Amino Acid Sequence Cys-Tyr-Ile-Thr-Asn-Cys-Gly-Leu-Gly-NH2 [Disulfide Bridge: 1-6] Biochem/physiol Actions Neuropeptide synthesized in the hypothalamus and involved in the control of lactation and parturition; selective ligand for central and peripheral oxytocin receptors.