Thyroid Hormone Flashcards
Thyroglobulin is composed of. ……….
115 tyrosine residue
The transporters that balance the Na/I transporter electrical gradient is
Na /K+ Atpase
Penidrin I-/Cl- antiporter on the apical membrane
Mutation in what genes are implicated in the Iodide uptake which can lead to thyroid diseases
PDS
NIS GENES
Oxidation of Iodide is catalysed by
Thyroperoxidase
Oxidation of Iodide is carried out by ……
H202
The oxidation of Iodide and incorporation into thyroglobulin is called
Organification of iodide
Tyrosine is iodinated at position ……… and ……… to form MIT and DIT respectively
3
3 and 5
The peculiarity of thyroid hormones is in their ability to be stored how does this come about
It is stored in the form of iodinated thyroglobulin
What fraction of thyroglobulin is iodinated
1/5th
The mechanisms through which TSH regulates thyroid hormone synthesis is ……
1.Uptake of Iodide by stimulating the transcription of Iodide transporters( main regulatory mechanism for TSH)
- Synthesis and secretion of thyroglobulin
- Generation of H2O2 and iodination of tyrosine
- Endocytosis and proteolytic
- Release of T4 and T3
- Blood flow to through the gland
What is the trophic action of thyroid hormone
Stimulating the transcription of genes for Iodide transporters and thyroglobulin.
Which thyroid hormone has the most significant negative feedback on thyroid hormone synthesis
T3
The storage level of T3 and T4 respectively are……
2×10^-9
1×10^-7
Thyroid hormones are transporter in thr circulation is
Thyroid binding globulin
The radioiodine used in the treatment of hyperthyroidism is ………
131
