| Project/Area Number |
05454303
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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 |
Radiation science
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
TAKAHASHI Masaji Kyoto University Chest Disease Research Institute, Department of Oncology, Professor, 胸部疾患研究所, 教授 (00026931)
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| Co-Investigator(Kenkyū-buntansha) |
SHIBAMOTO Yuta Chest Dis Res Inst, Dept Oncology, Associate Professor, 胸部疾患研究所, 助教授 (20144719)
SUZUKI Yasuhiro Chest Dis Res Inst, Dept Molecular Pathology, Professor, 胸部疾患研究所, 教授 (90027110)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥6,100,000 (Direct Cost: ¥6,100,000)
Fiscal Year 1994: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1993: ¥4,300,000 (Direct Cost: ¥4,300,000)
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| Keywords | Radiation pneumonia / Pulmonary surfactant / Surface tension forces / Gas-liquid interface / Artificial surfactant / 人口サーファクタント / アポ蛋白 / リン脂質 |
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| Research Abstract |
The present study examined the effect of radiation on lung surfactnt (PS) secretion in rats and its function of reducing surface tension forces at the gas-liquid interface. Increased amounts of phospholipid and apoproteins (SP-A and SP-B) extracted from materials collected by broncho-alveolar lavage of irradiated lung were noted at day 1-14 after 15Gy and 20Gy. These biochemical indices were then decreased to 50-60% of a control level at 8-16 weeks. Histological examination revealed that the stage of increased release of PS coincided with inflammatory stage of alveoli and that of decreased release of PS with a stage of thickening or onset of fibrosis of alveolar walls.
This suggested that abnormally increased release of lamellar bodies packaging PS occurred during the early 2 weeks after radiation and afterwards did the inhibition of PS synthesis in type II alveolar epithelial cells. None of changes in biochemical and morphological indices were noted at 5Gy. The measurement of surface tension forces (ST) using a pulsating bubble surfactometer showed a loss of function to reduce ST at the gas-liquid interface in all of lavaged materials containing PS.This implied the necessity of a surfactant supplement therapy with an artificial PS.We synthesized an artificial PS from a liposome (DPPC and egg PG) and SP-B which were considered playing a central role in reducing ST.SP-B was extracted from lavaged materials of a patients with alveolar proteinosis. This artificial PS showed such a function of reducing ST as sufficient for preventing alveolar collapse.
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