Abstract
The interaction between ubiquinones and vitamin E was studied in the inner membranes of rat liver mitochondria, liposomes and human erythrocyte plasma membranes. Free radicals were produced by addition of exogenous oxidants, and their reaction with chromanols and ubiquinone was followed by ESR and HPLC. Membranes were made deficient in ubiquinone but sufficient in α-tocopherol and were reconstituted with added ubiquinone. With these membrane preparations it was shown that (i) in the inner mitochondrial membranes there is a requirement for ubiquinone in the enzymatic recycling of vitamin E; (ii) succinate-ubiquinone reductase incorporated in liposomes cannot protect vitamin E in the absence of ubiquinone and (iii) in human erythrocyte plasma membranes protection against the loss of vitamin E can be provided by NADH-cytochrome-b 5-dependent enzymatic recycling. We conclude that ubiquinonols (ubisemiquinones) reduce vitamin E through electron transport.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call