Abstract
Lanthanum as a phosphate binding agent may pose a potential obstacle to efficient absorption of iron by mucosal cells and releasing it into blood. The aim of the present study was to exhaustively ascertain the potential disruptive influence of lanthanum on plasma transportation and biochemical processes governing iron metabolism. The binding of lanthanum to apo-transferrin was investigated spectrophotometry. The binding rate of iron and lanthanum to transferrin was investigated by the equilibrium dialysis technique. The binding constant (ka) of lanthanum to apo-transferrin was 3.41 × 10(6). Lanthanum-transferrin and iron-transferrin complexes exhibited distinct peaks with respective wavelengths at 240 nm and 465 nm, respectively. Binding of lanthanum to apotransferrin required a longer period of time than the time in which iron bound to apotransferrin. Augmented citrate levels in the incubation medium enhanced iron binding to transferrin although elevating citrate concentrations in the lanthanum medium reduced the formation of the lanthanum-apotransferrin complex. The results showed that lanthanum interferes with iron metabolism and causes changes in blood-related factors which influences biochemical processes related to iron by disturbing the process of intestinal absorption.