The Nrf2 Transcription Factor Contributes to the Induction of Alpha-Class GST Isoenzymes in Liver of Acute Cadmium or Manganese Intoxicated Rats: Comparison with the Toxic Effect on NAD(P):Quinone Reductase

The results on the effect of cadmium or manganese on glutathione peroxidase (GSPx) catalyzed by Se-dependent or by alpha-class glutathione S-transferase (GST) isoenzymes in rat liver 24 and 48 h after i.p. administration were presented. Enzyme activity in the subcellular fractions from control and treated rats was measured using a temperature-controlled spectrophotometer. It was shown that most of the activity of Se dependent Se-GSP sub(x) in rat liver was present in cytosol and less in mitochondria. In microsomes, the activity was almost completely absent and the low amount measured was probably due to contamination from other cell fractions. Results showed that when rats were treated with actinomycin D 3 h before metal intoxication, the stimulatory effect of cadmium or manganese on liver Se-independent GSPx was abolished.