| Project/Area Number |
63480182
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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 |
公衆衛生学
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| Research Institution | Saitama Medical University |
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Principal Investigator |
TAKEMOTO Kazuo Saitama Medical School, Faculty of Medicine, Professor, 医学部, 教授 (50049764)
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| Co-Investigator(Kenkyū-buntansha) |
KAWAMURA Ken Saitama Medical School, faculty of medicine, Research associate, 医学部, 助手 (60204773)
ODAGIRI Youichi Saitama Medical School, faculty of medicine, Research associate, 医学部, 助手 (20152506)
KATAYAMA Hiroo Saitama Medical School, junior collage, Professor, 短大, 教授 (20049810)
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| Project Period (FY) |
1988 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥4,200,000 (Direct Cost: ¥4,200,000)
Fiscal Year 1990: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1989: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1988: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | Diesel exhaust gas / Lung tumor / Mouse (C57BL, B6C3F_1) / Newborn / マウス(C57BL、B6C3F_1) / マウス(C57BL、B6C3F1) / ディーゼル排気ガス / マウス(C57BL、B6C3F) |
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| Research Abstract |
The experimental evidences of carcinogenicity of diesel engine exhaust in rodents have been recently reported. However, the effects of the deposited particulates in respiratory tracts on the development of lung cancer have not been well elucidated.
In the present study, the effect of exposure to diesel exhaust in the early stage of life-span on the development of lung tumor in elderly C57BL/6N or B6C3F_1 mice was investigated.
C57BL/6N and B6C3F_1 mice were exposed to diesel exhaust (NO_2 : 2-4 ppm, CO : 40-100 ppm, Particulates : 2-4 mg/m^3) for 9 months from their newborn stage. The first exposure was conducted within 24 hrs of their birth. Other groups of B6C3F_1 mice were initiated by maternal i. p. injection of etylnitrosourea (ENU) at doses of 0, 0.025 and 0.0125 mM/kg b. w. on the 15th pregnant day as initiation. Offspring were exposed to diesel exhaust for 9 months from their birth.
The deposited-particulates could be observed even 21 months after the ceasing of exposure. The first lung tumor was observed 9 months after the ceasing of exposure in C57BL/6N and B6C3F_1 mice. The incidence of lung tumor in the diesel-exposed mice was higher than that in the nonexposed controls.
In the mice which were received with ENU treatment, the development of lung tumor was observed before the ceasing of exposure. The incidence of lung tumor was much higher in the diesel-exposed groups. The rate of malignant tumor was also higher.
These results suggest that the exposure to diesel exhaust in young mice might be related to the development of lung tumor at an elderly age.
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