THE INFLUENCE OF VITAMIN-E AND SELENIUM ON LIPID-PEROXIDATION AND ALDEHYDE DEHYDROGENASE-ACTIVITY IN RAT-LIVER AND TISSUE

Malondialdehyde (MDA) production and cytosolic aldehyde dehydrogenase (ALDH) response were examined in rat liver tissues after feeding diffe rent levels of dietary vitamin E and/or selenium and polyunsaturated f at for 12-38 wk. MDA production was significantly increased by vitamin E deficiency or by high levels of polyunsaturated fat intake, but not by selenium deficiency. The activity of cytosolic ALDH increased upon increased production of MDA after 12-16 wk of feeding the lipid perox idation-inducing diets. However, ALDH activity was suppressed after 38 wk of feeding the vitamin E deficient diet. The results indicate that the hepatic cytosolic ALDH may be involved in the metabolism of MDA d uring a relatively short-term increase in in vivo lipid peroxidation, but that ALDH activity becomes suppressed after more severe in vivo Li pid peroxidation has been produced. Hepatic and plasma a-tocopherol le vels and lipid peroxidation products were measured for the various die tary groups.