Overview
Sermorelin (GHRH 1-29 NH₂) is a synthetic peptide corresponding to the first 29 amino acids of endogenous human growth hormone-releasing hormone (GHRH), which is itself a 44-amino acid hypothalamic neuropeptide. The 1-29 fragment retains full biological activity at the GHRH receptor, as the C-terminal residues of native GHRH are not required for receptor binding and activation. Sermorelin was one of the first GHRH analogues to be extensively characterized in research settings and has been used for decades as a standard tool for studying pituitary somatotroph function, GH secretion dynamics, and the GH/IGF-1 axis.
Mechanism
Sermorelin binds to and activates the GHRH receptor (GHRHR) on somatotroph cells in the anterior pituitary gland. Receptor activation stimulates adenylyl cyclase, increasing intracellular cAMP and activating protein kinase A, which in turn stimulates GH gene transcription and the exocytosis of stored GH from secretory granules. Unlike synthetic GH secretagogues that act via the ghrelin receptor (GHS-R), sermorelin acts through the physiological GHRH receptor pathway, producing GH pulses that mirror the natural pulsatile secretion pattern. This makes sermorelin a valuable research tool for studying the intact hypothalamic-pituitary axis without bypassing the normal GHRH receptor signaling cascade.
Research Areas
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Pituitary Somatotroph Research
Sermorelin is used as a standard GHRH receptor agonist to study somatotroph cell function, GH synthesis, and secretory granule dynamics in pituitary research models.
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GH/IGF-1 Axis Research
Research has employed sermorelin to study the relationship between GHRH receptor activation, pulsatile GH secretion, and downstream IGF-1 production in liver and peripheral tissues.
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Hypothalamic-Pituitary Axis Research
As a physiological GHRH pathway agonist, sermorelin is used to study the intact hypothalamic-pituitary feedback loop, including somatostatin-mediated GH suppression and GH pulse timing.
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Combination Secretagogue Research
Sermorelin is frequently studied in combination with ghrelin receptor agonists (such as ipamorelin) to examine the synergistic effects of simultaneous GHRH receptor and GHS-R activation on GH pulse amplitude and frequency.
Storage
Store lyophilized at -20°C. Reconstitute with sterile bacteriostatic water. Stable at 4°C for up to 30 days once reconstituted. Sermorelin is relatively stable compared to native GHRH but should be protected from repeated freeze-thaw cycles.