Endorphins having placental or pancreatic origin

摘要

A peptide endorphin having a molecular weight in the range of about 4500 to 5000 daltons is described. This peptide endorphin has beta -endorphin-like activity, reacting immunologically to rabbit antisera prepared against beta -endorphin and displacing Naloxone from opiate receptors in brain tissue. Unlike beta -endorphin, however, this peptide endorphin does not exhibit respiratory depressor effect when administered to mice. This peptide endorphin can be obtained from placental and pancreatic tissue, preferably by extracting with dilute mineral acid.