What is the function of sodium iodide Symporter?
The sodium/iodide symporter (NIS or SLC5A5) is an intrinsic membrane protein implicated in iodide uptake into thyroid follicular cells. It plays a crucial role in iodine metabolism and thyroid regulation and its function is widely exploited in the diagnosis and treatment of benign and malignant thyroid diseases.
How is iodine transported into the cell?
Iodine uptake is a result of an active transport mechanism mediated by the NIS protein, which is found in the basolateral membrane of thyroid follicular cells. As a result of this active transport, iodide concentration inside follicular cells of thyroid tissue is 20 to 50 times higher than in the plasma.
Where is sodium iodide Symporter found?
The sodium-iodide symporter is most highly expressed in thyroid epithelial cells. Lower levels of expression can be detected in mammary gland, salivary gland, stomach and colon, but none of these tissues is known to organify iodide.
Is sodium iodine a Symporter?
The sodium iodide symporter (NIS) is responsible for thyroidal, salivary, gastric, intestinal and mammary iodide uptake. It was first cloned from the rat in 1996 and shortly thereafter from human and mouse tissue.
What does sodium iodide do to thyroid?
Sodium iodide I 131 is taken by mouth, readily absorbed into the body and is trapped within the thyroid gland. The trapped sodium iodide I 131 irradiates the thyroid gland thereby damaging it. As a result, the activity of the thyroid gland (that is, the production and release of thyroid hormone) is reduced.
What method of transportation do thyroid cells use to take in iodine?
The iodide within the follicular cell moves towards the apical surface of the plasma membrane, to enter into the follicular lumen; this transport by a sodium independent iodide/chloride transporter called pendrin.
Which transports thyroid hormones into target cells?
Once made, the thyroid gland releases the hormones into the bloodstream where protein chaperones, called thyroid transport proteins, accompany them to target cells in tissues all over the body.
Is Sodium Iodide the same as iodine?
Sodium iodide is a water-soluble ionic compound with a crystal lattice. Sodium iodide is a source of iodine and can be administered as a supplement for total parenteral nutrition but is more commonly used in veterinary medicine.
What is a Symporter and Antiporter?
Uniporters, symporters, and antiporters are proteins that are used in transport of substances across a cell membrane. Antiporters transport molecules in opposite directions, while symporters transport molecules in the same direction.
What is primary and secondary active transport?
In primary active transport, the energy is derived directly from the breakdown of ATP. In the secondary active transport, the energy is derived secondarily from energy that has been stored in the form of ionic concentration differences between the two sides of a membrane.