Sister-chromatid exchange and chromosome aberrations for 4 aliphatic epoxides in mice

Sister-chromatid exchange (SCE) and chromosome aberrations (CA) in bone marrow cells were analyzed after in vivo exposure in mice to 4 aliphatic epoxides, namely 1-naphthyl glycidyl ether (NGE), 1-naphthyl propylene oxide (NPO), 4-nitrophenyl glycidyl ether (NPGE) and trichloropropylene oxide (TCPO). These compounds were selected as being among the most mutagenic aliphatic epoxides in our previous structure-mutagenicity studies with the Ames test. There were significant dose-related increases in SCE and CA results for all 4 epoxides. The order of genotoxicity as established through SCE was NGE greater than NPO greater than NPGE approximately equal to TCPO greater than solvent control. It is of interest that Ames Salmonella results are consistent with in vivo genotoxicity for these compounds. However, only the plate test version of the Ames procedure is consistent with this order of in vivo genotoxicity and neither preincubation Ames testing results nor chemical alkylation rates would have predicted this order.