Current and emerging challenges in toxicopathology: Carcinogenic threshold of phenobarbital and proof of arsenic carcinogenicity using rat medium-term bioassays for carcinogens
- First Department of Pathology, Osaka City University Medical School, Abeno-ku, Asahi-machi 1-4-3, Osaka 545-8585 (Japan)
For the last 25 years, Prof. Nobuyuki Ito and his laboratory have focused on the development of liver medium-term bioassay system for detection of carcinogens in F344 rats utilizing glutathione S-transferase placental form (GST-P)-positive foci as an end point marker. In this presentation, the outline and samples of medium-term bioassay systems were described. Furthermore, our data demonstrated the presence of a threshold for the non-genotoxic carcinogen, phenobarbital (PB), and the lack of linearity in the low-dose area of the dose-response curve, providing evidence for hormesis. In addition, the establishment and applications of multiorgan carcinogenicity bioassay (DMBDD model), used for the examination of the carcinogenicity of genotoxic and non-genotoxic chemicals, are discussed. Dimethylarsinic acid, one of organic arsenics, was found to be carcinogenic in rat bladder using DMBDD model and carcinogenicity test.
- OSTI ID:
- 20721913
- Journal Information:
- Toxicology and Applied Pharmacology, Vol. 207, Issue 2,suppl.1; Conference: ICT X 2004: 10. international congress of toxicology: Living in a safe chemical world, Tampere (Finland), 11-15 Jul 2004; Other Information: DOI: 10.1016/j.taap.2005.01.037; PII: S0041-008X(05)00254-1; Copyright (c) 2005 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0041-008X
- Country of Publication:
- United States
- Language:
- English
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