The Identification of a Mathematical Model for the Investigation of the Differences Between Monoferric and Diferric Transferrin in Man

Abstract

Abstract The internal iron exchange is mediated by transferrin, a carrier protein which has two iron binding sites. Recent studies, both “in vitro” and in animals, showed that a transferrin molecule bearing two iron atoms (diferric transferrin) delivers its iron to the tissues faster than a molecule bearing one iron atom (monoferric transferrin). We investigated the same phenomenon in man by using radioiron-labelled transferrin species. After having formulated a set of mathematical models able to describe the process, we studied the “a priori” identiftability of the models and designed the optimal experiment for parameters estimation. It consisted in the injection of two differently labelled samples of transferring one partially saturated with radioiron (a mixture of mono and diferrictransferrin) and the other completely saturated (diferric transferrin). The results obtained in normal subjects and patients with disorders of iron metabolism and erythropoiesis seem to indicate new interesting mechanisms of regulation of the iron transport from transferrin to tissues.