WE investigated dopamine (DA)- and DOPA-related release of iron from ferrit
in, and lipid peroxidation of liposomes induced by the released iron. Iron
release increased with increasing DA or DOPA concentrations. Effects of SOD
and an oxygen-reduced environment indicated that superoxide was partly res
ponsible for iron release. The released iron induced lipid peroxidation at
relatively low concentrations of DA or DOPA, while at high concentrations,
peroxidation was inhibited. These findings indicate that the risk df lipid
peroxidation depends on the DA/iron or DOPA/iron ratio even if the iron con
centration is low. Our findings suggest that DA-containing neurons are alwa
ys at risk of oxidative damage. Furthermore, DOPA therapy may modify the ni
gral degeneration by reducing or accelerating ferritin iron-dependent lipid
peroxidation. NeuroReport 10:1883-1887 (C) 1999 Lippincott Williams & Wilk
ins.