ASSAYING GLUTATHIONE S-TRANSFERASE ACTIVITY IN LUNG AND LIVER WITH STYRENE-H-3 OXIDE AS SUBSTRATE

As with many radioactive assay methods, the sensitivity of published procedures for assaying glutathione S-transferase activity with 3H-styrene oxide is limited by the background. The modifications described here for reducing this background increase the sensitivity of this assay so that it can easily be used with preparations containing low activity, such as the supernatant fraction from rat lung. Glutathione S-styrene oxide transferase activity is not catalyzed by a single enzyme, but rather by several (if not all) of the glutathione S-transferases. This activity is not inhibited by concentrations of 1,1,1-trichloropropene 2,3-oxide or cyclohexene oxide which totally inhibit epoxide hydratase. © 1979 The Italian Pharmacological Society.