copy 2

Question 1

What is the electron acceptor for the iodiation?

Answer 1

The immediate oxidant (electron acceptor) for the reaction is hydrogen peroxide
(H 2 O 2 )

Question 1

How is hydrogen peroxide generated in the follicular lumen?

Answer 1

Generation of H2O2 in the follicular lumen is catalyzed by dual oxidases (DUOX1, DUOX2.

Question 2

What enzyme diodinates MIT and DIT?

Answer 2

iodotyrosine deiodinase

Question 3

What are the receptors that T3 and T4 use to cross the membrane and flow into the blood?

Answer 3

T3 and T4 cross the membrane into the blood via monocarboxylate transporters MCT8 and MCT10.

Question 4

What are the 4 proteins that T3 and T4 bind to while circulating in the blood?

Answer 4

1. thyroxine-binding globulin (TBG) (70%)
2. Transthyretin (TTR) (10% to 15% )
3. Albumin (15% to 20%)
4. lipoproteins. (3%)

Question 5

What is Allan-Herndon-Dudley syndrome (AHDS)?

Answer 5

It is a syndrome where there is deficeny in the MCT8 receptor which doesn’t allow t3 and t4 to enter the brain

Question 6

What transports T4 in cerebrospinal fluid?

Answer 6

Transthyretin transports T4 in cerebrospinal
fluid and provides thyroid hormones to the
CNS.