Central oxytocin enhances antinociception in the rat

Peptides. 2007 May;28(5):1113-9. doi: 10.1016/j.peptides.2007.03.003. Epub 2007 Mar 12.


The study aimed to investigate the effect of oxytocin on antinociception in the rat. The pain threshold was elevated by oxytocin following intraventricular (icv) or intrathecal injection (ith), and reduced by anti-oxytocin serum (icv or ith). But the pain threshold was not altered by intravenous injection (iv) of oxytocin or anti-oxytocin serum. Pain stimulation induced oxytocin concentration decrease in the hypothalamic supraoptic nucleus, and increase in the locus coeruleus, raphe magnus nucleus, caudate nucleus and spinal cord, but no change in the hypothalamic paraventricular nucleus and plasma. The results indicated that central, not peripheral oxytocin could enhance antinociception.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dose-Response Relationship, Drug
  • Immune Sera / administration & dosage
  • Immune Sera / immunology
  • Immune Sera / pharmacology
  • Injections, Intravenous
  • Injections, Intraventricular
  • Injections, Spinal
  • Male
  • Oxytocin / administration & dosage
  • Oxytocin / immunology
  • Oxytocin / pharmacology*
  • Pain Measurement / methods
  • Pain Threshold / drug effects*
  • Paraventricular Hypothalamic Nucleus / drug effects
  • Paraventricular Hypothalamic Nucleus / physiopathology
  • Rabbits
  • Rats
  • Rats, Sprague-Dawley
  • Spinal Cord / drug effects
  • Spinal Cord / physiopathology
  • Suprachiasmatic Nucleus / drug effects
  • Suprachiasmatic Nucleus / physiopathology


  • Immune Sera
  • Oxytocin