Endorphins (contracted from "endogenous morphine") are endogenous opioid neuropeptides in humans and other animals. They are produced by the central nervous system and the 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". The class of endorphin compounds includes α-endorphin, β-endorphin, γ-endorphin, σ-endorphin, α-neo-endorphin, and β-neo-endorphin. The principal 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.
Contents
History
Opioid neuropeptides were first discovered in 1974 by two independent groups of investigators:
Activity
Endorphins are naturally produced in response to pain, but their production can also be triggered by various human activities. Vigorous aerobic exercise can stimulate the release of endorphins in the bloodstream, leading to an effect known as a "runner's high". Laughter may also stimulate endorphin production; a 2011 study showed that attendees at a comedy club showed increased resistance to pain.
Depersonalization disorder
Endorphins are suspected to play a role in depersonalization disorder. The opioid antagonists naloxone and naltrexone have both been proven to be successful in treating depersonalization. To quote a 2001 naloxone study, "In [3] of 14 patients, depersonalization symptoms disappeared entirely, and [7] 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 dreams in the Greek mythology, thus 'endo(genous) (mo)rphine’.