The carcinogenic activities of certain analogues of 2-acetyl-aminofluorene in the rat.

Abstract

1. The carcinogenic activities of 3-acetylaminodibenzothiophene, 3-acetylaminodibenzothiophene-5-oxide, and 3-acetylaminodibenzofuran were directly compared with that of 2-acetylaminofluorene in male and female rats. A fourth compound, 4-dimethylaminobiphenyl, was tested for carcinogenic activity in male rats. All of the compounds were fed for 8 months. 2. The data demonstrate that replacing the -CH2- bridge in 2-acetylaminofluorene by -S- as in 3-acetylaminodibenzothiophene did not alter the carcinogenicity of the molecule for either mammary gland or ear duct tissue. Substitution of for the -CH2- as in 3-acetylaminodibenzothiophene-5-oxide greatly lowered the activity towards these two tissues, while insertion of an -O- bridge as in 3-acetylaminodibenzofuran only partially diminished the activity of the molecule in these respects. Unlike the control compound, 2-acetylaminofluorene, however, none of these 3 compounds had any carcinogenic activity towards the liver. The tumors produced by all of these compounds appeared 4 to 8 months after the beginning of the experiment. ![Figure][1] 3. 4-Dimethylaminobiphenyl, a derivative in which the -CH2- bridge is absent, produced tumors in the mammary glands, ear duct, liver, and vertebral canal of male rats. These tumors appeared 8 to 10 months from the beginning of the experiment. [1]: pending:yes