HOSHI Kazuto Faculty of Dentisty, Japan Society for the Promotion of Science, NIIGATA UNIVERSITY, Special Investigator, 歯学部, 日本学術振興会特別研究員(PD)
AMIZUKA Norio Faculty of Dentisty, NIIGATA UNIVERSITY, Assistant, 歯学部, 助手 (30242431)
EJIRI Sadakazu Faculty of Dentisty, NIIGATA UNIVERSITY, Associate Professor, 歯学部, 助教授 (40160361)
IKEGAME Mika Faculty of Dentisty, NIIGATA UNIVERSITY, Assistant, 歯学部, 助手 (70282986)
NAKAMURA Hiroaki Okayama University, School of Dentisty, Associate Professor, 歯学部, 助教授 (50227930)
|Budget Amount *help
¥40,800,000 (Direct Cost: ¥40,800,000)
Fiscal Year 2000: ¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 1999: ¥38,200,000 (Direct Cost: ¥38,200,000)
Bone morphology is maintained by the balance among osteocytes, osteoblasts and osteoclasts, or interaction of surrounding tissues including cartilage, vessels, nerve, and tendon. However, the mechnisms by which bone morphology is diverse accodrding to the alteration of age, environment, and species remain unclear. In order to elucidate control system of bone morphology, we analyzed
(1) formation and mantenance mechanisms of calcified bone matrix, and (2) morphological alteration of bones, accoding to aging, environment, and species.
In osteoid, meshwork of proteoglycans are oberved among collagen fibrils. Calcium was localized at the sites of proteoglycans, while phosphorus was often mapped to collagen fibrils. These structures may preserve each minerals, and are thought to inhibit the increase of local calciumXpohosphorus product, leading to the maintenence of uncalcified state. In contrast, calcium and phosphorus were co-localized at the calcified nodules, while sizes of proteoglycan became smaller there. The co-localization of calcium and phosphorus following such fragmentation of proteoglycan was thought to play an important role in undergoing calcifications.
Regarding the second topics, bone morphology reaseably changes according to the metabolic or anabolic actions of various factors including estrogen, parathyroid hormone, bone morphogenetic protein, and tensile stress. Espepcially, it was revealed that osteoblastic differntiation promotes accoding to the tensile stress, mediated by increase of BMP-4 expression in preosoteoblasts and periosteoal cells.
In order to examine bone diversity among spepcies, teeth and surroudning bones of gold fish were evaluated by micro CT.In micro CT analysis, fragile organs can be easily investigated without any specific prepartion. Thus, characteristics of teeht and surrouning bones of gold fish were clarified.