Endorphins

Endorphins (contracted from 'endogenous morphine') are endogenous opioid neuropeptides and peptide hormones in humans and other animals. They are produced by the central nervous system and the pituitary gland. The term 'endorphins' 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 endorphins includes three compounds—α-endorphin (alpha endorphins), β-endorphin (beta endorphins), and γ-endorphin (gamma endorphins)—which preferentially bind to μ-opioid receptors. The principal function of endorphins is to inhibit the communication of pain signals; they may also produce a feeling of euphoria very similar to that produced by other opioids. Opioid neuropeptides were first discovered in 1974 by two independent groups of investigators: The three types of endorphins that exist are made through the fragmentation of precursor proteins. The original protein is called proopiomelanocortin (POMC). This protein is fragmented into many different smaller proteins including beta-lipotropin (β-LPH). β-LPH, a pituitary hormone with little opiate activity, is then continually fragmented into different peptides giving rise to α-Endorphin, β-Endorphin, γ-Endorphin and many other peptides. The class of endorphins includes three endogenous opioid peptides: Endorphins are naturally produced in response to pain. This phenomenon happens in both the Central Nervous System (CNS) and the Peripheral Nervous System (PNS). In the PNS, endorphins, primarily β-endorphin, are released from the pituitary gland and bind to μ-receptors. The binding of these two components inhibits the pain signal of the periphery nerves by blocking the neurotransmitter substance P. The mechanism in the CNS is similar but works by blocking a different neurotransmitter. When the endorphin binds to the μ-receptor, it inhibits the release of the neurotransmitter gamma-aminobutyric acid (GABA) which, in turn, increases the production and release of dopamine, the neurotransmitter associated with pleasure. Their production can also be triggered by various human activities. Vigorous aerobic exercise can stimulate the release of β-endorphin which contributes to a phenomenon 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. Endorphins are also released during various activities including eating food, sex, orgasm, listening to music and eating chocolate. Endorphins play a major role in the body's response to inhibiting pain but endorphins have also been looked at for their role in pleasure. There has been a lot of research in the euphoric state that is produced after the release of endorphins in cases such as runner's high, orgasms, and eating appetizing food. Endorphins have also been looked into as a way to aid in the treatment of anxiety and depression through exercising.