Iron and oxygen radicals in tissue damage: implications for the neuronal ceroid lipofuscinoses

The neuronal ceroid lipofuscinoses (NCL) are an important group of progressive encephalopathies characterized by accumulation of autofluorescent storage material, which probably arise during the destruction of cells by lipid peroxidation and the action of oxygen radicals such as superoxide (O.2-) and the hydroxyl radical (OH.). The rates of lipid peroxidation and of superoxide-dependent hydroxyl radical formation would be greatly accelerated by the presence of non-protein-bound iron salts. Cerebrospinal fluid from patients with different types of NCL has a higher level of non-protein-bound iron and lower antioxidant activity than that of controls. The raised iron content and decreased antioxidant protection found in cerebrospinal fluids may be symptomatic of a more general abnormality in iron metabolism and protection against its damaging effects.