What Hormones Are Secreted By The Thyroid Gland
In part one of this series, we took a look into how exactly the thyroid functioned and what could go wrong. The thyroid is a very complex gland that is responsible for a variety of functions in the body. It plays a massive role in all things homeostasis. The thyroid is responsible for spitting out T4, T3, and Calcitonin. The different actions of these hormones makes all of them vitally important. If there is a disruption in any of these hormones, it will throw the body off kilter very rapidly. The point of part 2 of this article is to understand what each of these hormones does, what medications can take their place when dysfunction arises, and what exactly T2 does.
This hormone is also called thyroxine or tetraiodothyronine. This is the main hormone that the thyroid produces. It makes T4 in much more abundance than it does T3, at a ratio of about 17:1. In all essence, T4 is the precursor hormone to T3. To get more T3, the body needs to convert T4 to T3. This process happens in several organs of the body.
This is also known as triiodothyronine. This is the active form of thyroid hormone found circulating in the blood stream. There are often two levels of T3 found on clinical tests, total T3 and free T3. Free T3 is available to go into the tissues to exert it’s effect. Most of the T3 found in circulation is actually bound by globulin proteins called thyroglobulins. In order for your body to elevate metabolic levels, it would need to cleave the bound T3 off the thyroglobulin. This is how the body regulates metabolic rates.
There are two versions of this hormone that are produced by the body; 3,3- Diodo-L-thyronine which is biologically inert and 3,5-Diodo-L-thyronine which according to studies is biologically active. According to many research articles, T2 is as a metabolically active as triiodothyronine affecting energy and lipid metabolism without thyromimetic side effects typically associated with T3 usage. It occurs naturally in the course of thyroid hormone production and was considered useless until recent research uncovered its ability to up-regulate metabolic activity.
The thyroid also secretes Calcitonin which has a function in bone health. Calcitonin is a hormone that is produced in humans by the parafollicular cells (commonly known as C-cells) of the thyroid gland. Calcitonin is involved in helping to regulate levels of calcium and phosphate in the blood, opposing the action of parathyroid hormone.
In a study addressing T2 and it’s ability to burn fat it was seen that decreased weight from fat of rats fed with a chow diet high in fat lost 13% while the rats fed the same diet without T2 gained 13% fat mass. The control group had a normal diet and did not change in total body mass, fat or otherwise.
Visceral fat is the fat that kills people. Best part is the visceral fat, the fat that kills, is half of the fat mass that was lost in the T2 group. That was twice as much as the control group, the high fat diet and no T2. While on T2, rats gained no visceral fat while on the high fat diet. The T2 rats livers were darker in color as, indicating less fat was stored in the liver.
This same study showed that there was no negative impact of 30 days of T2 use, that TSH (Thyroid Stimulating Hormone), Thyroid Releasing Hormone (TRH), heart size, heart rate, and all other markers were the same as in the control group. There also was no reduction in muscle mass reported in the T2 group. Studies on T3 have shown a reduction in fast twitch muscle fibers.
This could mean T2 is a thyroid supplement on par with prescriptions drugs T3 and T4, but without the side effects and possible more benefits. Try Mind and Muscle T2 and kick start your weight loss today!
- Notes on a variety of topics are available from Thyroid Foundation of Canada
- The Family Practice Notebook has significant information on thyroid function tests.
- David Gardners Page on thyroid function tests.
- The Merck Manual’s note on thyroid function.
- Harvey Kaslow on thyroid hormone.
- A summary from Tiwary clinical laboratory.
- Dr Bruce Stanley’s lecture from 1999; [URL: http://www.hmc.psu.edu/core/stanley/4Thyroid.pdf Accessed monday 13 May 2002 13:00].
- Bryan McIver’s PDF on Nonthyroid influences on thyroid function which discusses amiodarone thyroid toxicity and ‘euthyroid sick syndrome’ in some detail.
- endocrineweb interpretation of thyroid function tests.
- Fatourechi V. Subclinical thyroid disease. Mayo Clin Proc. 2001 Apr;76(4):413-6
- Endocrinology 2015 Jan;156(1):389-99. doi: 10.1210/en.2014-1604.