VITAMIN-C-DRIVEN FREE-RADICAL GENERATION FROM IRON

Circulating free iron is lethal. Humans have two circulating iron bind ing proteins to soak up free iron to prevent it from generating toxic quantities of free radicals. These proteins are transferrin, a high-af finity, low-capacity protein (2 atoms of iron per molecule of transfer rin) for which there are receptors on the surface of every iron-requir ing cell; and ferritin, a lower-affinity, high-capacity protein (maxim um of 4500 atoms of iron per molecule of ferritin) for which there are receptors only on the surface of iron-storage cells such as RE (retic ulo-endothelial) cells. Iron is trapped inside the ferritin protein sh ell as harmless Fe-3. When there is a high serum level of reduced asco rbic acid, it drives through the pores of the ferritin protein shell t o the inside surface, where it converts the Fe-3 to catalytic Fe-2, wh ich then leaks out of the pores of the ferritin protein shell and gene rates billions of free radicals. In normal individuals, per milliliter of serum, there are approximately 300,000 molecules of transferrin pe r molecule of ferritin. Ferritin protein is an acute phase reactant th at sharply rises in the presence of inflammation of any kind, whereas transferrin is a reverse acute phase reactant that falls in the presen ce of inflammation of any kind.