Exocytosis Thyro- globulin Pendrin Tyrosyl residue lodination — ТРО H202 TSH (cAMP) H202 generator Stored forms 0г Endocytosis of iodinated thyroglobulin See Fig. 25.2 Triiodotyrosine - ОН Follicular cell Colloid Tetratyrosine ОН Monoiodotyrosine (MIT) Diiodotyrosine (DIT) Coupling #T4 #T3