The effect of chromium on parameters related to iron metabolism.

The effect of chromium on some parameters related to iron metabolism was investigated. Preliminary experiments showed that this metal ion was taken up by serum proteins and was dependent on the amount of chromium present in the medium. It was also shown that the uptake of iron was reduced significantly in the presence of chromium. In vivo study showed that the serum levels of iron and total iron binding capacity (TIBC) were reduced by 28 and 11%, respectively, following daily administration of chromium (1 mg/kg) for 45 d. Serum ferritin was reduced by 22% under this condition. Hematocrit and hemoglobin levels were also affected in chromium-treated animals and were both reduced by 17%. Spectrophotometric titration of each individual amino acid located in the iron binding site of transferrin revealed that tyrosine might be the most suitable ligand for the binding of chromium to transferrin. These results suggest that chromium may compete with iron in binding to apo-transferrin, and influence iron metabolism and its related biochemical parameters.