Investigation on the transport of trace elements across barriers in humans: Studies of placental and mammary transfer

To evaluate the barrier function of the human mammary gland for trace eleme nts 27 corresponding maternal sera and colostrum samples (1-3 days post par tum) were studied. To investigate the impact of the human placenta on the t ransfer of trace elements from the mother to the baby maternal and correspo nding umbilical cord sera (UCS) were studied. To determine the uptake of tr ace elements from the UCS by the baby, arterial and venous UCS were investi gated in 9 cases; in colostrum the concentration of Ca was 222%, of Co 80%, of Cu 19%, of Mg 146%, of Mn 275%, of Mo 814%, of Se 47%, of Su 228% and o f Zn 1470% of that of the maternal sera. For Cd the corresponding value was 200% and for Pb 325%. These data show that the mammary gland can exert as well an activating as an inhibiting effect on trace element transfer. A con centration gradient mode of action of transfer could be found for Li, Mo an d Sr. In UCS the concentration of Ca was 120%, of Co 60%, of Cu 20%, of Mg 105%, of Mn 150%, of Mo 100%, of Se 55%, of Sn 85% and of Zn 148% of that o f the maternal sera. The corresponding values for Cd were 66% and for Pb 50 %; The findings indicate that the placenta can exhibit an activation and in hibition as well as a gradient mode of action like for Mo, Cs, Li and Sr. T he studies of uptake of trace elements from the venous UCS by the newborn s how the following data: for Ca 2,5%, for Zn 4%, for Mg 5%, for Cu 10%, for Mn and Mo 14%.