55-58 vol.% of carbon dioxide can be extracted from venous blood. Most of the CO2 extracted from the blood comes from salts present in plasma and red blood cells carbonic acid and only about 2.5 vol.% of carbon dioxide is dissolved and about 4-5 vol.% is combined with hemoglobin in the form of carbohemoglobin.

Carbonic acid is formed from carbon dioxide in red blood cells, which contain the enzyme carbonic anhydrase, which is a powerful catalyst that accelerates the hydration reaction of CO2.

Binding of carbon dioxide in the blood in the capillaries of the systemic circle. Carbon dioxide formed in the tissues diffuses into the blood of the blood capillaries, since the CO2 tension in the tissues significantly exceeds its tension in the arterial blood. CO2 dissolved in plasma diffuses into the red blood cell, where under the influence carbonic anhydrase it instantly turns into carbonic acid,

According to calculations, the activity of carbonic anhydrase in erythrocytes is such that the reaction of carbon dioxide hydration is accelerated by 1500-2000 times. Since all carbon dioxide inside the erythrocyte turns into carbonic acid, then the CO2 tension inside the erythrocyte is close to zero, so more and more new amounts of CO2 enter the erythrocyte. Due to the formation of carbonic acid from CO3 in the erythrocyte, the concentration of HCO3" ions increases, and they begin to diffuse into the plasma. This is possible because the surface membrane of the erythrocyte is permeable to anions. For cations, the erythrocyte membrane is practically impermeable. Instead of HCO3" ions, the erythrocyte ion enters chlorine The transition of chlorine ions from the plasma into the erythrocyte releases sodium ions in the plasma, which bind the HCO3 ions entering the erythrocyte, forming NaHCO3 Chemical analysis venous blood plasma shows a significant increase in bicarbonate in it.

The accumulation of anions inside the erythrocyte leads to an increase in osmotic pressure inside the erythrocyte, and this causes the passage of water from the plasma through the surface membrane of the erythrocyte. As a result, the volume of red blood cells in the systemic capillaries increases. A study using hematocrit revealed that red blood cells occupy 40% of the volume of arterial blood and 40.4% of the volume of venous blood. It follows from this that the volume of venous blood erythrocytes is greater than that of arterial erythrocytes, which is explained by the penetration of water into them.

Simultaneously with the entry of CO2 into the erythrocyte and the formation of carbonic acid in it, oxygen is released from oxyhemoglobin and converted into reduced hemoglobin. The latter is a much less dissociating acid than oxyhemoglobin and carbonic acid. Therefore, when oxyhemoglobin is converted into hemoglobin, H2CO3 displaces potassium ions from hemoglobin and, combining with them, forms the potassium salt of bicarbonate.

The liberated H˙ ion of carbonic acid binds to hemoglobin. Since reduced hemoglobin is a slightly dissociated acid, there is no acidification of the blood and the difference in pH between venous and arterial blood is extremely small. The reaction occurring in the red blood cells of tissue capillaries can be represented as follows:

KHbO2 + H2CO3= HHb + O2 + KHSO3

From the above it follows that oxyhemoglobin, turning into hemoglobin and giving up the bases associated with it to carbon dioxide, promotes the formation of bicarbonate and the transport of carbon dioxide in this form. In addition, gcmoglobin forms chemical compound with CO2 - carbohemoglobin. The presence of hemoglobin and carbon dioxide in the blood was determined by the following experiment. If potassium cyanide is added to whole blood, which completely inactivates carbonic anhydrase, it turns out that the red blood cells of such blood bind more CO2 than plasma. From this it was concluded that the binding of CO2 by erythrocytes after inactivation of carbonic anhydrase is explained by the presence of a hemoglobin compound with CO2 in erythrocytes. It was later discovered that CO2 attaches to the amine group of hemoglobin, forming a so-called carbamine bond.

The reaction of carbohemoglobin formation can go in one direction or the other depending on the tension of carbon dioxide in the blood. Although a small part of the total amount of carbon dioxide that can be extracted from the blood is combined with hemoglobin (8-10%), the role of this compound in the transport of carbon dioxide in the blood is quite large. Approximately 25-30% of the carbon dioxide absorbed by the blood in the systemic capillaries combines with hemoglobin to form carbohemoglobin.

Release of CO2 by blood in the pulmonary capillaries. Due to the lower partial pressure of CO2 in the alveolar air compared to its tension in the venous blood, carbon dioxide passes through diffusion from the blood of the pulmonary capillaries into the alveolar air. The CO2 tension in the blood drops.

At the same time, due to the higher partial pressure of oxygen in the alveolar air compared to its tension in the venous blood, oxygen flows from the alveolar air into the blood of the capillaries of the lungs. The O2 tension in the blood increases, and hemoglobin is converted into oxyhemoglobin. Since the latter is an acid, the dissociation of which is much higher than that of carbonic acid hemoglobin, it displaces carbonic acid from its potassium acid. The reaction goes as follows:

ННb + O2 + KНSO3= KНbO2+H2CO3

Carbonic acid, freed from its bond with bases, is broken down by carbonic anhydrase into carbon dioxide into water. The importance of carbonic anhydrase in the release of carbon dioxide in the lungs can be seen from the following data. In order for the dehydration reaction of H2CO3 dissolved in water to occur, with the formation of the amount of carbon dioxide that leaves the blood while it is in the capillaries of the lungs, it takes 300 seconds. Blood passes through the capillaries of the lungs within 1-2 seconds, but during this time, dehydration of carbonic acid inside the red blood cell and diffusion of the resulting CO2 first into the blood plasma and then into the alveolar air.

Since the concentration of HCO3 ions in erythrocytes decreases in the pulmonary capillaries, these ions from the plasma begin to diffuse into the erythrocytes, and chlorine ions diffuse from the erythrocytes into the plasma. Due to the fact that the tension of carbon dioxide in the blood of the pulmonary capillaries decreases, the carbamine bond is cleaved and carbohemoglobin releases carbon dioxide.

Dissociation curves of carbonic acid compounds in the blood. As we have already said, over 85% of the carbon dioxide that can be extracted from the blood by acidifying it is released as a result of the breakdown of bicarbonates (potassium in red blood cells and sodium in plasma).

The binding of carbon dioxide and its release into the blood depend on its partial tension. It is possible to construct dissociation curves for carbon dioxide compounds in the blood, similar to the dissociation curves for oxyhemoglobin. To do this, the volumetric percentages of carbon dioxide bound by blood are plotted along the ordinate axis, and along the abscissa axis - partial stresses carbon dioxide. The lower curve in Fig. 58 shows the binding of carbon dioxide by arterial blood, the hemoglobin of which is almost completely saturated with oxygen. The upper curve shows the binding of acid gas by venous blood.

The difference in the height of these curves depends on the fact that arterial blood, rich in oxyhemoglobin, has a lower ability to bind carbon dioxide compared to venous blood. Being a stronger acid than carbonic acid, oxyhemoglobin removes bases from bicarbonates and thereby contributes to the release of carbonic acid. In tissues, oxyhemoglobin, turning into hemoglobin, gives up the bases associated with it, increasing the binding of acid gas in the blood.

Point A on the lower curve in Fig. 58 corresponds to an acid voltage of 40 mmHg. Art., i.e. the voltage that actually exists in the arterial blood. At this voltage, 52 vol.% CO2 is bound. Point V on the upper curve corresponds to an acid gas voltage of 46 mmHg. Art., i.e. actually present in the venous blood. As can be seen from the curve, at this voltage, venous blood binds 58 vol.% carbon dioxide. The AV line connecting the upper and lower curves corresponds to those changes in the ability to bind carbon dioxide that occur when arterial blood is converted into venous or, conversely, venous blood into arterial.

Venous blood, due to the fact that the hemoglobin it contains is converted into oxyhemoglobin, releases about 6 vol.% CO2 in the capillaries of the lungs. If hemoglobin in the lungs were not converted into oxyhemoglobin, then, as can be seen from the curve, venous blood with a partial pressure of carbon dioxide in the alveoli equal to 40 mm Hg. Art.. would bind 54 vol.% CO2, therefore, would give up not 6, but only 4 vol.%. Likewise, if the arterial blood in the capillaries of the systemic circle did not give up its oxygen, that is, if its hemoglobin remained saturated with oxygen, then this arterial blood, at the partial pressure of carbon dioxide present in the capillaries of the body tissues, would not be able to bind 58 vol. .% CO2, but only 55 vol.%.

Carbon dioxide is a metabolic product of tissue cells and is therefore transported by the blood from the tissues to the lungs. Carbon dioxide performs vital important role in maintaining the pH level in the internal environments of the body by mechanisms of acid-base balance. Therefore, the transport of carbon dioxide in the blood is closely related to these mechanisms.

Not in blood plasma a large number of carbon dioxide is in a dissolved state; at PC02= 40 mm Hg. Art. 2.5 ml/100 ml of blood carbon dioxide is tolerated, or 5%. The amount of carbon dioxide dissolved in plasma increases linearly with the PC02 level.

In blood plasma, carbon dioxide reacts with water to form H+ and HCO3. An increase in carbon dioxide tension in the blood plasma causes a decrease in its pH value. The carbon dioxide tension in the blood plasma can be changed by the function of external respiration, and the amount of hydrogen ions or pH can be changed by the buffer systems of the blood and HCO3, for example, by their excretion through the kidneys in the urine. The pH value of blood plasma depends on the ratio of the concentration of carbon dioxide dissolved in it and bicarbonate ions. In the form of bicarbonate, the blood plasma, i.e. in a chemically bound state, transports the main amount of carbon dioxide - about 45 ml/100 ml of blood, or up to 90%. Erythrocytes transport approximately 2.5 ml/100 ml of carbon dioxide, or 5%, in the form of a carbamine compound with hemoglobin proteins. The transport of carbon dioxide in the blood from tissues to the lungs in the indicated forms is not associated with the phenomenon of saturation, as with the transport of oxygen, i.e., the more carbon dioxide is formed, the greater its amount is transported from the tissues to the lungs. However, there is a curvilinear relationship between the partial pressure of carbon dioxide in the blood and the amount of carbon dioxide carried by the blood: the carbon dioxide dissociation curve.

Carbonic anhydrase. (synonym: carbonate dehydratase, carbonate hydrolyase) is an enzyme that catalyzes the reversible reaction of carbon dioxide hydration: CO 2 + H 2 O Û H 2 CO 3 Û H + + HCO 3. Contained in red blood cells, cells of the gastric mucosa, adrenal cortex, kidneys, and in small quantities in the central nervous system, pancreas and other organs. The role of carbonic anhydrase in the body is associated with maintaining acid-base balance, CO 2 transport, formation of hydrochloric acid gastric mucosa. The activity of carbonic anhydrase in the blood is normally quite constant, but in some pathological conditions it changes dramatically. An increase in carbonic anhydrase activity in the blood is observed in anemia of various origins, circulatory disorders of the II-III degree, some lung diseases (bronchiectasis, pneumosclerosis), as well as during pregnancy. A decrease in the activity of this enzyme in the blood occurs with acidosis of renal origin, hyperthyroidism. With intravascular hemolysis, carbonic anhydrase activity appears in the urine, while normally it is absent. It is advisable to monitor the activity of carbonic anhydrase in the blood during surgical interventions on the heart and lungs, because it can serve as an indicator of the body's adaptive capabilities, as well as during therapy with carbonic anhydrase inhibitors - hypothiazide, diacarb.

Carbonic anhydrase I Carbonic anhydrase (synonym: carbonate dehydratase, carbonate hydrolyase)

an enzyme that catalyzes the reversible hydration reaction of carbon dioxide: CO 2 + H 2 O ⇔ H 2 CO 3 ⇔ H + + HCO 3. Contained in red blood cells, cells of the gastric mucosa, adrenal cortex, kidneys, and in small quantities in the central nervous system, pancreas and other organs. The role of acid in the body is associated with maintaining acid-base balance (acid-base balance) , transport of CO 2, formation of hydrochloric acid by the gastric mucosa.

To determine K.'s activity, radiological, immunoelectrophoretic, colorimetric, and titrimetric methods are used. The determination is made in whole blood taken with heparin or in hemolyzed red blood cells. For clinical purposes, the most acceptable colorimetric methods for determining K activity (for example, modifications of the Brinkman method), based on establishing the time required to shift the pH of the incubation mixture from 9.0 to 6.3 as a result of CO 2 hydration. Water saturated with carbon dioxide is mixed with an indicator-buffer solution and a certain amount of blood serum (0.02 ml) or a suspension of hemolyzed erythrocytes. Phenol red is used as an indicator. As carbonic acid molecules dissociate, all new CO 2 molecules undergo enzymatic hydration. To obtain comparable results, it should always take place at the same temperature; it is most convenient to maintain the temperature of melting ice at 0°. The control reaction time (spontaneous reaction of CO 2 hydration) is normally 110-125 With. Normally, when determined by this method, K activity is on average 2-2.5 conventional units, and in terms of 1 million red blood cells, 0.458 ± 0.006 conventional units (a 2-fold increase in the rate of the catalyzed reaction is taken as a unit of K activity).

Bibliography: Clinical evaluation of laboratory tests, ed. WELL. Titsa, . from English, p. 196, M., 1986.

1. Small medical encyclopedia. - M.: Medical encyclopedia. 1991-96 2. First aid. - M.: Great Russian Encyclopedia. 1994 3. encyclopedic Dictionary medical terms. - M.: Soviet encyclopedia. - 1982-1984.

See what "Carbonic anhydrase" is in other dictionaries:

Carbonic anhydrase... Spelling dictionary-reference book

An enzyme that catalyzes the reversible reaction of the formation of carbonic acid from carbon dioxide and water. Carbonic anhydrase inhibitors are used in medicine to treat some cardiovascular and other diseases... Big Encyclopedic Dictionary

Carbonic anhydrase, a carbonate hydrolyase, an enzyme of the lyase class, catalyzes the reversible hydration reaction of carbon dioxide. Found in animals, humans, plants, bacteria. Contains a Zn atom as a cofactor. Mol. m. 28,000 30,000.… … Biological encyclopedic dictionary

Noun, number of synonyms: 1 enzyme (253) ASIS Dictionary of Synonyms. V.N. Trishin. 2013… Synonym dictionary

carbonic anhydrase- Metal enzyme (contains zinc ions in the active center), catalyzing the reversible reaction of carbon dioxide hydration; K deficiency is the cause of marble disease in humans. [Arefyev V.A., Lisovenko L.A. English Russian Dictionary… … Technical Translator's Guide

An enzyme that catalyzes the reversible reaction of the formation of carbonic acid from carbon dioxide and water. Carbonic anhydrase inhibitors are used in medicine to treat certain cardiovascular and other diseases. * * * CARBONAN HYDRASE CARBONAN HYDRASE… encyclopedic Dictionary- carbonic anhydrase, carbonate hydrolyase, an enzyme of the lyase class (See Lyases), catalyzing the reversible formation of carbonic acid from carbon dioxide and water: CO2 + H2O ↔ H2CO3. K. metalloprotein containing Zn; molecular weight about 30... ... Great Soviet Encyclopedia

An enzyme that catalyzes the reversible reaction of the formation of carbonic acid from carbon dioxide and water. K inhibitors are used in medicine to treat certain cardiovascular and other diseases... Natural science. encyclopedic Dictionary

Which, paradoxically, are not independently used as diuretics (diuretics). Carbonic anhydrase inhibitors are mainly used for glaucoma.

Carbonic anhydrase in the epithelium of the proximal tubules of the nephron catalyzes the dehydration of carbonic acid, which is a key link in the reabsorption of bicarbonates. When carbonic anhydrase inhibitors act, sodium bicarbonate is not reabsorbed, but is excreted in the urine (urine becomes alkaline). Following sodium, potassium and water are excreted from the body in the urine. The diuretic effect of substances in this group is weak, since almost all of the sodium released into the urine in the proximal tubules is retained in the distal parts of the nephron. That's why Carbonic anhydrase inhibitors are currently not used independently as diuretics..

Carbonic anhydrase inhibitor drugs

Acetazolamide

(diacarb) is the most famous representative of this group of diuretics. It is well absorbed from the gastrointestinal tract and, unchanged, is quickly excreted in the urine (that is, its effect is short-term). Drugs similar to acetazolamide - dichlorphenamide(daranid) and methazolamide(neptazane).

Methazolamide also belongs to the class of carbonic anhydrase inhibitors. Has a longer half-life than acetazolamide and is less nephrotoxic.

Dorzolamide. Indicated for the reduction of elevated intraocular pressure in patients with open-angle glaucoma or ocular hypertension who are insufficiently responsive to beta-blockers.

Brinzolamide(trade names Azopt, Alcon Laboratories, Inc, Befardin Fardi MEDICALS) also belongs to the class of carbonic anhydrase inhibitors. Used to reduce intraocular pressure in patients with open-angle glaucoma or ocular hypertension. The combination of brinzolamide and timolol is actively used on the market under the trade name Azarga.

Side effects

Carbonic anhydrase inhibitors have the following main side effects:

• hypokalemia;
• hyperchloremic metabolic acidosis;
• phosphaturia;
• hypercalciuria with risk of kidney stones;
• neurotoxicity (paresthesia and drowsiness);
• allergic reactions.

Contraindications

Acetazolamide, like other carbonic anhydrase inhibitors, is contraindicated in cirrhosis of the liver, since alkalinization of the urine prevents the release of ammonia, which leads to encephalopathy.

Indications for use

Carbonic anhydrase inhibitors are primarily used to treat glaucoma. They can also be used to treat epilepsy and acute mountain sickness. Since they promote the dissolution and elimination of uric acid, they can be used in the treatment of gout.

Acetazolamide used in the following conditions:

• Glaucoma (reduces the production of intraocular fluid by the choroid plexus of the ciliary body.
• Treatment of epilepsy (petit mal). Acetazolamide is effective in treating most types of seizures, including tonic-clonic and absence seizures, although it has limited benefit as tolerance develops with long-term use.
• For the prevention of nephropathy during treatment, since the breakdown of cells releases a large amount of purine bases, which provide a sharp increase in the synthesis of uric acid. Alkalinization of urine with acetazolamide due to the release of bicarbonates inhibits nephropathy due to the precipitation of uric acid crystals.
• To increase diuresis during edema and correct metabolic hypochloremic alkalosis in CHF. By reducing the reabsorption of NaCl and bicarbonates in the proximal tubules.

However, for none of these indications is acetazolamide the primary pharmacological treatment (drug of choice). Acetazolamide is also prescribed for mountain sickness (as it causes acidosis, which leads to the restoration of the sensitivity of the respiratory center to hypoxia).

Carbonic anhydrase inhibitors in the treatment of mountain sickness

On high altitude partial pressure oxygen is lower, and people must breathe faster to get enough oxygen to live. When this happens, the partial pressure of carbon dioxide CO2 in the lungs is reduced (simply blown out when you exhale), resulting in respiratory alkalosis. This process is usually compensated by the kidneys through bicarbonate excretion and thereby causes compensatory metabolic acidosis, but this mechanism takes several days.

More immediate treatment is carbonic anhydrase inhibitors, which prevent bicarbonate uptake in the kidneys and help correct alkalosis. Carbonic anhydrase inhibitors also improve chronic mountain sickness.

First school lessons about the device human body are introduced to the main “inhabitants of the blood: red cells - erythrocytes (Er, RBC), which determine the color due to the blood they contain, and white cells (leukocytes), the presence of which is not visible to the eye, since they do not affect the color.

Human red blood cells, unlike animals, do not have a nucleus, but before losing it, they must go from the erythroblast cell, where the synthesis of hemoglobin just begins, to reach the last nuclear stage - which accumulates hemoglobin, and turn into a mature nuclear-free cell, the main a component of which is red blood pigment.

What people have not done with red blood cells, studying their properties: and around globe they tried to wrap them (4 times), and put them in coin columns (52 thousand kilometers), and compare the area of ​​erythrocytes with the surface area of ​​the human body (red blood cells exceeded all expectations, their area turned out to be 1.5 thousand times higher).

These unique cells...

Another important feature of red blood cells is their biconcave shape, but if they were spherical, then their total surface area would be 20% less than the real one. However, the abilities of red blood cells lie not only in the size of their total area. Thanks to the biconcave disc shape:

1. Red blood cells are able to carry more oxygen and carbon dioxide;
2. Show plasticity and freely pass through narrow openings and curved capillary vessels, that is, there are practically no obstacles for young, full-fledged cells in the bloodstream. The ability to penetrate into the most remote corners of the body is lost with the age of red blood cells, as well as in their pathological conditions, when their shape and size change. For example, spherocytes, sickle-shaped, weights and pears (poikilocytosis) do not have such high plasticity, macrocytes, and even more so megalocytes (anisocytosis), cannot penetrate into narrow capillaries, therefore the modified cells do not perform their tasks so flawlessly.

The chemical composition of Er is represented largely by water (60%) and dry residue (40%), in which 90 - 95% is occupied by red blood pigment - , and the remaining 5 - 10% are distributed between lipids (cholesterol, lecithin, cephalin), proteins, carbohydrates, salts (potassium, sodium, copper, iron, zinc) and, of course, enzymes (carbonic anhydrase, cholinesterase, glycolytic, etc.).

Cellular structures that we are accustomed to noticing in other cells (nucleus, chromosomes, vacuoles) are absent in Er as unnecessary. Red blood cells live for up to 3 - 3.5 months, then they age and, with the help of erythropoietic factors that are released when the cell is destroyed, give the command that it is time to replace them with new ones - young and healthy.

The erythrocyte originates from its predecessors, which, in turn, originate from a stem cell. If everything is normal in the body, red blood cells are reproduced in the bone marrow of flat bones (skull, spine, sternum, ribs, pelvic bones). In cases where, for some reason, the bone marrow cannot produce them (tumor damage), red blood cells “remember” that other organs (liver, thymus, spleen) were engaged in this during intrauterine development and force the body to begin erythropoiesis in forgotten places.

How many should there be normally?

The total number of red blood cells contained in the body as a whole and the concentration of red cells coursing through the bloodstream are different concepts. IN total number includes cells that have not yet left the bone marrow, went into depot in case of unforeseen circumstances, or set sail to fulfill their immediate duties. The totality of all three populations of red blood cells is called - erythron. Erythron contains from 25 x 10 12 /l (Tera/liter) to 30 x 10 12 /l red blood cells.

The norm of red blood cells in the blood of adults differs by gender, and in children depending on age. Thus:

• The norm for women ranges from 3.8 - 4.5 x 10 12 / l, respectively, they also have less hemoglobin;
• What is a normal indicator for a woman is called mild anemia in men, since the lower and upper limits of the norm for red blood cells are noticeably higher: 4.4 x 5.0 x 10 12 / l (the same applies to hemoglobin);
• In children under one year old, the concentration of red blood cells is constantly changing, so for each month (for newborns - each day) there is its own norm. And if suddenly in a blood test the red blood cells in a two-week-old child are increased to 6.6 x 10 12 / l, then this cannot be regarded as a pathology, it’s just that this is the norm for newborns (4.0 - 6.6 x 10 12 / l).
• Some fluctuations are observed after a year of life, but normal values ​​are not very different from those in adults. In adolescents aged 12-13 years, the hemoglobin content in red blood cells and the level of red blood cells themselves correspond to the norm for adults.

An increased amount of red blood cells in the blood is called erythrocytosis, which can be absolute (true) and redistributive. Redistributive erythrocytosis is not a pathology and occurs when red blood cells are elevated under certain circumstances:

1. Stay in mountainous areas;
2. Active physical labor and sports;
3. Psycho-emotional agitation;
4. Dehydration (loss of fluid from the body due to diarrhea, vomiting, etc.).

High levels of red blood cells in the blood are a sign of pathology and true erythrocytosis if they are the result of increased formation of red blood cells caused by unlimited proliferation (reproduction) of the precursor cell and its differentiation into mature forms of red blood cells ().

A decrease in the concentration of red blood cells is called erythropenia. It is observed with blood loss, inhibition of erythropoiesis, breakdown of red blood cells () under the influence of unfavorable factors. Low red blood cells and low red blood cell Hb levels are a sign.

What does the abbreviation mean?

Modern hematological analyzers, in addition to hemoglobin (HGB), low or high levels of red blood cells (RBC), (HCT) and other usual tests, can calculate other indicators, which are designated by a Latin abbreviation and are not at all clear to the reader:

In addition to all the listed advantages of red blood cells, I would like to note one more thing:

Red blood cells are considered a mirror that reflects the state of many organs. A kind of indicator that can “feel” problems or allows you to monitor the course of the pathological process is.

For a big ship, a long voyage

Why are red blood cells so important in diagnosing many pathological conditions? Their special role arises and is formed due to their unique capabilities, and so that the reader can imagine the true significance of red blood cells, we will try to list their responsibilities in the body.

Truly, The functional tasks of red blood cells are wide and diverse:

1. They transport oxygen to tissues (with the participation of hemoglobin).
2. They transfer carbon dioxide (with the participation, in addition to hemoglobin, of the enzyme carbonic anhydrase and the ion exchanger Cl- /HCO 3).
3. They perform a protective function, as they are able to adsorb harmful substances and transfer antibodies (immunoglobulins), components of the complementary system, formed immune complexes (At-Ag) on ​​their surface, and also synthesize an antibacterial substance called erythrin.
4. Participate in the exchange and regulation of water-salt balance.
5. Provide tissue nutrition (erythrocytes adsorb and transport amino acids).
6. Participate in maintaining information connections in the body through the transfer of macromolecules that provide these connections (creative function).
7. They contain thromboplastin, which is released from the cell when red blood cells are destroyed, which is a signal for the coagulation system to begin hypercoagulation and formation. In addition to thromboplastin, red blood cells carry heparin, which prevents thrombus formation. Thus, Active participation red blood cells in the process of blood clotting - obviously.
8. Red blood cells are capable of suppressing high immunoreactivity (acting as suppressors), which can be used in the treatment of various tumor and autoimmune diseases.
9. They participate in the regulation of the production of new cells (erythropoiesis) by releasing erythropoietic factors from destroyed old red blood cells.

Red blood cells are destroyed mainly in the liver and spleen with the formation of breakdown products (iron). By the way, if we consider each cell separately, it will not be so red, but rather yellowish-red. Accumulating into huge masses of millions, they, thanks to the hemoglobin contained in them, become the way we are used to seeing them - a rich red color.

Video: Lesson on Red Blood Cells and Blood Functions