甲状腺功能亢进症与甲状腺功能减退症课件.pptVIP

Thyroid pathophysiology Guo Qinglian New words and exprssions Thyroxine (T4) 　甲状腺素 Triiodothyronine (T3)　三碘甲腺原氨酸 Pathophysiology　病理 Iodination　碘化 Tyrosine　酪氨酸 Thyroglobulin　甲状腺球蛋白 Congenital　先天的 Skeletal 　骨骼 Albumin　白蛋白 Prealbumin　前白蛋白 Titre (titer)　效价 Goitre (goiter)　甲状腺肿 Euthyroid 　甲状腺功能正常的 Introduction Thyroid hormones are synthesized in the thyroid gland, including: thyroxine (T4) triiodothyronine (T3) The thyroid gland secretes mostly T4 (100nmol/L in plasma) and nearly 20% T3. The peripheral tissues (liver, kidney) deiodinate T4 to produce approximately two-thirds of the circulating T3 (around 2nmol/L). T3 has biologically activity. T3 can bind to receptors and triggers the end-organ effects of the thyroid hormones. In pathophysiologic situations, the quantity of reverse T3 (rT3) will increase. Thyroid hormone action Thyroid hormones are essential for the normal maturation and metabolism of all the tissues in the body. So, insufficient thyroid hormones can result some abnormal situations: permanent brain damage (congenital hypothyroidism) delayed skeletal maturation short stature delayed puberty (青春期) Thyroid hormone action Thyroid hormone effects on metabolism are diverse. For protein synthesis: normal concentration improve high concentration suppress For carbohydrate synthesis: improve liver-glycogen(糖原) decomposion inprove the metabolism of carbohydrate For lipid metabolism: improve the synthesis of cholesterol improve the metabolizing of cholesterol Binding in plasma In plasma, over 99.95% of T4 is transported bound to protein. 70% carried by thyroxine binding globulin(TBG) 25% by albumin 5% by prealbumin In plasma, over 99.5% of T3 is transported by the same protein. The free T3 or T4 are important for the biological effects of the hormones. Re