Cardiovascular effects of oxytocin.

The well known effects of oxytocin on uterine contraction and milk ejection were found as early as the beginning of the 20th century. Since then many other effects of oxytocin have been found and among them a great number of effects on the cardiovascular system. Oxytocin is released from the neurohypophysis into the circulation and from parvocellular neurons within the paraventricular nucleus (PVN) to many areas within the central nervous system (CNS). Indeed, oxytocin may modify blood pressure as well as heart rate both through effects within the CNS and through effects in other organs, such as the heart, blood vessels and kidney. Oxytocin may also cause cardiovascular effects by affecting other mediators, such as atrial natriuretic peptide (ANP), nitric oxide (NO) and alpha 2-adrenoreceptors.