A 26-week carcinogenicity study of 2-amino-3-methylimidazo[4,5-f]quinoline in rasH2 mice.
To evaluate the carcinogenic susceptibility of rasH2 mice to 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 7-week-old rasH2 mice and their wild-type littermates (non-Tg mice) of both the sexes were fed a diet containing 0 or 300 ppm IQ for 26 weeks. Microscopical examinations revealed that the proliferative lesions of the forestomach, including squamous cell hyperplasias, papillomas, and carcinomas, were frequently encountered in male and female rasH2 mice fed with IQ. In non-Tg mice, no significant differences in the incidence of forestomach lesions were observed between the 0 ppm and 300 ppm groups. Histopathological changes such as periportal hepatocellular hypertrophy and oval cell proliferation in the liver were more apparent in female rasH2 and non-Tg mice than in males, and the incidence of hepatocellular altered foci significantly increased in female rasH2 mice in the 300 ppm group as compared to that in the 0 ppm group. These results suggest that the carcinogenic potential of IQ can be detected in rasH2 mice by a 26-week, short-term carcinogenicity test.
Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, Fuchu City, Tokyo, Japan. mokamura@cc.tuat.ac.jp
Miwa
M
Okamura
Mitsuyoshi
M
Moto
Masako
M
Muguruma
Tadashi
T
Ito
Meilan
M
Jin
Yoko
Y
Kashida
Kunitoshi
K
Mitsumori
D000818:Animals; D015197:Carcinogenicity Tests; D002273:Carcinogens / Q000633:toxicity*; D006528:Carcinoma, Hepatocellular / Q000139:chemically induced / Q000473:pathology; D004198:Disease Susceptibility / Q000139:chemically induced*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D011905:Genes, ras; D006965:Hyperplasia / Q000139:chemically induced / Q000473:pathology; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000473:pathology; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009369:Neoplasms / Q000139:chemically induced* / Q000473:pathology; D010212:Papilloma / Q000139:chemically induced / Q000473:pathology; D011804:Quinolines / Q000633:toxicity*; D013274:Stomach Neoplasms / Q000139:chemically induced / Q000473:pathology; D013997:Time Factors
D002273:Carcinogens; D011804:Quinolines; C029216:2-amino-3-methylimidazo(4,5-f)quinoline