Mobilization of Liver Iron by Ferroxidase (Ceruloplasmin)

Iron was mobilized by human ferroxidase from dog liver into the perfusate under simulated physiological conditions. The rate of mobilization was estimated to be 1.8 µm per min per 4.9 µm ferroxidase. Human serum albumin with trace copper was found to be inactive in iron mobilization. The low Km and high k1 values of ferroxidase toward ferrous ion enabled us to deduce that the elimination of free iron in the perfusate by ferroxidase would generate a very steep concentration gradient between iron storage cells and the capillary system. This concentration gradient would promote a rapid iron out-flux from the cells by diffusion.