Have you ever experienced a feeling pleasure after exercise? That feeling is common and is known as runners high. When you exercise your body releases chemicals called endorphins. Endorphins are feel-good hormones that trigger positive feelings in one’s body. Endorphins are triggered by physical action.
Besides exercising there are many other ways to elecit the release endorphins one can listen to music, eat certain foods like chocolate, and meditate to assist the release of endorphins. One of the primary function of endorphins is to prevent the communication of pain signals. Endorphins are natural painkillers, or analgesics. Endorphins are often released when one is stressed or in pain. Endorphins work together with opiate receptors in the brain to diminish the sensitivity of pain. They diminish pain while simultaneously triggering positive feelings.
Endorphins are both endogenous opioid neuropeptides and peptide hormones located in both humans and animals. Opioid peptides were first discovered in 1975 by John Hughes and Hans Kosterlitz. The pair isolated a small peptide sequence from the brain tissue a pig and called it enkephalin from the Greek “in the brain”. At the same time in America an active molecule with morphine like properties was discovered and named endorphin. Overtime the term endorphin came to be used to refer to all endogenous peptides with morphine like activities. Later studies observe the differences between enkephalins and endorphins.
That the name endorphin comes from the word in endogenous morphine, meaning internally produced morphine. There are four main types of endorphins. The α-endorphin, β-endorphin, γ-endorphin, and the sigma-endorphin. The α-endorphin is the smallest and the β-endorphin is the largest and most powerful. Endorphins are produced and stored in the pituitary gland, located at the base of the brain.
Endorphins are fragments of the precursor protein proopiomelanocortin (POMC). POMC is synthesized in the pituitary gland in response to a signal from the hypothalamus. Hypothalamus is a small area in the brain right next to the pituitary gland. Although it is quite small the hypothalamus plays a very important role and has many functions. The signal sent by the hypothalamus is called corticotroponin-releasing hormone (CRH). The hypothalamus releases CRH when it senses pain or stress in the body. When the pituitary gland receives this signal from the hypothalamus it produces POMC. POMC is fragmented into many smaller proteins including a protein called beta-lipotropin (β-LPH).
Β-LPH is divided into more peptides including the α-endorphin, β-endorphin, and γ-endorphin. The structure of endorphins is similar to that of proteins but they have short sequence of amino acids. The α-endorphin has 16 amino acids, the β-endorphin has 31 amino acids, the γ- endorphin has 17 amino acids, and the sigma endorphin has 27 amino acids. Amino acids are what makes polypeptides which are very hard to break. They can only be broken down by enzymes. The endorphins are kept in the pituitary glands until they are needed.
Endorphins are released from the pituitary gland in response to pain. Endorphins are involved in both the central nervous system and the peripheral nervous system. The central nervous system is the part of the nervous system that contains the brain and the spinal cord. The peripheral nervous system contains nerves that travel from the brain and spinal cord to other parts of the body.
In the peripheral nervous system β-endorphins generate analgesia by attaching to opioid receptors, particularly of the mu subtype. Mu-receptors are placed throughout the nerves of the peripheral nervous system. When the endorphin binds to the opioid receptor substance P, a neurotransmitter, is blocked and cannot be released. Substance P is involved in the transmission of pain. If one has a high amount of substance P, then his awareness and sensitivity to pain is heightened. By attaching itself to a receptor and blocking substance P the endorphin inhibits the feeling of pain.
Endorphins perform similarly in the central nervous system. The difference is that in the central nervous system a different neurotransmitter is blocked. This neurotransmitter is called gamma-aminobutyric acid (GABA). The inhibition of GABA increases the production and release of dopamine. Dopamine is a neurotransmitter in the brain that is linked with pleasure. Therefore, when endorphins in the central nervous system are released, we feel happy and content.
Endorphins are not the only chemicals that produce happiness. There are three other brain chemicals that create happy feelings and all are necessary for one to feel good. They are dopamine, oxytocin, and serotonin. All three are triggered by different things. Dopamine is real eased when we archive a goal. When we get the feeling of success, that is our dopamine at work. Serotonin is triggered when one feels important, powerful, and esteemed. Low levels of serotonin can lead to depression.
Oxytocin is triggered when we trust those around us, when we are comfortable with the people closest to us. They are all happy chemicals but each of them triggers different parts of our happiness. In addition to endorphins our body needs these three chemicals in order to feel good. All our happy hormones work together but are not necessarily all released at the same time. They are each targeted at different parts of our happiness.
There are many diseases associated with endorphins. The classification of molecules as endorphins is based on their pharmacological activity, as opposed to a specific chemical formulation. Pharmacology is the study of drugs and medication. It involves man-made, natural, and endogenous drugs. Although there are similarities between man-made drugs and endogenous drugs like endorphins, endogenous drugs are not at all harmful. Endorphins can be compared to the drug morphine. Endorphins and morphine attach to the same receptors in the brain, and they both cause a feeling of high.
There are also many differences between the two. Endorphins are endogenous opioids and morphine is an exogenous opioid. Also, the analgesic caused by endorphins is much greater than that of morphine. In the case of heroin, an endorphin is a hundred times more powerful. Lastly, endorphins are metabolized quickly, and morphine is not, which is why endorphins as opposed to morphine is not addictive. Endorphins are not addictive because very soon after they bind to the opioid receptors they are broken down by enzymes. However other drugs that are resistant to the enzymes, and are not broken down, continue to reactivate the receptors.
They cause the feeling of euphoria to last longer and increase the chances of dependency on the drug. People have tried to produce a drug that would be addictive. in addition to discovering endorphins Posterity also conducted a study and found that there are subtypes of opiate receptors.This brings up the possibility that there might be one kind of receptor for pain relief and another one responsible for addiction to opiates. This discovery triggered research into trying to find drugs that might fit one receptor without stimulating the other, perhaps leading to non- addictive opiates
I’ve always like exercising because of the satisfaction and good feeling I get from it. I always knew that runners high is caused by endorphins but never really understood what they are and how they work. Learning about endorphins was really interesting and I am glad I chose this topic because it is very relevant to my life and gives me a greater appreciation of the way .It is amazing to see all the things our body can do and how intricate and complex it is.
