Thyrotropin-releasing hormone
thyrotropin-releasing hormone | |||||||
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Chr. 3 q13.3-q21 | |||||||
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Thyrotropin-releasing hormone (TRH) is a hypophysiotropic hormone produced by neurons in the hypothalamus that stimulates the release of thyroid-stimulating hormone (TSH) and prolactin from the anterior pituitary.
TRH has been used clinically for the treatment of
Synthesis and release
TRH is synthesized within parvocellular neurons of the
To produce the mature form, a series of enzymes are required. First, a protease cleaves to the C-terminal side of the flanking Lys-Arg or Arg-Arg. Second, a carboxypeptidase removes the Lys/Arg residues leaving Gly as the C-terminal residue. Then, this Gly is converted into an amide residue by a series of enzymes collectively known as peptidylglycine-alpha-amidating monooxygenase. Concurrently with these processing steps, the N-terminal Gln (
TRH synthesizing neurons of the paraventricular nucleus project to the medial portion of the external layer of the median eminence. Following secretion at the
The half-life of TRH in the blood is approximately 6 minutes.Structure
TRH is a tripeptide, with an amino acid sequence of pyroglutamyl-histidyl-proline amide.
History
The structure of TRH was first determined, and the hormone synthesized, by
Schally and Guillemin shared the 1977
Clinical significance
TRH is used clinically by intravenous injection (brand name Relefact TRH) to test the response of the
TRH has anti-depressant and anti-suicidal properties,[8] and in 2012 the U.S. Army awarded a research grant to develop a TRH nasal spray in order to prevent suicide amongst its ranks.[9][10] The antidepressant properties of TRH are present when TRH is administered intrathecally, or administration into the spine, and the effects are short-lived.[8] Some researchers are testing a prodrug approach to administer TRH orally and have TRH reach the brain without being degraded in the stomach or blood.[11]
TRH has been shown in mice to be an anti-aging agent with a broad spectrum of activities that, because of their actions, suggest that TRH has a fundamental role in the regulation of metabolic and hormonal functions.[12]
Side effects
Side effects after intravenous TRH administration are minimal.Thyrotropin-releasing hormone (TRH) Identifiers Symbol TRH Pfam PF05438 InterPro IPR008857 Available protein structures: Pfam
structures / ECOD
PDB RCSB PDB; PDBe; PDBj PDBsum structure summary See also
References
External links