Carbetocin

Carbetocin, an oxytocin (OT) analogue, is an oxytocin receptor agonist with a K_i of 7.1 nM. Carbetocin has high affinity to chimeric N-terminus (E1) of the oxytocin receptor (K_i=1.17 μM). Carbetocin has the potential for postpartum hemorrhage research. Carbetocin can crosse the blood-brain barrier and produces antidepressant-like activity via activation of oxytocin receptors in the CNS^[1][2][3]. In Vitro: Carbetocin is an agonist with about 10-fold lower affinity for the oxytocin receptor but with significantly higher stability and a longer duration of action. Carbetocin has higher affinity to the chimeric E1 receptor and especially to each of the combinations of E1 with the other extracellular domains, i.e. chimeric receptors E13 (K_i=13 nM), E123 (K_i=56 nM), and E1234 (K_i=37 nM)^[2].
In Vivo: Carbetocin (2-20 mg/kg; i.p.) has a significant effect of treatment on the percent time spent climbing, swimming and immobile^[1].
Carbetocin (1, 10,100 μg/rat, i.c.v.) reveals a dose-dependent increase in the percent time spent swimming and a corresponding reduction in immobility following acute administration of 100 μg/rat^[1].