Acceleration of the development of leukemia and induc­tion of tumors in AKR mice by neo-natal injection of 20-methy-Icholanthrene

A single subcutaneous injection of 20-methylcholanthrene into newborn AKR mice less than 24 hours old resulted in the acceleration of the development of lymphocytic leukemia, and induction of subcutaneous sarcomas and multiple-lung adenomas. Morphological descriptions of the respective tumors were given. It is suggested that the lungs of newborn mice of strain AKR may prove to be a sensitive organ to evaluate carcinogenicity of certain carcinogenic compounds.