Thyroxine
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Thyroxine | |
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Identifiers | |
CAS number | [ | ]
PubChem | |
MeSH | |
Properties | |
Molecular formula | C15H11I4NO4 |
Molar mass | 776.87 |
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
Thyroxine, or 3:5,3':5' tetraiodothyronine (often abbreviated as T4) 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 thyroxine binding prealbumin (TBPA) 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 being converted as required in the tissues by deiodinases.
Type II deiodinase converts T4 into T3.
The "D" isomer is called "Dextrothyroxine"[1] and is used as a lipid modifying agent.[2]
[edit] Reactions
[edit] References
Peptide hormones, Steroid hormones
Hypothalamus: TRH, CRH , GnRH, GHRH, somatostatin, dopamine - Posterior pituitary: vasopressin, oxytocin, lipotropin - Anterior pituitary: α (FSH, LH, TSH), GH, prolactin, POMC (ACTH, MSH, endorphins, lipotropin) - Pineal gland: melatonin
Thyroid: thyroid hormone (T3 and T4) - calcitonin - Parathyroid: PTH - Adrenal medulla: epinephrine, norepinephrine - Adrenal cortex: aldosterone, cortisol, DHEA - Pancreas: glucagon- insulin, somatostatin
Kidney: renin, EPO, calcitriol, prostaglandin - Heart atrium: ANP - Stomach: gastrin, ghrelin - Duodenum: CCK, GIP, secretin, motilin, VIP - Ileum: enteroglucagon - Liver: IGF-1 - Adipose tissue: leptin, adiponectin
Testis: testosterone, AMH, inhibin - Ovary: estradiol, progesterone, inhibin/activin, relaxin (pregnancy) - Placenta: hCG, HPL, estrogen, progesterone