Control of TH synthesis
Control of thyroid hormone synthesis and secretion
Each of the processes of thyroid hormone synthesis and secretion is under control of the thyroid-stimulating hormone (TSH) from the anterior pituitary. Binding of TSH to its receptor on the basal membrane of the thyroid epithelial cell stimulates the following processes:
- synthesis of the iodide transporter NIS
- synthesis of thyroglobulin
- synthesis of the thyroid peroxidase enzyme
By enhancing synthesis of these proteins, TSH stimulates the uptake of iodide and enhances the production of thyroid hormone. The magnitude of the TSH signal also sets the rate of endocytosis of the TG-T3/T4 complex. The higher the TSH binding, the faster the process of endocytosis and thus release of thyroid hormone into the circulation.