23-甲状腺及抗甲状腺药 PPT课件.ppt

甲状腺激素
及抗甲状腺药
目的与要求
、临床应用及应用注意事项。    ;大剂量碘抗甲状腺作用的机制、应用、不良反应和注意事项。    。
重点、难点
重点:硫脲类抗甲状腺药的药理作用、作用机制、临床应用。    难点:甲状腺激素的合成及各类抗甲状腺药的作用环节。
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
甲状腺激素
维持机体正常代谢、促进生长发育所必需的激素
1891年Murray用绵羊甲状腺提取物治疗粘液性水肿(myxedema, 甲减)
甲状腺激素包括
甲状腺素 T4 Thyroxine
三碘甲状腺原氨酸 T3 triiodothyroxine
甲状腺功能亢进(hyperthyroidism, 甲亢)
多种原因所致的以甲状腺激素分泌过多引发代谢紊乱为特征的综合症
Graves病毒性弥漫性甲状腺肿最常见
第一节甲状腺激素
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

、贮存、分泌与调节
(一)合成
碘的摄取:
甲状腺腺泡细胞主动摄碘,浓集碘(碘泵)
甲状腺中碘化物浓度为血中25倍,甲亢时为血中的250倍
碘的活化和酪氨酸碘化:
碘化物经过氧化酶的作用活性碘与甲状腺球蛋白酪氨酸残基结合生成MIT,DIT
缩合(耦联):
2 DIT T4 ;DIT + MIT T3 (过氧化酶)