《药理学》35甲状腺激素及抗甲状腺药.ppt

第三十五章 甲状腺激素及抗甲状腺药 thyroid hormones and antithyroid drugs 甲状腺激素是维持机体正常代谢，促进生长发育所必需的重要激素，分泌过多或过少均可引起疾病。 正常情况每天分泌:T3 25ug,T4 75ug 分泌过少：甲状腺功能低下 分泌过多：甲状腺功能亢进 碘的活化与酪氨酸碘化 一碘酪氨酸 (monoiodotyrosine: MIT ) 二碘酪氨酸  (di-iodotyrosine: DIT) 偶联：MIT+DIT ---T3 DIT+DIT---T4 所需要的酶：过氧化物酶， 合成场所：甲状腺球胆白（TG). 释放 在蛋白水解酶作用下，TG分解且释放出T3,T4,进入血液中。 调节 :主要受下丘脑---垂体系统的调节通过释放二种激素： 下丘脑：促甲状腺激素释放激素（thyrotropin releasing hormone,TRH）,腺垂体：促甲状腺激素（thyroid stimulating hormone,TSH) 食物中碘含量对T3 ，T4合成与释放的调节 甲状腺激素的作用 1 维持生长与发育：蛋白质合成 2促进代谢：促进物质氧化分解 3提高交感神经的敏感性 甲状腺激素药理作用1.维持正常生长发育：脑和长骨 A 44 yr. old man who has always been cared for by his mother is presented. He is severely retarded and cannot communicate. He is only 40?tall, his epiphyses are still open, although severely damaged. He has very thick, dry skin. His tongue is thick, and he has a saddle nose. He still has his primary teeth; the secondary teeth have not erupted. 甲状腺激素药理作用1.维持正常生长发育：脑和长骨 43 y/o patient with the chief complaint of decreased energy. She complains of fatigue, inability to finish tasks, sleeping more, yet always being tired. She has also noticed a decreased cold tolerance, constipation, and dryness of the skin. She comments that she is always cold, even in the summer. A 32 year old man presents with heat intolerance and weight loss. He has lost ten pounds in the last six weeks but says his appetite is very good. He says he is always hot, even in air-conditioned rooms. After questioning, he also admits to having increased nervousness, trouble concentrating, and palpitations. He is having trouble doing fine motor tasks because of a tremor. Physical exam reveals a patient with warm, smooth, moist skin and a diffuse goiter with a palpable thrill and bruit..  临床应用（甲状腺功能减退替代治疗） 4.T3抑制试验 摄碘抑制率 ＞50％单纯性甲状腺肿 ＜50％甲亢 作用机制： 与细胞膜上的T3,T4受体结合，被动转入细胞内，与胞浆结合蛋白结合，进一步调节细胞核内T3受体所中介的基因表达，增加相关mRNA及蛋白质的合成，而发挥作用。 临床应用： 甲状腺功能低下： 呆小病，黏液性水肿，单纯甲状腺