Oxytocin

Lore & Background

By the 1920s, oxytocin and vasopressin had been isolated from pituitary tissue and given their current names. Further work on different synthetic routes and analogues was performed in the following decade by Iphigenia Photaki.

Reader's Guide

Oxytocin is significant as the first polypeptide hormone to be both sequenced and synthesized, marking a milestone in biochemistry and endocrinology. Its discovery and synthesis by Vincent du Vigneaud enabled subsequent research into peptide hormones and their therapeutic applications. Beyond its medical uses, oxytocin is colloquially known as the 'cuddle hormone' or 'love hormone' due to its involvement in social bonding, maternal bonding, and mating behavior across species, including in animals as low as C. elegans. The hormone operates via a positive feedback mechanism during childbirth, lactation, and sexual activity. Its evolutionary history is ancient, with virtually all vertebrates possessing an oxytocin-like nonapeptide hormone, and a 2023 study in zebrafish suggests oxytocin-based empathy may have evolved from a common ancestor many millions of years ago. Oxytocin is also synthesized in non-neural tissues such as the corpus luteum, placenta, testes, retina, adrenal medulla, thymus, and pancreas, raising questions about its broader physiological roles.

Did You Know?

• Oxytocin is derived from Greek words meaning 'sharp' or 'swift' and 'childbirth'.
• Oxytocin is the first polypeptide hormone to be both sequenced and synthesized.
• A 2023 study found that zebrafish utilize oxytocin in reaction to the fear of other fish, suggesting empathy may have evolved from a common ancestor.