Smith C E, Warshawsky H
Anat Rec. 1977 Aug;188(4):407-15. doi: 10.1002/ar.1091880402.
Cytological examination of the rat incisor enamel organ with the light and electron microscope revealed a small number of ameloblasts which contained two and sometimes three or more nuclei per cell. A multinucleate ameloblast usually contained two vertically apposed nuclei situated near the base of the cell. A narrow cytoplasmic band was interposed between adjacent nuclear envelopes. The apical nucleus was often the more elongated of the two nuclei and it fitted a convexity or a concavity within the more basally positioned nucleus. In serial sections examined with the electron microscope no connections were observed between the nuclei. In animals injected with 3H-thymidine instances of multinucleate ameloblasts were found within the advancing front of labeling where only one of the nuclei contained label. Finally, quantitative analysis by nuclear counting established that multinucleate ameloblasts were 60 times more frequent within the maturation zone as in the secretory zone of amelogenesis. As well, the numbers of multinucleate ameloblasts increased progressively in the course of the maturation stage. It was concluded that multinucleate ameloblasts increase with cell age and likely arise by the process of cell fusion.
利用光学显微镜和电子显微镜对大鼠切牙釉质器进行细胞学检查，发现少数成釉细胞每个细胞含有两个，有时三个或更多细胞核。多核成釉细胞通常含有两个垂直并列的细胞核，位于细胞基部附近。相邻核膜之间有一条狭窄的细胞质带。顶端的核通常是两个核中较长的一个，它与更靠基部的核内的一个凸面或凹面相契合。在电子显微镜检查的连续切片中，未观察到细胞核之间有连接。在用3H-胸腺嘧啶核苷注射的动物中，在标记的前沿发现了多核成釉细胞，其中只有一个核含有标记。最后，通过核计数进行的定量分析确定，成熟区多核成釉细胞的出现频率是釉质形成分泌区的60倍。此外，在成熟阶段，多核成釉细胞的数量逐渐增加。得出的结论是，多核成釉细胞随着细胞年龄的增长而增加，可能是通过细胞融合过程产生的。
