INCREASED MALIC ENZYME-ACTIVITY IN SELENIUM-DEFICIENT RAT-LIVER

The activity of cytosolic malic enzyme as significantly higher (61%) i n the liver of rats fed a selenium-deficient diet compared with the co ntrols. Activities of two other NADPH-generating enzymes, glucose-6-ph osphate dehydrogenase and 6-phosphogluconate dehydrogenase, were also increased but to a lesser extent (13%). Glutathione reductase, an NADP H-consuming enzyme involved in the metabolism of glutathione, was high er (26%) in the liver of selenium-deficient rats, possibly as a result of an increase in glutathione synthesis and enzymic processes that ma intain glutathione in the reduced state. It is concluded that an incre ased demand for NADPH in selenium deficiency, possibly resulting from increased glutathione, metabolism may induce NADPH-generating enzymes, especially malic enzyme.