[Barrier role of ABC family of proteins in human placenta]

Both a pregnant woman and a fetus are exposed to a wide range of xenobiotics. Placenta provides the only link between the mother and the developing fetus. It plays a major protective role acting as a semi-permeable barrier to minimize fetal exposure to exogenous compounds. Membrane proteins taking part in the xenobiotic transport were found in human placenta, both in syncytiotrophoblast and fetal capillaries. Most importantly placental ABC transporters--P-glycoprotein, BCRP and MRP--protect placental and fetal tissues by the efflux of their substrates. However; a decline in placental ABC transporter expressions was observed in some disorders. As a result, many drugs may cross the placental barrier increasing the risk of teratogenic effects. Thus, knowledge about placental transport proteins and pharmacological control of ABC proteins activity has important clinical implications. It is very important in the context of effective and safe pharmacotherapy during pregnancy. In this review, we summarized the current state of knowledge about the barrier role of ABC transporters in the human placenta.