Expression of organic anion transporting polypeptide E (OATP-E) in human placenta

Purpose: To examine the expression of multifunctional Na+-Independent organic anion transporting polypeptide, termed OATP-E, involved in the transport of thyroid hormone in human placenta. Methods: Western blot analysis was performed using a specific antibody against OATP-E in human placenta to confirm the expression of OATP-E at the protein level. Immunohistochemistry was also performed using the specific antibody against OATP-E on frozen sections of human placenta. Results: By Western blot analysis, a single band for OATP-E was observed in human placenta. Immunohistochemistry revealed that OATP-E was predominantly expressed at the apical surface of the syncytiotrophoblasts in placenta. Conclusion: These results reveal that CATP-E is expressed in human placenta, suggesting a functional role for the transplacental transfer of thyroid hormone. (C) 2003 Elsevier Science Ltd. All rights reserved.