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Endorphins are endogenous opioid biochemical compounds. They are peptides produced by the pituitary gland and the hypothalamus in vertebrates, and they resemble the opiates in their abilities to produce analgesia and a sense of well-being. In other words, they work as "natural pain killers".
The term "endorphin" is used generally to refer to all of the endogenous opioid compounds and implies a pharmacological activity (analogous to the activity of the corticosteroid category of biochemicals) as opposed to a specific chemical formulation.
These opioid neuropeptides were first discovered by 1975 John Hughes and Hans Kosterlitz in the brain of a pig. They called their endorphins "enkephalins" (from the Greek egkephalos, "in the head"). Several other types of endorphins were discovered later. The word endorphin itself is abbreviated from "endogenous morphine", which means a morphine produced naturally in the body.
The best-known endorphins are α-, β- and γ-endorphin, of which β-endorphin appears to be most implicated in pain relief.
The amino acid residue sequence ( primary structureprotein primary structure is a chain of amino acids. In biochemistry, to specify the primary structure of an unbranched biopolymer, such as a molecule of DNA, RNA or protein, is to name the species of every subunit ( nucleotide or amino acid) in order fro) of β-endorphin is: Tyr-Gly-Gly-Phe-Met-Thr-Ser-Glu-Lys-Ser-Gln-Thr-Pro-Leu-Val-Thr-Leu-Phe-Lys-Asn-Ala-Ile-Ile-Lys-Asn-Ala-Tyr-Lys-Lys-Gly-GluOH (Fries, 2002).
How endorphins work is still not fully understood. What is sure, however, is that endorphins bind to the opioid receptorOpioid receptors are a group of G-protein coupled receptors with opioids as ligands. The endogenous opioids are dynorphins, enkephalins and endorphins. The opioid receptors are similar, ~40% homologous, to somatostatin receptors (SSTRs). Types of receptors in the brain. They disinhibit the dopamineDopamine is a neurotransmitter in the brain. As a member of the catecholamine family, dopamine is a precursor to epinephrine ( adrenaline) and norepinephrine ( noradrenaline) in the biosynthetic pathways for these neurotransmitters. Dopamine is synthesize pathways, causing more dopamine to be released into the synapsesnerve cells to communicate with one another through axons and dendrites, converting electrical signals into chemical ones. For the technology festival, see Synapse Festival. Synapses are specialized junctions through which cells of the nervous system sign.
Endorphins regulate feelings of painPain is both a sensory and emotional experience, generally associated tissue damage, or inflammation. Pain is ultimately a perception, and not an objective bodily state. Despite its unpleasantness, pain is a critical component of the body's defense system and hungerHunger is applied literally to the need or craving for food; it can also be applied metaphorically to cravings of other sorts. It is an extreme of a normal appetite. The term is commonly used more broadly to refer to cases of widespread malnourishment or and are connected to the production of sex hormones.
Oddly enough, they are also generated in response to certain spices, such as chili peppers. Chili peppers have thus been used as a treatment for certain types of chronic pain.
According to some reports, laughter also releases endorphins in the brain. So, besides widening the blood vessels, suppressing the production of stress hormones and raising antibody levels in the blood, laughing would thus also have an analgesic effect.
Another widely publicised situation of endorphin production, is the so-called "runner's high" which is supposed to occur when strenuous exercise takes a person over a certain threshold that activates endorphin production. However, some research questions the mechanisms at work believing the high comes from completing a challenge rather than just through the exertion.
One theory of why some people find BDSM activities pleasurable is that these activities stimulate endorphins in a controlled way.
Ultraviolet light may also stimulate the release of endorphins.