Thyreostimulin is a hormone that is produced in the pituitary gland and works with other hormones to regulate the thyroid gland. Until now, medical science has not known much about thyro-stimulin, as researchers only discovered it in 2002. However, it appears to indirectly affect bone formation and otherwise act similarly to thyrotropin.
What is thyroostimulin?
Thyrostimulin is a peptide hormone. It performs a mediating function and stimulates the thyroid gland to produce its hormones. Medical science has only known about thyrostimulin since 2002, although its individual components were already known before then. Thyreostimulin is structurally similar to the hormone thyrotropin (TSH or THS1) and appears to use the same receptors. The two substances transmit the signal to the thyroid gland to also produce and release hormones. For this reason, medicine also knows thyrostimulin by the abbreviation THS2. Thyreostimulin and thyrotropin are so-called peptide hormones. In biology, this refers to a specific group of hormones that consist of a protein component and a fat component. The amino acids of the proteins are linked by peptide bonds – hence the name peptide hormone. They act as messenger substances of the human body.
Function, effect and tasks
Thyrostimulin consists of two building blocks, each of which occurs in the form of a chain: The alpha chain (A2) and the beta chain (B5). According to their exact names, medicine also calls the chains GPA2 (after “glycoprotein hormone subunit alpha”) and GPB5 (after “glycoprotein hormone subunit beta”). Thyrostimulin has not been known to science for very long. It was not until 2002 that a research group led by Nakabayashi discovered the hormone. For this reason, only a few reliable data exist on the formation and the spectrum of action of thyro-stimulin. Thyreostimulin participates in the regulation of the thyroid gland, which is found in the neck of humans. Medicine also calls it the thyroid gland. It produces the thyroid hormones L-triiodothyronine (T3) and L-thyroxine (T4), which in turn influence many processes in the organism. Among other things, the thyroid hormones participate in the control of fat, carbohydrate and protein metabolism as well as heat and oxygen regulation. In addition, T3 and T4 influence the activity of neurons and muscle cells. Therefore, a deficiency of thyroid hormones often leads to fatigue, feelings of weakness, drowsiness, decreased performance, concentration problems, decreased metabolic rate, and weight gain. Elevated thyroid levels, on the other hand, evoke hyperactivity, alertness, sleep disturbances, increased metabolic rate, and weight loss.
Formation, occurrence, properties, and optimal levels
Thyrostimulin is found, among other places, in the anterior pituitary gland, where the human body synthesizes it. The anterior pituitary is a structural unit in the brain that is part of the pituitary gland. In addition to thyrostimulin, the anterior pituitary also produces other hormones, including follicle-stimulating hormone, luteinizing hormone, and prolactin. The cells contain the information to synthesize thyrostimulin in the form of deoxyribonucleic acid (DNA). The ribosome, a specialized enzyme, uses a copy of the DNA to convert it step by step into a chain of amino acids. Because this process resembles a translation, biology also refers to it as translation. Amino acids are molecules that differ from each other only by their specific residue and otherwise have the same structure. Many amino acids together form a polypeptide chain and ultimately a protein. The two building blocks of thyrostimulin also consist of such chains. Thyro-stimulin and thyrotropin not only stimulate the thyroid gland to release thyroid hormones, but also ensure that the body does not release too many thyroid hormones and stays within the normal range. Healthy people turn over about 30 µgT3 and about 80 µg T4 a day. Blood work can show whether the thyroid is functioning well.
Diseases and disorders
There is little definitive knowledge about thyrostimulin to date. What seems most assured is the effect of thyrostimulin on the thyroid gland. In animal studies, scientists have also been able to demonstrate a possible link between thyrostimulin and abnormalities in the skull bone. However, the way in which thyro-stimulin influences bone has not yet been clarified.A group of researchers led by Basselt showed that the peptide hormone has only an indirect effect on the formation of bone. The implications of this relationship are also still unclear. Since thyrostimulin, like thyrotropin, can bind to the THS receptors of the thyroid gland, it may also play a role in connection with thyroid diseases. The causes of disease in this organ may be due to the thyroid gland itself or to a dysfunction of the hormones that control the thyroid gland. An example of a THS receptor disorder is Graves’ disease. This is an autoimmune disease that does not have to be lifelong. The body mistakenly produces antibodies against the THS receptors. As a result, the characteristic triad of Graves’ disease manifests. The thyroid gland enlarges and, without treatment, eventually forms a goiter (goiter). The eyeball protrudes from the orbit and may make it impossible to close the eyelids. Medicine refers to this clinical picture as exophthalmos or exophthalmia. Depending on the severity of the disease, only one eye may be affected, or both eyeballs may protrude. The third core symptom of Graves’ disease manifests as a rapid heartbeat. The rapid heartbeat is characterized by a frequency of more than 100 beats per minute (tachycardia). In addition, a mutation in the genes encoding thyrostimulin may interfere with the synthesis of thyrostimulin. As a result, various thyroid dysfunctions can potentially manifest.
