TY - JOUR
T1 - Lack of initiation activity in rat liver of low doses of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline
AU - Fukushima, Shoji
AU - Wanibuchi, Hideki
AU - Morimura, Keiichirou
AU - Wei, Min
AU - Nakae, Dai
AU - Konishi, Yoichi
AU - Tsuda, Hiroyuki
AU - Takasuka, Nobuo
AU - Imaida, Katsumi
AU - Shirai, Tomoyuki
AU - Tatematsu, Masae
AU - Tsukamoto, Tetsuya
AU - Hirose, Masao
AU - Furukawa, Fumio
N1 - Funding Information:
This research was supported by a grant from the Japan Science and Technology Corporation, included in the Project of Core Research for Evolutional Science and Technology (CREST), and a Grant-in-Aid for Specially Promoted Research from the Ministry of Education, Science, Sports, Culture and Technology. The authors would also like to acknowledge the encouragement of Dr N. Ito (Emeritus Professor, Nagoya City University Medical School, Nagoya) and Dr T. Kitagawa (Director, Cancer Institute, Tokyo).
PY - 2003/2/28
Y1 - 2003/2/28
N2 - It has been generally accepted that genotoxic carcinogens have no threshold in exerting their potential for cancer induction. However, the non-threshold theory can be challenged for cancer risk assessment in humans. Here we examined low dose carcinogenicity of a food-derived, genotoxic hepatocarcinogen, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), using an in vivo medium-term bioassay to detect initiating activity for rat hepatocarcinogenesis. With MeIQx initiation at various doses followed by administration of phenobarbital, a well known hepatopromoter, no induction of glutathione S-transferase placental form-positive foci, assessed as preneoplastic lesions, was noted at doses of 0.001-1 ppm. The results imply a no-observed effect level for hepatocarcinogenicity with this genotoxic agent.
AB - It has been generally accepted that genotoxic carcinogens have no threshold in exerting their potential for cancer induction. However, the non-threshold theory can be challenged for cancer risk assessment in humans. Here we examined low dose carcinogenicity of a food-derived, genotoxic hepatocarcinogen, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), using an in vivo medium-term bioassay to detect initiating activity for rat hepatocarcinogenesis. With MeIQx initiation at various doses followed by administration of phenobarbital, a well known hepatopromoter, no induction of glutathione S-transferase placental form-positive foci, assessed as preneoplastic lesions, was noted at doses of 0.001-1 ppm. The results imply a no-observed effect level for hepatocarcinogenicity with this genotoxic agent.
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U2 - 10.1016/S0304-3835(02)00631-6
DO - 10.1016/S0304-3835(02)00631-6
M3 - Article
C2 - 12609707
AN - SCOPUS:0037470405
SN - 0304-3835
VL - 191
SP - 35
EP - 40
JO - Cancer Letters
JF - Cancer Letters
IS - 1
ER -