Open classification: medicine, leukotrienes
Product name: leukotriene
Pinyin: Bai Sanxi
English name: leukotriene letter message
Description: The eicosapentaenoic acid with conjugated triene structure is separated from the metabolites of arachidonic acid in white blood cells. According to the nature of substituents, it can be divided into six categories: A, B, C, D, E and F, in which the structure of LTA3 is 200 1 subscript 3 represents the total number of double bonds in the carbon chain. LTA4 is 5,6-epoxy-7,9, 1 1, 14- eicosatetraenoic acid; LTB4 is 5, 12- dihydroxy-6,8, 10, 14- eicosatetraenoic acid; LTC4 is 5- hydroxy -6-S- glutathione-7,9, 1 1, 14- eicosatetraenoic acid; LTD4, LTE4 and LTF4 are similar to LTC4, except that the 6-position substituent LTD4 does not contain glutamic acid, LTF4 does not contain glycine, LTE4 only contains cysteine, and other leukotrienes are similarly named. Leukotrienes can be prepared from arachidonic acid catalyzed by lipoxygenase. Although the content in the body is small, it has high physiological activity and is a chemical mediator in some allergic reactions, inflammation and cardiovascular diseases. The study of leukotriene and its analogues blockers is of great significance to the treatment of immunity, inflammation and allergy.
Biological function: increase the permeability of capillaries and venules, resulting in local edema.
Energy-rich phosphate compounds.
There are many phosphate compounds in the body, such as ATP, 3- phosphoglyceric acid, carbamoyl phosphate, phosphoenolpyruvate, creatine phosphate, arginine phosphate and so on. When their phosphate groups are hydrolyzed, they can release a lot of free energy. These compounds are called high-energy phosphate compounds. ATP is a typical representative of this kind of compounds. When ATP is hydrolyzed into ADP and inorganic phosphoric acid, it can release 7.3 kilocalories (30.52 kilojoules) of free energy. Generally, the free energy released during hydrolysis is above 5.0 kilocalories (20.9 kilojoules), which is called high-energy compound. Compounds below 5.0 kcal are called low-energy compounds. Chemists believe that bond energy refers to the energy required to break a bond, while biochemists refer to the free energy released by hydrolysis of compounds containing high-energy bonds. High-energy bonds are represented by "~".
In the energy metabolism of organisms, ATP is the most critical high-energy compound and a direct energy supplier in life activities. When organisms need to use energy, they are all obtained from the hydrolysis of high-energy compound ATP. ATP can be produced in two ways: substrate level phosphorylation and oxidative phosphorylation (electron transfer level phosphorylation).
File 1: What is creatine?
Creatine is a natural nutrient in human body, which consists of three essential amino acids: arginine, glycine and methionine. It is essential for the production of adenosine triphosphate (ATP), the energy of human cells, and can provide rapid and explosive exercise for muscles. About 95% of creatine in human body is concentrated in skeletal muscle, and B is in heart, brain and testis. The human body can obtain creatine from general food or nutritional supplements; If the creatine content in the body is insufficient, the human body can also synthesize a small amount of creatine by itself through the liver, pancreas and kidney for use.
Document 2: Basic Functions of Creatine
1. Increase the water content of muscle cells:
When you first start using creatine, you will obviously feel that your muscles are getting bigger and stronger. This is because creatine can make muscle cells of human body store a lot of water; When all muscle cells absorb more water and increase their volume, muscles will naturally become fuller and more tangible.
2. Help muscle cells store energy:
There are two different forms of creatine in human muscle fibers: unbound creatine and phosphocreatine, of which phosphocreatine accounts for about two-thirds of the total creatine. When muscles contract to produce exercise, the body uses a compound called ATP as an energy source. Unfortunately, human muscle cells can only provide ATP energy for rapid contraction in less than ten seconds, and more ATP must be produced to maintain continuous exercise. At this time, creatine phosphate stored in muscle will sacrifice its own phosphate and make ATP biosynthesis again. Therefore, if there is more creatine in muscle, muscle will have greater potential power to play.
In addition, creatine supplementation can also help the tired muscle cells recover their vitality, because when the ATP energy in the muscle is exhausted, the body will activate another ATP production system (glycolysis) to produce lactic acid. When the body is exercising vigorously, a lot of lactic acid will make muscles feel sore and tired; At this time, if more creatine phosphate can be stored in the muscle to provide ATP, the body will reduce the production of lactic acid and reduce the fatigue of muscle cells, so that we can exercise more persistently and explosively.
3. Increase biosynthesis in protein:
The intake of creatine can make the body use more protein to grow muscles. And two protein structures in muscle; Actin and myosin are the most important components that make muscle fibers contract and produce movement. Therefore, if we can supplement enough creatine, let the body reduce protein's energy consumption and synthesize more actin and myosin cells, muscles will naturally become stronger and stronger.
File 3; Who is creatine good for?
Anyone, at any age, who wants to gain muscle, increase explosive power and muscle endurance during exercise, or just want to be stronger can benefit from the use of creatine. Although there is not much research on creatine to improve various sports performance at present, according to the existing research reports, athletes who need explosive force or instantaneous action can get the greatest benefit from creatine. Some sports, such as bodybuilding, weightlifting, sprinting, swimming, baseball, rugby and even martial arts, wrestling and so on. It is often necessary to make dynamic actions of instantaneous overload, so if muscles can get the maximum energy in a short time through creatine supplementation, their relative explosive power and sports performance will definitely improve a lot.
On the other hand, creatine has not been proved by scientists to be beneficial to endurance sports such as marathon and free car. However, studies have confirmed that we can delay fatigue and reduce the accumulation of lactic acid after exercise by increasing the utilization rate of creatine, thus reducing fatigue and shortening recovery time.
File 4; Can I get enough creatine from food?
Generally speaking, the average person's daily intake of creatine is1~ 2g, but the demand for creatine is far greater than this figure for people who often exercise or exercise. Creatine mainly exists in animal foods such as meat and fish, and the content of plant foods is quite small; In addition, excessive cooking can also destroy the creatine content in food. We can get about 1 g of creatine from our diet every day on average.
It should be noted that although creatine can be ingested from a large number of animal foods, it is usually mixed with a large amount of oil and cholesterol (such as beef and pork), which will do harm to our health. Therefore, the best intake method is to use defatted and cholesterol-free creatine monohydrate.
File 5; Is creatine safe?
Creatine is metabolized into creatinine through the kidney in the body. Can taking too much lead to renal insufficiency? At present, scientists have confirmed that taking 20 grams of creatine every day has no side effects on human body. The only finding is that when the body load is exceeded, diarrhea will occur, but this diarrhea will stop with the decrease of dose; Creatine is indeed safe and reliable for other steroid enhancers that may cause serious side effects.
A compound composed of creatine and phosphoric acid, which is a temporary storage form of high-energy phosphate groups, exists in muscles and other excited tissues, such as brain and nerve cells. In vertebrates, creatine reacts with ATP to reversibly produce creatine phosphate, which is catalyzed by creatine kinase.
The function of creatine phosphate is to maintain a high ATP level in muscles, especially skeletal muscles. When the cell is at rest and the ATP concentration is relatively high, the reaction proceeds towards the net synthesis of creatine phosphate. When cells have high metabolic activity and low ATP concentration, the equilibrium shifts to the net synthesis of ATP. Therefore, creatine phosphate plays a role in tissues containing creatine kinase. Usually, vertebrates have enough creatine phosphate in their skeletal muscle at rest, which can provide their free energy demand for a few minutes (but only a few seconds at the maximum). Arginine phosphate has the same function as creatine phosphate in the muscles of some invertebrates, such as crabs.
Norepinephrine
Open classification: medicine, pharmacology, adrenergic drugs, α receptor agonists.
The original text can also be written as norepinephrine or l-arterenol, which is a hormone extracted from the medulla of accessory kidney together with adrenaline (in a broad sense). In mammals, it is secreted from the end of sympathetic nerve as a chemical transmission substance. It is a substance that removes N- methyl from adrenaline. The contents of norepinephrine and epinephrine in the medulla of bovine accessory kidney were 1∶4( 1 norepinephrine, 4 epinephrine). Epinephrine on the market contains 10-20% norepinephrine. Its function is similar to that of adrenaline shown in the table, but it is slightly different in quantity and or quality. Norepinephrine is converted into epinephrine by demethylation, which requires the presence of enzymes and ATP in the accessory kidney. Many chromaffin tissues outside the medulla can also secrete norepinephrine.
Norepinephrine is a vasoconstrictor and a positive inotropic agent. The cardiac output can increase or decrease after drug action, and the result depends on vascular resistance, left ventricular function and various reflexes, such as carotid baroreceptor reflex.
Norepinephrine often causes renal and mesenteric vasoconstriction. Severe hypotension (systolic blood pressure
Specific usage of norepinephrine: Add 4 mg of norepinephrine or 8 mg of norepinephrine bitartrate (the potency of 2 mg of norepinephrine bitartrate is the same as that of 1 mg of norepinephrine) into 250 ml of balanced solution with or without salt to prepare 16 μ g/ml of norepinephrine solution or 32 μ g/ml of norepinephrine bitartrate solution. The initial dose of norepinephrine was 0.5- 1.0ug/ min, and gradually adjusted to the effective dose. Patients with intractable shock need 8-30ug/ min of norepinephrine. It should be noted that the alkaline liquid cannot be administered in the same infusion tube during administration, which will inactivate the drug. In case of drug leakage, 10- 15ml physiological saline containing 5- 10mg phentolamine should be given as soon as possible to avoid necrosis and tissue shedding.
Function: It mainly excites α receptor, but has a weak effect on β receptor, and has a strong vasoconstrictive effect, which makes the arterioles and venules of the whole body contract (but the coronary vessels expand), the peripheral resistance increases, and the blood pressure increases. Stimulating the heart and inhibiting smooth muscle are weaker than adrenaline. Clinically, it is mainly used for intravenous infusion of various shocks (but hemorrhagic shock is forbidden) to raise blood pressure and ensure blood supply to important organs (such as brain). & lt/P & gt； The use time of<P> should not be too long, otherwise it will cause continuous strong contraction of blood vessels and aggravate tissue hypoxia. Using phentolamine to resist excessive vasoconstriction can usually improve tissue blood supply during shock.
Administration and dosage: (1) intravenous drip: dilute before use, drip 4 ~ 10μ g per minute, and adjust the dosage according to the condition. 1 ~ 2 mg can be added with normal saline or 5% glucose 100ml for intravenous drip, and the dropping speed can be controlled according to the situation. After the blood pressure rises to the required level, it can slow down the dripping speed and keep the blood pressure within the normal range. If the effect is not good, switch to other antihypertensive drugs. For critical cases, 1 ~ 2 mg can be diluted to 10 ~ 20 ml, and slowly pushed into the vein, and the dosage can be adjusted according to blood pressure. Once blood pressure rises, it is maintained by intravenous drip. & lt/P & gt； & ltP & gt(2) Oral administration: To treat upper gastrointestinal bleeding, inject 1 ~ 3 ml (1 ~ 3 mg) each time, three times a day, and add appropriate amount of cold physiological saline. & lt/P & gt； & ltP & gt
Precautions: (1) If you continue to use this product or other vasoconstrictors for a long time in the rescue process, important organs such as heart and kidney will be adversely affected by poor capillary perfusion, and even lead to irreversible shock, which should be paid attention to.
(2) Patients with hypertension, arteriosclerosis and anuria are contraindicated.
(3) This product will gradually change color when exposed to light, so it should be stored away from light. If the injection is brown or precipitated, it should not be used again.
(4) It should not be injected with weakly alkaline drugs such as sulfadiazine sodium and aminophylline to avoid failure; In alkaline solution, if you encounter drugs containing iron ion impurities (such as sodium glutamate, sodium lactate, etc. ), it will turn purple, reducing the boost effect.
(5) When the concentration is high, reactive vasospasm and local skin pallor will appear in and around the injection area, which may cause ischemic necrosis for a long time. Therefore, it is necessary to prevent the leakage of liquid medicine during drip, and take measures to relieve pressure (such as cotton pad) before drip. If necrosis is found, except vasodilator, it should be hot compressed as soon as possible and blocked with large dose of procaine. Children should choose thick intravenous injection and change the injection site. Intravenous injection must prevent liquid medicine from leaking from blood vessels.
(6) Blood pressure should be measured at any time during medication, and the administration speed should be adjusted to keep blood pressure within the normal range.
(7) See adrenaline for others.
5- HT
Open classification: chemistry, compound, organic matter
5- HT
Indole derivatives The molecular formula is C 10H 12N2O. It is ubiquitous in animal and plant tissues.
Tryptophan is catalyzed by tryptophan hydroxylase to produce 5- hydroxytryptophan, which is then catalyzed by 5- hydroxytryptophan decarboxylase to produce 5- hydroxytryptamine.
Serotonin, also known as serotonin, was first found in serum and widely exists in mammalian tissues, especially in cerebral cortex and synapses. It is also an inhibitory neurotransmitter. In peripheral tissues, serotonin is a strong vasoconstrictor and a stimulator of smooth muscle contraction. In vivo, serotonin can be catalyzed by monoamine oxidase to produce serotonin and 5- hydroxyindoleacetic acid, which are excreted with urine.
5- hydroxytryptamine can react with acids to form crystalline salts. The melting point of its hydrochloride is167 ~168℃; The melting point of picrate is 185 ~ 189℃. The concentration of 5- hydroxytryptamine in brain tissue is high, which is an important substance to regulate nerve activity. When affected by certain drugs, some body tissues can release 5- hydroxytryptamine. For example, a reserpine molecule can release hundreds of serotonin molecules from the affected tissues, thus producing a series of physiological effects of reserpine.
As a self-active substance, about 90% is synthesized and distributed in intestinal chromaffin cells, and is usually stored in cell particles together with ATP and other substances. Under the action of stimulating factors, 5-HT is released from granules, diffused into blood, absorbed and stored by platelets, accounting for about 8% of the whole body. As a neurotransmitter, 5-HT is mainly distributed in the pineal gland and hypothalamus, and may be involved in the regulation of physiological functions such as pain, sleep and body temperature. The abnormal content and function of 5-HT in the central nervous system may be related to the onset of many diseases such as psychosis and migraine.
5-HT must be mediated by the corresponding receptor to play its role. The typing of 5-HT receptor is complex, and 7 subtypes have been found. 5-HT has different pharmacological effects by exciting different subtypes of 5-HT receptor, but 5-HT itself has no clinical application value.
spy
Open classification: chemistry, unit, Islam, physical quantity, middle ages
spy
Mole is the unit to express the quantity of matter, and each mole of matter contains Avon Gadereau constant particles.
Moore is called Mo for short, and the symbol is mol.
According to the accurate determination of scientific experiments, it is known that the number of carbon atoms in 12g carbon with a relative atomic mass of12 is about 6.02× 10 23.
Scientifically, the collective containing 23 particles of 6.02×10 is regarded as a unit, which is called Mo. Mol is the unit (symbol n) representing the quantity of a substance, which is referred to as Mo for short, and the unit symbol is mol.
The carbon atom of 1mol contains 6.02× 10 23 carbon atoms, and its mass is 12g.
The sulfur atom of 1mol contains 6.02× 10 23 sulfur atoms with a mass of 32g. Similarly, the mass of any atom in 1mol is in grams, which is numerically equal to the relative atomic mass of the atom (formula).
Similarly, we can calculate that the mass of any substance in 1 mol is in grams, which is numerically equal to the molecular formula of the substance.
The molecular formula of water is 18, the mass of 1mol is 18g, and it contains 6.02× 10 23 water molecules.
Generally, the mass of 1mol is called the molar mass of the substance (symbol m), and the unit of molar mass is g/mol (symbol "g/mol"). For example, the molar mass of water is 18g/mol, written as m (H2O) = 18g/mol.
What is the relationship between mass (M), quantity (N) and molar mass (M)?
Chemical equations can express the ratio of quantity and mass of substances between reactants and products. For example:
The ratio of coefficients is 2∶ 1∶2.
The ratio of particle number is 2∶ 1∶2.
The ratio of substances is 2∶ 1∶2.
The mass ratio is 4∶32∶36.
From the above analysis, it can be seen that the ratio of the coefficients of each substance in the chemical equation is the ratio of the amount of substances between them. Using this principle, we can calculate the amount of each substance according to the chemical equation.
The unit of quantity of matter, with the symbol of mole, is one of the seven basic units of the international system of units. Mole is the amount of substance in a system, and the number of elementary particles in the system is equal to the number of atoms in 12g 12C. When using moles, you should specify basic particles, which can be atoms, molecules, ions and other particles, or a specific combination of these particles.
12C= 12, which is the international standard (formula) of relative atomic mass. It is known that 12g 12C contains 6.022 1367× 10 23 carbon atoms. This number is called Avon Gadereau number, so it can also be said that the amount of matter containing several Avon Gadereau elementary particles is 1mol. For example, 1mol oxygen molecule O2 contains 23 oxygen molecules of 6.0221367×10. Its mass is 3 1.9988g 1mol hydrogen ion H+ contains 6.0221367x10 23 hydrogen ions, and its mass is1.00794g.
Moore is the seventh basic unit of the International System of Units (SI), which is 197 10 international metrology conference plus 4 1 country. Mole is used to calculate the number of particles, the mass of matter, the volume of gas, the concentration of solution, the change of heat during the reaction and so on.
197 1 The 14th International Metrology Conference defined the mole in the following two paragraphs: "Mole is the amount of substances in a system, and the number of basic units contained in this system is equal to the number of atoms in 0.0 12kg carbon-12." "When using moles, you should specify the basic unit, which can be atoms, molecules, ions, electrons and other particles, or a specific combination of these particles." The last two paragraphs should be regarded as a whole. The number of carbon atoms in 0.0 12kg carbon-12 nuclide is Avon Garderot constant (NA). At present, the approximate value measured in the experiment is NA = 6.02× 10 23. Mole is different from ordinary units. It has two characteristics: ① The basic units for measuring micro, such as molecules and ions, cannot be used to measure macro-substances. (2) it takes Avon Gadereau number as the unit of measurement, and it is a batch, not a number, to measure the number of particles such as molecules and atoms. It can also be used to measure the specific combination of microscopic particles. For example, the amount of sulfuric acid is measured in moles, that is, 1mol sulfuric acid contains 6.02× 1023 sulfuric acid molecules. Molar is the most widely used unit of measurement in chemistry, such as calculation of chemical reaction equation, calculation in solution, preparation and dilution of solution, calculation of chemical equilibrium, molar volume of gas, thermochemistry and so on.