Hormone · Synthetic gonadotrophin-releasing hormone receptor agonist
Histrelin
Also known as —
A modified GnRH nonapeptide used to investigate receptor activation and gonadotroph adaptation to sustained stimulation.
- Length
- 9 amino acids
- Half-life
- Not well characterised
- Mechanism
- Histrelin activates the gonadotrophin-releasing hormone receptor (GnRHR), principally engaging Gq/11-dependent phospholipase C signalling and intracellular calcium mobilisation. Sustained receptor stimulation can reduce gonadotroph responsiveness through receptor and downstream signalling adaptations.
- Studied in
- Pituitary cell cultures, recombinant GnRHR assays and animal endocrine models use histrelin to investigate receptor activation, gonadotrophin secretion and adaptation to sustained stimulation.
About Histrelin
Histrelin belongs to the synthetic analogue series developed from mammalian gonadotrophin-releasing hormone, a hypothalamic decapeptide whose structure was established in 1971. Its nine-residue backbone retains the N-terminal pyroglutamate of GnRH but incorporates D-histidine bearing a benzyl substituent at position 6. The native terminal glycinamide is replaced by an N-ethylamide on proline at position 9. These changes distinguish histrelin from the endogenous hormone and alter receptor-binding and proteolytic properties.
At the pituitary GnRH receptor, histrelin functions as an agonist rather than a competitive blocker. Short-term assays commonly examine calcium mobilisation, phosphoinositide signalling or luteinising hormone release, whereas longer incubations explore reduced responsiveness during persistent stimulation. Results depend on receptor abundance, exposure duration and the model's gonadotroph phenotype. Receptor desensitisation should not automatically be equated with rapid internalisation, because mammalian type I GnRH receptors lack the conventional cytoplasmic C-terminal tail.
Laboratory notes
- Confirm peptide identity, purity, counterion and peptide content from the batch certificate; salt mass is not necessarily equivalent to peptide mass.
- Prepare aliquots using supplier-validated solvent and storage conditions, and minimise repeated freeze–thaw cycles.
- Include a native GnRH comparator and time-matched controls to distinguish initial agonism from reduced responsiveness after sustained exposure.
Storage and reconstitution basics: storage guide.
Questions about Histrelin
Why is histrelin described as a nonapeptide?
It contains nine amino acid residues. The terminal glycine of native GnRH is absent, and proline at position 9 carries an N-ethylamide.
Which receptor does histrelin target?
Its principal target is GnRHR. Receptor species and expression system should be specified when reporting binding or functional activity.
Can a calcium assay establish sustained desensitisation?
An initial calcium response establishes acute signalling activity, not sustained desensitisation. The latter requires a defined pre-exposure period followed by a controlled functional challenge.
Is Histrelin for human use?
No. It is supplied strictly for in-vitro laboratory research and is not for human or animal consumption.
Related research peptides
All products are sold for laboratory research use only. Not for human consumption, not a medicine, not for diagnosing, treating or preventing any condition.