Oxytocin receptor

The oxytocin receptor, also known as OXTR, is a protein which functions as receptor for the hormone and neurotransmitter oxytocin. In humans, the oxytocin receptor is encoded by the OXTR gene which has been localized to human chromosome 3p25.

Function and location

The OXTR protein belongs to the G-protein coupled receptor family, specifically G_q, and acts as a receptor for oxytocin. Its activity is mediated by G proteins that activate several different second messenger systems.

Oxytocin receptors are expressed by the myoepithelial cells of the mammary gland, and in both the myometrium and endometrium of the uterus at the end of pregnancy. The oxytocin-oxytocin receptor system plays an important role as an inducer of uterine contractions during parturition and of milk ejection.

Oxytocin receptors are also present in the central nervous system. These receptors modulate a variety of behaviors, including stress and anxiety, social memory and recognition, sexual and aggressive behaviors, bonding (affiliation) and maternal behavior. (See the oxytocin article for more details.)