Tyrosine is contraindicated. Dietary supplement Twinlab L-Tyrosine (L-Tyrosine, L-Tyrosine) - “Improves thought processes, increases intelligence! And no side effects! How can you refuse this? "

L-Tyrosine is a dietary supplement that is used in medicine for certain indications. As part of the drug, the main active ingredient is the nonessential amino acid tyrosine, which takes part in many of the body's reactions necessary to maintain homeostasis.

Interestingly, this amino acid owes its name to cheese. "Tyri" in translation from Greek means "cheese". In 1846, tyrosine was first identified in the protein casein by the German scientist Justus von Liebig.

Composition of the preparation and sources of tyrosine

L-tyrosine as a dietary supplement usually contains 500 mg active substance, which fully compensates for the lack of a component in the body in a few weeks of application. Also, the capsule contains other additional substances that maintain the desired size, shape, weight and taste of the dietary supplement - magnesium stearate and stearic acid.

What foods can tyrosine be found in? The amino acid is found in protein-rich foods. To replenish the reserves of a substance in the body, you must include in your diet:

• turkey;
• chicken;
• dairy products;
• fish;

In addition, the bulk of tyrosine is metabolized by phenylalanine. This amino acid cannot remain unchanged in the body, since its accumulation leads to pathology of the nervous system and disruption of the functions of other organs. It turns into a useful amino acid. Therefore, tyrosine is a kind of phenylalanine metabolism product. As a result, there is a very low likelihood of a situation with a lack of L-tyrosine in the body.

Useful properties of tyrosine

Tyrosine is an activator of the breakdown of protein components that are included in various cellular structures and many enzyme molecules. It also plays an important role in biological processes due to its structure - the presence of a phenolic ring. It provides the exchange of phosphate groups, taking them from various proteins. This action ensures the maintenance of the phosphorylation reaction in the body, which is necessary for the catabolism of many substances, which is important in the function of cellular respiration.

Tyrosine is a precursor to many hormones. Medical research has shown that the amino acid is essential for the production of enough stress hormones such as adrenaline and norepinephrine. With good homeostasis, it increases the level of these neurotransmitters in the blood. Interestingly, when the mood is in order, the amino acid has no effect on it.

But in the case of stress, mood decline, tyrosine is the remedy, the key amino acid that activates the centers of the brain to improve mood and activate the cerebral cortex. It improves physical and cognitive abilities, eliminates emotional stress against the background of prolonged monotonous work, and improves appetite. The effect is more pronounced when taking large doses of the drug, which amounted to about 100 mg / kg, but such an amount of tyrosine is not recommended.

Let's take a closer look at the effect of tyrosine on individual organ systems.

Neurology

Since L-tyrosine is a precursor for the synthesis of norepinephrine and adrenaline, special attention must be paid to the nervous system.

• Memory.At the moment, there is no clearly proven effectiveness of the drug on memory function. But in the laboratory, studies have been conducted that indicate that the addition of tyrosine helped prevent the development of post-stress amnesia. IN real conditions there was a decrease in the likelihood of developing such a symptom against the background of a stressful situation.
• Attention... This phenomenon has also been insufficiently tested. But at this stage of the research, one can definitely note an improvement in concentration in people who took the supplement along with proper nutrition.
• Wakefulness. It has already been shown that taking tyrosine medications during sleep deprivation reduces the cognitive impairment caused by this situation. When taken, memory, concentration of attention improves, and drowsiness also decreases.
• Stress.This point should be given due attention, since tyrosine increases the concentration of the hormones catecholamines in the blood. Norepinephrine is known to be a stressor. This is a kind of protective reaction of the body in response to strong stimulation of the nervous system. Adequate intake of tyrosine has a milder effect on brain function under conditions of emotional overload. It reduces cognitive dysfunction, normalizes the speed of active thinking, and also reduces side effects stress (aggressiveness, tension and irritation). IN laboratory research the group taking the drug had a much milder "cold reaction".

Interestingly, L-tyrosine has an effect on the neurons in the brain. It is a powerful antioxidant and neuroprotective agent. Since catecholamines have a protective function for nerve tissue, tyrosine alleviates the manifestations of dementia.

The cardiovascular system

Tyrosine has a positive effect on arterial pressure... Long-term use of the drug provokes a persistent decrease in systolic and diastolic blood pressure against the background of hypertension. Normal comfort pressure numbers do not decrease.

It is noticed that taking tyrosine increases metabolism, and also has a fat burning effect.

Indications for use

The main indications for the use of tyrosine are neurological disorders... Since this is a dietary supplement, it can also be taken to prevent the development of certain conditions:

• neurosis;
• insomnia;
• stress;
• cognitive impairment;
• violation of concentration of attention;
• syndrome chronic fatigue;
• depression;
• nervous exhaustion;
• hyperactivity in childhood;
• vitiligo;
• vegetative vascular dystonia;
• parkinson's disease;
• erectile disfunction;
• phenylketonuria;
• improving the condition of the skin appendages;
• obesity.

Instructions for use

L-Tyrosine is taken half an hour before meals. This ensures better absorption of the drug and its bioavailability.

The drug must be taken one capsule at a time. The multiplicity of admission ranges from 1 to 3. It depends on the severity clinical manifestationsas well as the purpose of taking a dietary supplement. You need to drink a capsule with half a glass of pure non-carbonated water. An alternative can be unsweetened, weak tea.

It is worth paying close attention to the drug and not exceeding the indicated recommendations and dosages, as the risk of side effects increases.

Contraindications

Biologically active additives are not medicines, and yet have their own characteristics of impact on the body. Tyrosine is a fairly active amino acid, so there are a number of limitations.

1. It should not be used by people with individual intolerance to the components.
2. During pregnancy and lactation, it is also necessary to exclude the use of this drug, since the extra load on fragile organism a child - to nothing.
3. It is forbidden to take tyrosine with other antidepressants. Most of the representatives of this group of drugs belong to the group of monoamine oxidase inhibitors. They additionally affect the rate of dopamine metabolism in the brain.
4. In schizophrenia, taking the drug is also contraindicated, since the main basic therapy necessarily includes medicinesthat affect the metabolism of dopamine in the brain.
5. It is worth limiting admission to the age of 18.

Based on the feedback on the use of L-tyrosine, side effects usually occur when the instructions for use are not followed or the amino acid is overdose. This can be triggered by taking capsules against the background of an active intake of food with food. Overdose has the following side symptoms:

• allergic manifestations: itching, urticaria, hyperemia;
• headache;
• fatigue;
• insomnia;
• nausea;
• heartburn;
• epigastric pain.

It is worth remembering that uncontrolled intake of even a harmless biological supplement without first consulting a doctor can provoke a cascade of pathological processes that are difficult to treat.

The amino acid tyrosine is found in every cell in our body and is also found in many protein foods. It belongs to the nonessential amino acids. This means that the body healthy people produces the required amount of tyrosine to meet its needs.

general characteristics

Tyrosine, also known by its chemical name 4-hydroxyphenylalanine, is one of the 20 amino acids required for protein synthesis.

And since the human body is able to independently produce this substance, it is considered a nonessential amino acid. This means that a healthy person does not need additional supplements to provide themselves with the necessary amount of tyrosine. This amino acid influences many processes in the body, including the production of neurotransmitters.

The word "tyrosine" comes from the Greek and translates as "cheese". The amino acid got its name in 1846, when it was first discovered by the German chemist Liebig in casein, a protein found in cheese. And its chemical name indicates that tyrosine can also be synthesized from another amino acid, phenylalanine.

There are 3 forms of tyrosine: L-tyrosine is an amino acid found in proteins of all living organisms, D-tyrosine is a neurotransmitter found in enzymes, DL-tyrosine has no optical energy.

How it works in the body

IN human body tyrosine is made from another amino acid, phenylalanine, but the body metabolizes it in the form of catecholamines, in particular dopamine, norepinephrine, and adrenaline. These substances are able to correct neurophysiological processes such as attention, energy, mood, memory, alertness. Individuals with insufficient amounts of catecholamines experience all sorts of cognitive dysfunctions. And the only way to increase the synthesis of catecholamines is to eat foods high in tyrosine and phenylalanine (chicken, fish, turkey). To meet these needs, you can resort to dietary supplements and preparations containing tyrosine. True, in addition to a number of advantages, they also have a large number of side effects.

In the body, tyrosine is able to cross the blood-brain barrier and quickly penetrate into the central nervous system... By increasing the levels of adrenaline, norepinephrine and dopamine, tyrosine is able to influence a wide range of processes and functions in the body.

Another meaning of tyrosine is the production and synthesis of additional chemical substances and hormones such as melanin (the pigment that determines skin and hair color). Tyrosine also helps the organs responsible for the production and regulation of hormone levels in the body. And these are the adrenal glands, pituitary gland, thyroid gland. Also directly involved in the creation of almost all proteins in the body.

Positive properties of tyrosine:

• improves mood and creates a sense of subjective well-being;
• increases cognitive function during stress;
• protects the body from the effects of nervous shocks and anxiety;
• improves attention and invigorates;
• promotes the production of dopamine (the hormone of pleasure and happiness).

Functions in the body:

1. Protein synthesis.

One of the main roles of tyrosine is participation in protein synthesis. The human body uses combinations of 20 amino acids to build protein molecules, and tyrosine is one of them. Proteins have a number of functions in the body. Some control the activity of genes, while others promote chemical reactions or provide structural support for cells. The body's ability to synthesize proteins allows for the growth of new cells, which is especially important for newborns. And this is not a small merit of tyrosine.

1. Brain work.

By consuming tyrosine, you don't have to worry about brain problems. Tyrosine is needed to create the neurotransmitters dopamine and norepinephrine, the compounds that transmit impulses between neurons. Do you enjoy a cup of invigorating coffee in the morning? Well, without dopamine, you wouldn't feel it. Maybe you would be visited by some other sensations, but without the presence in the body of dopamine, created from tyrosine, you would have to forget about the sensations of pleasure. As for norepinephrine, it is, so to speak, a close chemical relative of adrenaline and is responsible for the development of memory. So, sitting in the morning with the same cup of coffee, you may be remembering something pleasant. And again, all this is the merit of the neurotransmitter, but this time already norepinephrine. So it turns out that without tyrosine, morning coffee (and not only that) would be many times sadder.

1. Stress and the nervous system.

One of the most interesting potential benefits of tyrosine is its ability to relieve stress. This function is also associated with the production of adrenaline and norepinephrine. A number of studies have confirmed that tyrosine mitigates the negative effects of not only stress, but also cold, relieves fatigue, especially after hard work, and even affects the quality of sleep. In addition, there is evidence that this amino acid improves mental performance and intellectual potential. May be effective remedy against depression, as dopamine helps to improve mood. It is also believed that tyrosine improves the transmission of impulses throughout the body. And scientists at New York University believe that tyrosine increases alertness, especially in sleepy people. But this assumption still requires additional study.

1. Melanin.

Tyrosine also has a number of physiological functions in the body. For example, this substance is involved in the production of melanin, a protein pigment that gives the skin its natural color and protects it from the sun.

1. Hormones.

The thyroid gland (which regulates metabolism and cell growth) and the pituitary gland (which controls reproductive health) are constantly exposed to tyrosine. By increasing the levels of the hormones norepinephrine and epinephrine, the amino acid is able to reduce fat storage and suppress excessive appetite.

Side effects

Taking tyrosine as a supplement can cause a number of unpleasant side effects. People with excessive activity should be treated with extreme caution. thyroid gland.

1. Anxiety.

Anxiety of unknown nature can be a side effect of tyrosine intake. This amino acid influences cognitive abilities and also acts as a central nervous system stimulant. And taking a pharmacy analogue of tyrosine can increase the frequency of impulses in the brain several times. An increased sense of fear and anxiety is a possible result of regular intake of the substance.

1. Digestive upset.

Tyrosine in the form of a dietary supplement affects the health of the digestive system. First of all, its not the best effect is felt by the mucous membrane of the digestive tract. Irritation from the amino acid causes stomach discomfort. If there are blood impurities in the stool, you should immediately stop taking tyrosine and see a doctor.

After hitting digestive system "Chemical" tyrosine reflux can develop. Due to the action of the amino acid, the sphincter in the alimentary canal relaxes and allows stomach contents back into the esophagus, causing heartburn and other unpleasant sensations.

1. Migraine.

Severe and prolonged migraine is one of the side effects of long-term intake of the amino acid. In this case, you should stop taking the drug containing tyrosine and replenish its reserves exclusively from natural food.

1. Tachycardia.

Fluttering in the chest can be caused by tyrosine, which stimulates the central nervous system to speed up and intensify the heartbeat.

1. Nervousness.

Influencing the nervous system, it can cause the development of nervousness, which appears, it would seem, for no reason. In fact, there is a reason - the body's inadmissibility of a preparation containing an amino acid.

1. Dependencies.

It is believed that tyrosine helps to more easily cope with addictions: caffeine, narcotic, medication.

Daily rate

Clinical studies show that supplemental tyrosine can be consumed up to 12 grams per day.

Meanwhile, doctors advise against resorting to such high doses unless urgently needed. Moreover, an adequate generally accepted daily intake for healthy people ranges between 1 and 5 grams of the substance (approximately 16 mg per 1 kg of human weight). This is quite enough for tyrosine to efficiently perform its functions in the body.

But people with excess weight, poor memory, abnormalities in the thyroid gland, a tendency to depression or hyperactivity need tyrosine more than healthy people. Also increase daily rate amino acids can help relieve unpleasant PMS symptoms, slow the progression of Parkinson's disease, and improve brain function. Individuals working physically or actively involved in sports should also take care of getting a slightly higher dose of tyrosine.

Elderly, hypertensive patients, people with low temperature body and digestive disorders, as well as with Felling's disease or using antidepressants, on the contrary, it is not advised to abuse supplements containing amino acid.

Overdose symptoms

Abnormal heart rate, irritability, anxiety, loss of appetite, changes in blood pressure (both up and down), chest pain, diarrhea, difficulty breathing, dizziness, drowsiness, fatigue, headaches, heartburn, insomnia, nausea, joint pain, allergic rash, stomach pain, thyroid dysfunction, weight loss. All this possible signs the fact that the body needs less amino acid intake.

Food sources

Tyrosine is found in many high-content foods, and there are over 100 items. Among the most popular are: chicken, turkey, fish, peanuts, almonds, avocados, milk, yogurt, bananas, soy products, and more. The amino acid is found in large quantities in seeds, seafood and beans. But, given that the name of the substance comes from the word "cheese", it is logical that it is in it that tyrosine should be looked for in the first place. Also found in many foods that promote the loss of excess weight.

In addition to these foods, you can get your daily intake of tyrosine and other health benefits from different types cheeses such as gruyere, edam, mozzarella, hard goat, cottage cheese. Among meat products, lamb and turkey dishes are also useful. The fish list for good health consists of tuna, mackerel, cod, halibut, and shrimp and crab. As a snack, you should choose healthy sesame seeds, sunflower seeds, pistachios, almonds, pine nuts. In the dairy section, give preference to natural yoghurts and milk. Lentils, various types of beans, chickpeas, and whole grain foods, which also have an increased concentration of tyrosine, will help improve memory and mood.

Digestibility

The body will better absorb the amino acid if:

• take on an empty stomach in combination with vitamins B1, B2, B3, B6, C (tyrosine can be diluted with orange juice) and in combination with the enzyme tyrosine hydroxylase;
• drink together with St. John's wort, valerian, lemon balm, chamomile, mint (in this case, the effect on the nervous system increases).

Interaction with other substances

Tyrosine with monoamine oxidase inhibitors can raise blood pressure and, in some cases, cause heart attack or stroke. Taking thyroid hormones in combination with an amino acid can cause hyperthyroidism. But with, ascorbic acid, niacin and reacts positively.

Tyrosine is one of the most important amino acids and an integral part of structural proteins. It can be used to enhance memory and strengthen the immune system. But inappropriate consumption leads to hyperthyroidism and other problems.

This amino acid can rightfully be considered a remedy for sadness and depression, a substance that adds strength, energy, mental and physical activity. But in order to achieve these effects, it is not necessary to resort to pharmaceutical preparations. Nature has everything so that a person can fully draw on amino acid reserves from natural food. Moreover, in this case, they almost never cause side effects.

Which is produced in the body and is present in various products nutrition. It is used as a dietary supplement to treat a variety of medical conditions, but it should be avoided by people with certain medical conditions or taking certain medications.

People who are tyrosine deficient but cannot significantly increase their nutrient intake from food should take tyrosine as food additives... Natural sources of this amino acid are dairy products, eggs, fish, oatmeal, wheat, legumes, and nuts. Tyrosine formulations are available in both capsule and powder form.

If you are allergic to nuts, yeast, wheat protein, seafood, lactose, or soy, you should make sure that the tyrosine preparation you are taking does not contain the listed ingredients. Vegetarians and vegans should look for animal-free supplements, as some tyrosine formulations may contain organ meats.

Tyrosine: beneficial properties

If you suffer from phenylketonuria, tyrosine supplements are definitely useful for you. Phenylketonuria - hereditary diseasein which the body cannot synthesize its own tyrosine. And since tyrosine is the most important amino acid our body needs, doctors recommend that their patients increase their nutrient intake through dietary supplements.

An increase in the concentration of tyrosine in the body is accompanied by an increase in the acuity of perception and focus; this means tyrosine preparations can help insomniacs stay alert and energized throughout the day. Tyrosine may also be helpful in treating certain forms of depression and attention deficit disorder in both adults and children.

There are many other possible but unproven useful properties tyrosine. Potential uses of the nutrient include Alzheimer's disease, chronic fatigue syndrome, erectile dysfunction, cardiac disease, premenstrual syndrome, and Parkinson's disease. Tyrosine may also be helpful in treating schizophrenia.

Among other useful properties of tyrosine, it is also mentioned that it prevents or slows down skin aging. Tyrosine preparations, which are used in the form of a cream, will help you get rid of wrinkles and restore tone skin, and at the same time return a healthy color to the skin damaged by the active summer sun.

Tyrosine: side effects

Typically, adults can safely take small amounts of tyrosine without fear of side effects. However, the recommended dosage regimen should still be followed. Although not everyone faces the negative effects of taking a nutrient, the likelihood of side effects, including headache, heartburn, and nausea, cannot be completely ruled out. Also, taking tyrosine can provoke arthralgia.

Despite the fact that tyrosine drugs increase concentration and sharpening of perception, some people are faced with the opposite side effect and experience increased fatigue. Until you understand exactly how your body reacts to tyrosine, we recommend avoiding administration vehicles after taking the nutrient.

It is not safe for children to take tyrosine-based supplements. Until there are definitive results from relevant research, you should not give tyrosine to a child without a doctor's approval. As with most drugs, the effects of tyrosine on pregnant or breastfeeding women have not been studied, so it is best to refrain from taking the nutrient during gestation and lactation.

An increase in thyroxine synthesis is a side effect of taking tyrosine. The increase in thyroxine production can aggravate the course of hyperthyroidism and Graves' disease. If you have been diagnosed with a thyroid disorder, you should not take tyrosine medications without your doctor's approval.

If you are taking thyroid medications or the drug levodopa, which is usually used to treat Parkinson's disease, you should not start taking tyrosine-based supplements. The interaction of tyrosine with these drugs can reduce the effectiveness or increase the severity of the side effects of drug therapy.

Tyrosine: method of administration

The single and daily dose of tyrosine is largely determined by the reasons that prompted you to take this nutrient. You can follow the recommendations on the package, or you can consult your doctor or pharmacist about the dosage regimen.

People who have insomnia and take tyrosine in the morning after a sleepless night may need 150 mg of tyrosine per day. This is the maximum dose usually given by an adult. It should also be borne in mind that although you can take tyrosine at 150 mg per day, it is recommended to limit the course of taking the drug to three months.

In phenylketonuria, the recommended dose of tyrosine can vary over a wide range, reaching 6 grams for every 100 grams of protein consumed. It is important to consult with your doctor in order to choose the appropriate dose for the treatment of phenylketonuria and at the same time to avoid the development of unwanted side effects.

Some tyrosine drug manufacturers recommend taking 5 grams of this amino acid twice a day. Taking 10 grams per day is believed to increase endurance and thereby boost athletic performance.

If you are taking tyrosine to increase your workout performance while trying to reduce body weight, then taking the drug will guarantee you adequate thyroid function and maximum training efficiency.

Tyrosine is a representative of essential amino acids that the human body receives exclusively from food. For muscle growthL -tyrosine has no direct effect, but it has numerous other properties useful for athletes and just for all people.

Unlike many other essential amino acids, the human body can synthesize tyrosine, but this process is associated with another amino acid - phenylalanine. With a lack of phenylalanine, tyrosine is not able to form in the required amount. Therefore, L-tyrosine is vital for people with phenylketonuria, a disorder of phenylalanine metabolism. The diet of such people does not include foods containing phenylalanine, so as not to exacerbate the disease. So a person with phenylketonuria receives little phenylalanine, which means that tyrosine in his body is in short supply, which can only be eliminated by eating it.

Tyrosine has an effect on tissues and cells, both directly and indirectly, due to the effect on the functions of the pituitary gland, thyroid gland and adrenal glands. This leads to a change in metabolic processes and the normalization of physical condition.

The importance of the hormones triiodothyronine and thyroxine, produced by the thyroid gland, is widely known in bodybuilding and other sports. From a physiological point of view, both of these hormones are regulators of the metabolism of fats, carbohydrates and proteins and affect the metabolic rate. These hormones actively influence the development and growth of the body, and also regulate the heart rate, water-salt balance and body temperature. Since neither triiodothyronine nor thyroxine can be synthesized without the presence of tyrosine in sufficient quantities, the high importance of this amino acid becomes visible.

The production of the "hormone of happiness"

Tyrosine can act as a precursor to dopamine, which is responsible for regulating renal excretory function and blood pressure. Popularly, this hormone is often called "the hormone of happiness", because when its level in the brain increases, mood improves. This is due to the fact that dopamine is converted into norepinephrine, which, being concentrated in the brain, provides the effect of increasing mood. Therefore, tyrosine can be used to treat a number of depressive conditions.

Tyrosine, together with adrenaline and norepinephrine, not only affect mood, but also provide energy metabolism. But if the amount of tyrosine is sufficient, the maximum effect of these hormones on lipolysis, glucose mobilization and activation of the nervous sympathetic system... It also suggests that many people depend on the availability of sufficient reserves of tyrosine in the body. important processes in the body.

Athletes often use a mixture of aspirin, caffeine and ephedrine, also called ECA. If tyrosine is added to its composition, the effectiveness of the effect increases. But at the same time side effects this composition does not decrease, and it is necessary to use such an "explosive mixture" only under careful monitoring of the state of health. For those who are contraindicated in caffeine, tyrosine supplements should also be avoided. It is better to refuse the use of ECA altogether, especially since there are safe fat burners.

As many athletes say, tyrosine use has a positive effect on concentration and motivation. Therefore, tyrosine is used not only by athletes in pursuit of high sports results, but also by ordinary people, for example, managers or workers. This amino acid is useful for overcoming the bouts of depression and raising the "spiritual tone".

The use of tyrosine supplements by athletes in sports requiring extreme endurance results in later fatigue. True, the effects of tyrosine are still not well understood. Athletes who have tried tyrosine for weight loss report that it leads to decreased appetite.

Dosages when taking

A single dose of tyrosine is usually in the range of 5-10 grams. It is with this dose that you can start taking it, especially since it does not cause any side effects. It is advisable not to take more than 10 grams at a time, so as not to cause an imbalance in amino acid metabolism.

With a total dose of tyrosine of more than 1450 mg per kilogram of body weight, its toxic effect may manifest itself. For a bodybuilder weighing 80 kilograms, this means 115 grams per day. Single 5-gram doses taken several times a day will remain harmless.

Even for those who do not play sports, but simply want to have tanned skin and a spectacular appearance, tyrosine can be useful. This determines the moment that the synthesis of melanin, a pigment that stains the skin in a dark color, also depends on tyrosine. By taking 5 grams of tyrosine before going to the solarium, you can ensure the formation of melanin in an amount sufficient for a beautiful tan. Bodybuilders do just that before competing.

Those who do not want to use tyrosine in the form of various supplements can be recommended to add foods in which it is found in its natural form to their diet. Good sources of tyrosine include milk protein, egg yolk, beans, peanuts, cheese, and chocolate. It is important to keep in mind that after taking tyrosine, short-term effects of increasing motivation and the ability to concentrate are possible. The effect of stimulants taken together with it is enhanced. It is undesirable to take caffeine and alcohol together with tyrosine.

Tyrosine can be considered an amino acid that is beneficial for everyone, not just bodybuilders. Tyrosine can be used by people seeking to lose weight and those suffering from depression to achieve their goals.

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Tyrosine, which can also be synthesized in the body from, is found in many protein-rich food productssuch as chicken, turkey, fish, peanuts, almonds, avocado, milk, cheese, yogurt, cottage cheese, beans, pumpkin seeds, sesame seeds, bananas, and soy products.

Biosynthesis

Plants and most microorganisms produce tyrosine via prefenate, an intermediate in the shikimate biosynthetic pathway. The prefenate is oxidatively decarboxylated while retaining the hydroxyl group to produce p-hydroxyphenylpyruvate, which is transaminated using glutamate as a nitrogen source, resulting in tyrosine and alpha-CH. Mammals synthesize tyrosine from essential amino acid (Phe) obtained from food. The conversion to tyrosine is catalyzed by the enzyme hydroxylase, a monooxygenase. This enzyme catalyzes the reaction by causing the addition of a hydroxyl group to the end of the 6-carbon of the aromatic ring, which ultimately creates tyrosine.

Metabolism

Phosphorylation and sulfation

Some of the tyrosine residues can be combined into a phosphate group (i.e., phosphorylated) via protein kinase. The phosphorylated form of tyrosine is called phosphotyrosine. Phosphorylation of tyrosine is considered one of the key steps in signal transduction and regulation of enzymatic activity. Phosphotyrosine can be detected using specific antibodies. Tyrosine residues can also be modified by adding a sulfate group, a process known as tyrosine sulfation. Tyrosine sulfation is catalyzed by tyrosyl protein sulfotransferase (TPST). Like the phosphotyrosine antibodies discussed above, antibodies capable of detecting sulfothyrosine have recently been described.

Precursor to neurotransmitters and hormones

In the dopaminergic cells of the brain, tyrosine is converted to by the action of the enzyme tyrosine hydroxylase (TH). TH is a rate-limiting enzyme involved in the synthesis of the neurotransmitter dopamine. Dopamine can then be converted to catecholamine norepinephrine and epinephrine. The thyroid hormones triiodothyronine (T3) and thyroxine (T4) in the thyroid colloid system are also produced from tyrosine.

Precursor to alkaloids

The milky sap of the Papaver Somniferum plant (opium poppy) is able to convert tyrosine to morphine, and this bio-pathway is carried out with the participation of carbon-14 radioactively labeled tyrosine in order to trace all synthesis in vivo. A producing cactus is capable of biosynthesizing tyrosine into mescaline when administered by injection.

Precursor to natural phenols

Tyrosine ammonia lyase (TAL) is an enzyme in the metabolic pathway of biosynthesis of natural phenols. It converts L-tyrosine to p-coumaric acid.

Pigment precursor

Tyrosine is also a precursor of the pigment melanin.

Decay

The degradation of L-tyrosine (synonymous with para-hydroxyphenylanine) begins with transamination, depending on a-ketoglutarate via tyrosine transaminase, into para-hydroxyphenylpyruvate. “Para,” abbreviated p, means that the hydroxyl groups and side chains on the phenyl ring are opposite each other. In the next step, oxidation, p-hydroxyphenylpyruvate-dioxygenase is catalyzed and the CO2 homogentisate (2,5-dihydroxyphenylacetic acid) is eliminated. In order to separate the homogentisate from the aromatic ring, further dioxygenase, homogentisate oxygenase, is required. Thus, by incorporating the O2 molecule, maleyl acetoacetate is created. Furamyl acetate is created by maleyl acetoacetate-cis-trans isomerase by rotation of the carboxyl group created from the hydroxyl group by oxidation. This cis-trans isomerase is used as a coenzyme. Furamylacetoacetate is finally cleaved by furamylacetoacetate hydrolase by the addition of a water molecule. This releases fumarate (which is also a metabolite in the citric acid cycle) and acetoacetate (3-ketobuturate). Acetoacetate is a ketone body that is activated by succinyl-CoA, and then can be converted to acetyl-CoA, which in turn can be oxidized by the citric acid cycle or used to synthesize fatty acids. Floretinic acid is also a urinary tyrosine metabolite in rats.

Betaines

Ortho and meta tyrosine

There are three isomers of tyrosine. In addition to total L-tyrosine, which is a para-isomer (para-tyrosine, p-tyrosine, or 4-hydroxyphenylalanine), there are two additional regioisomers, namely meta-tyrosine (m-tyrosine or 3-hydroxyphenylalanine or Lm-tyrosine ) and ortho-tyrosine (o-tyrosine or 2-hydroxyphenylalanine), which occur naturally. M-tyrosine and o-tyrosine, rather rare isomers, arise as a result of non-enzymatic free radical hydroxylation under conditions of oxidative stress. M-tyrosine and its analogs (rare in nature, but synthetically available) are used in the treatment of Parkinson's disease, Alzheimer's disease and arthritis.

Medical Uses of Tyrosine

Tyrosine is a precursor to several neurotransmitters. It increases plasma levels of neurotransmitters (particularly dopamine and norepinephrine), but has little or no effect on mood. The effect on mood is more noticeable in people under stress. Several studies have shown that tyrosine can be used in situations such as stress, cold, fatigue, loss of a loved one (death or divorce), prolonged work and sleep deprivation, as it causes a decrease in the levels of stress hormones, reduces stress-induced loss weight, which has been proven in animal tests; and also improves cognitive and physical performance in human trials. However, due to the fact that tyrosine hydroxylase is a rate-limiting enzyme, tyrosine exhibits less effects than L-dopa. Under normal conditions, Tyrosine has no significant effect on mood, cognitive function, or physical performance. The daily dose for clinical analysis reported in the literature is about 100 mg / kg for an adult, that is, about 6.8 grams per 150 lbs. The usual dosage is up to 500-1500 mg per day (the dose suggested by most manufacturers is usually equivalent to 1-3 capsules of pure tyrosine). It is not recommended to exceed the dose of 12,000 mg (12 g) per day. In fact, excessive dosages cause a decrease in dopamine levels in the body. Tyrosine can decrease absorption of other amino acids at high or chronic doses. This reduces the absorption of L-dopa.

Pharmacology

Serum

150 mg / kg of L-tyrosine mixed with applesauce can increase the plasma L-tyrosine concentration from 56.3 nmol / L (baseline) to 140-168 nmol / L within 90 minutes. The readings remained within this concentration until the termination of measurements at 150 minutes. The significant difference from placebo lasted for 30 minutes and was approximately 80 nmol / L. These changes in plasma tyrosine concentration were not compared with the increase in plasma norepinephrine levels, which was similar in different groups. A similar spike in serum tyrosine was noted in rats (serum was not tested for norepinephrine), and the increase in serum tyrosine lasted 4 hours, and then the values \u200b\u200breturned to their baseline level. Tyrosine is rapidly absorbed from the intestines into the bloodstream, and is kept at a high level for 2-4 hours after ingestion.

Effects on the body

Neurology

Mechanisms

Since L-tyrosine acts as a precursor of the neurotransmitters norepinephrine and dopamine, it directly accelerates the synthesis of catecholamines.

Memory

L-Tyrosine (200-400mg / kg) can significantly increase the concentration of norepinephrine (also known as norepinephrine or NE) in the pituitary gland and prevent an acute decrease in the concentration of NE in cold-exposed rats. This may be because L-Tyrosine may reverse stress-induced memory loss in humans while the body is in cold conditions. This study (n \u003d 8) showed that 150 mg / kg L-tyrosine (dissolved in applesauce, consumed by mouth, with the placebo group given just applesauce without additives) was performed in a room where the temperature was reduced from 22 ° C up to +4 ° С. Test subjects who were given L-tyrosine coped with the task in a shorter period of time and increased the number of correct answers in cold conditions. However, when changing temperatures to higher temperatures, the difference between the groups was less pronounced (L-tyrosine did not contribute to further improvement in performance). There is currently no evidence that L-Tyrosine supplementation can improve memory function over baseline, but under stress it can alleviate memory impairment.

Attention

A study in children diagnosed with ADHD showed that a combination of tyrosine and 5-HTP supplementation (doses were titrated, with the lowest content being 1,500mg tyrosine and 150mg 5-HTP, and the highest being 3,750mg and 425mg, respectively). that supplementation resulted in a significant reduction in symptoms as measured by ADHD-RS; this study also used a number of other nutrients (1000 mg, 220 mg calcium citrate, 75 mg vitamin B6, 400 mcg, 500 mg, 2,500-4,500 mg and 200-400 mg). Although L-Tyrosine significantly improves alertness, this has not been sufficiently tested to date. Only isolated cases were considered, so it is impossible to determine with certainty what its effect is.

Cheerfulness

A study of L-tyrosine, which used “prolonged wakefulness,” showed that 150 mg / kg L-tyrosine attenuated the cognitive decline associated with sleep deprivation. L-Tyrosine can improve cognitive function during insomnia without significantly affecting sleep.

Stress

Acute uncontrolled tension, which can deplete the concentration of norepinephrine (NE) in the nervous tissue, especially in the hypothalamus and brain stem (containing blue spots), and behavioral changes associated with the depletion of NE were recorded in the study of animal behavior, which manifested itself as an escape, spontaneous physical activity, aggressive behavior, and swimming. Short-term uncontrolled stress is a phenomenon due to which the level of norepinephrine in the nervous tissue, especially in the hypothalamus and brain stem... In animals, a lack of norepinephrine leads to the development of spontaneous motor activity, behavior associated with evasion and avoidance, and aggressive behavior. Taking L-tyrosine can mitigate the development of behavioral abnormalities associated with acute uncontrollable stress factors in laboratory animals, in the dose range of 200-400 mg / kg (oral or intravenous) 30-60 minutes before the stressful situation. L-Tyrosine mitigates some of the overt signs of acute and uncontrollable stress (as opposed to adaptogenic molecules that may be effective against chronic and controlled stress). Some studies have been conducted specifically under conditions of cold stress (called "cold therapy"). A dose-dependent decrease in immobility time was noted in mice using injection of 200-400 mg / kg L-tyrosine or 5-20 mg / kg phenylpropanolamine. Tyrosine synergistically reduced immobility time when taken with either phenylpropanolamine or amphetamine. These effects correlate with the concentration of norepinephrine in the pituitary gland, which is maintained at the proper level with the use of L-tyrosine. These protective effects have been noted in human studies. This supplement also reduces the negative effects of cold stress, and there is evidence from human studies (effects on memory function). One human study found high level protective action of L-tyrosine against acute stress. There was a decrease in symptoms of acute overexertion, while taking 100 mg / kg L-tyrosine (in two doses, at intervals of an hour) was associated with a decrease in headache, stress, fatigue, apathy, drowsiness, muscle pain... This study also noted improvements (relative to placebo) in general indicators mood and happiness and cognitive performance. Similar studies using the same oral dose after intense noise stress have noted a rapid reduction in acute stress. In a study with a week of strength training, there was a positive effect of stress relief in subjects using 42 g of protein (2 g of which was tyrosine), there was a preservation of cognitive function, but there was no significant improvement in mood in the subjects.

Aging neurons

Increasing the level of L-tyrosine in the brain is currently being considered as a pharmaceutical method for alleviating neurological impairment, since a decrease in catecholamines is associated with dementia. Surprisingly, catecholamines are neuroprotective and may act as antioxidants in the brain.

Cardiovascular diseases

Arterial pressure

When 150 mg / kg L-tyrosine was taken prior to the cognitive test (under acute stress), there was no significant effect on blood pressure or on the spike in blood pressure caused by acute stress. Testing of cadets in combat training who consumed 42 grams of protein (2 grams of tyrosine was mixed with others) found that the supplement reduced systolic blood pressure by 10.4% from baseline. The placebo group experienced smaller and minor reductions in blood pressure. No significant changes were noted in diastolic pressure, however, a downward trend was noted. In another study with acute noise stress, it was found that taking L-tyrosine reduced diastolic blood pressure within 15 minutes after taking the drug orally at a dose of 100 mg / kg. This decrease in diastolic blood pressure has been noted previously in animal studies. Although there is not enough reliable data on the drug, L-tyrosine appears to be ineffective in lowering blood pressure. The studies were conducted under stress conditions (high blood pressure), therefore the effects of L-tyrosine cannot be considered in isolation from the characteristics of the body's responses to stress.