Enkephalins and immune inflammatory reactions

Acta Neurol (Napoli). 1991 Oct;13(5):433-41.


Methionine-enkephalin (Met-Enk) and leucine-enkephalin (Leu-Enk) belong to family of opioid peptides. In vivo studies on immunomodulating activity of enkephalins performed in the rat revealed the following: (a) both neuropentapeptides showed a dual, dose-dependent effect, i.e., high doses suppressed while low doses potentiated immune responses; (b) Met-Enk is more potent immunomodulator than Leu-Enk; (c) high doses of Met-Enk suppressed immune inflammatory reactions, such as systemic anaphylactic shock, Arthus and delayed hypersensitivity skin reactions to protein antigen, allograft rejection, adjuvant arthritis, and experimental allergic encephalomyelitis. Met-Enk is more efficient when applied intracerebroventricularly. A preliminary clinical trial showed that intrathecally given Met-Enk exerted a beneficial effect on 13 patients with chronic severe progressive multiple sclerosis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Anaphylaxis / immunology
  • Anaphylaxis / physiopathology
  • Animals
  • Arthus Reaction / immunology
  • Arthus Reaction / physiopathology
  • Autoimmune Diseases / immunology
  • Autoimmune Diseases / physiopathology
  • Enkephalins / pharmacology
  • Enkephalins / physiology*
  • Graft Rejection / immunology
  • Humans
  • Hypersensitivity, Delayed / immunology
  • Hypersensitivity, Delayed / physiopathology
  • Immune Tolerance / drug effects
  • Inflammation / immunology
  • Inflammation / physiopathology*
  • Neuroimmunomodulation / physiology*
  • Rats
  • Receptors, Opioid / drug effects
  • Receptors, Opioid / physiology


  • Enkephalins
  • Receptors, Opioid