| Project/Area Number |
10671715
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Morphological basic dentistry
|
|---|
| Research Institution | TOKYO DENTAL COLLEGE |
|---|
Principal Investigator |
SAWADA Takashi TOKYO DENTAL COLLEGE, DEPARTMENT OF DENTISTRY,ASSISTANT PROFESSOR, 歯学部, 助教授 (60125010)
|
|---|
| Project Period (FY) |
1998 – 1999
|
| Project Status |
Completed (Fiscal Year 1999)
|
| Budget Amount *help |
¥2,700,000 (Direct Cost: ¥2,700,000)
Fiscal Year 1999: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1998: ¥1,600,000 (Direct Cost: ¥1,600,000)
|
|---|
| Keywords | TOOTH GERM / BASEMENT MEMBRANE / AMELOBLAST / ODONTOBLAST / ELECTRON MICROSCOPY / IMMUNOHISTOCHEMISTRY / TOOTH DEVELOPMENT / PROMATES |
|---|
| Research Abstract |
1. In the developing tooth of monkey and rat a characteristic fibrillar layer associated with the basement membrane of inner enamel epithelium was found to be a highly specialized lamina fibroreticularis of the basement membrane which is unusually rich in basotubules, 10nm wide microfibril-like structures. Dental papilla cell processes were inserted into the lamina fibroreticularis and their surface was closely associated with numerous parallel basotubles. With high-resolution observations the space between neighbouring basotubules were bridged by 1.5-3 nm wide filaments running perpendicular to the axis of basotubules. These results indicate that the processes of dental papilla cells are linked to groups of basotubules by mean of 1.5-3nm wide filaments. Immunoperoxidase staining showed the presence of fibronectin along baseotubules as well as within the space between the process and basotubules. This result indicates that these 1.5-3nm wide filaments are composed of fibronectin. Basot
… More
ubules, thought to be basement membrane-incorporated microfibrils, in the lamina fibroreticularis in this study are likely to function as an anchoring device to immobilize dental papilla cells along the basement membrane. Such an arrangement of mesenchymal cells is known to be crucial for the successful differentiation of odontoblasts in the developing tooth.
2. A basement membrane-like structure associated with the maturation stage ameloblasts of the monkey was composed of a lamina lucida and lamina densa. The latter was made up of a fine "cords" network, the major constituent of the basement membrane. It was closely associated with the third layer of a 200nm wide looser cord network. In specimens without demineralization the third layer and a part of the lamina densa were calcified, and it formed the edge of the enamel. The particular area had a higher electron density, and the size, shape, and arrangement of mineral crystals were different from those of the rest of the enamel. Also, mineralization appeared to be proceeding along the cords. These observations indicate that this dense layer is a highly specialized basement membrane which mediates the firm association of maturation stage ameloblasts with the enamel by means of the mineralization of a part of this basement membrane itself which becomes integrated as a part of the enamel. Less
|
