Today, we are discussing crucial thyroid hormones, tests, their functions, production processes, intriguing peptide bioregulators, and more. Let's dive in by providing a broad overview of the thyroid's anatomy.
The thyroid gland, a vital endocrine organ, resides in the neck's front, just below the larynx. Its distinctive butterfly shape consists of two lobes, the right and left, connected by a slender isthmus.
Within these lobes, spherical structures known as thyroid follicles form the functional units. These follicles are lined with thyroid follicular cells and contain colloid, a protein-rich fluid serving as a precursor reservoir for thyroid hormone synthesis. To recap: the thyroid lobes house follicles lined by follicular cells and contain colloid.
Follicular cells synthesize thyroglobulin, a significant glycoprotein serving as a storage molecule for thyroid hormones like T4 and T3. To achieve this, thyroglobulin requires iodine, which is transported into follicular cells from the bloodstream within the thyroid follicles. Enzymatic iodination of tyrosine residues within thyroglobulin results in the creation of iodinated thyroglobulin.
Iodinated tyrosines within iodinated thyroglobulin are then coupled together by thyroid peroxidase (TPO) enzyme, forming both T3 and T4 within the thyroglobulin structure. This iodinated thyroglobulin, containing synthesized thyroid hormones T3 and T4, is stored within the colloid, a protein-rich fluid in the thyroid follicles, which are lined by follicular cells.
When the body needs thyroid hormones, thyroid-stimulating hormone (TSH) from the pituitary gland stimulates the release of stored thyroglobulin from the colloid. Surrounding follicular cells reabsorb and digest thyroglobulin, releasing T3 and T4 into the bloodstream.
However, the release of these thyroid hormones is ultimately regulated by the hypothalamus-pituitary-thyroid (HPT) axis. The hypothalamus secretes thyrotropin-releasing hormone (TRH), prompting the pituitary gland to produce TSH. TSH, in turn, stimulates the thyroid gland, completing the feedback loop.
Free T3, Free T4, Total T3, Reverse T3
Now, let's explore T3 and T4 in more depth. T4, or Thyroxine, contains four iodine atoms attached to a tyrosine molecule, making it less biologically active than T3. Nonetheless, the thyroid gland produces the majority (about 80-90%) of thyroid hormone as T4 (T4 can be converted to T3 in the periphery). After production, it (along with T3) is stored within the thyroid gland's colloid as part of the thyroglobulin molecule. When the body needs thyroid hormones, the thyroglobulin molecule is absorbed and digested within the follicular cells in order to release free T3 and T4. Free T3, the biologically active form of T3, can easily bind to carrier proteins in the bloodstream; this is what we counsider to be bound T3 (biologically inactive).
Additionally, there's reverse T3, an inactive and biologically inert thyroid hormone. T4 can convert to either free T3 or reverse T3 in peripheral tissues, depending on the type of deiodinase enzyme involved. Reverse T3 is biologically inert and does not significantly affect metabolic processes (reverse T3 is NOT the same as bound T3).
High reverse T3 levels are generally undesirable and may increase in response to stress or certain medical conditions, serving as an energy-conservation mechanism.
To assess thyroid health comprehensively, a thyroid panel should include tests for free T3, free T4, reverse T3, TSH, anti-thyroglobulin antibodies (autoantibodies produced by the immune system that target that thyroglobulin molecule), and anti-thyroid peroxidase antibodies (autoantibodies produced by the immune system that target thyroid peroxidase, which is the enzyme that plays a critical role in the production of thyroid hormones by assisting in the iodination of thyroglobulin). Additionally, assessing iron, vitamins, minerals, sex hormones, and stress hormones provides a more complete picture.
Aging also affects thyroid hormones, leading to decreased T4 to T3 conversion, increased reverse T3 levels, and elevated TSH levels. These changes result in lower metabolic rates and may present as fatigue.
Thyreogen Peptide Bioregulator
Thyreogen is a peptide bioregulator that plays a role in restoring thyroid function by reducing peptide deficiency and enhancing protein synthesis within thyroid cells. It has been show to balance overactive and underactive thyroid function by acting at the level of the thyroid cell's DNA.
Thyreogen is available as an oral capsule supplement, with typical courses lasting for 10 or 30 days, containing either 20 or 60 capsules, respectively. Thyreogen is also considered to be a cytomax, a natural peptide extract, which suggests it has longer-lasting effects compared to synthesized cytogens, which have shorter durations.
In summary, thyroid health is crucial, and understanding its hormones, testing, and peptide bioregulators like thyreogen can help restore balance. Aging and stress are just 2 of the many things that can disrupt thyroid function, and we will be sure to dive into a variety of other root causes in future posts.
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