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
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
VL - 191
SP - 35
EP - 40
JO - Cancer Letters
JF - Cancer Letters
SN - 0304-3835
IS - 1
ER -