THE POSSIBLE ROLE OF SELENIUM IN ANTIOXIDATION IN MARINE WADERS - A PRELIMINARY-STUDY

In a marine wader, the oystercatcher (Haematopus ostralegus), the acti vity of the selenium-dependent enzyme glutathione peroxidase (GSH-Px) in the red blood cells (RBC) was measured. The average activity, 97 +/ - 19 units/g Hb, is within the range reported for mammals. No correlat ion was observed between the selenium concentration and GSH-Px activit y in the erythrocytes and it is calculated that only a small percentag e of the selenium present in the RBC is bound to the enzyme. Therefore , it is concluded that the high selenium concentrations in the avian r ed cells cannot be ascribed to GSH-Px. It is argued that a function of selenium in antioxidation is still possible. The positive relationshi p found between selenium and iron concentrations in the tissues of the oystercatcher directs to such a role. A pitfall in the measurement of GSH-Px activity is outlined.