Arg residue swings aside, forming an interaction with the Asp on the adjacent c subunit in the ring and displacing the proton from that Asp; this adjacent proton exits through the second half- channel to the N side, completing the movement of one proton equivalent from outside to inside the matrix.

TLS Online TPP Program

#Id: 5784

#Unit 7. System Physiology – Animal

Basolateral membranes of thyrocytes contain a symporter Na+/I –symporter (NIS) 

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#Id: 5785

#Unit 7. System Physiology – Animal

Process of concentrating the iodide in the cell is called iodide trapping

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#Id: 5786

#Unit 7. System Physiology – Animal

Na+/I – symporter (NIS) is capable of producing intracellular I – concentrations that are 20– 40 times as great as the concentration in plasma

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#Id: 5787

#Unit 7. System Physiology – Animal

Wolff –Chaikoff effect large doses of iodide act directly on the thyroid to produce a mild and transient inhibition of organic binding of iodide and hence of hormone synthesis.

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#Id: 5788

#Unit 7. System Physiology – Animal

Thyroid stimulating hormone induces both NIS expression and the retention of NIS in the basolateral membrane.

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#Id: 5789

#Unit 7. System Physiology – Animal

Iodide is transported out of the thyroid cells across the apical membrane into the follicle by a chloride-iodide ion counter- transporter molecule called pendrin.