noun, plural: vasotocins
A vasopressin characterized by its amino acid sequence: Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Arg-Gly-NH2 and chemical formula: C43H67N15O12S2
Vasotocin is one of the members of the vertebrate vasopressin family. Vasopressin is a nonapeptide hormone, being comprised of nine amino acids. The other three forms of vasopressins identified in vertebrates are argipressin, lypressin, and phenypressin. In particular, the vasotocin is comprised of the following amino acid sequence: Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Arg-Gly-NH2.
Vasotocin is found in non-mammalian vertebrates such as birds, fish, amphibians, etc. It is believed to be present as well in mammals but only during the fetal stage. Its predominant form, arginine vasotocin (AVT) is involved in the regulation of REM sleep, water balance, and osmotic homeostatis. It is also presumed to have an influence in social and sexual behavior of non-mammalian vertebrates. For instance, it was observed to have a role in the pair bonding behavior as well as in establishing social hierarchy. A study on the quails showed that a day after administering AVT, the quails displayed more dominant behavior towards familiar birds but not towards unfamiliar birds.1
Similar to other vasopressin, AVT is produced in the hypothalamus and then secreted from the posterior pituitary.
1 Riters, L. V. & Panksepp, J. (2006). Effects of vasotocin on aggressive behavior in male Japanese quail. Annals of the New York Academy of Sciences, 807(1): 478-480.