Canadian Medical Guide > Chemicals and Drugs > Hormones, Hormone Substitutes, and Hormone Antagonists > Hormones > Thyroid Hormones Terms and Definitions

Thyroid Hormones

	Dextrothyroxine - The dextrorotary isomer of the synthetic THYROXINE.
	Diiodotyrosine - A product from the iodination of MONOIODOTYROSINE. In the biosynthesis of thyroid hormones, diiodotyrosine residues are coupled with other monoiodotyrosine or diiodotyrosine residues to form T4 or T3 thyroid hormones (THYROXINE and TRIIODOTHYRONINE).
	Monoiodotyrosine - A product from the iodination of tyrosine. In the biosynthesis of thyroid hormones (THYROXINE and TRIIODOTHYRONINE), tyrosine is first iodized to monoiodotyrosine.
	Thyroid Gland, Desiccated - A powder preparation of dried thyroid glands after the removal of fat and connective tissue. It is a yellowish to buff-colored amorphous powder containing 0.17-0.23% of iodine.
	Thyronines - A group of metabolites derived from THYROXINE and TRIIODOTHYRONINE via the peripheral enzymatic removal of iodines from the thyroxine nucleus. Thyronine is the thyroxine nucleus devoid of its four iodine atoms.
	Thyroxine - The major hormone derived from the thyroid gland. Thyroxine is synthesized via the iodination of tyrosines (MONOIODOTYROSINE) and the coupling of iodotyrosines (DIIODOTYROSINE) in the THYROGLOBULIN. Thyroxine is released from thyroglobulin by proteolysis and secreted into the blood. Thyroxine is peripherally deiodinated to form TRIIODOTHYRONINE which exerts a broad spectrum of stimulatory effects on cell metabolism.

Thyroid Hormones Medical Definitions and Terms