A fine-structural analysis of mouse molar odontoblast maturation

Abstract

The first mandibular molars of the Swiss albino mice, 1 through 4 days of age, were fixed in glutaraldehyde or Karnovsky’s fixative. The tissues were postfixed in Os04, dehydrated and embedded in Epon. The prepolarizing, polarizing and secretory odontoblasts were described. The prepolarizing cells, located in the vicinity of the cervical loop, were mesenchymal-like in morphology. The cells of the polarizing stage possessed organelles indicative of protein synthesis. The nucleus was located proximally. Aperiodic fibers were evident in the wide basement membrane. The secretory odontoblasts were long, slender, polarized cells closely adjoining one another. Each odontoblast possessed six morphologically discernible regions: (1) an infranuclear region, limited in size and containing few cellular organelles; (2) a nuclear region, housing the oval nucleus and a few associated lamellae of rough endoplasmic reticulum as well as a limited number of mitochondria; (3) a supranuclear rough endoplasmic reticulum region, possessing an abundance of these organelles as well as some mitochondria and secretory vesicles; (4) a Golgi region, occupying the middle third of the cell, housing the elements of an extensive Golgi apparatus which was surrounded by peripherally located profiles of rough endoplasmic reticulum; additionally, this region contained smooth endoplasmic reticulum, mitochondria, numerous secretory granules and vesicles and occasional intracellular collagen fibers; (5) an apical rough endoplasmic reticulum region, containing a rough endoplasmic reticulum component that was less extensive than its supranuclear counterpart; in addition, this region was the one richest in mitochondria and contained a plethora of secretory vesicles and granules; (6) the odontoblastic process, a region mostly void of organelles, containing various secretory products, some of which appeared to be in the process of being released extracellularly into the surrounding dentin matrix.

Morphometric analysis of the nucleolus during the life cycle of human odontoblasts

“…1). The pre-odontoblasts' morphology resembled those described in rodents (Takuma and Nagai, 1971;Gartner et al, 1979;Tominaga et al, 1984). Secretory odontoblasts presented fully developed secretory organelles as in fetal germs of deciduous teeth described by Matthiesen and von Bulow (1970) and in secretory odontoblasts of other species (Nylen and Scott, 1958;Jessen, 1967;Garant et al, 1968;Weinstock and Leblond, 1974;Sasaki et al, 1982).…”

Comparative radioautographic study of the effects of L-azetidine-2-carboxylic acid on matrix secretion and golgi of the mouse incisor

“…These structures form the intermediate vesicles believed to be responsible for the translocation of secretory product and membrane from the rough endoplasmic reticulum to the Golgi apparatus [25]. These features of the normal odontoblast Golgi complex have been previously reported [26][27][28][29] and are presented here mainly as a basis for appreciating the effects of LACA treatment on the odontoblast.…”

Distribution and organization of peripheral capillaries in dental pulp and their relationship to odontoblasts

“…Odontoblasts show remarkable differences in the degree of polarity, the quantity of cytoplasmic organelles, and the shape of the cell bodies during dentin formation, both in continuously growing rodent incisors (Takuma and Nagai, 1971; Suzuki, 1985;Semba, 1987, 1990;Ohshima and Yoshida, 1992) and in teeth of limited growth (Gartner et al, 1979;Tominaga et al, 1984;Couve, 1986;Yoshida et al, 1988aYoshida et al, , 1990. Since morphological changes in odontoblasts have been considered to reflect their secretory activity, positional changes of the peripheral capillaries must be related to the rate of dentin deposition.…”