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Fine structure of the secretory and non‐secretory ameloblasts in the frog. II. Fine structure of the non‐secretory ameloblast
Author(s) -
Zaki A. E.,
MacRae Edith K.
Publication year - 1978
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.1051580205
Subject(s) - ameloblast , dentin , odontoblast , microbiology and biotechnology , enamel paint , biology , secretory vesicle , mineralized tissues , amelogenesis , anatomy , secretion , materials science , exocytosis , biochemistry , composite material
The non‐secretory ameloblasts present at the enamel‐free surfaces of maxillary teeth in the frog Rana pipiens were examined by electron microscopy at different stages of tooth development. Their main fine structural features seem to reflect a transport function. During early tooth development, the non‐secretory ameloblasts adjacent to odontoblasts and predentin exhibit extensive lateral surface specializations and numerous cytoplasmic vesicles. During late tooth development, the non‐secretory ameloblasts adjacent to mineralizing dentin show numerous cellular junctions, well‐developed intercellular channels with numerous interdigitating processes and labyrinthine configurations at their distal surfaces. An intact basal lamina is present between the non‐secretory ameloblasts and the dentin surface until the dentin becomes fully mineralized. At this stage the adjacent cells no longer exhibit surface specializations. It is suggested that the non‐secretory ameloblasts may participate in the mineralization of adjacent dentin at the enamel‐free surfaces. This surface dentin becomes fully mineralized at a later stage of development than the underlying dentin.