Endocrine Abstracts

Introduction: The biological activity of thyroid hormone (TH) is largely mediated by binding of T3 to nuclear T3 receptors (TRs). Before TH can mediate its effects, it needs to be transported across the plasma membrane. Several TH transporters, such as MCT8, facilitate this transport. Inactivating mutations in MCT8 lead to a severe phenotype of psychomotor retardation. In addition to transport into the cell, MCT8 is also able to transport TH out of the ce...

The importance of thyroid hormone (TH) transporters for brain development has been unequivocally demonstrated by the identification of mutations in the transporter MCT8. Patients have mental retardation, hypotonia and low body weight (BW). Their biochemical phenotype typically shows high serum T3, low serum T4 and normal TSH levels. Recently, it has been shown that MCT8 is prerequisite for normal TH release from the thyroid. To date, no curative therapy i...