Abstract
The role of MT and metal transporters was investigated in the mechanism of Cd transportation from mother to fetus and newborn rat. Female Wistar rats were given Cd (as CdCl2) at a dose of 0, 1, 2, and 5 mgCd/kg/day by gastric tube daily for 6 consecutive days each week for 10 weeks. The concentrations of Cd, Zn and Cu in the uterus and the placenta were determined. Gene Expressions of iso-MT (I, II, and III) and metal transporters such as DMT1, ZIP8, ZIP14, ZnT-1, ZnT-2, ZnT-4 and ATP7 in the uterus and the placenta were measured using real-time PCR. Cd concentration in these tissues increased depended on dose of Cd. However, Cu concentration decreased in contrast. Histopathological examination of placenta tissue had revealed atrophy of syncytiotrophoblast cell in mother rats of the 5 mg/kg group. Significant increase of MT-II gene expression by Cd accumulation was observed in uterus and placenta. It was suggested that MT-II act primarily in trapping Cd in the uterus and placenta and prevent Cd transport into the fetus. Gene expressions of metal transporters such as DMT1, ZIP-14 and ZnT-1 in the placenta were changed dose-dependently. Gene expression of ZIP14 was up-regulated, whereas that of ZnT-1 was down-regulated in the placenta. It was considered that the metal transporter DMT1, ZIP14 and ZnT-1 mediate mechanism in the placenta about the Cd transport from mother into fetus.
