thyroxine n : hormone produced by the thyroid glands to regulate metabolism by controlling the rate of oxidation in cells; "thyroxine is 65% iodine" [syn: thyroxin, tetraiodothyronine, T]

English

Noun

1. A hormone (an iodine derivative of tyrosine), produced by the thyroid gland, that regulates cell metabolism and growth.

Translations

Thyroxine, or 3,5,3',5'-tetra­iodothyronine (often abbreviated as T4), a form of thyroid hormones is the major hormone secreted by the follicular cells of the thyroid gland.

T4 is transported in blood, with 99.95% of the secreted T4 being protein bound, principally to thyroxine-binding globulin (TBG), and, to a lesser extent, to transthyretin and serum albumin. T4 is involved in controlling the rate of metabolic processes in the body and influencing physical development.

Note: Thyroxine is a prohormone and a reservoir for the active thyroid hormone triiodothyronine (T3). T4 is converted in the tissues by deiodinases to T3. The "D" isomer is called "Dextrothyroxine" and is used as a lipid modifying agent. The half-life of thyroxine once released into the blood circulatory system is about 1 week.

The hormone was synthesised in 1927 by British chemists Charles Robert Harington and George Barger.

Reactions

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References