The Function of Thyrotropin Releasing Hormone

Releasing hormones and inhibiting hormones are hormones whose main purpose is to control the release of other hormones, either by stimulating or inhibiting their release. The hypothalamus uses thyrotropin-releasing hormone TRH or thyroliberin tell the pituitary to release thyrotropin. The anterior pituitary glands produces the following hormones and releases them into the bloodstream adrenocortical hormones, which stimulates the adrenal glands to secrete steroid hormones, principally cortisol.

Thyrotropin-releasing hormone is one of the smallest hormones in the body, consisting of a miniature chain of just three acid building blocks. It is made by a cluster of nerve cells in the hypothalamus, an area at the base of the brain just above the pituitary gland. This nerve cell cluster is known as the paraventricular nucleus the nerve fibres that comes out of carry the thyrotropin releasing hormones and releases it into the blood surrounding the pituitary glands, where it has its most important action. This is to regulate the formation and secretion of thyroid hormones in the thyroid stimulating hormones in gland. Thyrotropin-releasing hormones is very short lived, lasting for a matter of two minutes and traveling less than an inch in the bloodstream to the pituitary gland before it is broken down.

As its name implies, the main effect of thyrotropin-releasing hormones is to stimulate the release of thyrotropin also known as thyroid stimulating hormones from the pituitary glands. Thyrotropin releasing hormone is the master regulator of thyroid gland growth and function including the secretion of the thyroid hormones thyroxine and triiodothyronine. These hormones control the body's metabolic rate heat generation neuromuscular function and heart rate among other things. If there is insufficient thyroid hormone available for the brain this will be detected by the hypothalamus and thyrotropin releasing hormones releasing hormones will be released into the blood supplying the pituitary gland. The effect of thyrotropin releasing hormone on pituitary gland is to trigger thyroid stimulating hormone release, which stimulates the thyroid gland to make more thyroid hormone.

If someone has too little thyrotropin releasing hormone, they will develop thyroid underactivity hypothyroidism. This is a rare scenario in which a specific injury or tumor destroys this area of the hypothalamus. This situation is referred to as secondary or central hypothyroidism.

Works Cited

Gspr, E, et al. “Thyrotropin Releasing Hormone (TRH): a New Player in Human Hair-Growth Control.” FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology., U.S. National Library of Medicine, Feb. 2010. www.ncbi.nlm.nih.gov/pubmed/19825978.

Utiger, Robert D. “Thyrotropin-Releasing Hormone.” Encyclopedia Britannica, Encyclopedia Britannica, Inc., 12 May 2014.