Iron

Iron in high concentrations have been demonstrated on mice to be carcinogenic. The tests were done by injecting an iron-dextran complex, imferon, into the muscles of the mice, and it was demonstrated that iron was the carcinogenic component [1].

Iron in the form of Fe(II) modify Ca²⁺ transport across sarcoplasmic reticulum (an organelle similar to smooth endoplasmic reticulum in muscle cells). The underlying mechanism of Fe(II) on sarcoplasmic reticulum Ca²⁺ transport is a direct and potent action on the ryanodine receptor, resulting in the inhibition of the Ca²⁺ release channel of cardiac sarcoplasmic reticulum. This may be important in pathological states of the heart during iron overload. Iron(III) has negligible activity on active Ca²⁺ accumulation into sarcoplasmic reticulum and on the binding of [3H]ryanodine [7].