Aminoethylcysteine Ketimine-Decarboxylated Dimer Protects Submitochondrial Particles from Lipid Peroxidation at a Concentration Not Inhibitory of Electron Transport

In contrast with other inhibitors of the NADH dehydrogenase of the respiratory chain, the decarboxylated dimer of aminoethylcysteine ketimine protects bovine heart submitochondrial particles (SMP) from the NADH-Fe+3-ADP-induced lipid peroxidation. This effect, measured as inhibition of malondialdehyde formation, is concentration-dependent in the range 0.02-0.2 mM. This range of concentration is not inhibitory on NADH-oxidase activity of SMP. Furthermore the dimer is able to counteract the malondialdehyde formation stimulated by the Complex I inhibitors rotenone and N-methyl-4-phenylpyridinium (MPP+).