PHAR 471 Lecture Notes - Lecture 3: Thyroid Peroxidase, Follicular Cell, Postpartum Thyroiditis

• School: UBC
• Department: Pharmaceutical Sciences
• Course: PHAR 471
• Professor: Tara Klassen

Document Summary

Follicles consist of spheres of a layer of thyroid epithelial cells, surrounding colloid. Iodide is concentrated into the follicles via active transport (cid:894)agai(cid:374)st iodide(cid:859)s (cid:272)o(cid:374)(cid:272)e(cid:374)tratio(cid:374) gradie(cid:374)t(cid:895) (cid:271)y the na+/i+ symporter (nis). Energy comes from na+ goi(cid:374)g alo(cid:374)g it(cid:859)s (cid:272)o(cid:374)(cid:272)e(cid:374)tration gradient. Na/k pump maintains the sodium gradient (pumps out na+, pumps in k+) Iodide is effluxed into the extracellular colloid by the iodide channel in the apical membrane. Iodide is oxidized to iodine thyroglobulin is iodinated. Requires thyroid peroxidase (tpo) located on the apical surface of the thyroid follicular cell. Incorporates iodine into either carbon 3 and/or carbon 5 of tyrosine residues in thyroglobulin. The mit and dits are coupled forms t3 and t4. This is referred to as the (cid:862)orga(cid:374)ifi(cid:272)atio(cid:374)(cid:863) of iodi(cid:374)e. Allows use of radioactive iodine for diagnosis and treatment of hyperthyroidism and thyroid cancer with limited effects on other organs. Lysosomes degrade thyroglobulin release t3 and t4.