Posted by Larry Hoover on February 14, 2009, at 18:28:12
In reply to Re: Thyroid Function Test » psyclist, posted by bleauberry on February 14, 2009, at 18:06:09
> To make it even more complicated, as my doctor told me, we can measure thyroid in the blood, but we cannot measure thyroid within the cells where it actually works...in other words, it might not be getting in the cells where it is supposed to work. Causes could be genetic, heavy metal blockage, or some other unknown reason.
I'd like to expand on that idea. T4 is a prohormome. Virtually all of the activity attributed to thyroid hormone comes from T3, which is the same molecule with one crucial difference.....one less iodine atom. The enzyme that accomplishes this transformation is called deiodinase, and Type 2 deiodinase is the crucial form. It is localized in tissues that will utilize the T3 (heart, muscle, fat, CNS, and the thyroid itself). Its activity depends on selenocysteine being in good supply. That is an unusual amino acid wherein a selenium atom replaces the sulphur atom found in cysteine.
A genetic deficiency in this enzyme can only be treated with supplemental T3. A deficiency in selenocysteine can be corrected with selenium supps, especially those forms based on selenium yeast. The yeast will have incorporated selenium into methionine and cysteine already, making it immediately bioavailable. Another kind of deficiency can occur because of heavy metal toxicity, especially via mercury, as mercury is extremely reactive with selenium atoms which in the hydrogenated form seen in selenocysteine or selenomethionine. Again, selenium supps can help with that issue.
If you're "low normal" on thyroid indexes, you may feel a heck of a lot better if you receive supplemental hormones to push you to "high normal".
Lar
poster:Larry Hoover
thread:879453
URL: http://www.dr-bob.org/babble/20090213/msgs/880148.html