Defective electron transfer in complexes I and IV in patients with aceruloplasminemia

Aceruloplasminemia is a disorder of iron metabolism caused by mutations in the ceruloplasmin gene. It is characterized by progressive neurodegeneratio n of the retina, basal ganglia, dentate nucleus and cerebral cortex in asso ciation with iron accumulation in these tissues. Enzyme activities in the m itochondrial respiratory chain of the cerebral cortices of two patients wer e reduced to 62% and 71% for complexes I and IV. Malondialdehyde, a marker of lipid peroxidation, was three times higher than the control value and wa s accompanied by increased expression of superoxide dismutase 2 (Mn SOD). T hese findings suggest that iron-mediated free radicals contribute to the im pairment of mitochondrial energy metabolism in aceruloplasminemia (C) 2000 Elsevier Science BN. All rights reserved.