GRF (1-44) (human)

Description

GHRH is expressed and secreted from the hypothalamic neurons of the arcuate nucleus (ARC). GHRH stimulates the release of growth hormone (GH) in the anterior pituitary. In 1982, three isoforms of GHRH(1–37, 1–40, 1–44 aa residues) were initially isolated from human pancreatic tumors that caused acromegaly, and the latter two were found in the human hypothalamus. The aa sequence of GHRH was also identified in various vertebrates from rodents to fish, including a protochordate. In nonmammalian vertebrates, GHRH-like peptide (pituitary adenylate cyclase-activating polypeptide (PACAP)-related peptide in mammals) was first isolated like GHRH, although the GHRH-like peptide had less activity on GH release. Later, actual GHRH, which was more phylogenetically and structurally similar to mammalian GHRH and showed GH-releasing activity, was isolated in nonmammalian vertebrates.

Clinical Use

Sermorelin, a functional peptide fragment of GHRH (1–29), has been used in the diagnosis and treatment of children with idiopathic growth hormone deficiency. Tesamorelin, a stabilized synthetic peptide analog of GHRH(1–44), received US Food and Drug Administration approval in 2010 for the treatment of lipodystrophy in HIV patients under highly active antiretroviral therapy, and was investigated for effects on certain cognitive functions in adults with cognitive impairment as well as healthy older adults.