Oxytocin Acetate

Oxytocin is a 9-residue cyclic peptide whose intramolecular disulfide bridge between Cys1 and Cys6 forms a six-residue ring that is essential for receptor engagement. The molecule binds the oxytocin receptor (OXTR), a class A G-protein-coupled receptor coupled primarily to Gq/PLC signaling and to additional Gi and Gs interactions documented across published binding-affinity studies. Pharmacokinetic descriptors documented in published animal-model investigations include rapid plasma clearance and a short systemic half-life on the order of minutes under standard parenteral paradigms. Interaction profile in the literature spans OXTR-mediated calcium mobilization in receptor-expressing cell models, mammary-tissue contraction assays, and central-nervous-system neuropeptide signaling research in animal-model behavioral paradigms. All activity descriptors here are framed as documented in published work. Structural confirmation is established by mass spectrometry and HPLC-validated purity on each Certificate of Analysis.

Experimental domains documented in the published literature include OXTR receptor-binding affinity studies, structure-activity work probing the role of the intramolecular disulfide bridge in receptor engagement, mammary-tissue contraction assays, calcium-signaling kinetics in OXTR-expressing cell lines, social-bonding and parental-behavior research in rodent models, and comparative work alongside vasopressin (a closely related nonapeptide) to dissect OXTR-versus-V1aR receptor selectivity. Investigators have also characterized oxytocin in studies probing receptor desensitization and in screening assays for OXTR-selective ligand discovery. Use in laboratory research extends to mechanism-elucidation paradigms where the molecule serves as a defined reference for cyclic-nonapeptide signaling. The reference standard is supplied for these and equivalent in-vitro and animal-model experimental contexts only, with no associated guidance for human, clinical, or veterinary application.

Each lot is characterized by reverse-phase HPLC for chromatographic purity and by mass spectrometry for molecular-ion confirmation against the C45H70N12O14S2 empirical formula. Purity is reported as an HPLC-area percentage on the Certificate of Analysis distributed with every lot, alongside the molecular-weight match within instrument tolerance. Counter-ion content (acetate) is reported when included in the lot's release specification. Peptide content where applicable is determined by amino-acid analysis or nitrogen-content assay following the analytical method specified on the COA. Residual solvent and water content are reported categorically when these parameters are part of the lot's release specification. The COA records the lot identifier, manufacturing date, and analytical method versions used, providing a traceable provenance chain from synthesis through release.

For laboratory storage, the lyophilized reference standard should be held at −20°C in its sealed, light-protected container until ready for analytical use. Allow vials to equilibrate to ambient temperature before opening to avoid moisture condensation on the lyophile. Reconstitution for in-vitro experimental use is typically performed in bacteriostatic water or a researcher-selected buffer compatible with the downstream assay; once reconstituted, store the working solution at 2–8°C and characterize stability in the relevant buffer prior to extended storage. The intramolecular disulfide bridge is sensitive to reducing conditions — avoid reductant-containing buffers unless specifically required by the downstream assay. Avoid repeated freeze-thaw cycles of reconstituted material. These handling parameters reflect general best-practice for cyclic peptide reference standards and do not constitute preparation guidance for human or veterinary application.