Lack of susceptibility of heterozygous p53-knockout CBA and CIEA mice to phenolphthalein in a 6-month carcinogenicity study.
Phenolphthalein has carcinogenic activity, causing malignant lymphomas in B6C3F1 mice at a dietary dose of 3000 ppm in a 2-year carcinogenicity study and in female heterozygous p53-knockout TSG mice (C57BL/6 background) at the same dose in a 6-month study. To examine whether carcinogenic potential of phenolphthalein can be detected in other p53-knockout mouse [p53 (+/-)] strains such as p53 (+/-) CBA mice or p53 (+/-) CIEA mice (C57BL/6 background) and their littermates, they were given a diet containing 0, 6000 or 12000 ppm for 6 months. Unequivocal induction of neoplastic lesions was not apparent, suggesting that p53 (+/-) CBA mice and p53 (+/-) CIEA mice are resistant to the induction of malignant lymphomas by the treatment of phenolphthalein.
Okamura
Miwa
M
Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchuu-city, Tokyo 183-8509, Japan. mokamura@cc.tuat.ac.jp
Kashida
Yoko
Y
Watanabe
Takao
T
Yasuhara
Kazuo
K
Onodera
Hiroshi
H
Hirose
Masao
M
Usui
Toshimi
T
Tamaoki
Norikazu
N
Mitsumori
Kunitoshi
K
D000284:Administration, Oral; D000818:Animals; D015197:Carcinogenicity Tests; D002273:Carcinogens / Q000008:administration & dosage / Q000633:toxicity*; D004032:Diet; D004305:Dose-Response Relationship, Drug; D016158:Genes, p53; D020022:Genetic Predisposition to Disease; D006579:Heterozygote; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D018345:Mice, Knockout; D009374:Neoplasms, Experimental / Q000235:genetics* / Q000473:pathology; D020113:Phenolphthalein / Q000008:administration & dosage / Q000633:toxicity*
D002273:Carcinogens; D020113:Phenolphthalein