Regulation of Nutrient Transport across the Placenta

Figure 1

The syncytiotrophoblast represents the primary barrier for transfer of nutrients from mother to fetus. Maternal blood pools in the intervillous space and bathes the microvillous membrane (MVM). The basal plasma membrane (BM) of the syncytiotrophoblast is oriented toward the fetal circulation. Transporters mediating the transfer of amino acids, glucose (GLUTs), and fatty acids (FATPs) are expressed in both plasma membranes of the syncytiotrophoblast. For transfer of lipids, extracellular lipases release fatty acids from maternal lipoproteins and intracellular binding proteins (FABPs) guide the fatty acids within the cytosol of the syncytiotrophoblast.