Wanibuchi Hideki, Wei Min, Karim M Rezaul, Morimura Keiichirou, Doi Kenichiro, Kinoshita Anna, Fukushima Shoji
Department of Pathology, Osaka City University Medical School, Osaka, 545-8585, Japan.
Toxicol Pathol. 2006;34(3):232-6. doi: 10.1080/01926230600713632.
There is increasing evidence of the existence of no effect levels for genotoxic carcinogens. However, only limited information is available regarding dose-response curves for combination effects of multiple carcinogens at low dose. In the present study, 280 male F344 rats were divided into 14 groups to determine the effects of co-administration of various doses of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 10% ethanol on the development of glutathione S-transferase placental form (GST-P)-positive foci in the liver. The results provided concrete evidence for the existence of no effect levels for hepatocarcinogenicity of MeIQx either in presence or absence of ethanol and, therefore, for a practical threshold for this genotoxic carcinogen.
越来越多的证据表明遗传毒性致癌物存在无效应水平。然而，关于多种致癌物低剂量联合效应的剂量反应曲线，目前仅有有限的信息。在本研究中，将280只雄性F344大鼠分为14组，以确定不同剂量的2-氨基-3,8-二甲基咪唑并[4,5-f]喹喔啉（MeIQx）与10%乙醇共同给药对肝脏中谷胱甘肽S-转移酶胎盘型（GST-P）阳性灶形成的影响。结果为MeIQx在有或无乙醇存在时的肝癌致癌性存在无效应水平提供了确凿证据，因此也为这种遗传毒性致癌物的实际阈值提供了证据。
