Selenium-independent glutathione peroxidase

Rat fiver microsomes exhibit selenium-independent glutathione peroxidase (EC 1.11.1.9) activity which is associated with glutathione S-transferase (EC 2.5.1.18) activity (Reddy et al. 1981). 

In its ability to catalyze reduction of H2O2 as well as alkyl hydroperoxides, glutathione peroxidase differs from a group of selenium-independent peroxidases, the glutathione S-transferases, that can use only the alkyl hydroperoxides as substrates. GSH peroxidase, rather than catalase, appears responsible for removing most of the adventitious H2O2 produced in cells the peroxidase reaction occurs more rapidly than that catalyzed by catalase when H2O2 is present at the low concentrations expected in cells. ... 

One way that selenium appears to act is as a non-specific stimulant of immune competent tissues and cells contributing to its anti-inflammatory, immunopotentiation and carcinostatic attributes. Additional data suggests other effects of Se upon cells of the immune system perhaps independent of GSHPx activity such as ubiquinone biosynthesis, (Coenz3one Q 10) which in turn affects host-defense mechanisms (Frost, 1975). A third possibility to explain the effects attributed to Se above is to propose that increases in levels of the selenium dependent enzyme glutathione peroxidase and perhaps other specific selenium-dependent functions in lymphocytes and macrophages is the reason for immunoenhancement. This subject has been addressed by Schauzer (1979) and is amplified here by the author. 

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