Oxytocin and its receptor in the process of parturition

OBJECTIVE: To review the potential roles of oxytocin (OT) and its receptor (OTR) in the regulation of parturition. METHODS: We reviewed the literature to describe the molecular aspects of the mechanisms of action and the regulation of OT and its receptor, particularly in relation to changes that occur at parturition. RESULTS: The literature provides strong support for a role for the OT/OTR system in the regulation of human parturition. Paracrine rather than endocrine mechanisms might be more important, and the regulation of the receptor might be more important than the ligand. The system is regulated by a wide variety of chemical and physical factors, including sex steroids, orphan receptors, uterine stretch, and many others. There also might be important interactions with the immune system. CONCLUSION: The OT/OTR system provides a potentially important therapeutic target for regulating the timing of human birth.