Hepatic distribution of iron, copper, zinc and cadmium-containing proteins in normal and iron overload mice

Subcellular distribution of metal-containing proteins of Fe, Cu, Zn and Cd were determined in the liver samples of iron overload mice by size exclusion high performance liquid chromatography with on-line coupling to UV and inductively coupled plasma mass spectrometry. Collision cell techniques was used to remove polyatomic interferences for some elements, such as Fe. Comparative molecular weight (MW) information of the elemental fraction was obtained within a retention time of 40 min. Fe was present only in high-MW (HMW) protein; Cu, Zn and Cd were found in different MW proteins. It was also observed that these four elements studied showed predominant association with HMW fractions. Moreover, compared with the normal group, we found that the contents of these elements except Cu significantly increased and the distribution of some elements like Cd changed in iron overload mouse liver. It means that excessive iron accumulation in vivo may affect the metabolism of other element such as Zn and Cd.