ТТГ

Использование

Thyrogen (Genzyme).

Определение

A hormone secreted by the anterior lobe of the pituitary gland. It increases the rate of removal of iodine from the blood by the thyroid gland, synthesis of the thyroid hormone, and its release into the bloodstream. The thyrotropic hormone is a protein with a low molecular weight (about 10,000) that contains some carbohydrate.

Показания

TSH, or thyrotropin, is a glycosylated protein of two subunits,  and . TSH stimulates the thyroid gland to produce thyroid hormones. Deficiencies are treated by giving thyroxine itself rather than TSH, but TSH is available for diagnostic purposes to differentiate between pituitary and thyroid gland failure as causes of hypothyroidism.

Общее описание

The thyrotropic hormone, also called thyrotropin and thyroidstimulatinghormone (TSH), is a glycoprotein consisting oftwo polypeptide chains. This hormone promotes productionof thyroid hormones by affecting the kinetics of the mechanismby which the thyroid concentrates iodide ions from thebloodstream, thereby promoting incorporation of the halogeninto the thyroid hormones and release of hormones by thethyroid.
TSH (Thyropar) appears to be a glycoprotein (relativemolecular mass [Mr] 26,000–30,000) containing glucosamine,galactosamine, mannose, and fucose, whose homogeneityis yet to be established. It is produced by thebasophil cells of the anterior lobe of the pituitary gland.TSH enters the circulation from the pituitary, presumablytraversing cell membranes in the process. After exogenousadministration, it is widely distributed and disappears veryrapidly from circulation. Some evidence suggests that thethyroid may directly inactivate some of the TSH by an oxidationmechanism that may involve iodine. TSH thus inactivatedcan be reactivated by certain reducing agents.TSH regulates the production by the thyroid gland of thyroxine,which stimulates the metabolic rate. Thyroxinefeedback mechanisms regulate the production of TSH bythe pituitary gland.

Клиническое использование

Recombinant form of human thyroidstimulating hormone (rhTSH). Used diagnostically for serum thyroglobulin testing.