Fukushima Shoji, Morimura Keiichirou, Wanibuchi Hideki, Kinoshita Anna, Salim Elsayed I
First Department of Pathology, Osaka City University Medical School, Abeno-ku, Asahi-machi 1-4-3, Osaka 545-8585, Japan.
Toxicol Appl Pharmacol. 2005 Sep 1;207(2 Suppl):225-9. doi: 10.1016/j.taap.2005.01.037.
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.
