World Library  
Flag as Inappropriate
Email this Article

Endorphins

Article Id: WHEBN0000060825
Reproduction Date:

Title: Endorphins  
Author: World Heritage Encyclopedia
Language: English
Subject: Reference desk/Archives/Science/2008 July 12, Exercise addiction, Scarification, Horse behavior, Sports nutrition
Collection:
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Endorphins

Endorphins ("endogenous morphine") are endogenous opioid inhibitory neuropeptides. They are produced by the central nervous system and pituitary gland. The term implies a pharmacological activity (analogous to the activity of the corticosteroid category of biochemicals) as opposed to a specific chemical formulation. It consists of two parts: endo- and -orphin; these are short forms of the words endogenous and morphine, intended to mean "a morphine-like substance originating from within the body."[1] The class of endorphin compounds includes α-endorphin, β-endorphin, γ-endorphin, α-neo-endorphin, and β-neo-endorphin. The principle function of endorphins is to inhibit the transmission of pain signals; they may also produce a feeling of euphoria very similar to that produced by other opioids.[2]

History

Opioid neuropeptides were first discovered in 1974 by two independent groups of investigators:

  • Around the same time, in a calf brain, Rabi Simantov and Solomon H. Snyder of the United States found[5] what Eric Simon (who independently discovered opioid receptors in vertebral brains) later termed "endorphin" by an abbreviation of "endogenous morphine", meaning "morphine produced naturally in the body".[1] Importantly, recent studies have demonstrated that human and diverse animal tissues are in fact capable of producing morphine itself, which is not a peptide.[6][7]

Activity

Scientists sometimes debate whether specific activities release measurable levels of endorphins. Much of the current data comes from animals which may not be relevant to humans. The studies that do involve humans often measure endorphin plasma levels, which do not necessarily correlate with levels in the central nervous system. Other studies use a blanket opioid antagonist (usually naloxone) to indirectly measure the release of endorphins by observing the changes that occur when any endorphin activity that might be present is blocked.

Depersonalization disorder

Endorphins are known to play a role in depersonalization disorder. The opioid antagonists naloxone and naltrexone have both been proven to be successful in treating depersonalization.[8][9] To quote a 2001 naloxone study, "In three of 14 patients, depersonalization symptoms disappeared entirely and seven patients showed a marked improvement. The therapeutic effect of naloxone provides evidence for the role of the endogenous opioid system in the pathogenesis of depersonalization."

Etymology

From the words ἔνδον / Greek: éndon meaning "within" (endogenous, ἐνδογενής / Greek: endogenes, "proceeding from within") and morphine, from Morpheus (Μορφεύς / Ancient Greek: Morpheús, the god of sleep in the Greek mythology, thus 'endo(genous) (mo)rphine’.

References

  1. ^ a b Goldstein A, Lowery PJ (September 1975). "Effect of the opiate antagonist naloxone on body temperature in rats". Life Sciences 17 (6): 927–31.  
  2. ^ "Is there a link between exercise and happiness?". Retrieved 2014-09-18. 
  3. ^ "Role of endorphins discovered". PBS Online: A Science Odyssey: People and Discoveries. Public Broadcasting System. 1998-01-01. Retrieved 2008-10-15. 
  4. ^ Hughes J, Smith T, Kosterlitz H, Fothergill L, Morgan B, Morris H (1975). "Identification of two related pentapeptides from the brain with potent opiate agonist activity". Nature 258 (5536): 577–80.  
  5. ^ Simantov R, Snyder S (1976). "Morphine-like peptides in a mammalian brain: isolation, structure elucidation, and interactions with an opiate receptor". Proc Natl Acad Sci USA 73 (7): 2515–9.  
  6. ^ Poeaknapo C, Schmidt J, Brandsch M, Dräger B, Zenk MH (September 2004). "Endogenous formation of morphine in human cells". Proceedings of the National Academy of Sciences of the United States of America 101 (39): 14091–6.  
  7. ^ Kream RM, Stefano GB (October 2006). "De novo biosynthesis of morphine in animal cells: an evidence-based model". Medical science monitor : international medical journal of experimental and clinical research 12 (10): RA207–19.  
  8. ^ Nuller YL, Morozova MG, Kushnir ON, Hamper N (June 2001). "Effect of naloxone therapy on depersonalization: a pilot study". J. Psychopharmacol. (Oxford) 15 (2): 93–5.  
  9. ^ Simeon, Daphne. "An Open Trial of Naltrexone in the Treatment of Depersonalization Disorder". Journal of Clinical Psychopharmacology. Retrieved 2011-10-13. 

External links

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.