Endorphins are endogenous hormones which are commonly known as happy chemicals as they produce a state of pleasure. Endorphins have opioid-like characteristic and it resembles morphine. Endorphins as a neuropeptide are released from body endogenously to combat stress. It is commonly known as natural painkiller produced by the body itself to relieve pain and stress.
Endorphin was first discovered in the 1970s. Endorphins have their own specific binding or receptor sites that are known as µ-receptors and naloxone is used as a common clinical antagonist to study the effects of endorphins.
Types of Endorphins:
Endorphins are generally classified into four types on the basis of type and number of amino acids present in the polypeptide chain of endorphins.
1- Alpha- endorphin
2- Beta-endorphin
3- Gamma- endorphin
4- Sigma endorphin
β-endorphins are largest with 31 amino acids and more common as compared to other types because researchers have done a huge work on β-endorphins. Very short information is available related to alpha, gamma and sigma endorphins. Researchers are flourishing their investigation towards these types to find their regulatory roles and other functions in animals.
Molecular biology of Endorphins:
Endorphins contain 16 to 31 amino acids in their polypeptide chain. The pro-opiomelanocortin polypeptide chain is considered as a precursor of endorphins which is produced and released from master gland known as the pituitary gland. Enzyme peptidase breaks this complex polypeptide into 13 different short peptides including endorphins.
Endorphins are neurotransmitters that are produced in response to physiological changes and stress in the body and their unique electrical properties make stress-related excitation of neurons difficult.
Mechanism of stress management of Endorphins:
Any physiological change related to stress and pain triggers the hypothalamus to produce corticotrophin- releasing a hormone which is a neurotransmitter and abbreviated as CRH. This CRH travels to the pituitary gland and activates upregulation and cleavage of POMC polypeptide. Each of the byproducts of POMC has its specific receptor site and specific physiological response.
Β-Endorphin acts in two ways during stress or pain management. It affects the element that transmits pain sensation as well as produce a state of well-being during stress. During whole, process β-Endorphin interacts with a variety of elements.
1- Beta-Endorphin serves as a primary ligand for µ-subtype receptor site and binds to pre-synaptic as well as post-synaptic nerve terminals of µ-receptors in the peripheral nervous region. The activated receptors consequences up-regulation of gamma-Aminobutyric acid (GABA). The GABA directly effects the protein known as substance-P this protein is involved in the transmission of pain.
2- β-Endorphin binds with µ-receptors at only presynaptic nerve terminals in the central nervous system and this time it hinders the release of GABA. This inhibition of GABA by beta-endorphin results in up-regulation of dopamine. Thus over-produced dopamine results in a feeling of well-being and pleasure. Thus, indirectly β-Endorphin provides relief during the state of stress and pain by minimizing pain transmission and producing pleasure.
Isolation of Endorphins:
Endorphins are richly present in cerebrospinal fluid. Endorphins are also present in very low quantity in blood plasma. In the 1980s, usually, bioassays were employed to isolate endorphins from body fluids of experimental animals. With the development of technology, a new method was invented lately through which isolation of endorphins became easier. Radio-immuno-assay became a more reliable technique to isolate endorphins from body fluids.
Functions of Endorphins:
Endogenous release of Endorphins is involved in different physiological functions and produce the following effects:
1- Pain management:
Endorphins, especially, β-Endorphin acts as pain modulator. Levels of beta-endorphin increases in blood plasma during postoperative pain after oral, abdominal and other surgeries. This means beta-endorphin start working for minimizing pain after surgeries by activating µ-receptors.
2- Neuro-protection:
Endorphins provide neurons protection from injury.
3- Immune regulators:
Lymphocytes contain receptors for endorphins. These receptors play a functional role in regulating the immune system. Endorphins play a pathogenic role during diseases related to immunological defects. Endorphins can also affect numerous immune functions such as for example antibody production, lymphocyte propagation, and natural killer cytotoxicity.
4- Ionic Hemostasis:
Endorphins activate receptors that eventually act to repair ionic imbalance induced by hypoxia.
5- Energy homeostasis:
Cleavage of POMC peptide gives rise to endorphin which likely has some complementary relation with energy homeostasis.
6- Euphoria
The release of beta-endorphin activates µ-receptors and cause a feeling of well-being and Euphoria.
77- Cancer prevention:
Chorionic stress triggers tumor growth and progression by increasing release of the stress hormone, weakening immune system and suppressing tumor suppressor genes. Beta-endorphin suppresses the release of the stress hormone, positively influences the immune system and up-regulate tumor suppressor genes. So, endorphins play a vital role in the prevention of tumor development.
8- Cardio-protection
9- Sedation
Effects of exogenous opioids:
In post-operative conditions, prescribed exogenous opioids are administrated to patients to overcome post-operative pain. These exogenous opioids have various side effects. Administration of exogenic opioid analgesic effects the body’s innate ability of pain management through the release of natural endogenous endorphins and related opioids. The efficiency of opioid receptors is also got disturbed due to external administration of prolonged analgesia. Body starts depending on exogenic opioid and a stage of drug tolerance is reached where only more strong analgesics work.
Activities that trigger Endorphin release:
Following activities trigger up-regulated release of endorphin in the brain.
Eating:
Researchers have found that eating delicious food triggers a significant release of endogenous endorphin that causes a feeling of pleasure. Tasteless nutritional food also shows this effect but food good in taste shows a significant effect on opioid release in the brain.
Yoga and Exercise:
Prolonged exercise and yoga excite CRH which results in significant release of endorphin for the stability of the body.
Acupuncture:
Acupuncture, especially, electroacupuncture technique is a very reliable source to increase the level of endorphins in body and brain. This method is employed to relieve pain and produce analgesia.
Listening Music:
Good music also influences the release of endorphin in the brain. Music therapy produces a sense of euphoria and pleasure by increasing the level of endorphins in the body.
Comments
Post a Comment