Chapter 41 Thyroid hormones and antithyroid drugs
A Metabolism of thyroid hormones
A. Metabolism ofthyroid hormones 1. Uptake ofiodide 2. Oxidation of iodide(peroxidase) and iodination and coupling of tyrosine 3. Formation of thyroxine(T,) and triiodothyronine (3)from iodotyrosine 4. Secretion of thyroid hormones(proteolytic enzymes) 5. Regulation by thyroid stimulating hormone (TSH), T4 T3
TPO g TPo g METABOLIC STEP INHIBITOR lumen卜 o、9DTH2O2Dr HO or T a lodide transport CIO, SCN- B lodination PTU MMI EOI C Coupling PTU MMI D Colloid resorption Colchicine, Li2+, Cytochalasin B E Proteolysis F Deiodination of DIT MIT Dinitrotyrosine G Deiodination of T4 PTU L og apical membran p cel E MIT DIT. 5de- T4 T G ECF A basement membrane Metabolism of thyroid hormones
NH 2 HO -CH -CH-COOH L-tyrosine HO CH2-CH-COOH CH2一CH-cOOH monoiodotyrosine(MIT) diiodotyrosine(DIT) NH 2 HO CH.-CH-COOH Formation of 3,5,3-triodothyronine (T3) thyroxine(Ta) and triiodothyronine(T3) from iodotyrosine HO- CH.-CH-COOH 3, 5, 3, 5, tetraiodothyronine(Ta) ( thyroxine
HO CH2 cHoon Ho0①-R HO R 3 3 R R 3,5-T2 3,3-T2 3,5-T2 R HO R 3-T1 3-十1 Different forms of thyroid hormones
D2 Distribution of Brain thyroid hormones Pituitary BAT Heart Skeletal Muscle 3 T 4 3 D3 D1 Placenta Liver Skin Kidney Br rain Thyroid
Lumen Storage area MIT Apical cell I+Tg T Secretion of thyroid hormones( lysosomal od Lysosome proteolytic enzymes Golgi 0 0 Endoplasmic TA Nucleus Basement Bloodstream
A. Metabolism of thyroid hormones a Therapeutic drugs on thyroid function a Hyperthyroidism: a antithyroid drugs: thiourea derivatives iodine and iodides B receptor antagonists d surgery radioiodines: 1311. 1251 a Hypothyroidism: thyroid hormones
B. Antithyroid drugs
