0129

FUNCTION OF FERRITIN RECEPTOR IN PLACENTAL IRON UPTAKE

Liu Yufeng¹, Liao Qingkui²

¹Department of Pediatrics, First Affiliated Hospital of Henan Medical University, Zhengzhou, China.

² Hematology/Oncology Laboratory of pediatrics, West China University of Medical Science

Objective: To explore the function of ferritin receptor (FnR) in placental iron uptake.

Methods: The protein (pro) of human placental microvillous membrane was isolated by the differential centrifugation and the basal membrane by the discontinues sucrose-density-gradient centrifugation. FnR was detected by receptor radioligand assay (RRA ) and 26 cases of term pregnant woman�s placenta including 11 cases of healthy pregnant women, 14 cases of� women with mild iron deficiency (IDA ) and 1 case woman with moderate IDA were detected.

Results: The FnR expression in 11 cases healthy placental microvillous membrane was (3.534 � 1.105) x 10¹² sites/mg.pro, and the association constant (Ka) was (2.203 �0.622) x10^-7mol^-1∙L, in mild IDA was (8.936 �2.407) x10¹² sites/mg.pro, and the association constant (Ka) was (1.249 �0.365) x10⁷mol^-1∙L and 1 case moderate IDA was 3.345x10¹² sites/mg.pro, and the association constant (Ka) was 1.560 x10^-7mol^-1∙L. The data of 3 groups were compared with each other and showed that the FnR of mild IDA was higher than healthy about 2.53 times (P<0.05), the FnR in 1 case moderate IDA agreed with healthy. In addition, the FnR in basal membrane was not detected by the same test.

Conclusions: The placenta is able to regulate the maternal-fetal iron metabolism by changing the amount of FnR expression during the iron deficiency pregnant, but there was limited. When mother with mild, the FnR expression on placenta was increased to enhance the placental iron uptake and increased the iron supply to feta. However, when mother with moderate IDA, the FnR expression on placenta was the same as normal, it indicated that the placental iron uptake was decreased. In other words, when mother with moderate IDA, for benefit of mother self, the FnR expression on placenta was decreased to reduce the placental iron uptake and reduced the iron supply to feta relatively. The FnR in basal membrane was not detected. It indicated that the function of FnR was to increase the iron accumulation of placenta and not to transfer the iron from mother to feta directly.

Keywords: ferritin receptor, placenta, iron