Effects Produced in the Livers of Mice by Azonaphthalenes and Related Compounds

The results described below are based upon the examination of the organs, and especially of the livers, of 1004 mice under treatment with, in all, 84 compounds, as follows: The primary object of the investigation was to seek for any evidence of the production of cancer of the bladder by pure chemical compounds, which might throw light upon the occupational incidence of this form of cancer in chemical workers and especially in those handling β-naphthylamine. No tumours of the bladder have been obtained, but some peculiar changes in that organ were produced by 1:29-azonaphthalene, and by no other of the compounds hitherto tested. This result has led to further experiments, now in progress, with other compounds related to 1:29-azonaphthalene. Systematic examination of the livers of animals receiving compounds under test has been carried out since the detection, by one of the authors of the present paper, of neoplastic changes in the livers of mice receiving 3:4:5:6-dibenzcarbazole (Boyland and Brues 1937). Hence a large amount of comparative histologic material has been collected which serves to demonstrate the specificity of action of the very few compounds, out of the 84 named in this paper, which produce any considerable change in the structure of the liver.