THE REDUCING ABILITY OF IRON CHELATES BY NADH-CYTOCHROME B(5) REDUCTASE OR CYTOCHROME B(5) RESPONSIBLE FOR NADH-SUPPORTED LIPID-PEROXIDATION

We studied iron reduction, NADH oxidation, and lipid peroxidation in t he presence of iron chelates with a chelator, such as nitrilotriacetat e, ADP, citrate, and pyrophosphate, in NADH-supported reconstituted sy stem. The results showed the selectivity of NADH-cytochrome b(5) reduc tase or cytochrome b(5) towards iron chelates and the subsequent abili ty of this system to promote lipid peroxidation. The lipid peroxidatio n was partially inhibited by superoxide dismutase. in the presence of any iron chelate, hydrogen peroxide was produced in the systems includ ing the reductase, and the production was accompanied with an increase in NADH oxidation.