Human growth hormone-releasing factor TFA (Growth Hormone Releasing Factor human TFA) is a hypothalamic polypeptide and stimulates GH production and release by binding to the GHRH Receptor (GHRHR) on cells in the anterior pituitary[1].
The GHRHR is a member of the class II B GPCR family, which couples predominantly to the Gs-adenylate cyclase-cAMP signaling pathway. Peptide hormones that activate class II GPCRs include GHRH, secretin, glucagon-like peptides, gastric-inhibitory peptide (GIP), pituitary adenylate cyclase-activating peptide, corticotropin-releasing hormone, vasoactive intestinal peptide, parathyroid hormone, and calcitonin-related peptides[1].GHRH, expressed in the arcuate nucleus of the hypothalamus and released into portal vasculature, directly stimulates growth hormone synthesis and secretion from the pituitary somatotropes by activating the corresponding GHRH receptors[1].
[1]. Fridlyand LE, et al.Growth Hormone-Releasing Hormone in Diabetes.Front Endocrinol (Lausanne). 2016 Oct 10;7:129. eCollection 2016.