| Project/Area Number |
12470406
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Conservative dentistry
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
AKAMINE Akifumi Faculty of Dental Science, Kyushu University, Prof., 歯学研究院, 教授 (00117053)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAZA Takayoshi Faculty of Dental Science, Kyushu University, Res. Ass., 歯学研究院, 助手 (80304814)
HASHIGUCHI Isamu Faculty of Dental Science, Kyushu University, Res. Ass., 歯学研究院, 助手 (10150476)
YOSHIMINE Yoshito Faculty of Dental Science, Kyushu University, Ass. Prof., 歯学研究院, 助教授 (80183705)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥16,500,000 (Direct Cost: ¥16,500,000)
Fiscal Year 2001: ¥4,600,000 (Direct Cost: ¥4,600,000)
Fiscal Year 2000: ¥11,900,000 (Direct Cost: ¥11,900,000)
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| Keywords | odontoblast / nitric oxide / nitric oxide synthase (NOS) / endothelial NOS (eNOS) / inducible NOS (iNOS) / NF-κB / reparative dentin / 形態学的検索 / 分子生物学的検索 |
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| Research Abstract |
In this study, the expression of nitric oxide synthases (NOSs), especially endothelial NOS (eNOS) and inducible NOS (iNOS), and NF-κB, which is considered to takes part in the translation of iNOS gene, was examined in the dental pulp after tooth preparation of rat molars compared to normal dental pulp with immunohistochemistry. Any immunoreactivity for eNOS and iNOS was not found in odontoblast at the dentin/pulp interface of normal tooth. NF-κB positive reaction localized in the odontoblasts. Any other cell in the pulp was not positive for eNOS, iNOS, or NF-κB. On the other hand, 2 days after tooth preparation, the layer of big columnar cells (odontoblasts) was found along the dentin/pulp interface under the prepared cavity. At the interface, reparative dentin formation started and invasion of neutrophils were found. After 11 days abundant reparative dentin was formed under the cavity. After 2 days operation, the cells at the dentin/pulp interface beneath the cavity were positive for eNOS and iNOS. Positive reaction for iNOS was also found in the round-shaped cells arranged to odontoblasts and invaded neutrophils. Strong immunoreactivity for NF-κB was found in whole dental pulp cells, especially odontoblasts and neutrophils after 2 days tooth preparation. These finding suggested that NF-κB is activated in odontoblasts and neutrophils by mechanical stimulation. Therefore, it is indicated that abundant NO production is induced in odontoblasts directly stimulated by tooth preparation. It is suggested that NO may take a part in odontoblast differentiation and reparative dentin formation after tooth irritant. Furthermore, it is speculated that NF-κB controls several gene expression in the progression of pulpitis and formation of reparative dentin.
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