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Quercetin and Ca2+ -calmodulin system
373 aziridine compounds. Agents that showed mean M / S values (1 _< M / S < 10) were methylating agents, N-(2-hydroxyethyl)ethyleneimine, fl-propiolactone, PUVA treatment, 4-nitroquinoline-1oxide, quinacrine mustard and so forth. For most agents positive in SCE induction, toxicity dependency of induced SCEs was biphasic. A maximal difference in SCEs among agents at equitoxic doses was several ten times.
38 Nishimura, T., S. Goto, T. Shiozaki, N. Zhu 1, A. Wan I and H. Matsushita, Institute of Public Health, Tokyo (Japan) and i Research Associate Institute of Environmental Chemistry, Beijing (People's Republic of China) Mutagenicity and polynuclear aromatic hydrocarbon contents of airborne particulates in Tokyo and Beijing Airborne particulates at Minato-ku in Tokyo and at Beixinan (industrial area), Dongdan (commercial area), Huairou (country area) in Beijing were collected by high volume sampler once a week from July to December 1982. Mutagenicities of organic components, extracted with benzeneethanol (3:1, v/v), were measured in Salmonella typhimurium TA100 and TA98 with and without $9 mix. The extracts showed positive mutagenic response for both strains with and without $9 mix. The arithmetical mean values of mutagenicities for both strains were in the following order: Beixinan > Dongdan > Huairou > Tokyo with $9 mix, Dongdan > Beixinan > Tokyo > Huairou without $9 mix. The order of each arithmetical mean value of 3 polynuclear aromatic hydrocarbons (PAHs) (benzo[a]pyrene, benzo[g,h,i]perylene, benzo[k]fluoranthene) contents was Beixinan > Dongdan > Huairou > Tokyo. Mutagenic activity and the PAH contents in winter were higher than those in summer.
39 Nishino, H., Department of Biochemistry, Kyoto Prefectural University of Medicine, Kyoto (Japan) Quercetin and Ca2+-caimodulin system It has been reported that quercetin, a flavonoid, has mutagenic activity, although it was found to be non-carcinogenic in animal tests. We have recently found that quercetin shows inhibitory effects on a wide variety of tumor promoter-induced phenomena, and suggested that anti-tumor promoter activity of quercetin may result in lack of development of tumor despite its mutagenicity. Calmodulin is known to be the major calcium-regulatory protein in various kinds of cells, and reported to be participating in the mechanism of action of tumor promoters. Therefore it appeared interesting to investigate the effect of quercetin on Ca2÷-calmodulin system to know why quercetin shows anti-tumor promoter activity. In this study, we show that quercetin interacts directly with calmodulin, and suggest that quercetin may act as a calmodulin antagonist in vivo to inhibit calmodulin-dependent phenomena caused by biologically active agents, including tumor promoter.
40 Nito, S., N. Miyashita i and K. Moriwaki ~, Tanabe Pharmaceutical Company, Osaka and 1 National Institute of Genetics, Mishima (Japan) Effects of H-2 genes on mutagen-induced micronuclei and chromosome aberrations in mouse bone-marrow cells We examined the effects of the H-2 complex on the mutagen-induced micronuclei and chromosome aberrations among the H-2 congenic and recombinant mouse strains. In the B10 congenic strains, B10.A was more sensitive to the urethaneinduced micronuclei and chromosome breaks than B10. The same tendency was observed with the other mutagens such as cyclophosphamide, mitomycin C, adriamycin, potassium cromate and r-ray. Additionally, we performed the mapping study to determine the specific region in the H-2
38 Nishimura, T., S. Goto, T. Shiozaki, N. Zhu 1, A. Wan I and H. Matsushita, Institute of Public Health, Tokyo (Japan) and i Research Associate Institute of Environmental Chemistry, Beijing (People's Republic of China) Mutagenicity and polynuclear aromatic hydrocarbon contents of airborne particulates in Tokyo and Beijing Airborne particulates at Minato-ku in Tokyo and at Beixinan (industrial area), Dongdan (commercial area), Huairou (country area) in Beijing were collected by high volume sampler once a week from July to December 1982. Mutagenicities of organic components, extracted with benzeneethanol (3:1, v/v), were measured in Salmonella typhimurium TA100 and TA98 with and without $9 mix. The extracts showed positive mutagenic response for both strains with and without $9 mix. The arithmetical mean values of mutagenicities for both strains were in the following order: Beixinan > Dongdan > Huairou > Tokyo with $9 mix, Dongdan > Beixinan > Tokyo > Huairou without $9 mix. The order of each arithmetical mean value of 3 polynuclear aromatic hydrocarbons (PAHs) (benzo[a]pyrene, benzo[g,h,i]perylene, benzo[k]fluoranthene) contents was Beixinan > Dongdan > Huairou > Tokyo. Mutagenic activity and the PAH contents in winter were higher than those in summer.
39 Nishino, H., Department of Biochemistry, Kyoto Prefectural University of Medicine, Kyoto (Japan) Quercetin and Ca2+-caimodulin system It has been reported that quercetin, a flavonoid, has mutagenic activity, although it was found to be non-carcinogenic in animal tests. We have recently found that quercetin shows inhibitory effects on a wide variety of tumor promoter-induced phenomena, and suggested that anti-tumor promoter activity of quercetin may result in lack of development of tumor despite its mutagenicity. Calmodulin is known to be the major calcium-regulatory protein in various kinds of cells, and reported to be participating in the mechanism of action of tumor promoters. Therefore it appeared interesting to investigate the effect of quercetin on Ca2÷-calmodulin system to know why quercetin shows anti-tumor promoter activity. In this study, we show that quercetin interacts directly with calmodulin, and suggest that quercetin may act as a calmodulin antagonist in vivo to inhibit calmodulin-dependent phenomena caused by biologically active agents, including tumor promoter.
40 Nito, S., N. Miyashita i and K. Moriwaki ~, Tanabe Pharmaceutical Company, Osaka and 1 National Institute of Genetics, Mishima (Japan) Effects of H-2 genes on mutagen-induced micronuclei and chromosome aberrations in mouse bone-marrow cells We examined the effects of the H-2 complex on the mutagen-induced micronuclei and chromosome aberrations among the H-2 congenic and recombinant mouse strains. In the B10 congenic strains, B10.A was more sensitive to the urethaneinduced micronuclei and chromosome breaks than B10. The same tendency was observed with the other mutagens such as cyclophosphamide, mitomycin C, adriamycin, potassium cromate and r-ray. Additionally, we performed the mapping study to determine the specific region in the H-2