Amino acid transporters in the human placenta

Pediatr Res. 2001 Feb;49(2):141-7. doi: 10.1203/00006450-200102000-00003.


Amino acid transport across the human placenta is active, mediated by specific transporters in syncytiotrophoblast plasma membranes. Using functional criteria such as substrate specificity and sodium dependence, approximately 15 transport systems have been identified in the human placenta. Recently, the area of molecular biology of amino acid transporters has evolved rapidly and at least 25 cDNA clones coding for mammalian amino acid transporters or transporter subunits have been identified. The primary objective of this review is to integrate the available functional data on placental amino acid transport systems with recent molecular information on mammalian amino acid transporters. Furthermore, models for the mechanisms for net materno-fetal transfer of amino acids are discussed. Finally, the evidence to suggest that alterations in placental amino acid transport systems may play a crucial role in the regulation of fetal growth are presented briefly.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Amino Acid Transport Systems
  • Amino Acids / metabolism
  • Biological Transport
  • Carrier Proteins / metabolism*
  • Female
  • Humans
  • Maternal-Fetal Exchange
  • Placenta / metabolism*
  • Pregnancy


  • Amino Acid Transport Systems
  • Amino Acids
  • Carrier Proteins