Dynorphin A(1-17), a Kappa-opioid receptor-selective heptadccapeptide, Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Ile-Arg-Prolo-Lys-Leu-Lys-Trp-Asp-Asn-Glu, was originally isolated from porcine pituitary. It is found in the anterior hypothalamus and substantia nigra. and it is associated with spinal anesthesia and sedation.
Alford DR, Renugopalakrishnan V, Duzgunes N Dynorphin-phospholipid membrane interactions: role of phospholipid head-group and cholesterol Int J Pept Protein Res 1996 Jan-Feb;47(1-2):84-90