epinephrine | hormone | Britannica.com Epinephrine adrenal gland Epinephrine, also called adrenaline, hormone that is secreted mainly by the medulla of the adrenal glands and that functions primarily to increase cardiac output and to raise glucose levels in the blood. Epinephrine typically is released during acute stress , and its stimulatory effects fortify and prepare an individual for either “fight or flight” (see fight-or-flight response ). Epinephrine is closely related in structure to norepinephrine , differing only in the presence of a methyl group on the nitrogen side chain. In both substances, the amine (nitrogen-containing) group is attached to a catechol group (a benzene ring with two hydroxyl groups)—a structure unique to the catecholamines . Both substances are key stimulatory components of the sympathetic nervous system (part of the autonomic nervous system ), hence their pharmacological classification as sympathomimetic agents. In cells the stimulatory effects of epinephrine are mediated through the activation of a second … Encyclopædia Britannica, Inc.

Production of epinephrine Epinephrine is produced specifically in the adrenal medulla, where the amino acid tyrosine is transformed through a series of reactions to norepinephrine. An enzyme known as phenylethanolamine N-methyltransferase, which is found in the chromaffin cells of the adrenal medulla, catalyzes the methylation of norepinephrine to epinephrine. In addition to the release of epinephrine from the adrenal glands, small amounts of the hormone are also released from the ends of sympathetic nerves. Physiological actions The actions of epinephrine are complex, owing to its stimulatory effects on α- and β-adrenergic receptors (or adrenoceptors, so named for their reaction to the adrenal hormones), which produce various responses, depending on the specific receptor and the tissue in which it occurs. Hence, epinephrine causes constriction in many networks of minute blood vessels but dilates the blood vessels in the skeletal muscles and the liver . In the heart , it increases the rate and force of contraction, thus increasing the output of blood and raising blood pressure .

In the liver, epinephrine stimulates the breakdown of glycogen to glucose, resulting in an increase in glucose levels in the blood. It also acts to increase the level of circulating free fatty acids . The extra amounts of glucose and fatty acids can be used by the body as fuel in times of stress or danger, when increased alertness and exertion are required. The physiological actions of epinephrine are terminated by metabolic breakdown with catechol-O-methyltransferase (COMT) or monoamine oxidase (MAO), by reuptake into nerve endings, and by diffusion from active sites. Clinical significance androgen Purified active epinephrine is obtained from the adrenal glands of domesticated animals or prepared synthetically for clinical use. Epinephrine may be injected into the heart during cardiac arrest to stimulate heart activity. Epinephrine is also used to treat anaphylaxis (acute systemic allergic reaction), which can occur in response to exposure to certain drugs, insect venoms, and foods (e.g., nuts and shellfish).

It is also occasionally used in the emergency treatment of asthma , where its relaxation of smooth muscle helps to open the airways in the lungs, and in the treatment of glaucoma , where it appears to both decrease the production of aqueous humour and increase its outflow from the eye, thereby lowering intraocular pressure. In turn, certain disease states are associated with abnormalities in epinephrine production and secretion. For example, epinephrine and other catecholamines are secreted in excessive amounts by pheochromocytomas (tumours of the adrenal glands). Discovery of epinephrine Epinephrine was discovered in the late 1800s. English physiologists George Oliver and Sir Edward Albert Sharpey-Schafer were among the first to describe the blood-pressure-raising effect of a substance from the adrenal medulla. By 1900 epinephrine had been isolated and identified by American physiological chemist John Jacob Abel and, independently, by Japanese American biochemist Jokichi Takamine . In 1904 German chemist Friedrich Stolz became the first to synthesize the hormone.

Epinephrine and Norepinephrine | definition of Epinephrine and Norepinephrine by Medical dictionary Epinephrine and Norepinephrine | definition of Epinephrine and Norepinephrine by Medical dictionary Related to Epinephrine and Norepinephrine: dopamine , cortisol , acetylcholine epinephrine [ep″ĭ-nef´rin] a hormone produced by the adrenal medulla ; called also adrenaline (British). Its function is to aid in the regulation of the sympathetic branch of the autonomic nervous system . At times when a person is highly stimulated, as by fear, anger, or some challenging situation, extra amounts of epinephrine are released into the bloodstream, preparing the body for energetic action. Epinephrine is a powerful vasopressor that increases blood pressure and increases the heart rate and cardiac output. It also increases glycogenolysis and the release of glucose from the liver, so that a person has a suddenly increased feeling of muscular strength and aggressiveness. Some disorders of the adrenal glands, such as addison's disease , reduce the output of epinephrine below normal.

By contrast, excessive activity of those glands, as sometimes seen in highly emotional persons, tends to produce tenseness, palpitation, high blood pressure, perhaps diarrhea, and overaggressiveness. Certain adrenal tumors also result in the production of too much epinephrine. Removal of the tumor relieves symptoms. Epinephrine is also produced synthetically and can be administered parenterally, topically, or by inhalation. It acts as a vasoconstrictor, antispasmodic , and sympathomimetic , and it is used as an emergency heart stimulant as well as to relieve symptoms in allergic conditions such as urticaria (hives), asthma, and other conditions requiring bronchodilation and as a adjunct to local and regional anesthesia. It is the most effective drug for counteracting the lethal effects of anaphylactic shock. It is also used topically in the eye in the treatment of glaucoma . ep·i·neph·rine (ep'i-nef'rin), A catecholamine that is the chief neurohormone of the adrenal medulla of most species; also secreted by certain neurons.

The l-isomer is the most potent stimulant (sympathomimetic) of adrenergic α- and β-receptors, resulting in increased heart rate and force of contraction, vasoconstriction or vasodilation, relaxation of bronchiolar and intestinal smooth muscle, glycogenolysis, lipolysis, and other metabolic effects; used in the treatment of bronchial asthma, acute allergic disorders, open-angle glaucoma, cardiac arrest, and heart block, and as a topical and local vasoconstrictor. Generally used salts are epinephrine hydrochloride and epinephrine bitartrate, the latter most frequently used in topical preparations. [epi- + G. nephros, kidney, + -ine] epinephrine /epi·neph·rine/ (-nef´rin) a catecholamine hormone secreted by the adrenal medulla and a central nervous system neurotransmitter released by some neurons. It is stored in chromaffin granules and is released in response to hypoglycemia, stress, and other factors.

It is a potent stimulator of the sympathetic nervous system ( adrenergic receptors ), and a powerful vasopressor , increasing blood pressure, stimulating the heart muscle, accelerating the heart rate, and increasing cardiac output. It is used as a topical vasoconstrictor , cardiac stimulant, systemic antiallergic, bronchodilator , and topical antiglaucoma agent; for the last two uses it is also administered as the bitartrate salt. Called also adrenaline (Great Britain). epinephrine (ĕp′ə-nĕf′rĭn) n. 1. A hormone secreted by the adrenal medulla that is released into the bloodstream in response to physical or mental stress, as from fear or injury. It initiates many bodily responses, including the stimulation of heart action and an increase in blood pressure, metabolic rate, and blood glucose concentration. Also called adrenaline. 2. A white to brownish crystalline compound, C9H13NO3, isolated from the adrenal glands of certain mammals or synthesized and used in medicine as a heart stimulant, vasoconstrictor, and bronchial relaxant.

epINEPHrine [ep′ənef′rin] Etymology: Gk, epi + nephros, kidney an endogenous adrenal hormone and synthetic adrenergic agent. It acts as an agonist at alpha-1, alpha-2, beta-1, and beta-2 receptors. Also called adrenaline . indications It is prescribed to treat anaphylaxis, acute bronchial spasm, and nasal congestion and to increase the effectiveness of a local anesthetic. contraindication Known hypersensitivity to this drug prohibits its use. adverse effects Among the most serious adverse effects are arrhythmias, increases in blood pressure, rebound congestion (when it is used as a decongestant), tachycardia, and nervousness.

adrenaline A sympathomimetic catecholamine hormone synthesised in the adrenal medulla and released into the circulation in response to hypoglycemia and sympathetic nervous system—i.e., splanchnic nerve stimulation due to exercise and stress; it acts on α- and β-receptors, resulting in vasoconstriction or vasodilation, decreased peripheral blood flow, increased heart rate, increased force of contractility, increased glycogenolysis and increased lipolysis. Pharmacologic doses of epinephrine are used as bronchodilator for acute asthma, to increase blood pressure and in acute myocardial infarctions, to improve myocardial and cerebral blood flow. Adrenaline is the official British pharmacopoeia name for epinephrine.

epinephrine Physiology A sympathomimetic catecholamine hormone synthesized in the adrenal medulla and released into the circulation in response to hypoglycemia and sympathetic nervous system–splanchnic nerve stimulation due to exercise and stress; it acts on α– and β-receptors, resulting in vasoconstriction or vasodilation, ↓ peripheral blood flow, ↑ heart rate, ↑ force of contractility, ↑ glycogenolysis, ↑ lipolysis; pharmacologic epinephrine is used as bronchodilator for acute asthma to ↑ BP and in acute MIs to improve myocardial and cerebral blood flow. See Fight-or-flight response , High-dose epinephrine . ep·i·neph·rine (ep'i-nef'rin) A catecholamine that is the chief neurohormone of the medulla of the suprarenal gland.

The l-isomer is the most potent stimulant (sympathomimetic) of adrenergic α- and β-receptors, resulting in increased heart rate and force of contraction, vasoconstriction or vasodilation, relaxation of bronchiolar and intestinal smooth muscle, glycogenolysis, lipolysis, and other metabolic effects; used in the treatment of bronchial asthma, acute allergic disorders, open-angle glaucoma, and heart block, and as a topical and local vasoconstrictor. see ADRENALINE . Epinephrine Also called adrenalin, a secretion of the adrenal glands (along with norepinephrine) that helps the liver release glucose and limits the release of insulin. Norepinephrine is both a hormone and a neurotransmitter, a substance that transmits nerve signals. Mentioned in: Adrenal Gland Cancer , Catecholamines Tests , Hypoglycemia , Liposuction , Smoking epinephrine adrenaline; catecholamine neurohormone, released from adrenal medulla as part of the 'fight or flight' mechanism, i.e.

the unconscious and automatic response to real or perceived danger (Table 1); most potent stimulant (sympathomimetic) of adrenergic alpha and beta receptors (see Table 2); added to local anaesthetic (LA) solutions (e.g. lidocaine or bupivacaine, at 1:200 000, equivalent to 5 μg/mL of LA) as a vasoconstrictor, so that anaesthetic is absorbed more slowly into systemic circulation, anaesthetic effect is prolonged and a smaller dose of the drug can be administered (note: LA solutions containing epinephrine must never be injected into a digit; they should be avoided in pregnant women as epinephrine can cross the placenta to affect the fetus); drug of choice in immediate treatment of anaphylaxis, delivered by intramuscular injection at rate of 500 μg (0.5 mL of a 1:1000 solution) every 5 minutes to a maximum of three doses for a 70-kg adult Table 1: The systemic effects of adrenaline (epinephrine) Site of action Plus signs indicate degree of effect.

epinephrine (eh·pi·neˑ·frin), n neurochemical produced by the adrenal glands that arouses the sympathetic response. Also called adrenaline. adrenaline (epinephrine) A hormone of the adrenal medulla which, instilled in the eye, causes a constriction of the conjunctival vessels, dilates the pupil and diminishes the intraocular pressure. See adrenergic receptors ; ocular decongestant ; naphazoline ; neurotransmitter ; noradrenaline (norepinephrine) . ep·i·neph·rine (ep'i-nef'rin) A catecholamine that is the chief neurohormone of the adrenal medulla of most species; also secreted by some neurons; used to treat bronchial asthma, acute allergic disorders, open-angle glaucoma, cardiac arrest, and heart block, and as a topical and local vasoconstrictor.

You & Your Hormones | Hormones | Adrenaline You & Your Hormones Email article to a friend | Last updated: January 15, 2015 Adrenaline is a hormone released from the adrenal glands and its major action, together with noradrenaline, is to prepare the body for fight or flight. Image of an eye showing a dilated or enlarged pupil - one of the effects of adrenaline released during a "fight or flight" response. Alternative names for adrenaline Epinephrine. What is adrenaline? Adrenaline and noradrenline are two separate but related hormones and neurotransmitters. They are produced in the medulla of the adrenal glands and in some neurons of the central nervous system. They are released into the bloodstream and serve as chemical mediators, and also convey the nerve impulses to various organs. Adrenaline has many different actions depending on the type of cells it is acting upon. However, the overall effect of adrenaline is to prepare the body for the ‘fight or flight’ response in times of stress, ie, for vigorous and/or sudden action.

Key actions of adrenaline include increasing the heart rate, increasing blood pressure, expanding the air passages of the lungs, enlarging the pupil in the eye (see figure), redistributing blood to the muscles and altering the body’s metabolism , so as to maximise blood glucose levels (primarily for the brain). A closely related hormone, noradrenaline, is released mainly from the nerve endings of the sympathetic nervous system (as well as in relatively small amounts from the adrenal medulla). There is a continuous low level of activity of the sympathetic nervous system resulting in release of noradrenaline into the circulation, but adrenaline release is only increased at times of acute stress. Adrenaline, like noradrenaline, is also used as a transmitter by some nerve cells to communicate with other cells (a neurotransmitter). Very little adrenaline is used in this way. How is adrenaline controlled? Adrenaline is mainly released in response to stressful events to prepare the body for the ‘fight or flight’ response. These events lead to the activation of nerves connected to the adrenal glands, which trigger the secretion of adrenaline and thus increase the levels of adrenaline in the blood. This process happens relatively quickly, within 2 to 3 minutes of the stressful event being encountered.

When the stressful situation ends, the nerve impulses to the adrenal glands are lowered, meaning that the adrenal glands stop producing adrenaline. Stress also stimulates the release of adrenocorticotropic hormone from the pituitary gland , which promotes the production of the steroid hormone cortisol from the cortex of the adrenal glands. This steroid hormone is more important in altering the body’s metabolism (ie, raising plasma glucose) under conditions of longer-term, ongoing ( chronic ), rather than acute, stress. What happens if I have too much adrenaline? Overproduction of adrenaline is rare. Too much adrenaline can be caused by a variety of things, including a rare tumour of the adrenal medulla (a phaeochromocytoma ). Symptoms may include rapid heart beat, high blood pressure, anxiety, weight loss, excessive sweating and palpitations. What happens if I have too little adrenaline? Suffering from too little adrenaline is very unusual. Among other things, it would result in an inability to prepare the body for action in response to a stressful or physically demanding situation. What is Epinephrine (Adrenaline)? What is Epinephrine (Adrenaline)?

By April Cashin-Garbutt , BA Hons (Cantab) Epinephrine (ep-uh-nef-rin, -reen) is also known as adrenaline. It is a hormone that is secreted by the adrenal glands. (1, 3) Adrenalin, without the e, was originally used as a trademark for a product made by an American pharmaceutical firm Parke, Davis & Co. The usage of the word, with and without the e, however, was not very consistent, thus many seem to use the terms interchangeably. (2) Structure of epinephrine Epinephrine is derived from tyrosine, an amino acid. Epinephrine is sometimes referred to as a catecholamine as it contains the catechol moiety. This is a part of the molecule that contains the group C6H4(OH)2. Dopamine and norepinephrine are also referred to as catecholamines. They too are synthesized from tyrosine and contain the catechol moiety. (4) What role does epinephrine play in the body? Epinephrine is involved in the fight or flight response in humans.

The fight or flight response occurs when a person is subject to a threat. This causes a signalling process to occur, which causes the body to react to the potential danger. Specifically, once a threat is perceived, a signal is sent to the brain. The brain then sends nerve impulses to the adrenal gland in the kidneys. When the nerve signal reaches the adrenal gland, chromaffin cells, in the medulla of the adrenal gland, release epinephrine. Epinephrine then enters the bloodstream. It is thus carried around the body to cells in various locations, where it initiates several responses. (5) Despite initiating several different responses, epinephrine’s effects have a collective purpose – to provide energy so that the major muscles of the body can respond to the perceived threat. (4) Epinephrine and liver cells One of the places where epinephrine has an effect is in the liver. Epinephrine, along with another hormone called glucagon, is responsible for the breakdown of glycogen in liver cells. Glycogen is a form of energy storage in animals. Epinephrine binds to a receptor on the outside of a liver cell causing a conformational change to occur.

This change means that a G protein can now bind. Consequently, adenylate cyclase and ATP can bind to the complex. Adenylate cyclase breaks down ATP into a second messenger molecule called cyclic AMP, commonly referred to as cAMP. The second messenger then causes the activation of a protein kinase which activates phosphorylaze. Phosphorylaze is an enzyme which catalyzes the breakdown of glycogen to glucose. (3) Epinephrine and the skin Could artificial intelligence help to combat stress? An interview with Davide Morelli The effect of epinephrine on the skin is mainly caused by it binding to alpha-adrenergic receptors, the alpha-2-adrenergic receptor in particular. Restriction of the arteries is caused by the binding of epinephrine to these alpha-adrenergic receptors. This cuts off blood supply to the skin. (4) A signalling cascade is also stimulated. This results in the contraction of the smooth muscle cells in the skin, which cause the raising of the hairs on the surface of the skin. (5) Epinephrine and the lungs The lungs contain smooth muscle. Epinephrine causes smooth muscles to relax.

(6) Specifically, epinephrine binds to beta-2-adrenergic receptors on bronchiole muscle cells. This allows the bronchioles to relax, which enables intensified respiration. (5) Epinephrine and the heart Epinephrine binds to beta-adrenergic receptors on heart muscle cells. This causes the contraction rate of the heart to increase. This ultimately leads to increased blood supply to the tissues in the body. (4) Medical uses of epinephrine Epinephrine is used in a medical context. One of the most widely known uses is in epinephrine injections to relieve the symptoms of allergic reactions. Epinephrine is also sometimes used in cardiopulmonary resuscitation (CPR). Epinephrine injections for allergic reactions Perhaps one of the most widely known uses of epinephrine is in injections for life-threatening allergic reactions.

(7) Such potentially life-threatening allergic reactions are referred to as anaphylaxis and can be caused by: Common symptoms of anaphylaxis are: breathing difficulties and wheezing, caused by narrowing of the airways low blood pressure, often associated with feeling faint an itchy skin rash consisting of red raised welts, called hives (9) swelling of the eyes, lips, hands and feet nausea and vomiting a metallic taste in the mouth (7, 10) Epinephrine injections work to counteract the symptoms of anaphylaxis by: opening the airways to reduce breathing difficulties narrowing the blood vessels to combat low blood pressure and to ease the faint feelings. (11) Epinephrine has a short half-life, however, so the relief from the symptoms is only temporary. Consequently the individual needs to be taken immediately to hospital. (3) Epinephrine use in Cardiopulmonary Resuscitation (CPR) Epinephrine is sometimes used in CPR as it is an adrenergic receptor stimulator. (12) It stimulates both alpha and beta-adrenergic receptors which cause enhanced myocardial and cerebral blood flow.

This means that CPR is more effective as a central blood reserve is maintained due to increased peripheral resistance. (13) There are potential side effects of using epinephrine, however, as it has been linked to brain and heart damage. (3) Extensive epinephrine treatment induces proliferation of cardiac muscle cells. This is partly due to the activation of the Mitogen-activated protein (MAP) kinase cascade. This can lead to cardiac hypertrophy. (4) Cardiac hypertrophy results in the size of the chambers of the heart being decreased – in particular the left and right ventricles. (14) Sometimes cardiac hypertrophy can result in heart disease. (4) Epinephrine | Define Epinephrine at Dictionary.com epinephrine [ep-uh-nef-rin, -reen] /ˌɛp əˈnɛf rɪn, -rin/ Spell noun 1. Biochemistry. a hormone secreted by the adrenal medulla upon stimulation by the central nervous system in response to stress, as anger or fear, and acting to increase heart rate, blood pressure, cardiac output, and carbohydrate metabolism. 2. Pharmacology.

a commercial form of this substance, extracted from the adrenal glands of sheep and cattle, or synthesized: used chiefly as a heart stimulant, to constrict the blood vessels, and to relax the bronchi in asthma. Expand 1895-1900; epi- + Greek nephr(ós) kidney + -ine 2 Dictionary.com Unabridged British Dictionary definitions for epinephrine Expand a US name for adrenaline Word Origin C19: from epi- + nephro- + -ine² Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012 Word Origin and History for epinephrine Expand n. 1883, from epi- "upon" + Greek nephros "kidney" (see nephron ) + chemical suffix -ine (2). So called because the adrenal glands are on the kidneys.

Online Etymology Dictionary, © 2010 Douglas Harper epinephrine ep·i·neph·rine or ep·i·neph·rin (ěp'ə-něf'rĭn) n. A catecholamine hormone of the adrenal medulla that is the most potent stimulant of the sympathetic nervous system, resulting in increased heart rate and force of contraction, vasoconstriction or vasodilation, relaxation of bronchiolar and intestinal smooth muscle, glycogenolysis, lipolysis, and other metabolic effects. Also called adrenaline. A white to brownish crystalline compound isolated from the adrenal glands of certain mammals or synthesized and used in medicine as a heart stimulant, vasoconstrictor, and bronchial relaxant. The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company. Epinephrine Epinephrine Ephedra, Ephedrine, Ma Huang Epinephrine, more commonly known as adrenaline, is a hormone secreted by the medulla of the adrenal glands.

Strong emotions such as fear or anger cause epinephrine to be released into the bloodstream, which causes an increase in heart rate, muscle strength, blood pressure, and sugar metabolism. This reaction, known as the ï¿½Flight or Fight Responseï¿½ prepares the body for strenuous activity. In medicine epinephrine is used chiefly as a stimulant in cardiac arrest, as a vasoconstrictor in shock, and as a bronchodilator and antispasmodic in bronchial asthma. Epinephrine is found in small amounts in the body and is essential for maintaining cardiovascular homeostasis because of its ability to divert blood to tissues under stress. During cardiac arrest the top priority is to maximize the amount of blood flow through the coronary artery. Epinephrine, when injected into an intravenous fluid solution, will increase the coronary artery pressure thereby promoting increased coronary blood flow. Increased doses of epinephrine quicken the response, but some studies have shown that brain and heart damage are some of the side effects.

Anaphylactic shock is caused whenever the heart is unable to pump enough blood throughout the body due to an allergic reaction, weakening of the heart muscle, or shrinking of the veins (vasodilation). Injection of epinephrine into the blood stream will cause an increase of blood flow throughout the body. The relief is only temporary due to the short half-life of adrenaline; therefore, immediate hospitalization is required to ensure safety to the individual. Individuals who are prone to asthma attacks have lung passages that are more susceptible to inflammation and swelling. The swelling causes constriction of the muscles around the airway tubes and an increase in mucus. The combination of these three leads to the shortness of breath, coughing, or wheezing common to those who suffer from asthma. When inhaled in small doses, epinephrine causes short-term relief from the symptoms by widening the bronchial tubes allowing air to pass through. Once again epinephrine is not the best cure, but a temporary relief when an asthma inhaler is not present. Formation of Epinephrine in the Body (1) Tyrosine is hydroxylated to L-DOPA by tyrosine hydroxylase.

(2) L-DOPA is decarboxylated to dopamine. (3) A secondy hydroxylation yields norepinephrine. (4) Methylation of norepinephrineï¿½s amino group produces epinephrine. Epinephrine and Its Effect on Smooth Muscle Cells Relaxation and contraction of smooth muscle cells (i.e. heart, arteries, and veins) are controlled through epinephrine receptors. The click here to view the figure which represents the mechanism of this control. Contraction occurs through binding of calmodulin to Calcium ions when the concentration is ten times larger than normal in the cell. The Calcium-Calmodulin complex then activates the myosin light chain kinase (MLCK), which in turn phosphorylates the LC2 causing contraction. Binding of epinephrine to the epinephrine receptors activates adenylyl cyclase producing cyclic AMP from ATP. Cyclic AMP activates a protein kinase thereby phosphorylating the MLCK. This has a lower affinity for Calcium-Calmodulin complex and is thus inactive; thereby, relaxing the smooth muscle tissue. For this reason epinephrine is used for cardiac arrests, asthma, and anaphylactic shock patients.

Epinephrine and Its Effects in Liver Cells Glycogen synthesis and degradation occurs in the liver cells. It is here that the hormone insulin (the primary hormone responsible for converting glucose to glycogen) acts to lower blood glucose concentration. Insulin stimulates glycogen synthesis; thereby, inhibiting glycogen degradation as shown in the figure (click here to view figure) . Epinephrine, on the other hand, is one of the two primary hormones (the other being glucagon) that breakdown glycogen. Epinephrine will bind to the receptor on the outside of a liver cell allowing a conformational change to occur. This receptor shape change allows G protein to bind, and become active. The activation G protein causes a conformational change on the molecule causing adenylate cyclase to bind. Once adenylate cyclase has been activated ATP binds to the complex. Adenylate Cyclase breaks down ATP into Cyclic AMP, which becomes the second messenger protein in this process. Cyclic AMP activates protein kinase, which activates phosphorylase catalyzing the breakdown of glycogen to glucose. For a better understanding of this process, a PowerPoint slide presentation is found here.

( ) (Note: Click on View Image to show the PowerPoint presentation.) Ephedra, Ephedrine, Ma Huang Epinephrine exists as an extremely regulated hormone in the body. Medication containing this hormone must be prescribed by a doctor or administered in a hospital for severe cases of asthma, shock or cardiac arrest. Ephedrine is a protein extracted from a Chinese plant that acts similar to epinephrine and acts on the same receptors. Ephedra equisetina (also known as its 5000 year-old Chinese name Ma Huang) is this desert shrub from which ephedrine is extracted. It contains two substances, ephedrine and pseudoephedrine. The first helps to relieve asthma and stimulates the sympathetic nervous system, while pseudoephedrine acts as a nasal decongestant. Since epinephrine receptors will recognize ephedrine molecules, ephedrine can also cause the breakdown of glycogen in the liver. For this reason, Ma Huang is one of the more popular dietary herbal supplements on the market, which can be found at any pharmacy, grocery store or General Nutrition Center in the nation.

For dieters it suppresses the appetite and stimulates the thyroid gland increasing thermogenic metabolism. Metabolism similar to that if one were exercising for a prolonged period of time, such as, during a cardiovascular routine. The adrenal glands dump epinephrine into the blood stream, which leads to an increase in body temperature thereby burning more calories. Although, ephedrine will not cure a poor diet, weight loss has only been proven in people in coordination with Calorie restriction. For athletes ephedrine, in theory, could enhance athletic abilities by opening the lungs, enhancing muscle contractility, and increasing blood glucose levels during competition. Responses similar to an ï¿½adrenaline rushï¿½ felt by athletes. If used at all for helping to improve athletic performance, the best situation would be in the gym. Ephedrine has fast acting effects that may tire an athlete on the playing field, but not during a shorter workout routine. However, long-term reliance on this compound to ï¿½energizeï¿½ them for a particular workout is not a good idea and will eventually lead to negative effects on the playing field.

Also, college athletes should be aware that the IOC, NCAA, and the Olympic committee all ban the use of this product. No high schools have placed any band on any herbal supplement. Ma Huang does have several negative effects to it, which have warranted action by the FDA to attempt to ban this drug. Ephedrine can increase blood pressure and heart rate, while causing dizziness, insomnia, and headaches. The Food and Drug Administration proposed limits on ephedrine levels in supplements and to be taken for no longer than 7 day intervals. They should also contain a warning label indicating the overdosing (more than 25 mg/day) may cause heart attack, stroke, seizures, or death. Last year the FDA did not provide conclusive evidence needed to put restrictions on ephedra. One major reason that the FDA did not provide enough evidence is the fact that a 1994 law removed dietary supplements from control of the FDA, and as a result, they are not subjected to the strict clinical tests as prescription medication. Like any drug (prescribed, over-the-counter, or dietary supplement) the daily dosage should not be exceeded for risk of long-term affects on the body.

Adrenaline, Cortisol, Norepinephrine: The Three Major Stress Hormones, Explained | The Huffington Post Adrenaline, Cortisol, Norepinephrine: The Three Major Stress Hormones, Explained 04/19/2013 08:42 am ET Sarah Klein Senior Editor, Health & Fitness; Certified Personal Trainer Getty Images Thanks to the work of our sympathetic nervous system, the "fight or flight" system that takes over when we're stressed, when you see your boss's name in your inbox late at night, your body reacts like there's a lion on the loose. Behind the wide range of both physical and mental reactions to stress are a number of hormones that are in charge of adding fuel to the fire. Adrenaline What It Is: Commonly known as the fight or flight hormone , it is produced by the adrenal glands after receiving a message from the brain that a stressful situation has presented itself. What It Does: Adrenaline, along with norepinephrine (more on that below), is largely responsible for the immediate reactions we feel when stressed.

Imagine you're trying to change lanes in your car, says Amit Sood, M.D., director of research at the Complementary and Integrative Medicine and chair of Mayo Mind Body Initiative at Mayo Clinic. Suddenly, from your blind spot, comes a car racing at 100 miles per hour. You return to your original lane and your heart is pounding. Your muscles are tense, you're breathing faster, you may start sweating. That's adrenaline. Along with the increase in heart rate, adrenaline also gives you a surge of energy -- which you might need to run away from a dangerous situation -- and also focuses your attention. Norepinephrine What It Is: A hormone similar to adrenaline, released from the adrenal glands and also from the brain, says Sood. What It Does: The primary role of norepinephrine, like adrenaline, is arousal, says Sood. "When you are stressed, you become more aware, awake, focused," he says. "You are just generally more responsive." It also helps to shift blood flow away from areas where it might not be so crucial, like the skin, and toward more essential areas at the time, like the muscles, so you can flee the stressful scene.

Although norepinephrine might seem redundant given adrenaline (which is also sometimes called epinephrine), Sood imagines we have both hormones as a type of backup system. "Say your adrenal glands are not working well," he says. "I still want something to save me from acute catastrophe." Depending on the long-term impact of whatever's stressing you out -- and how you personally handle stress -- it could take anywhere from half an hour to a couple of days to return to your normal resting state, says Sood. Cortisol What It Is: A steroid hormone, commonly known as the stress hormone , produced by the adrenal glands. What It Does: It takes a little more time -- minutes, rather than seconds -- for you to feel the effects of cortisol in the face of stress, says Sood, because the release of this hormone takes a multi-step process involving two additional minor hormones. First, the part of the brain called the amygdala has to recognize a threat. It then sends a message to the part of the brain called the hypothalamus , which releases corticotropin-releasing hormone (CRH).

CRH then tells the pituitary gland to release adrenocorticotropic hormone (ACTH), which tells the adrenal glands to produce cortisol. Whew! In survival mode, the optimal amounts of cortisol can be life saving. It helps to maintain fluid balance and blood pressure, says Sood, while regulating some body functions that aren't crucial in the moment, like reproductive drive, immunity, digestion and growth. But when you stew on a problem, the body continuously releases cortisol, and chronic elevated levels can lead to serious issues . Too much cortisol can suppress the immune system, increase blood pressure and sugar, decrease libido, produce acne, contribute to obesity and more. "Ducks walk out of a lake, flap their wings and they fly off," says Sood. "When you face something stressful, particularly if it's not likely to repeat or doesn't have a huge long-term impact, you want to be able to shake it off and move on with life." Of course, he adds, estrogen and testosterone are also hormones that affect how we react to stress, as are the neurotransmitters dopamine and serotonin. But the classic fight-or-flight reaction is mostly due to the three major players mentioned above. How do you react to stress? Let us know in the comments.

Related on HuffPost: Epinephrine - used, first, blood, body, produced, function, Early Research and Use, Hormones and the Body, Catecholamines, Vasopressors Medical Discoveries » Enz-Ho » Epinephrine Epinephrine Epinephrine, also known as adrenaline, is a hormone secreted by the medulla (inner part) of the adrenal glands, located on the kidneys. The adrenal glands are one of the body's endocrine glands (glands producing substances that are distributed by way of the bloodstream). Epinephrine was the first hormone to be discovered. Hormones are substances produced by body cells that circulate in body fluid and influence the activity of cells in another part of the body. In the 1950s, the American pharmacologist Earl Sutherland (1915-1974) discovered that epinephrine does not act directly on cells, but stimulates production of cyclic AMP, a second messenger that regulates cell activity.

Epinephrine is produced continuously in small amounts by the adrenal glands, but when the body is threatened in times of excitement, danger, or emotional stress, the brain sends messages to the adrenal glands, which respond by increasing epinephrine production. This increase in epinephrine stimulates the heart, raises blood pressure, constricts small blood vessels, releases sugar stored in the liver, and relaxes certain involuntary muscles while it contracts others. These changes in the body prepare it for "fight or flight," meaning the body is more alert, physically stronger, and has greater energy. The person is now better prepared to face the danger at hand (fight) or escape from the danger or stress (flight). Early Research and Use The power of adrenal extracts was first observed by the British physiologist Edward Sharpey-Schafer (1850-1935). In 1894 he injected an adrenal extract into an experimental animal, causing its blood vessels to narrow and forcing an increase in blood pressure.

Japanese American chemist Jokichi Takemine (1854-1922) isolated epinephrine in 1901, based on preliminary work done in 1897 by American pharmacologist John Jacob Abel (1857-1938). Epinephrine was soon available for medical purposes such as reviving persons suffering from hemorrhage and shock. It was once prepared using adrenal glands of animals, but is now produced synthetically. Hormones and the Body In 1905 the British physiologists William Bayliss (1860-1924) and Ernest Starling (1866-1927) introduced the concept of a hormone, a sub-stance that is produced by one organ and carried by the blood to another organ, where it influences its functions. Only then did scientists realize that epinephrine was a hormone. The significance of epinephrine and other hormones in the body's operations was discovered by the American physiologist Walter Bradford Cannon (1871-1945), after he worked with injured World War I (1914-1918) soldiers.

Other scientists had already studied the body as an internal environment and the interrelation of metabolism, hormones, and the immune system. In 1926 Cannon developed the concept of homeostasis (an organism's ability to remain stable internally, even when the surrounding environment exerts great stress upon it, such as hunger, thirst, and sudden danger). Homeostasis in turn led to such ideas as biofeedback (the interaction of internal and external signals and responses in the body). Catecholamines Epinephrine is one of several structurally related compounds in the body called catecholamines. These compounds help regulate the sympathetic nervous system, which is part of the autonomic nervous system. The autonomic nervous system helps the body maintain homeostasis. The autonomic nervous system makes rapid adjustments to changes in environment by freeing chemical agents that act as they are released. The endocrine system acts more slowly by releasing agents over periods of hours or days. Because it releases hormones but acts so quickly, the adrenal medulla cannot be strictly classified as part of the nervous system or part of the endocrine system. The neurohumoral theory may explain how the two act as one in many cases.

Other catecholamines are norepinephrine (also called noradrenaline or levoarterenol) and dopamine. The general function of norepinephrine seems to be the maintenance of normal blood circulation. It is also the chemical agent that is responsible for transmission of nerve impulses in the sympathetic nervous system. When a person has certain tumors of the adrenal glands, large amounts of epinephrine and norepinephrine are produced, causing a great increase in blood pressure. Dopamine is also a nerve impulse transmitter. Synthetic (synthesized) catecholamines are important in medicine as heart stimulants and vasoconstrictors (substances that cause blood vessels to narrow), as well as relaxants of the bronchial and other muscles. Vasopressors Epinephrine is one of the most powerful vasopressor (causing a rise in blood pressure) drugs known. It increases the strength of heart muscle contractions as well as the heart rate, and it constricts blood vessels and veins. Because it is a powerful heart stimulant, it is used in emergency medicine to restore heart rhythm in cases of shock and in certain cases of cardiac arrest (heart attack).

The most common use of epinephrine in medicine is to relieve breathing distress in patients with asthma, bronchitis, and emphysema. The synthetic catecholamine isoproterenol is also used in the treatment of these diseases. Epinephrine is a powerful bronchodilator, meaning it relaxes bronchial muscle. It also constricts pulmonary vessels (in the lung), and inhibits the release of histamines triggered by allergic reactions. As a bronchodilator it is most often inhaled by mouth as a spray or through another breathing apparatus. Epinephrine is also used on the skin or mucous membranes to control bleeding of wounds because it constricts blood vessels. It is sometimes used for the same reason during surgery of the nose, throat, and larynx, where it also shrinks mucosa (membranes that secrete slime), making surgery easier. Epinephrine increases metabolism, accelerates blood coagulation, and lowers pressure inside the eye in some types of glaucoma.

User Contributions: Steve Oct 3, 2012 @ 7:07 am Just so everyone knows, and does not get confused by it, Cardiac Arrest IS NOT the same thing as a Heart Attack as indicated in the article above. Although cases of Cardiac Arrest are commonly caused by an MI, not all heart attacks result in SCA. Many people including this author tend to use them interchangeably. However an MI (Heart Attack) is caused by the occlusion of the coronary arteries via clot/plaque/spasm etc. resulting in cardiac tissue death below the site of occlusion. Cardiac Arrest is when the cardiac function suddenly ceases, most commonly caused by an arrhythmia. Epi is used in Arrest, it is CONTRAINDICATED and should be used cautiously in patients with MI's. Otherwise, a sound article. Note to the author- Check your sources before providing false information. Nothing personal, just can not stand when people use Cardiac Arrest and MI/Heart Attack interchangeably. Comment about this article, ask questions, or add new information about this topic: Name: What is Norepinephrine? What is Norepinephrine?

By Marcia Purse Updated March 13, 2016 Norepinephrine, also known as noradrenaline, is both a hormone and a brain neurotransmitter. It's mainly stored in the neurons of the sympathetic nervous system with small amounts also stored in adrenal tissue. What Does Norepinephrine Do? As a hormone, norepinephrine is secreted into the bloodstream by the adrenal glands and works alongside adrenaline, also known as epinephrine, to give the body sudden energy in times of stress, known as the "fight or flight" response. As a neurotransmitter , norepinephrine passes nerve impulses from one neuron to the next. Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs) Medications that inhibit the reuptake of norepinephrine and serotonin , another neurotransmitter, called serotonin-norepinephrine reuptake inhibitors (SNRIs), have been found to be effective in treating mood disorders like depression, bipolar disorder and anxiety disorders. SNRIs are also sometimes prescribed for chronic pain and fibromyalgia.

How SNRIs Work Serotonin and norepinephrine reuptake inhibitors prevent serotonin and norepinephrine from being absorbed by the brain and change the way these and other neurotransmitters communicate with each other, which in turn helps to boost your mood. SNRIs for Mood Disorders The SNRIs approved for use in major depression include Cymbalta (duloxetine), Effexor (venlafaxine) and Pristiq (desvenlafaxine), but there are others approved for other illnesses as well. Although no antidepressants, including SNRIs, have been approved by the U.S. Food and Drug Administration (FDA) for the treatment of bipolar disorder, they are often prescribed as part of an individual treatment plan. Common Side Effects of SNRIs These side effects often go away after a couple weeks, but if they don't or they are particularly bothersome, be sure to contact your doctor. Common side effects of SNRIs include: Dizziness Difficulty urinating The Family of Serotonin-Norepinephrine Reuptake Inhibitors Each of these SNRIs is a little bit chemically different from the others, which is why they are approved for various illnesses.

Effexor (Venlafaxine) Effexor was the first SNRI to be approved in the United States in 1993. It has been approved by the FDA for depression, panic disorder, social phobia and generalized anxiety disorder (GAD). Effexor inhibits the reabsorption of serotonin quite a bit more than it does norepinephrine. Cymbalta (Duloxetine) In 2004, Cymbalta was the second SNRI to be approved in the United States.Because of the way it works, it has the highest number of FDA-approvals to treat illnesses, including diabetic peripheral neuropathy, depression, generalized anxiety disorder, fibromyalgia, osteoarthritis and nerve pain. Like Effexor, Cymbalta also favors inhibiting the reabsorption of serotonin over norepinephrine, but to a lesser degree. Pristiq (Desvenlafaxine) Pristiq, the third SNRI to be approved in 2008, has only been approved to treat major depression so far. Chemically, Pristiq works very similarly to Cymbalta.

Savella (Milnacipran) The fourth SNRI to be approved in the U.S. in 2009, Savella has only been approved to treat fibromyalgia as of now, though it has been used in France since 1997 to treat major depression as well. Savella works at inhibiting the reabsorption of both serotonin and norepinephrine equally and may even favor norepinephrine, according to some sources. Fetzima (Levomilnacipran) The most recent member introduced to the SNRI family, Fetzima was approved by the FDA in 2013 and has also only been FDA-approved for treating depression. Fetzima inhibits norepinephrine reabsorption twice as much as serotonin reabsorption, making it unique among the SNRIs. Sources: Schatzburg, A.F., and Schildkraut, J.J. (2000). "Recent Studies on Norepinephrine Systems in Mood Disorders." Retrieved October 8, 2006 from Rogers, K. "Norepinephrine." Encyclopaedia Britannica (2015).

"Serotonin and norepinephrine reuptake inhibitors (SNRIs)." Mayo Clinic (2013). Sansone, R.A., Sansone, L.A. "Serotonin Norepinephrine Reuptake Inhibitors: A Pharmacological Comparison." Innovations in Clinical Neuroscience. 2014;11(3-4):37-42. Continue Reading

Question: Which hormone is called epinephrine in the USA?
Answer: Adrenalin