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In thyroid disease the immune system makes antibodies that damage thyroid cells and interfere with their ability to make thyroid hormone. Over time, thyroid damage can cause thyroid hormone levels to be too low. This is called an underactive thyroid or hypothyroidism (heye-poh-THEYE-royd-ism). An underactive thyroid causes every function of the ...
The Plummer effect lasts about 7 to 10 days, but unlike the Wolff-Chaikoff effect, it isn't subject to an escape phenomenon. [ 8 ] The three different mechanisms of high iodine response, the Plummer effect, the Wolff-Chaikoff inhibition effect, and the adaptive escape phenomenon, synergistically work together to fend off potentially harmful ...
At the cellular level, T 3 is the body's more active and potent thyroid hormone. [2] T 3 helps deliver oxygen and energy to all of the body's cells, its effects on target tissues being roughly four times more potent than those of T 4. [2] Of the thyroid hormone that is produced, just about 20% is T 3, whereas 80% is produced as T 4.
In general, this happens as a result of thyroid hormones being released into the blood following the radioactive iodine-mediated destruction of thyroid cells that contain thyroid hormone. In some people, treatment with medications such as beta blockers ( propranolol , atenolol , etc.) may be useful during this period of time.
Hashimoto's Thyroiditis is a T-lymphocyte mediated attack on the thyroid gland. [15] T helper 1 cells trigger macrophages and cytotoxic lymphocytes to destroy thyroid follicular cells, while T helper 2 cells stimulate the excessive production of B cells and plasma cells which generate antibodies against the thyroid antigens, leading to ...
In thyroid cancer or Graves' disease, ablation therapy with radioactive iodine (131 I) can be used to remove trace thyroid tissue that may remain after thyroidectomy (surgical excision of the gland). For 131 I therapy to be effective, the trace thyroid tissue must be avid to iodine, which is achieved by elevating the person's TSH levels. [ 6 ]
Inactivation of thyroid hormones occurs by removal of an iodine atom on the inner ring, which converts thyroxine to the inactive reverse triiodothyronine (rT 3), or which converts the active triiodothyronine to diiodothyronine (T 2). The major part of thyroxine deiodination occurs within the cells. Deiodinase 2 activity can be regulated by ...
The thyroid hormones cross the follicular cell membrane towards the blood vessels by an unknown mechanism. [31] Text books have stated that diffusion is the main means of transport, [35] but recent studies indicate that monocarboxylate transporter (MCT) 8 and 10 play major roles in the efflux of the thyroid hormones from the thyroid cells. [32 ...