Structural features of forming and developing blood capillaries of the enamel organ of rat molar tooth germs observed by light and electron microscopy

Structural features of forming and developing blood capillaries of the enamel organ of rat molar tooth germs observed by light and electron microscopy

Autor Manzke, E. Google Scholar
Katchburian, E. Google Scholar
Faria, F. P. Google Scholar
Freymuller, E. Google Scholar
Instituição Universidade Federal de São Paulo (UNIFESP)
Univ Vale Itajai
Resumo The process of vascularization of the enamel organ, a unique epithelial structure, occurs when the tooth germ is fully developed, i.e., at the onset of dentinogenesis. Although the three-dimensional organization of the capillaries has been previously investigated, the structural features underlying the formation of the new capillaries remains poorly understood. Thus, in the hope of better understanding the mechanism of formation of the stellate reticulum capillaries, upper first molar tooth germs of newborn and 3-day-old rats were fixed in glutaraldehyde-formaldehyde and processed for light and electron microscopy. Our results showed that blood capillaries are initially in close proximity to the outer enamel epithelium. Between and intercalated with the capillaries are round/ovoid clusters of cells, some of which are vacuolated, closely apposed to the outer enamel epithelium. the outer enamel epithelium is not a continuous layer, but exhibits gaps between the cells. This suggests that the capillaries penetrate the enamel organ through these gaps, since no invagination of the epithelium was observed. the presence of a cluster of cells containing vacuoles suggests that vasculogenesis is taking place. Images showing loss of the basal lamina, proliferation of endothelial cells, presence of filopodia and lateral sprouting suggests that angiogenesis is also occurring. Thus, neoformation of capillaries of the molar enamel organ of rat seems to occur simultaneously by mechanisms of vasculogenesis and angiogenesis.
Palavra-chave rat molar
enamel organ
vasculogenesis
angiogenesis
ultrastructure
Idioma Inglês
Data de publicação 2005-09-01
Publicado em Journal of Morphology. Malden: Wiley-Blackwell, v. 265, n. 3, p. 335-342, 2005.
ISSN 0362-2525 (Sherpa/Romeo, fator de impacto)
Publicador Wiley-Blackwell
Extensão 335-342
Fonte http://dx.doi.org/10.1002/jmor.10363
Direito de acesso Acesso restrito
Tipo Artigo
Web of Science WOS:000231690300008
Endereço permanente http://repositorio.unifesp.br/handle/11600/28441

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