Int. J. Dev. Biol. 54: 367 - 375 (2010)

https://doi.org/10.1387/ijdb.082773hs

Vol 54, Issue 2-3

Special Issue: Placenta

Receptor-mediated uptake and transport of macromolecules in the human placenta

Review | Published: 21 September 2009

Henning Schneider and Richard K. Miller*

¹Department of Obstetrics and Gynecology, Insel Spital, University of Berne, Berne, Switzerland and ²Departments of Obstetrics and Gynecology, Environmental Medicine and Pathology, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA

Abstract

The human placenta is required to be the anchor, the conduit and the controller during pregnancy. The survival of the baby and its associated placenta is dependent upon the placenta shielding the embryo/fetus from harm, e.g., autoimmune disease - thrombophilia, antiphospholipid syndrome or infections, while simultaneously providing for the passage of critical nutrients (e.g., amino acids, vitamins) and beneficial immunoglobulins. In a number of instances, the movements of macromolecules into and through the placenta can result in the passage of the intact molecules into the fetal circulation or in the case of proteins - catabolism to amino acids which are utilized by the placenta and the fetus for continued growth and development. The transfer of two such macromolecules, immunoglobulin G (IgG) and vitamin B12 (cyanocobalamin or B12), are examined as to the unique receptor-mediated transfer capability of the human placenta, its transfer specificity as related to specific receptors and the role of endogeneous placental proteins (trancobalamins) in facilitating the recognition and transport of specifically B12. Brief comparisons will be made to other animal species and the differences in specific organ transfer capabilities.

Keywords

immunoglobulin IgG, transcobalamin, vitamin B12, placental transport, human