Distribution of selenium binding proteins in liver from two species of penguins from Bouvetøya

Abstract

Chinstrap penguin Pygoscelis antarctica and macaroni penguin Eudyptes chrysolophus were collected at Bouvettfya in the south Atlantic. The average hepatic selenium levels for the two species were 6.6 ± 2.9 and 23.6 ± 3.4 ng/g wet weight (P < 0.001), respectively. The total hepatic glutathione peroxidase (GSH-Px) activity in the two species was 629 ± 58 and 838 ± 88 u.kat/kg (P < 0.001), respectively. The average selenium dependent GSH-Px activity was 96 ± 3.2% of the total activity. All selenium was present in the cytosol. The selenium binding compounds were separated on Sephadex G-75 into three fractions, a high molecular weight fraction, a metallothionein fraction, and a third non-protein selenium containing fraction. There seems to be an agreement between the amount of selenium recovered in the first fraction and the GSH-Px activity. In chinstrap and macaroni penguins, the percentage of hepatic selenium recovered in the third non-protein fraction was 83 ± 2.6 and 94 ± 1.1% (P < 0.001), respectively.