Endocrine Abstracts

Thyroid hormone controls multiple physiological processes in both development and adult homeostasis. The majority of thyroid hormone actions that are understood at the molecular level involve transcriptional regulation of target genes mediated by hormone binding to the nuclear thyroid hormone receptors. However, a large number of thyroid hormone actions occur on a rapid time scale through unknown mechanisms that do not involve gene transcription. We have recently identified a novel series of thyroid hormone metabolites, called thyronamines, which chemically resemble neurotransmitters such as dopamine and serotonin. We have also found that these substances are potent agonists of a family of orphan G protein-coupled receptors, called the trace amine receptors. Moreover, we have found that these substances induce profound physiological changes when administered in vivo, including alterations in thermal regulation, cardiac drive, and energy utilization. In this presentation data will be presented to show the current situation with this new aspect of thyroid hormone research.