Promoting effects of 6-mercaptopurine on carcinogenesis in various organs of F344 rats.
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.
Matsushima
Y
Y
Division of Pathology, National Institute of Health Sciences, Tokyo, Japan.
Onodera
H
H
Nagaoka
T
T
Mitsumori
K
K
Lu
J
J
Maekawa
A
A
D000818:Animals; D002273:Carcinogens; D005038:Ethylnitrosourea; D005260:Female; D015122:Mercaptopurine / Q000633:toxicity*; D009374:Neoplasms, Experimental / Q000139:chemically induced*; D051381:Rats; D011916:Rats, Inbred F344
D002273:Carcinogens; D015122:Mercaptopurine; D005038:Ethylnitrosourea