Detection of the carcinogenic nitrofuran derivative VR-6 as a mutagen in the Salmonella/microsome test.

The carcinogenic nitrofuran, VR-6, was evaluated for mutagenicity in Salmonella typhimurium TA 100 using the plate assay (Ames test). The dose-response curve indicated that S. typhimurium TA 100 is a very sensitive genetic indicator for this chemical class and that basepair substitution appears to be the molecular mechanism with VR-6. The results reported here provide evidence, that VR-6 is a directly acting mutagen for S. typhimurium TA 100 and that the chemical is partially deactivated in the presence of rat liver homogenates. Comparison of the results obtained with this agent in the Ames test with data from a subacute animal study, showed a good agreement in predicting the carcinogenic risk.