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The neutralization of ammonia in the body
In the process of conversion of amino acids in tissues, their final metabolic products are formed - carbon monoxide, water and ammonia. Water is used by the body to provide biochemical processes. Carbon monoxide is partially removed from the body with exhaled air, its other part is utilized in the synthesis processes (for example, in the synthesis of fatty acids, purine bases, etc.).
Ammonia resulting from the deamination of amino acids is a toxic substance, an increase in its concentration in the blood and other tissues has an adverse effect, especially on the nervous system. The toxicity of ammonia is due to the fact that it contributes to the reductive amination of alpha-ketoglutaric acid in mitochondria. This leads to its removal from the Krebs cycle and, as a result, to a decrease in tissue respiration and excessive formation of ketone bodies from acetyl-CoA (acetyl coenzyme A).
In the process of evolution, living organisms have developed various effective mechanisms for the neutralization of the toxic effects of ammonia, the main of which are: the formation of glutamine or asparagine amines, reductive amination, acid neutralization, and urea synthesis.
The synthesis of glutamine or asparagine is of great importance to the body. It occurs in places of direct ammonia formation (for example, in the liver, brain), and there is also an enzyme that catalyzes this process - glutamine synthetase, which belongs to the class of ligases. The synthesis of amides requires the delivery of energy in the form of ATP, the presence of glutamic or aspartic acids, free ammonia, and the corresponding specific enzymes. The amide synthesis reaction is associated with the decomposition of ATP.
Asparagine is formed similarly.
As a result of the interaction of ammonia with glutamic and aspartic acids, its binding occurs and thus ammonia is neutralized. Bound ammonia can be used as a nitrogen source (for example, for the synthesis of purine and pyrimidine bases, mucopolysaccharides). Glutamine and asparagine not only neutralize ammonia, but also act as its transport form. In bound form, ammonia is delivered to the place of final disposal - to the liver, where urea is synthesized from it.
One of the most effective methods of neutralizing ammonia is the synthesis of urea. The urea synthesis scheme was first proposed by the Russian biochemist M.V. Nentsky, who believed that urea is formed from two ammonia molecules and one carbonic acid molecule, but this theory turned out to be erroneous.
In special experiments M.V. Zalessky and S.S. Salazkina on animals (laboratory of Acad. I.P. Pavlova), it was found that if venous blood is sent not to the liver, but bypassing it into the inferior vena cava, then there is a sharp increase in the ammonia content in the blood and poisoning. Based on these results, it was concluded that the liver is the organ in which the neutralization of ammonia in the body occurs.
In the works of X.A. Krebs and other researchers have shown the participation in this process of substances and enzymes that catalyze the synthesis of urea. English biochemist H.A. Krebs made a great contribution to the modern theory of urea synthesis. He established that this process is cyclical in nature and indicated the role of ornithine in it.
A prerequisite for creating a theory of urea synthesis was the detection in the liver of the amino acid ornithine and the arginase enzyme that breaks down arginine into ornithine and urea. According to Krebs theory, urea synthesis begins with the interaction of ornithine with ammonia and carbogen oxide. In this case, the amino acid citrulline is formed, which interacts with another ammonia molecule with the release of arginine. The latter is hydrolyzed by arginase to ornithine and urea. Ornithine in these reactions acts as a catalyst. For the opening of this cycle, X. A. Krebs was awarded the Nobel Prize.
The closed cycle of urea synthesis can conditionally be divided into three stages. At the first and second stages, two ammonia molecules are bonded into a compound harmless to the body, and at the third stage, urea is formed.
Due to the energy of ATP, carbomoyl phosphate is synthesized from an ammonia molecule and carbogen oxide. Then there occurs a condensation of carbomoylphosphate with ornithine, as a result of which citrulline is synthesized. Inorganic phosphate is released. The synthesis of citrulline is provided by the energy accumulated in carbomoylphosphate.
Thus, one molecule of ammonia is fixed in citrulline.
Another ammonia molecule is bound to glutamic acid by reductive amination with alpha-ketoglutaric acid. Glutamic acid transfers the fixed ammonia molecule as NH2-groups on oxaloacetic acid, is converted into aspartic acid (transamination process):
alpha-ketoglutaric acid NOOC (CH2)2C (O) COOH + NH3 + 2H + - H2O -> glutamic acid COOH = CH2= CH2= CH (NH2) = COOH + oxalacetic acid CO2H — COCH2CO2H -> Aspartic acid HOOCCH2CH (NH2) COOH + alpha-ketoglutaric acid HOOC (CH2)2C (O) UNC
The third stage.
At this stage, urea synthesis is carried out. Citrulline, interacting with the amino group of aspartic acid, forms arginine succinic acid (argininosuccinate). In this process, the energy of another ATP molecule is used.
Citrulline H2NCONH (CH2)3CH (NH2) COOH + Aspartic Acid HOOCCH2CH (NH2) COOH + ATP -> arginine succinic acid HNC = N-CH (COOH) (CH2COOH) NH (CH2)3CH (NH2) COOH + ADP + H3PO4 -> fumaric acid HO2CCH = CHCO2H
Arginine succinic acid is broken down into arginine and fumaric acid. Fumaric acid is included in carbohydrate metabolism, turning into malic acid, which by dehydrogenation passes into oxalacetic acid.
Oxalacetic acid can add ammonia to itself and again turn into aspartic acid or, undergoing decarboxylation, into pyruvic acid, and then into coenzyme A, which is used in various biosynthesis reactions or oxidized to CO2 and H2ABOUT.
Arginine, formed under the action of arginase, is hydrolytically split into ornithine and urea. The released ornithine can again react with a new carbomoylphosphate molecule and the process repeats.
It is estimated that in a state of nitrogen equilibrium, the adult body consumes and accordingly releases 15 g of nitrogen, from urea excreted with urine, about 85%, creatinine - 5%, ammonium salts - 3%, uric acid - 1%, and others forms - 6%.
Urea is a harmless compound, its synthesis occurs in the liver, the dysfunction of which leads to a slowdown of the process, a decrease in the content of urea in the blood and a decrease in its excretion in the urine.
"Ammonia neutralization in the body" - this is the fourth article from the cycle "Protein metabolism in the human body." The first article is “Protein digestion in the digestive tract.” The second article is "The neutralization of products of rotting proteins in the intestines e." Third article, “The exchange of amino acids in tissue x”
How to produce ammonia
Ammonia is a gas without color, but with a very pungent odor. It is a cool substance that absorbs heat. Its boiling point is -36 ° C and its melting point is -77.73 ° C. The substance is highly soluble in water and alcohol. NH3 is obtained during the synthesis of nitrogen and hydrogen. It also exists in nature when decomposition of organic compounds occurs.
Pure ammonia in 1774 was received by chemist philosopher from England Joseph Priestley. But on an industrial scale, ammonia has been produced since the beginning of the 20th century. German chemists Karl Bosch and Fritz Haber in 1913 developed industrial technology and launched the production process. For this development, they were awarded the Nobel Prize.
The process of obtaining NH3 is very energy intensive, which is its main disadvantage. Because of this, for many years, scientists have been developing to reduce costs in the production of ammonia. The production principle is based on the principle of circulation. All processes must go on continuously. The remains of the starting components are filtered from the main substance and again go into the production process. Because of this, the synthesis of the product is cyclical and cannot be stopped abruptly.
As raw materials use hydrocarbon - natural gas. Before entering the NH3 production process, the gas is treated several times and hydrogen is released. Next, hydrogen is fed into the synthesis column under high pressure together with nitrogen. All processes take place at high temperatures; therefore, the process of obtaining ammonia is an energy-consuming and very dangerous chemical production.
Where is NH3 used?
Ammonia is a very important substance in the modern chemical industry. The bulk of the substance is used to produce nitric acid, fertilizers, and dyes. Ammonia is also used to produce explosives. Aqueous solutions of ammonia are used in a number of production processes of other substances.
From all known products, with the help of ammonia receive:
- baking soda, do most of the hair dye,
- ammonia-based fertilizers,
- ammonium nitrate,
What is ammonia dangerous for and what do they do when a substance leaks
To avoid ammonia spills during transportation, special steel cylinders and tanks are used. Also transported in special tankers. In industries, pipelines are used for transportation. Ammonia in contact with air turns into an explosive mixture. It is ignited in the presence of a fire source. Ammonia tanks can explode if overheated due to the low boiling point of the substance.
Ammonia gas is a very toxic toxic compound. When the concentration of ammonia in the air is more than 350 mg / m3, all work must be stopped. People must go beyond the gassed territory.
When inhaled, ammonia affects the respiratory tract and also affects vision, with a sharp high concentration a person can die from poisoning. Symptoms of poisoning:
- severe choking cough,
- exposure to high concentration - overexcitation and delirium,
- skin contact - severe burn with blisters, swelling,
- frequent presence in the zone of emission of ammonia of low concentration - there is a digestive upset, hearing loss, catarrh of the upper respiratory tract.
In case of ammonia poisoning, it is urgent to leave the danger zone and rinse your eyes and exposed skin with water, then you should contact your doctors.
In the event of a leak, explosion, fire with ammonia, the accident can be eliminated only in chemically insulating suits, for example, Sagittarius insulating suits.
In suits Sagittarius AJ TASK or Sagittarius KIO TASK you can safely carry out work in areas of the distribution of highly concentrated ammonia to eliminate leaks and eliminate the consequences. Ammonia is neutralized with a large amount of water, which is sprayed under pressure in the form of a spray from a maximum distance from the source of ignition.
Exercises to eliminate leakage of ammonia in suits Sagittarius KIO
Emergency Card (AHOV)
AMMIAK (anhydrous), TOXIC DANGER CLASS - 4
|CAS No. 7664-41-7; UN No. 1005EC; No. 007-001-00-5||NH3Molecular mass: 17.03||UN classification UN hazard class: 2.3 UN secondary hazard: 8|
In case of fire in the vicinity, all extinguishing media are permitted.Evacuate the danger zone!
In case of fire: cool the cylinders by dousing them with water.
NEVER direct a stream of water at a liquid. Consult a specialist! Ventilation. Remove gas using fine spray of water. Keep upwind. Vapor precipitate with finely divided water. Do not stop burning if leaking.
Directly at the scene of the accident and in the vicinity of the source of infection, work is carried out in insulating gas masks IP-4M, IP-5 (on chemically bound oxygen) or breathing apparatus ASV-2, DASV (on compressed air), KIP-8, KIP-9 (on compressed oxygen) and tools skin protection (L-1, KIH-4, KIH-5, etc.). At a distance of more than 250 meters from the focus, skin protection can not be used, and industrial gas masks with boxes of brands KD, G, M are used to protect the respiratory system, VK, as well as civilian gas masks GP-5, GP-7, PDF-2D, PDF-2Sh complete with an additional cartridge DPG-3. At concentrations less than 20 mg / m3, an RPG-67 respirator with KD or VK cartridges can be used.
Neutralize ammonia with the following solutions:
- 10% solution of hydrochloric or sulfuric acid, for which 1 part of concentrated acid is mixed with 9 parts of water (for example, 10 liters of acid + 90 liters of water),
- 2% solution of ammonium sulfate, for which 2 parts of ammonium sulfate are diluted in 98 parts of water (for example, 2 kg of ammonium sulfate + 98 liters of water).
If ammonia gas leaks spray water to extinguish the vapor. The rate of water consumption is not standardized.
When spilling liquid ammonia the spill site is enclosed with an earthen rampart, poured with a solution of hydrochloric or sulfuric acid, or with water. To neutralize 1 ton of liquid ammonia, 10-15 tons of a solution of hydrochloric (sulfuric) acid or 18-20 tons of water are needed. To neutralize 1 ton of liquid ammonia, 20-30 tons of hydrochloric (sulfuric) acid solution are needed. It is advisable not to neutralize liquid ammonia with water, because high concentrations of ammonia can form in the air, which is unsafe, since explosive mixtures form 15-28 volume percent of ammonia with air.
For spraying water or solutions, water-jetting and fire engines, autofilling stations (AC, PM-130, ARS-14, ARS-15), as well as hydrants and special systems available at chemically hazardous facilities, are used.
In the infected area: plentiful washing of eyes with water, putting on a gas mask, copious washing of affected skin with water, urgent exit (withdrawal) of victims from the infection zone.
After evacuation from the infected area: provide rest, warmth, with physical pain in the eyes, drip 2 drops of 1% solution of novocaine or 2% solution of boric acid, apply lotions of 3-5% solution of boric, acetic or citric acids to the affected skin, take warm milk with baking soda inside , give painkillers (1 ml. 1% solution of morphine or promedol, subcutaneously inject 1 ml. 0.1% solution of atropine sulfate, with respiratory arrest - mechanical ventilation), immediate evacuation to a medical institution. Half-sitting position. When frostbite DO NOT remove clothing!
PHYSICAL STATE; APPEARANCE:
COLORLESS COMPRESSED LIQUEFIED GAS WITH PUNGENT ODOR
Gas is lighter than air.
Shock-sensitive compounds are formed with mercury, silver, and gold oxides. The substance is a strong base, it reacts violently with acid and is corrosive. Reacts violently with strong oxidizing agents and halogens. Aggressive against copper, aluminum, zinc and their alloys. It dissolves in water with the release of heat.
WAYS OF ARRIVAL:
The substance can be absorbed into the body by inhalation.
If the contents leak, a dangerous concentration of this gas in the air is reached very quickly.
INFLUENCE OF SHORT-TERM EXPOSURE:
The substance is corrosive to the eyes, skin and respiratory tract. Inhalation of high concentrations may cause pulmonary edema (see Notes). Rapid evaporation of the liquid can cause frostbite.
AVAILABILITY OF AMMONIA DETERMINE:
In the air of the industrial zone by aspirators AM-5, AM-0055, AM-0059, NP-3M with indicator tubes for ammonia, gas analyzers HOBBIT-T-NH3, gas detectors IGS-98-NH3, ESSA-NH3, HOBBIT-NH3.
In open space - KIPSAR-X SIW devices.
Indoors - SIP "VEGA-M"
Температура кипения: -33°C
Температура плавления: -78°C
Относительная плотность (вода = 1): 0.7 at -33°C
Растворимость в воде, г/100 мл при 20°C: 54
Vapor pressure, kPa at 26 ° C: 1013
Relative vapor density (air = 1): 0.59
Auto-ignition Temperature: 651 ° C
Explosive limits, vol% in air: 15-28
In the air of settlements: daily average 0.4 mg / m3, maximum single concentration: no more than 15 minutes, no more than 4 times per shift - 0.2 mg / m3.
In the air of the working area of industrial premises 20 mg / m3.
In water, 2 mg / m3. Odor Threshold 0.5 mg / m3. At concentrations of 40-80 mg / m3 there is a sharp irritation of the eyes, upper respiratory tract, headache, with 1200 mg / m3 - cough, pulmonary edema is possible.
Concentrations of 1500 - 2700 mg / m3, acting for 0.5-1 hours, are considered fatal. The maximum permissible concentration of ammonia for filtering industrial and civil gas masks is 15,000 mg / m3.
Liquid ammonia is a transparent chemical substance with a sharp repulsive odor. Ammonia is a 10% chemical aqueous solution of ammonium hydroxide. Ammonia has found application both in the medical industry and in everyday life. In medical language, ammonia is often called “Ammonia solution” or “Ammonia bufus”.
Ammonia has the following characteristics:
- Respiratory center stimulator for fainting conditions,
- Irritant nerve endings and receptors,
- Acid scavenger
- Disinfector, etc.
Important: it is noteworthy that the sharp ammonia smell, which is so annoying to a healthy person, is in most cases liked by people with iron deficiency anemia. Therefore, if you noticed that the smell of ammonia does not repel you, it is better to donate blood for analysis and determine the level of hemoglobin in it.
Use of ammonia
Ammonia is used not only in medicine, but also in everyday life. That is why it is in almost 90% of houses at hand at the hostesses. So, if there is a drinker in the house, such a tool should be kept away from him. The very name "alcohol" can mislead the alcoholic. And the consequences of this can be the most sad.
In everyday life, ammonia is used as a means for cleaning glasses, painted surfaces, furniture upholstery and the dome of an umbrella. At the same time, ammonia is used not in its pure form, but in the form of solutions mixed with water / glycerin / hydrogen peroxide, etc.
As for medical manipulations, here ammonia is used in most cases, as an irritant of the respiratory center in fainting conditions. The mechanism of action on the human body in this case is as follows:
- Cotton wool moistened with ammonia is brought to the nose of a person who is unconscious.
- Ammonium vapor penetrates into the lungs through the nasopharynx and thereby irritate the nerve endings of the respiratory center.
- A person takes a deep breath and thereby stimulates the brain.
- At the same time, the body is protected from excessive penetration of ammonia vapor into the body (a protective reflex is triggered).
Important: with excessive inhalation of ammonia vapor, the inhibition of the respiratory center occurs. In this case, a person may even fall into a coma.
In addition, ammonia is used in alcohol poisoning as a mild sobering and emetic. Here you need to add 2-3 drops of ammonia to a glass of water, mix everything thoroughly and drink. Vomiting will not take long. But, unfortunately, often a drunk person does not observe the proportions of the solution (by mistake or unknowingly) and increases the dose of ammonia in a glass of water. The consequences of this can be very different, but at least a person is threatened with ammonia poisoning in a mild form.
Ammonia vapor poisoning
You should know that ammonia is very dangerous with prolonged inhalation of its vapor. That is, in an effort to bring a drunk person or an unconscious person to life with the help of ammonia, it is important not to overdo it. It is considered safe to inhale ammonia vapor for 2-3 seconds. Prolonged inhalation of vapors leads to poisoning. And the longer the impact of ammonia vapors on the human body will be, the more severe his condition will be in the end. Symptoms of ammonia poisoning are:
- Pallor of the skin,
- Stupid condition of the patient,
- Increase the pulse to the level of 180 beats / min.
Important: if at this stage the source of ammonia vapor is neutralized, the patient is able to come to a normal state without serious consequences. However, in most cases, damage to the mucous layer of the lungs is still noted.
Longer inhalation of ammonia vapor leads to the following consequences:
- Cough and suffocation
- Wheezing and wheezing in the lungs
- Visual impairment
- Movement coordination disorder,
- Panic attacks,
- Soreness in the heart,
- Pulse 140 beats / min,
- Vomiting and persistent nausea
- Loss of consciousness.
If we continue the impact of ammonia vapors on the human body, then the patient, in the end, will fall into a coma. In this case, without medical assistance, the patient dies.
Important: with special care, contact with ammonia is necessary for people who have a history of allergic disorders or diseases of the cardiovascular system. The chance of poisoning with ammonia in such people is many times higher.
First aid for poisoning with ammonia vapors
To help such a patient, it is necessary to take a number of such measures:
- Remove the source of ammonia vapor,
- To free the upper body from tightening clothes (tie, shirt collar, squeezing bra, etc.),
- Ensure the flow of air into the room (or take the patient to the balcony / street).
It is believed that if within a few minutes the patient regained consciousness, then the degree of poisoning was mild, which means that medical assistance is not required. If the patient is still unconscious, then it is necessary to call paramedics. You can’t do without their help.
Ammonia poisoning when ingested
This type of ammonia poisoning is considered the most dangerous from the point of view of the forecast. Moreover, even if 50 ml of ammonia gets inside, in 98% of cases a fatal outcome occurs. Serious symptoms indicating a serious condition of the patient with ammonia ingested are:
- Sharp pains and burning in the lower abdomen,
- Asphyxia (asphyxiation) and the inability to take even a little deep breath,
- Heat and temperature rise to around 39 degrees,
- Nausea and vomiting (possibly with blood)
- Increased production of saliva in the mouth,
- Sweating enhancement,
- Darkness in the eyes, characterized by a short duration,
- Pulse up to 180 beats / min.,
- As a result - a drop in blood pressure,
- Pain shock with a burn of the mucous membrane of the trachea, esophagus, stomach,
- Fainting and coma.
Important: at the first suspicion of ingestion of even a small dose of pure ammonia, an urgent call should be urgently called. With timely help, the poisoner has a chance of salvation. However, it is worth remembering that even with timely assistance in 5% of cases, death occurs. And if the patient drank 100 ml of ammonia or more, then death occurs inevitably.
Assisting poisonous ammonia
Here you need to understand thoroughly whether it is possible to independently treat at home a person who has been poisoned with ammonia. So, in any case, you must call an ambulance, even if the dose of drunk ammonia is not large. Further actions will depend on the condition of the patient. First of all, it is necessary to find out if there is severe pain in the abdomen / stomach / peritoneum. If the answer is yes, then there must be a perforation of the tissues (through burns through the mucous membrane of the stomach or esophagus). In this case, first aid in any form is prohibited, it is strictly forbidden to drink the patient. It will only get worse.
If there is no pain, then there is a chance to flush a person’s stomach and thereby save him. To neutralize ammonia, it is necessary to water the patient with water with acetic or citric acid added to it. In extreme cases, lemon juice added to the water is suitable. To 1 liter of pure water add 0.5 tsp. acetic acid or vinegar or as much citric acid. Juice can be added about 1-2 tablespoons. Lemon juice can also be given in pure form, 1 tbsp every 5 minutes before the arrival of paramedics. The same is done with water on acetic acid.
It is advisable to reassure the patient, since a panic state increases the number of heart contractions. And this can lead to hypertension, which will complicate further treatment of the patient.
Important: first aid with soda is completely prohibited. It is strictly forbidden to rinse your mouth with soda solution or drink it. Alkali when reacting with ammonia will cause significant harm to the patient's body.