Grant-in-Aid for Scientific Research (B)
|Allocation Type||Single-year Grants|
Public health/Health science
|Research Institution||TOHOKU UNIVERSITY|
SATOH Hiroshi Graduate School of Medicine, Tohoku University, Professor, 大学院・医学系研究科, 教授 (40125571)
NOHMI Takehiko Genetics and Mutagenesis, National Institute of Health Science, Chief investigator, 変異遺伝部, 主任研究員 (30150890)
MATSUMOTO Yutaka Hokkaido Research Institute for Environmental Science, Chief investigator, 環境保全部, 主任研究員
SHIMIZU Hidesuke School of Medicine, The Jikei University, Professor, 教授 (80056879)
TANAKA Noriho Laboratory of Cell Toxicology, Investigator, 秦野研究所・細胞毒性学研究室, 研究員
永瀬 久光 岐阜薬科大学, 薬学部, 教授 (40141395)
佐藤 孝彦 岐阜薬科大学, 薬学部, 教授 (50082970)
|Project Period (FY)
1997 – 1999
Completed(Fiscal Year 1999)
|Budget Amount *help
¥13,000,000 (Direct Cost : ¥13,000,000)
Fiscal Year 1999 : ¥3,800,000 (Direct Cost : ¥3,800,000)
Fiscal Year 1998 : ¥3,600,000 (Direct Cost : ¥3,600,000)
Fiscal Year 1997 : ¥5,600,000 (Direct Cost : ¥5,600,000)
|Keywords||Urban airborne particulate / Nitroarene / Polynulear Aromatic Hydrocarbon / Genotoxicity / Ame test / Mouse lymphoma mutation assay (MLA) / In vitro micronucleus test / Nitroarene metabolic enzyme deficient strain / Ames test / YG7126 / 7130株 / L5178Y細胞 / ニトロ還元酵素欠損株 / PAH / Ames-test / YG7126-7130株 / TA1535 / pSK1002菌株|
To investigate genotoxicity of airborne particles, the airborne particulate samples collected in Sapporo, the most northern large city in Hokkaido, Japan, during the period of 24 years from 1974 were analyzed. The results obtained are followings :
1. Concentrations of carcinogenic substances and mutagenicity assayed by Ames test.
Concentrations of polycyclic aromatic hydrocarbons (PAHs) markedly decreased during the observation period of 24 years, while concentrations of nitroarenes did not. Mutagenic activities assayed by TA98 and TA100 strains did only slightly decrease. These results indicates that concentrations of PAHs is not an appropriate indicator for the atmospheric risk of lung cancer and further the risk to human health did not significantly decrease over the observation period in terms of mutagenicity in airborne particles.
2. Mutanenicity assayed by mouse lymphoma cells.
Mutagenicity assay using the L5178Y cell, a cell line of mouse lymphoma cells, efficiently detected mutatio
ns and chromosomal aberration induced by the airborne particulate samples. The indirect mutagenic activities (+S9) clearly decreased over the period, while direct mutagenic activities (-S9) did not.
3. Mutagenicity assayed by in vitro micronucleus test.
It was shown that mutagenicity of airborne particles is possibly assayed by in vitro micronucleus test using Chinese hamster lung fibroblast cells. The incidences of induced micronucleus were rather stable for +S9 test system over the observation period. For the -S9 test system, the incidences were elevated in early 1980s with small fluctuations for other years.
4. Development of new test strains with metabolic deficits.
By gene disruption, new test strains for Ames assay, YG7128 and YG7132 with completely and partially inhibited nitroreductase activities, were established. YG7126 and YG7130, O-acetyltransferase deficient strains, were also established. These strains effectively detect nitroarenes and it was shown that contribution by nitroarenes was considerable among the total mutagenic activities in the airborne particulate samples. Less