caa a22 4500 397570031 CHVBK 20180308164838.0 cr unu---uuuuu 161202e199612 xx s 000 0 eng 10.1093/oxfordjournals.jmicro.a023472 doi (NATIONALLICENCE)oxford-10.1093/oxfordjournals.jmicro.a023472 Ultrastructure of Kitten Molar Secretory Ameloblasts after Quick-Freezing and Freeze-Substitution [Elektronische Daten] [Hisaho Yoshida, Megumi Inoue, Satoshi Inoue, Toshitaka Akisaka] In order to clarify the intra- and extracellular structures in kitten secretory ameloblasts, we examined quick-frozen, and freeze-substituted samples and compared them with samples conventionally processed by chemical fixation. In cryofixed material, various membranous structures showed a smooth profile. The cytoplasmic matrix was densely packed with micro-filaments and stained homogeneously, suggesting better preservation of the cytoskeleton and less extraction of the soluble ground substance. Secretory ameloblasts showed various degrees of membrane infoldings at the distal part of the Tomes' process, which contained stippled materials. Coated pits and vesicles were often observed at the membrane of the Tomes' process, which means the site of newly formed enamel. Stippled material, which appeared to be composed of interconnected lacy strands, was consistently found at the front of enamel formation. A large accumulation of the stippled material was noted in the intercellular space at the level of the distal terminal junction. These observations suggest that a stippled material exists as a precursor material secreted by ameloblasts, and that it forms a well-developed tubulovesicular system extending from the Golgi area to the distal part of the Tomes' process. A direct connection between secretory granules and some dense bodies with the tubulovesicular structure was demonstrated. This study revealed better preservation of ameloblasts and their surrounding extracellular matrix, thereby extending our knowledge of the ultrastructure in the secretory stage of ameloblasts and their extracellular regions. © 1996 Oxford University Press Full-length Papers nationallicence secretory ameloblast nationallicence stippled material nationallicence tubulo-vesicular structure nationallicence kitten molar nationallicence freeze-substitution nationallicence Yoshida Hisaho Department of Anatomy, Asahi University School of Dentistry, Hozumi 1851, Motosu-gun, Gifu, 501-02 Japan aut Inoue Megumi Department of Anatomy, Asahi University School of Dentistry, Hozumi 1851, Motosu-gun, Gifu, 501-02 Japan aut Inoue Satoshi Department of Anatomy, Asahi University School of Dentistry, Hozumi 1851, Motosu-gun, Gifu, 501-02 Japan aut Akisaka Toshitaka Department of Anatomy, Asahi University School of Dentistry, Hozumi 1851, Motosu-gun, Gifu, 501-02 Japan aut Microscopy Oxford University Press 45/6(1996-12), 483-490 0022-0744 45:6<483 1996 45 jmicro https://doi.org/10.1093/oxfordjournals.jmicro.a023472 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/oxfordjournals.jmicro.a023472 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yoshida Hisaho Department of Anatomy, Asahi University School of Dentistry, Hozumi 1851, Motosu-gun, Gifu, 501-02 Japan aut NATIONALLICENCE 700 1- Inoue Megumi Department of Anatomy, Asahi University School of Dentistry, Hozumi 1851, Motosu-gun, Gifu, 501-02 Japan aut NATIONALLICENCE 700 1- Inoue Satoshi Department of Anatomy, Asahi University School of Dentistry, Hozumi 1851, Motosu-gun, Gifu, 501-02 Japan aut NATIONALLICENCE 700 1- Akisaka Toshitaka Department of Anatomy, Asahi University School of Dentistry, Hozumi 1851, Motosu-gun, Gifu, 501-02 Japan aut NATIONALLICENCE 773 0- Microscopy Oxford University Press 45/6(1996-12), 483-490 0022-0744 45:6<483 1996 45 jmicro Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford