Oxytocin free acid (9-Deamidooxytocin) is an analog of oxytocin in which the glycinamide residue at position 9 in oxytocin has been replaced by a glycine residue. Oxytocin is a pleiotropic, peptide hormone with broad implications for general health, adaptation, development, reproduction, and social behavior.
Free acid form of oxytocin, which is a hormone involved in many aspects of mammalian reproduction as well as other physiological processes such as bond pairing and cardiovascular homeostasis.
Oxytocin is a cyclic 9-peptide that, like somatostatin, contains a ring that encompasses a
disulfide bridge. Oxytocin has uterotonic action, contracting the muscles of the
uterus during gestation, and plays an important role in milk ejection (not milk secretion, which is
regulated by the peptide hormone prolactin) from the mammary ducts into the nipples.
Exogenous oxytocin most commonly is used for induction of labor, wherein it improves uterine
contractions to achieve early vaginal delivery for fetal or maternal reasons (e.g., preeclampsia,
Rh factor problems, pregnancy that has exceeded 42 weeks). It also finds use following delivery
of the placenta, because it promotes contraction and vasoconstriction and helps to control
postpartum bleeding.
In humans, estimates of median plasma half-life of oxytocin range from 3.2 min after a single 2 U bolus injection to 4.8 min during a 500 mU min-1 infusion. Oxytocin is rapidly metabolised in the liver and kidneys, and also in the plasma during pregnancy by secreted oxytocinase (leucyl/cystinyl aminopeptidase), with some degree of metabolism also taking place in the mammary glands[1].
[1] C. Ding, F. Magkos, M. K.-S. Leow. “Oxytocin in metabolic homeostasis: implications for obesity and diabetes management.” Obesity Reviews 20 1 (2018): 22–40.
