Introduction
Endorphins (endomorphins) are neuropeptides, i.e. proteins produced by nerve cells. The name “endorphin” means “endogenous morphine“, which means the body’s own morphines (painkillers). There are three different types of hormones, whereby beta-endorphins are the best studied: The following description refers to beta-endorphins.
- Alpha-Endorphins
- Beta-Endorphins
- Gamma-Endorphins
Education
The endorphins are formed in the hypothalamus and pituitary gland. These hormones are produced from a precursor protein, proopiomelanocortin (POMC). POMC is formed in the hypothalamus, from which endorphins (beta-endorphin) are split off in the pituitary gland along with other substances (ACTH, MSH, lipotropin). Corresponding receptors are opiate receptors (opioid receptors), which belong to the group of cell surface receptors. They are located in the spinal cord, the brain, the autonomic nervous system and probably in other structures of the body.
Effect
The term endorphins is an abbreviation for ‘endogenous morphines’. This means that endorphins are substances produced by a certain part of the brain (endogenous = endogenous), which mainly have an analgesic effect (morphine = painkiller). Beta-Endorphins bind to μ1-, to μ1-, to M- and to K-receptors, which all belong to the opiate receptors.
The strongest affinity (binding) is to μ1 receptors, followed by μ2 and M receptors. There is only a very low affinity to K-receptors. The endorphins formed reach their receptors in the brain and the rest of the body.
In the spinal cord, all sensations are transmitted from our body to the brain. Here, the effect of the endorphins mainly takes place via μ1 receptors, which are located at certain interconnection points of the nerves (presynapses) of the spinal cord. At these pre-synapses, information is transmitted between two nerves by the release of messenger substances (neurotransmitters) such as GABA (gamma-aminobutyric acid) or dopamine.
The endorphin binding to the presynaptic μ receptors prevents the release of GABA and increases the release of dopamine. This reduces the sensitivity of pain-conducting nerve endings in the spinal cord and the pain is no longer perceived by the brain. By docking to the receptors, the endorphins thus block the transmission of information to our brain, which normally tells us that our injury hurts. We therefore do not feel the pain as strongly.
