Is the sodium iodide Symporter a secondary active transport?

As its name indicates, the sodium-iodide symporter simultaneously transports both Na+ and I- ions from extracellular fluid (i.e. blood) into the thryoid epithelial cell. This process is an example of secondard active transport.

What kind of transport is necessary to transport iodine into a 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.

How is iodine transported in the body?

Metabolism and Transport of Iodine Iodide, supplied by food, is bound to serum proteins, especially to albumin. Uncoupled iodide is excreted via the urine (70%) and a minor part is excreted via the gastrointestinal system.

How does iodine produce thyroid hormone?

Thyroid cells are the only cells in the body which can absorb iodine. These cells combine iodine and the amino acid tyrosine to make T3 and T4. T3 and T4 are then released into the blood stream and are transported throughout the body where they control metabolism (conversion of oxygen and calories to energy).

How does the sodium iodine Symporter work?

NIS uses the sodium gradient generated by the Na+/K+-ATPase to actively transport iodide into thyrocyte cells. The iodide ions cross the cells and are organified (covalently linked) inside the thyroid follicles by thyroid peroxidase (TPO) onto thyroglobuline tyrosine residues.

Which of the following is the transporter responsible for the transport of iodine into the thyroid cells against the concentration gradient?

As illustrated in Figure 1, the NIS (SLC5A5), a member of the solute carrier family 5, located at the basolateral plasma membrane of the thyroid follicular cells actively transports iodide into the thyroid using the electrochemical gradient generated by the Na,K-ATPase [9-11].

What is iodine absorption?

Iodine from the diet is absorbed throughout the gastrointestinal tract. Dietary iodine is converted into the iodide ion before it is absorbed. The iodide ion is bio-available and absorbed totally from food and water. This is not true for iodine within thyroid hormones ingested for therapeutic purposes.

Where is iodine digested in the body?

Iodide is the easiest form to absorb, so most of the bound iodine and iodate is converted to iodide by glutathione. The iodide ions are easily absorbed through the walls of the digestive tract in the stomach and small intestine. After it’s absorbed, most of it concentrates in the thyroid gland.

What is the role of iodine in thyroid?

Control of the thyroid by iodine Its main effects are to decrease the response of the thyroid to thyrotropin (TSH); to acutely inhibit its own oxidation; to reduce its trapping after a delay; and, at high concentrations, to inhibit thyroid hormone secretion12).

What is the role of iodine in thyroid disorders?

Iodine is an element that plays an essential role in the functioning of a healthy thyroid. It is used for the production of thyroid hormones. It is particularly important in women who are pregnant as it is needed to ensure the development of a baby’s brain during pregnancy and early life.