The carcinogenicity of certain compounds related to p-dimethylaminoazobenzene.

Many aminoazobenzene derivatives have been tested for carcinogenic activity in the rat (1-7). N,N-dimethyl-p-aminoazobenzene and N-methyl-paminoazobenzene have been found to be equally carcinogenic (4, 7). They produced cholangiomas and hepatomas in all animals tested in approximately the same period of time. N,N-dimethyl-3'methyl-4-aminoazobenzene was more carcinogenic than the parent compound N,N-dimethyl-p-aminoazobenzene (4); but the N,N-dimethyl-2'-methyl4-aminoazobenzene and N,N-dimethyl-4'-methyl-4aminoazobenzene were very much less active. N,Ndiethyl-p-aminoazobenzene and all other higher alkyl homologues of N,N-dimethyl-p-aminoazobenzene tested failed to produce cirrhosis or neoplastic changes in the liver of the rat when fed in equimolecular amounts (7). The investigation has been extended to several compounds of this series which have not been previously tested.