Increased iron staining in the cerebral cortex of cholesterol fed rabbits

The link between hypercholesterolemia and neuronal damage is not clear. In the present study, we studied some of the possible effects of hypercholesterolemia on the brain, using the cholesterol fed New Zealand White rabbit as a model. An increase in the number of iron positive cells (i.e. oligodendrocytes) was observed in the brain parenchyma, in rabbits treated with a high cholesterol diet for 8 weeks. At this time, no neuronal death was observed, indicating that the increased iron did not occur as a consequence of neuronal injury. No heme oxygenase-1 (HO-1) or bilirubin immunoreactivity was observed in the brains in these rabbits, indicating that the iron accumulation did not occur as a consequence of increased breakdown of heme. It is postulated that cholesterol could have subtly damaged brain endothelial cells, resulting in increased iron transport across brain endothelial cells. Hypercholesterolaemia is known to be associated with increased plasma lipid peroxidation which might contribute to such damage.