Inflammatory siderosis of the nervous system in rats.

Large intravenous doses of a relatively nontoxic iron polymaltose complex were taken up by liver and spleen and did not enter the central nervous system (CNS) of normal rats. When the injections were given during development of the inflammatory lesions of experimental allergic encephalomyelitis (EAE), many iron-laden macrophages entered vessels, perivascular cuffs and neural parenchyma. Iron polymaltose injected before the EAE lesions started to develop, or during the healing phase, did not enter the lesions. This model of CNS siderosis may be useful for studies on long-term effects of iron and for neuroimaging by nuclear magnetic resonance.