Apoptosis in the early developing periodontium of rat molars

Apoptosis in the early developing periodontium of rat molars

Author Cerri, Paulo Sergio Autor UNIFESP Google Scholar
Freymüller-Haapalainen, Edna Autor UNIFESP Google Scholar
Katchburian, Eduardo Autor UNIFESP Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Abstract Development of the periodontium involves a series of complex steps that result in the formation of root dentine, cementum, bone and fibres of the ligament. These precisely controlled and timed events require the participation of the enamel organ derived epithelial cells of Hertwig's (HRS) and ectomesenchymal cells of the dental follicle. These events involve rapid turnover of the tissues and cells, including disappearance of epithelial cells of HRS, Thus, it seemed likely to us that programmed cell death (apoptosis) may play a role in the development of the periodontium.Fragments of first molars, obtained from 14- and 29-day-old rats, were fixed in glutaraldehyde-formaldehyde and processed for light and electron microscopy. For the TUNEL method for detection of apoptosis, specimens were fixed in 4% formaldehyde and embedded in paraffin.Results confirmed that epithelial cells of HRS maintain a close relationship with the forming dentine root, and that they may become trapped in the dentino-cemental junction. Some of the epithelial cells exhibited ultrastructural features which are consistent with the interpretation that they were undergoing programmed cell death, i.e. apoptosis. Periodontal fibroblast-like cells showed typical images of apoptosis and engulfed apoptotic bodies; TUNEL positive structures were present in all corresponding regions. It seems therefore that apoptosis of epithelial cells of HRS and fibroblast-like cells of the periodontal Ligament constitutes an integral part of the developmental process of the tissues of the periodontium. Anat Rec 258:136-144, 2000. (C) 2000 Wiley-Liss, Inc.
Keywords apoptosis
Hertwig's root sheath
periodontal ligament
periodontium
cementum
Language English
Date 2000-02-01
Published in Anatomical Record. New York: Wiley-liss, v. 258, n. 2, p. 136-144, 2000.
ISSN 0003-276X (Sherpa/Romeo, impact factor)
Publisher Wiley-Blackwell
Extent 136-144
Origin http://dx.doi.org/10.1002/(SICI)1097-0185(20000201)258:2<136
Access rights Open access Open Access
Type Article
Web of Science ID WOS:000085120800003
URI http://repositorio.unifesp.br/11600/42533

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