Oxytocin (α-Hypophamine) is a mammalian neurohypophysial hormone; its actions are mediated by specific, high-affinity oxytocin receptors; ligand of oxytocin receptor.
Oxytocin is a cyclic nonapeptide hormone with amino acid sequence CYIQNCPLG that also acts as a neurotransmitter in the brain; the principal uterine-contracting and milk-ejecting hormone of the posterior pituitary. Together with the neuropeptide vasopressin, it is believed to influence social cognition and behaviour. It has a role as an oxytocic and a vasodilator agent. It is a peptide hormone and a heterodetic cyclic peptide.|Oxytocin is an Oxytocic. The physiologic effect of oxytocin is by means of Increased Uterine Smooth Muscle Contraction or Tone.|Recombinant Oxytocin is a synthetic cyclic peptide form of the naturally occurring posterior pituitary hormone oxytocin. Oxytocin binds to oxytocin receptors in the uterine myometrium, which triggers the G-protein coupled receptor signal transduction cascade that causes increased intracellular calcium concentrations. Increased calcium concentration levels activate myosin light chain kinase which, in turn, induces the formation of the contractile protein actomyosin. This stimulates uterine smooth muscle contractions. This agent also stimulates smooth muscles in the mammary glands, thereby causing lactation.|A nonapeptide hormone released from the neurohypophysis (PITUITARY GLAND, POSTERIOR). It differs from VASOPRESSIN by two amino acids at residues 3 and 8. Oxytocin acts on SMOOTH MUSCLE CELLS, such as causing UTERINE CONTRACTIONS and MILK EJECTION.