Oxytocin (medication)
Oxytocin, sold under the brand name Pitocin among others, is a medication made from the peptide "oxytocin". As a medication, it is used to cause contraction of the uterus to start labor, increase the speed of labor, and to stop bleeding following delivery. For this purpose, it is given by injection either into a muscle or into a vein.
The use of oxytocin as a medication can result in excessive contraction of the uterus that can risk the health of the baby. Common side effects in the mother include nausea and a slow heart rate. Serious side effects include rupture of the uterus and with excessive dose, water intoxication. Allergic reactions including anaphylaxis may also occur.
Oxytocin was discovered in 1952. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. , the wholesale cost in the developing world is US$0.10 to 0.56 per dose.Oxytocin injection (synthetic) is contraindicated in any of these conditions:Oxytocin is relatively safe when used at recommended doses, and side effects are uncommon. These maternal events have been reported:Excessive dosage or long-term administration (over a period of 24 hours or longer) has been known to result in tetanic uterine contractions, uterine rupture, postpartum hemorrhage, and water intoxication, sometimes fatal.
Supraoptic nucleus
Vasopressin neurons and oxytocin neurons make many other neuroactive substances in addition to vasopressin and oxytocin, though most are present only in small quantities. However, some of these other substances are known to be important. Dynorphin produced by vasopressin neurons is involved in regulating the phasic discharge patterning of vasopressin neurons, and nitric oxide produced by both neuronal types is a negative-feedback regulator of cell activity. Oxytocin neurons also make dynorphin; in these neurons, dynorphin acts at the nerve terminals in the posterior pituitary as a negative feedback inhibitor of oxytocin secretion. Oxytocin neurons also make large amounts of cholecystokinin as well as the cocaine and amphetamine regulatory transcript (CART).