Relation of Bile Hydrogen Peroxide Level and Liver Super Oxide Dismutase Activity in Selenium-Deficient Rats

Abstract

The relationship of hydrogen peroxide (H₂O₂) levels in bile with liver SOD and GSH-Px activity in selenium (Se)-deficient rats is discussed. Normal rats and 7 groups of rats fed a Se-deficient diet with different feeding periods were examined. H₂O₂ levels in bile were measured using the spin-trapping method with electron spin resonance (ESR). Bile H₂O₂ levels in the initial stage (20-60min from start of the cannulation) of measurement were increased depending on the length of the feeding period with the Se-deficient diet and absence of Se. Bile H₂O₂ levels in the later stage (60-120min) of measurement first increased with the length of feeding with the Se-deficient diet and then decreased with longer feeding periods. Bile H₂O₂ levels immediately after the operation were relatively low in almost all cases. The operation may result in oxidative stress to generate H₂O₂. Liver GSH-Px activity decreased depending on the length of the feeding period with the Se-deficient diet and existence of Se. Liver SOD activity increased in Se-deficient groups. It is suggested that the H₂O₂ levels in bile are related to decreased GSH-Px activity, SOD activity, and also the oxidative stress caused by surgery. Therefore the H₂O₂ levels in bile can be used as an index of sensitivity to oxidative stress. Although severe oxidative stress may decrease SOD activity, Se deficiency can induce liver SOD activity.