What is Oxytocin Antagonists (OAs/CAPs)?
This placental CRH acts on placental tissues to synthesize and produce ACTH (26), which indeed stimulates the placental and peripheral tissues to synthesize and release cystine amino-peptidases (CAP1 & CAP2) and many other substances. Both these enzymes (Oxytocinases), were found to increase progressively with pregnancy progress till term (2,14,15,16,30,34), at which time the placenta fails (physiological failure) to produce these substances and delivery of normal baby is the final outcome. Two molecular species of oxytocinases were found in human placenta (CAP I/ CAPII). (8) In my opinion the mode of action of such enzymes is a competitive inhibition of oxytocin, by interaction with oxytocin receptors in the uterus and breast throughout the whole pregnancy (3). The first maintains uterine relaxation till fetal maturity while the other well prevent milk ejaculation till delivery, so oxytocin well be acting most of the time on the placenta to produce CRH, because no free ORs. This expla
