Radioimmunoassay for neuropeptide Y (NPY): chromatographic characterization of immunoreactivity in plasma and tissue extracts

Scand J Clin Lab Invest. 1985 Jun;45(4):355-65. doi: 10.3109/00365518509161019.


A sensitive and specific radioimmunoassay was developed to determine the occurrence and concentration of neuropeptide Y (NPY) in plasma and tissue extracts. Furthermore, NPY-like immunoreactivity (NPY-Li) was characterized by means of three different chromatographic systems. The NPY antiserum used (NI) did not cross-react with related peptides of the pancreatic polypeptide family except avian pancreatic polypeptide (1% cross-reactivity). Unextracted plasma contained high molecular weight proteins which interfered in the assay. Acid ethanol extraction removed this protein interference allowing a 90% recovery of NPY-Li. The content of NPY-Li in human plasma from healthy subjects was close to or below the detection limit (less than 22 pmol/l). Sympathetic nerve stimulation in the cat increased the output of NPY-Li from the splenic vein suggesting the release of this peptide upon sympathetic activation. The major peak of NPY-Li in spleen extracts and splenic vein plasma co-eluted with synthetic porcine NPY and a minor peak with larger Stokes radius was also present. The present radioimmunoassay enables further studies on the physiological and pathophysiological role of NPY.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cats
  • Chromatography, Gel
  • Chromatography, High Pressure Liquid
  • Immune Sera
  • Isotope Labeling
  • Male
  • Nerve Tissue Proteins / analysis*
  • Nerve Tissue Proteins / immunology
  • Neuropeptide Y
  • Radioimmunoassay / methods*
  • Specimen Handling
  • Tissue Distribution


  • Immune Sera
  • Nerve Tissue Proteins
  • Neuropeptide Y