甲状腺刺激ホルモン 化学特性,用途語,生産方法
性質
α鎖はLH-αと同じ，β鎖が生物活性の特異性を決定．β-Asn43にオリゴ糖鎖が結合
解説
甲状腺刺激ホルモン，甲状腺の機能の発達、維持（甲状腺ホルモンの合成・放出）に関与する下垂体前葉ホルモンで、TSH（thyroid stimulating hormoneの略）と表記されることが多い。TSHは糖タンパクで、α(アルファ)とβ(ベータ)の2本の鎖からできている。分子量は2万5000～2万8000で、ホルモンとしての活性部位はβ鎖にある。正常なヒトの血漿(けっしょう)中ではTSHの濃度は1ミリリットル当り5ナノグラム以下で、分泌されたホルモンは代謝されて1時間たらずで半減してしまう。
作用
TSHは甲状腺濾胞細胞に存在する細胞膜を7回貫通するG蛋白質共役型受容体に結合して，濾胞細胞の増高，濾胞細胞のヨード摂取，サイログロブリンの生合成，コロイド滴の形成，甲状腺ホルモンの生合成および分泌の促進作用や甲状腺の重量増加作用を示す．
天然物の起源
ヒト下垂体前葉，α鎖：25～116, β鎖：21～132
使用
Thyrogen (Genzyme).
定義
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.
適応症
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.
一般的な説明
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.
臨床応用
Recombinant form of human thyroidstimulating hormone (rhTSH). Used
diagnostically for serum thyroglobulin
testing.
甲状腺刺激ホルモン 上流と下流の製品情報
原材料
準備製品