Oxytocin

Synonyms

Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Leu-Gly-NH2, cyclic 1-6 disulfide

Ocytocin

Pitocin

Syntocinon

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.