rat incisor could be divided into proliferation stage,difference stage and mature stage.Enameloblasts expressed special periodic changes in mature stage:SA legion and RA legion presented altermately.Histochemical study indicated that most of amelogenin stayed in enamel matrix and others diffused to dentin,dental tube and odontoblast layer.Conclusion:① The proliferation stage,difference stage and mature stage of tooth of development of enamel organ in rat were similar to the bud stage,cap stage and bell stage of human being.There was a relationship between the RA legion in mature enameloblast and mineral substance pouring into them.RA legion was presented because water and protein lost.②That amelogenin spread into dentin could promote the odontoblast differentiation and induce dentin calcification.