title: Promoting effects of 6-mercaptopurine on carcinogenesis in various organs of F344 rats.
abstract: Possible promoting effects of 6-mercaptopurine (6-MP) on carcinogenesis in various organs, including the hematopoietic system, were investigated in female F344 rats, using a 2-stage carcinogenesis model. 6-MP was given as a dietary supplement (50 ppm) for 35 weeks subsequent to wide-spectrum initiation with N-ethyl-N-nitrosourea (ENU). Various tumors were observed in the carcinogen-initiated groups. No significant influence of 6-MP on their development, including the occurrence of leukemia, was apparent. However, the incidences of some proliferative lesions in the lung, intestine and kidney were slightly higher in the ENU/6-MP group than the ENU group. Further studies may be needed on promoting effects of 6-MP, based on dose-effect relation using several 6-MP doses and/or other initiators.
authors.affiliation: Division of Pathology, National Institute of Health Sciences, Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Matsushima
authors.forename: H
authors.initials: H
authors.lastname: Onodera
authors.forename: T
authors.initials: T
authors.lastname: Nagaoka
authors.forename: K
authors.initials: K
authors.lastname: Mitsumori
authors.forename: J
authors.initials: J
authors.lastname: Lu
authors.forename: A
authors.initials: A
authors.lastname: Maekawa
mesh_terms: D000818:Animals; D002273:Carcinogens; D005038:Ethylnitrosourea; D005260:Female; D015122:Mercaptopurine / Q000633:toxicity*; D009374:Neoplasms, Experimental / Q000139:chemically induced*; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D002273:Carcinogens; D015122:Mercaptopurine; D005038:Ethylnitrosourea