Lack of a Dose‐response Relationship for Carcinogenicity in the Rat Liver with Low Doses of 2‐Amino‐3,8‐dimethylimidazo[4,5‐f]quinoxaline or N‐Nitrosodiethylamine
| Autor: | Hiroyuki Tsuda, Masae Tatematsu, Masao Hirose, Hideki Wanibuchi, Yoichi Konishi, Tomoyuki Shirai, Katsumi Imaida, Nobuaki Uehara, Keiichirou Morimura, Dai Nakae, Fumio Furukawa, Min Wei, Tetsuya Tsukamoto, Shoji Fukushima, Keiji Wakabayashi, Yukari Totsuka |
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| Jazyk: | angličtina |
| Rok vydání: | 2002 |
| Předmět: |
Male
Cancer Research Pathology medicine.medical_specialty Low dose carcinogenicity Pharmacology medicine.disease_cause Article chemistry.chemical_compound DNA Adducts Quinoxaline Liver Neoplasms Experimental Quinoxalines medicine Animals Diethylnitrosamine Carcinogen Risk assessment Glutathione Transferase Dose-Response Relationship Drug Glutathione NDEA Rats Inbred F344 Rats Dose–response relationship Oncology chemistry MeIQx Toxicity Carcinogens Carcinogenesis Precancerous Conditions Genotoxicity DNA Carcinogenicity threshold |
| Zdroj: | Japanese Journal of Cancer Research : Gann |
| ISSN: | 1876-4673 0910-5050 |
| Popis: | For a long period, it has been generally considered that carcinogens, particularly genotoxic ones, have no threshold in exerting their potential for cancer induction. However, the non-threshold theory can be challenged with regard to assessment of cancer risk to humans. Here we show that a food-derived, genotoxic hepatocarcinogen, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, forms DNA adducts at low doses, but does not induce glutathione S-transferase placental form (GST-P)-positive foci (considered to be preneoplastic lesions) or 8-hydroxy-2'-deoxyguanosine in rat liver. Moreover a N-nitroso compound, N-nitrosodiethylamine, at low doses was also found not to induce GST-P-positive foci in rat liver. These results imply that there is a no-observed effect level for hepatocarcinogenesis by these genotoxic carcinogens. |
| Databáze: | OpenAIRE |
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