[Arg8] vasotocin is a 9-mer peptide corresponding to aa20-28 sequence from the vasotocin-neurophysin VT precursor. Vasotocin is an antidiuretic hormone present in the neurohypophysis. Vasotocin is related to vasopressin and oxytocin hormones with similar oxytocic and vasoconstrictor properties.H-Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Arg-Gly-NH2 (Cys1-Cys6) or H-CYIQNCPRG-NH2 (Cys1-Cys6)