| Background: | | The oxytocin receptor belongs to the vasopressin/oxytocin family of GPCRs because it binds similar cyclic nonapeptide hormones. The oxytocin receptor functions primarily during labor and lactation. There is a dramatic increase in the number of oxytocin receptors just before the onset of labor causing the uterine muscles to become exceedingly sensitive to oxytocin. The activated oxytocin receptor causes an inward membrane current that results in smooth muscle contraction during labor and milk ejection during lactation. This receptor also plays a role in natriuresis, kaliuresis and may have an antistress effect. Oxytocin receptor has been reported in breast, central nervous system, heart, ovary, placenta, prostate, salivary gland, testis, uterus, and vessel. ESTs have been isolated from connective tissue, embryo, heart, lung, and melanocyte/uterus/fetal heart, skin, and uterus libraries. |