Met-enkephalin was first discovered in 1975 by John Hughes and Hans Kosterlitz at the University of Aberdeen in Scotland. They were searching for endogenous ligands for the opioid receptors, which had been discovered a few years earlier.
Hughes and Kosterlitz isolated met-enkephalin from pig brains and found that it had potent opiate-like activity. They also showed that met-enkephalin was identical to a pentapeptide that had previously been identified in the pituitary gland.
The discovery of met-enkephalin was a major breakthrough in the field of opioid research. It showed that the body produces its own natural painkillers, and it paved the way for the development of new synthetic opioids that are more potent and less addictive than morphine.
In the years since its discovery, met-enkephalin has been studied extensively. Researchers have learned a great deal about its structure, function, and role in the body. Met-enkephalin has also been investigated as a potential therapeutic agent for a variety of conditions, including pain, addiction, and depression.
Met-enkephalin structure and function
Met-enkephalin is a pentapeptide with the following sequence: Tyr-Gly-Gly-Phe-Met. It is synthesized from the precursor protein proenkephalin, which is also the precursor for leu-enkephalin.
Met-enkephalin binds to both the μ- and δ-opioid receptors, but it has higher affinity for the δ-opioid receptor. The opioid receptors are a family of G protein-coupled receptors that are found throughout the body, including the brain, spinal cord, and peripheral nervous system.
When met-enkephalin binds to an opioid receptor, it triggers a cascade of events that leads to the inhibition of pain signaling. Met-enkephalin also has a number of other effects in the body, including reducing stress, improving mood, and regulating gut function.
Met-enkephalin and pain
Met-enkephalin is thought to play a major role in pain modulation. It is released in response to pain and helps to reduce the perception of pain. Met-enkephalin levels are also increased in response to exercise and sexual activity, which may help to explain why these activities can reduce pain.
Met-enkephalin and addiction
Met-enkephalin levels are decreased in people with addiction. This may contribute to the cravings and withdrawal symptoms that are experienced by people who are trying to quit using drugs.
Met-enkephalin is being investigated as a potential treatment for addiction. Animal studies have shown that met-enkephalin can reduce cravings for drugs and alcohol. Met-enkephalin is also being tested in human clinical trials for the treatment of addiction.
Met-enkephalin and mood
Met-enkephalin levels are decreased in people with depression and other mood disorders. This may contribute to the symptoms of these disorders.
Met-enkephalin is being investigated as a potential treatment for mood disorders. Animal studies have shown that met-enkephalin can improve mood and reduce symptoms of depression. Met-enkephalin is also being tested in human clinical trials for the treatment of mood disorders.
Met-enkephalin is a naturally occurring opioid peptide with a variety of potential therapeutic uses. It is being investigated as a potential treatment for pain, addiction, mood disorders, and other conditions. However, more research is needed to determine the safety and efficacy of met-enkephalin for these uses.
