noun, plural: growth hormone-releasing hormones
A releasing hormone produced by the neuroendocrine cells of the arcuate nucleus of the hypothalamus, and acts on the somatotroph of the anterior pituitary to release pituitary growth hormone
The growth hormone-releasing hormone is one of the various hormones produced by the hypothalamus. It is a releasing hormone, influencing the anterior pituitary to release pituitary growth hormone (GH).
The growth hormone-releasing hormone is a peptide hormone comprised of 44 amino acids. It is synthesized and released chiefly by the neuroendocrine cells of the arcuate nucleus of the hypothalamus. The hypothalamus is the main site; however, apart from the hypothalamus, the growth hormone-releasing hormone is also expressed in the pancreas and the epithelial mucosa of the gastrointestinal tract.
The growth hormone-releasing hormone synthesized and released by the hypothalamus is carried by the hypothalamo-hypophyseal portal system in order to reach target cells (i.e. somatotrophs) in the anterior pituitary. The binding of the growth hormone-releasing hormone and the growth hormone-releasing hormone receptor on the cell surface of the somatotroph leads to the activation of the cell to release pituitary GH. The pituitary GH, in essence, is the hormone that plays a role in the promotion of a wide range of activities in the body that stimulate growth. Generally, this will involve promoting protein synthesis, while the hormone also promotes the lengthening of bones, which in turn helps to provide support for the future growth of the organism.
The growth hormone-releasing hormone is used clinically. An example of the pharmacological form of this hormone is somatorelin. It is used as a diagnostic agent to determine growth hormone deficiency.