Effect of selenium deficiency on hydroperoxide-stimulated release of glutathione from isolated perfused liver of rainbow trout (Salmo gairdneri).

1. Duplicate groups of rainbow trout (Salmo gairdneri) were each given partially purified diets which were either adequate or depleted in selenium for 40 weeks. 2. Although there was no significant difference in weight gain, liver Se concentration was significantly lower in fish given the deficient diet. 3. Glutathione (GSH) peroxidase (EC 1.11.1.9) activity was significantly reduced in liver of Se-deficient fish but a differential assay did not indicate the presence of a non-Se-dependent GSH peroxidase activity, although liver GSH S-transferase (EC 2.5.1.18) was significantly increased. 4. Perfusion of livers from trout given Se-adequate diets with t-butyl hydroperoxide (BuOOH) or hydrogen peroxide caused an increase in the rate of release of glutathione disulphide (GSSG) into the perfusate. 5. Perfusion of livers from Se-deficient trout with BuOOH or H2O2 did not result in any change in rate of release of GSSG into the perfusate. 6. These findings confirm the absence of any compensatory non-Se-dependent peroxidase activity in Se-depleted trout.