甲状腺及抗甲状腺素药ppt课件.ppt

甲状腺激素和抗甲状腺药
Thyroid Hormones and Antithyroid Drugs
The two major thyroid hormones are thriiodothyronine(T3) and thyroxine(T4).They are essential for normal growth and development and play an important role in energy metabolism.
The predominant actions of thyroid hormones are mediated by binding to nuclear thyroid hormone receptors and modulating transcription of specific genes.
Antithyroid drugs consist of thioureas, iodide, radioiodine (131I) and β-adrenoceptor antagonist.
Thioureas inhibit the synthesis of thyroid hormones. Propythiouracil can also block the conversion of T4 to T3 in peripheral tissues.
Key Concepts
High concentrations of iodide appear to influence almost all important aspects of iodide metabolism by the thyroid gland,especially including an inhibition of the release of thyroid hormones.
131I exerts a destruction of thyroid gland by beta particles.
The major indications for the therapeutic use of thyroid hormones are for hormone replacement therapy in patients with hypothyroidism or cretinism,and antithyroid drugs are for the treatment of hyperthyroid individual.
Key Concepts
学****目的与要求
熟悉甲状腺激素的生物合成、分泌
调节、作用用途和不良反应
掌握硫脲类和碘及碘化物的药理作
用、临床应用和不良反应
了解放射性碘和β受体阻断药等抗
甲状腺药
提要
甲状腺激素
硫脲类
碘和碘化物
放射性碘
β受体阻断药
甲状腺激素
甲状腺是人体内最大的内分泌器官,主要由甲状腺腺泡构成,腺泡是生成和分泌甲状腺激素的主要场所。
甲状腺
腺泡
含碘的甲状
腺球蛋白
T4
T3
水解
T3作用强而快
T4量较T3多,
作用弱而持久
anterior pituitary
paraventricular nucleus
Hypothalamus
Anterior Pituitary
Thyroid gland
TRH
+
+
TSH
Thyroid
T4, T3
-
甲状腺激素—调节
甲状腺激素—体内过程
Po易吸收,T3和T4的吸收率分别为50%~75%及90%~95%。
血浆蛋白结合率均达99% ,T3与蛋白亲和力低于T4,其游离量为T4的10倍,T3作用快而强,维持时间短,T4则慢而弱、维持时间长。t1/2较长,T4为5天,T3为2天。
主要在肝、肾线粒体内脱碘,并与葡萄糖醛酸或硫酸结合而经肾排泄。
可通过胎盘和进入乳汁、妊娠和哺乳期妇女应慎用。