甲状腺激素及抗甲状腺药Thyroidhormonesandantithyroid.ppt

甲状腺激素和抗甲状腺药Thyroid hormones and antithyroid drugs 北京协和医学院基础医学院药理学系 叶菜英 Summary Thyroid hormones Necessary to maintain normal metabolism, growth and development. Hypothyroidism Cause Cretinism if it happens in embryo or neonatal period. Cause myxedema if it happens in adults when the thyroid hormone could be used in replacement therapy. Hyperthyroidism A syndrom characterized by thyroid oversecretion and metabolic disorder caused by multiple reasons. It can be treated with radioactive iodine (131I) irradation, antithyroid drugs and operation. Thyroid hormones Thyroxine, T4 Triiodothyreninum natricum, T3 Synthesized and secreted by thyroid 抗甲状腺药 分为4类： 硫脲类 Thiourea 碘和碘化物 （复方碘溶液， lugol’s solution） ） 放射性碘（131I） β受体阻断药（心得安等从略） 硫脲类 硫氧嘧啶类（thiouracil）： 甲基硫氧嘧啶（methykthiouracil） 丙基硫氧嘧啶（propylthiouracil） 咪唑类（imidazoles） 他巴唑（Tapazole，甲巯咪唑methimazole） 甲亢平（卡比马唑Carbimazole） Thyroid hormones Thyroid hormones are iodic amino acids Active components Thyroxine, T4 Triiodothyreninum natricum, T3 Chemical constitution 甲状腺激素的化学结构 Physiological disposition of thyroid hormones Absorbed rapidly when take orally , activity T3T4，maintaining time T4T3. T1/2 of T4 and T3 are 6－7 days and 1－2 days, respectively. Deiodination in mitochondria of liver and kidney, eliminated by kidney affer conjugated with glucuronic acid and sulfuric acid. T3, T4 can also pass the placenta and enter milk. Figure: the amount of normal adults’ thyroid hormones produced and metabolized daily. Synthesis, storage and regulation of thyroid hormones Iodine uptake Iodine activation and tyrosine iodation Condensation and storage Disintegration and release Regulation Steps of thyroid hormones synthesis, release and regulation (Ⅰ) Iodine uptake: I－ in blood can be uptaken into cells by iodine pump in the adenocyte membrane . The amino acids can be used to synthesize thyroid globulin in cells. Iodine activation and tyrosine iodation: