How is thyroxine synthesized?

How is thyroxine synthesized?

Thyroxine hormone is produced in the thyroid gland from tyrosine and iodine. Thyrotropin-releasing hormone (TRH) is produced by the hypothalamus. It stimulates the production of thyroid-stimulating hormone (TSH) in the anterior pituitary gland, which affects the thyroid-stimulating hormone receptor (TSHR).

How T3 and T4 hormone is synthesized?

Through a reaction with the enzyme thyroperoxidase, iodine is bound to tyrosine residues in the thyroglobulin molecules to form monoiodotyrosine (MIT) and diiodotyrosine (DIT). Linking two moieties of DIT produces T4. Combining one particle of MIT and one particle of DIT produces T3.

What are the steps in thyroid hormone synthesis and secretion?

The thyroid hormone synthetic pathway comprises the following steps: (1) thyroglobulin synthesis and secretion into the follicular lumen; (2) iodine uptake into the follicular epithelial cells; (3) iodine transport and efflux into the follicular lumen; (4) oxidation of iodine, iodination of thyroglobulin tyrosine …

What is important in the synthesis of thyroid hormone?

For thyroid hormone synthesis, sufficient supply of the thyroid gland with essential micronutrients such as iodine and selenium is crucial. The most important target tissues of thyroid hormones are the central nervous system, the cardiovascular system and the skeleton.

How does thyroid peroxidase catalyze thyroid hormone synthesis?

Thyroid peroxidase catalyzes two sequential reactions: Iodination of tyrosines on thyroglobulin (also known as “organification of iodide”). Synthesis of thyroxine or triiodothyronine from two iodotyrosines. Through the action of thyroid peroxidase, thyroid hormones accumulate in colloid, on the surface of thyroid epithelial cells.

How is thyroid hormone synthesis based on TG?

Thyroid Hormone Synthesis Thyroid hormone synthesis requires basal-to-apical transport of iodide and Tg. Conversely, hormone secretion is based on apical-to-basal transport of Tg and hormones; From:Encyclopedia of Food Sciences and Nutrition (Second Edition), 2003 Related terms: Graves’ Disease Serum (Blood) Iodide Iodine Deficiency Iodine

Where does thyroid hormone synthesis and secretion take place?

Control of Thyroid Hormone Synthesis and Secretion Each of the processes described above appears to be stimulated by thyroid-stimulating hormonefrom the anterior pituitary gland. Binding of TSH to its receptors on thyroid epithelial cells stimulates synthesis of the iodine transporter, thyroid peroxidase and thyroglobulin.

How is thyroxine converted to its active metabolite?

This enzyme catalyzes the conversion of thyroxine (T 4) to its active metabolite triiodothyronine (T 3) in the liver and kidney, and selenium deficiency results in an increase in levels of plasma T 4 and a corresponding decrease in levels of more active T 3.