Brain uptake through the blood-brain barrier, pharmacokinetics and analgesic effect of [$^3$H]Oxytocin in the rat

Oxytocin (OT) is a neurohypophyseal nonapeptide which plays an important role in CNS function as well as uterine contraction during delivery. Furthermore, recently it has been reported that OT may also have analgesic effect and found that the release of OT is related with opioid receptors, especially $\kappa$ and ${\mu}$.