Biomaterial Database

The odontoclasts of Ambystoma mexicanum. 2000

J Wistuba, and M Bolte, and G Clemen

Institut für Spezielle Zoologie und Vergleichende Embryologie, Münster, Germany.

The resorption of teeth in Ambystoma mexicanum during postembryonal ontogenesis and induced metamorphosis occurs by means of light-microscopic detectable giant-cells. These have morphological and functional characters similar to those of odontoclasts of other vertebrates. The multinucleated odontoclasts resorb not only the pedicel (base), but the stalk of the tooth, too. When active, the cells form a ruffled border and a sealing zone. In this way they are able to demineralize the hard tissues of teeth (dentin and mineral of the pedicel) and to dissolve the extracellular matrix. Resorption of enamel has not been observed. Marks of resorption resemble the Howship's lacunae of other tetrapods. TRAP as a typical enzyme of odontoclasts could not be detected histochemically. Dependence of PTH, which is supposed to be necessary for the formation and activation of odontoclasts as well as of thyroxine can be excluded, although the resorbing cells are functionally and cytologically identical with those of other vertebrates. This demands some other mechanism for the formation and regulation of the odontoclasts in A. mexicanum.

UI	MeSH Term	Description	Entries
D008675	Metamorphosis, Biological	Profound physical changes during maturation of living organisms from the immature forms to the adult forms, such as from TADPOLES to frogs; caterpillars to BUTTERFLIES.	Biological Metamorphosis,Biological Metamorphoses,Metamorphoses, Biological
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D008855	Microscopy, Electron, Scanning	Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.	Scanning Electron Microscopy,Electron Scanning Microscopy,Electron Microscopies, Scanning,Electron Microscopy, Scanning,Electron Scanning Microscopies,Microscopies, Electron Scanning,Microscopies, Scanning Electron,Microscopy, Electron Scanning,Microscopy, Scanning Electron,Scanning Electron Microscopies,Scanning Microscopies, Electron,Scanning Microscopy, Electron
D010010	Osteoclasts	A large multinuclear cell associated with the BONE RESORPTION. An odontoclast, also called cementoclast, is cytomorphologically the same as an osteoclast and is involved in CEMENTUM resorption.	Odontoclasts,Cementoclast,Cementoclasts,Odontoclast,Osteoclast
D000558	Ambystoma mexicanum	A salamander found in Mexican mountain lakes and accounting for about 30 percent of the urodeles used in research. The axolotl remains in larval form throughout its life, a phenomenon known as neoteny.	Axolotl,Mexican Salamander,Ambystoma mexicanums,Axolotls,Salamander, Mexican,mexicanums, Ambystoma
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014091	Tooth Resorption	Resorption of calcified dental tissue, involving demineralization due to reversal of the cation exchange and lacunar resorption by osteoclasts. There are two types: external (as a result of tooth pathology) and internal (apparently initiated by a peculiar inflammatory hyperplasia of the pulp). (From Jablonski, Dictionary of Dentistry, 1992, p676)	Resorption, Tooth,Resorptions, Tooth,Tooth Resorptions