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Sodium-Iodide Symporter

Meaning

The Sodium-Iodide Symporter (NIS) is a crucial transmembrane glycoprotein located predominantly on the basolateral membrane of thyroid follicular cells, responsible for actively transporting iodide from the bloodstream into the thyroid gland against a concentration gradient. This active uptake mechanism is the essential first step in the biosynthesis of the thyroid hormones, triiodothyronine (T3) and thyroxine (T4), effectively concentrating the necessary precursor element within the gland. The functional integrity of NIS is indispensable for maintaining systemic thyroid hormone levels and overall metabolic regulation.