COMPOUNDS 2,4,6-TRINITROTOLUENE AND 2,4-D IAMINO-6-NITROTOLUENE - THEABSENCE OF RECA-DEPENDENT MUTAGENESIS

The genotoxicity of 2,4,6-trinitrotoluene (2,4,6-TNT) and its amino de rivative, 2,4-diamino-6-nitrotoluene (2,4-DA-6-NT), was studied using the Escherichia coil tester strain PQ37 in the SOS chromotest. The com pound 2,4,6-TNT, without metabolic activation, virtually failed to ind uce an SOS effect in cells of the tester bacteria. Consequently, mutag enic activity of 2,4,6-TNT, which was shown earlier in the Ames test, does not depend on SOS mutagenesis. It was demonstrated that metabolic activation with the microsomal S9 human placenta fraction results in a threefold increase in the induction factor of the SOS effect caused by 2,4,6-TNT. The absence of the SOS-inducing activity of 2,4-DA-6-NT, regardless of the presence of a microsomal activating mixture is show n. Thus, 2,4-DA-6-NT does not belong to metabolites of 2,4,6-TNT, resp onsible for the genotoxicity of this compound.