Chemical identification of the mammalian oxytocin in a holocephalian fish, the ratfish (Hydrolagus colliei).

Research paper by G G Michel, J J Chauvet, M T MT Chauvet, C C Clarke, H H Bern, R R Acher

Indexed on: 01 Nov '93Published on: 01 Nov '93Published in: General and Comparative Endocrinology


The neurohypophysial hormones of the ratfish (Hydrolagus colliei), a species belonging to the subclass Holocephali of cartilaginous fishes, have been investigated. An oxytocin-like hormone has been isolated from acetone-desiccated pituitary glands by using successively molecular sieving and high-pressure liquid chromatography. The peptide has been identified as oxytocin by coelution with synthetic oxytocin in HPLC, amino acid sequencing, mass spectrometry, and C-terminal sequencing through carboxypeptidase Y. Vasotocin may be present in a very small amount. Cartilaginous fishes appear to display a great diversity in their oxytocin-like hormones since five different peptides have been identified in rays and sharks that belong to the second subclass Selachii.