Plasma oxytocin increases in the human sexual response

Area of Science:

• Neuroendocrinology
• Human sexual response

Background:

• Oxytocin (OT) is a hormone implicated in social bonding and reproduction.
• Its role in the physiological processes of human sexual response remains incompletely understood.

Purpose of the Study:

• To investigate plasma oxytocin (OT) level changes during human sexual responses.
• To characterize the temporal dynamics of OT secretion in relation to sexual arousal and orgasm.

Main Methods:

• Plasma OT levels were quantified using radioimmunoassay (RIA) in 9 men and 13 women.
• Continuous blood sampling via venous catheters occurred before, during, and after self-stimulation to orgasm.
• Objective physiological measures of sexual arousal and orgasm included photoplethysmography and electromyography.

Main Results:

• Plasma OT levels demonstrated a significant increase during sexual arousal in both sexes.
• OT levels were significantly elevated during orgasm/ejaculation compared to baseline.
• The temporal secretion pattern suggests a potential correlation with smooth muscle contractions during orgasm.

Conclusions:

• Plasma oxytocin levels dynamically change during human sexual response, increasing with arousal and peaking at orgasm.
• These findings support a role for oxytocin in the physiological events of human orgasm.
• The observed secretion pattern may be associated with reproductive system smooth muscle activity.