tetraiodothyronine

Thesaurus

Noun

tetraiodothyronine - hormone produced by the thyroid glands to regulate metabolism by controlling the rate of oxidation in cells; "thyroxine is 65% iodine"thyroxin, thyroxine, Tthyroid hormone - any of several closely related compounds that are produced by the thyroid gland and are active metabolically

tetraiodothyronine

thyroxine

(T₄) [thi-rok´sin] a thyroid hormone that contains iodine" >iodine and is a derivative of the amino acid tyrosine" >tyrosine, occurring naturally as l-thyroxine; its chemical name is tetraiodothyronine. It is formed and stored in the thyroid follicles as thyroglobulin and released from the gland by the action of a proteolytic enzyme. It is deiodinated in peripheral tissues to form triiodothyronine (T₃), which has a greater biological activity.

Thyroxine acts as a catalyst in the body and influences a great variety of effects, including metabolic rate (oxygen consumption); growth and development; metabolism of carbohydrates, fats, proteins, electrolytes, and water; vitamin requirements; reproduction; and resistance to infection. Pharmaceutical preparations of thyroxine, extracted from animals or made synthetically, are called levothyroxine.free thyroxine the fraction of thyroxine in the serum that is not bound to a binding protein.