NON-INDUCIBILITY OF THE GLUTATHIONE TRANSFERASES OF THE EARTHWORM EISENIA-ANDREI

1. Earthworms were exposed to solutions of potential biotransformation enzyme inducers, i.e. trans-stilbene oxide (0.1 mM), 3-methylcholanthrene (50 mu M) or 1,4-bis[2-(3,5-dichloropyridoxyl)]benzene (30 mu M) for 1 hr each day in three successive days. 2. Glutathione transferase (GST) was determined in cytosolic extracts of the worms the day after the last treatment, with chloro-2,4-dinitrobenzene, 1,2-dichloro-4-nitrobenzene and ethacrynic acid as electrophilic substrates. Activity toward 1,2-epoxy-3-[p-nitro-fenoxy]propane was not detected. 3. With all three substrates, the specific activity in the cytosol was similar in treated animals and controls. 4. Ion exchange chromatography was performed on a NeoBar AQ(TM) column (The ''Low Pressure High Performance'' technique), and GST eluted in four distinct peaks. 5. The elution profiles of GST activity were almost identical for exposed earthworms and controls. 6. The results suggest that earthworms may not have inducible GST, perhaps because they are detritus eaters, and do not need to detoxicate poisonous secondary plant metabolites.