FACTORS INFLUENCING INDUCTION OF TUMOURS OF URINARY BLADDER AND LIVER BY 2-ACETYLAMINOFLUORENE IN MOUSE

The administration of 2-acetylaminofluorene to mice of the IF and RIII strains induced tumours of the bladder epithelium and liver. The incidence of tumours was shown to depend on the strain of mouse, the method of administration of the chemical, the sex of the mice and whether or not there was a foreign body in the bladder. An attempt was made ta determine the mimimum period of administration of 2-acetylaminofluorene in the diet required for the induction of bladder tumours, but periods of administration of up to 20 weeks did not induce tumours before 40 weeks in the IF strain. It was shown that in these mice there was no apparent correlation between the degree of hyperplasia in the early stages of treatment and the ultimate development of malignancy. © 1969.