| Project/Area Number |
01480468
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
外科・放射線系歯学
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| Research Institution | Osaka University |
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Principal Investigator |
FUCHIHATA Hajime Osaka University, Faculty of Dentistry Professor, 歯学部, 教授 (70028728)
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| Co-Investigator(Kenkyū-buntansha) |
KATO Yukio Osaka University, Faculty of Dentistry Associate Professor, 歯学部, 助教授 (10112062)
KATOH Kazuo Osaka University, Faculty of Dentistry Assistant, 歯学部, 助手 (10194804)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥6,500,000 (Direct Cost: ¥6,500,000)
Fiscal Year 1990: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1989: ¥5,600,000 (Direct Cost: ¥5,600,000)
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| Keywords | X-ray irradiation / Growth plate chondrocyte / Cytodifferentiation / Calcification / Growth factor / 成長軟骨細胞 / 細胞増殖 / 遠心管培養系 |
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| Research Abstract |
Irradiation often causes retardation of skeletal growth, and this may be explained by injury of growth-plate cartilage. However there are no appropriate models in vitro. In the present study, we investigated the effects of X-ray irradiation on proliferation, proteoglycan (PG) synthesis, alkaline phosphatase activity and calcium content, and effects of insulin like growth factor-I (IGF-I) or parathyroid hormone (PTH) on recovery from irradiation damage of growth-plate chondrocytes. Chondrocytes were isolated from growth-plate of the ribs of 4-week old rabbits and cultivated as a packed mass in a 15-ml plastic centrifuge tube.
1) The cells were exposed to single doses of X-ray between 0.3 and 10Gy on day 7 or day 14. Irradiation at 3-10Gy on day 7 caused significant decreases in DNA synthesis, alkaline phosphatase activity and Ca deposition without inhibition of PG shnthesis. Irradiation at 10Gy on day 14 caused 30% decreases in alkaline phosphatase and calcification, although it had little effect on DNA and PG synthesis.
2) The cells were irradiated at 10Gy of a single dose on day 7. The addition of IGF-I from day 14 stimulated proliferation of chondrocytes and PTH addition from day 14 stimulated alkaline phosphatase activity. These results suggest that chondrocytes in pelleted cultures are a useful model for studies on the mechanisms involved in radiation damage of chondrocytes and their recovery from the damage.
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