Effects of Selenium on the Activity of Antioxidant Enzymes in the Shrimp, Neocaridina heteropoda

The effects of a selenium-supplemented diet on the antioxidant enzyme activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) in muscles of the shrimp, Neocaridina heteropoda, were investigated. Purified diets with six levels (0, 0.15, 0.30, 0.45, 0.60, and 0.75 μg/g) of supplemental Se were fed to N. heteropoda for three months. CAT and GPX activity was determined after one month and SOD activity was determined every month. The activity of the enzymes was dose dependant; activity of all three enzymes was significantly higher in shrimp fed Se-sup- plemented diets than in those fed the unsupplemented control diet. SOD activity significantly rose and fell during the three months and was higher in the second month than in the first or third. For all three enzymes, antioxi- dant activity reached a maximum when the Se concentration was 0.45 μg/g.