The Sound of Evolution
Atosiban
Mechanism of action:
Atosiban is an oxytocin receptor antagonist. Atosiban competitively blocks the binding of oxytocin to oxytocin receptors on the surface of uterine smooth muscle cells. By inhibiting activation of the Gq/11-coupled oxytocin receptor, it reduces intracellular IP₃ production and suppresses the release of Ca²⁺ into the cytoplasm, leading to relaxation of uterine smooth muscle.
Reference(s):
1. Lamont RF et al. (2003). The development and introduction of anti-oxytocic tocolytics. BJOG.
2. Fjellestad-Paulsen A et al. (1996). Metabolism of vasopressin, oxytocin and their analogues in human kidney and liver homogenates. Regul Pept.
3. Reversi A et al. (2005). The oxytocin receptor antagonist atosiban inhibits cell growth via a biased agonist mechanism. J Biol Chem.