Increase of 2,3-epoxybutane mutagenicity by glutathione-S-transferases

The mutagenicity of 2,3- epoxybutane (2,3-EB) towards Salmonella FFphimurium TA1530 is increased by rat liver S9 mix. This enhancement can be induced by Aroclor 1254 (ARO) or phenobarbitone (PB) pretreatment. Comparative assays with purified subcellular liver fractions demonstrated that cytosol is the most active in increasing the mutagenic effect of 2,3-EB. Addition of reduced glutathione (GSH) to metabolic activating mixtures containing S9 or cytosol, strengthened this effect. From these results it is suggested that 2,3-EB is stabilized through enzymic conjugation with GSH.