Water-salt exchange. Hormones that regulate water-salt metabolism Water-salt metabolism biochemistry

Subject Meaning: Water and substances dissolved in it create the internal environment of the body. The most important parameters of water-salt homeostasis are osmotic pressure, pH, and the volume of intracellular and extracellular fluid. Changes in these parameters can lead to changes in blood pressure, acidosis or alkalosis, dehydration and tissue edema. The main hormones involved in the fine regulation of water-salt metabolism and acting on the distal tubules and collecting ducts of the kidneys: antidiuretic hormone, aldosterone and natriuretic factor; renin-angiotensin system of the kidneys. It is in the kidneys that the final formation of the composition and volume of urine takes place, which ensures the regulation and constancy of the internal environment. The kidneys are distinguished by an intensive energy metabolism, which is associated with the need for active transmembrane transport of significant amounts of substances during the formation of urine.

A biochemical analysis of urine gives an idea of the functional state of the kidneys, metabolism in various organs and the body as a whole, helps to clarify the nature of the pathological process, and makes it possible to judge the effectiveness of the treatment.

Purpose of the lesson: to study the characteristics of the parameters of water-salt metabolism and the mechanisms of their regulation. Features of metabolism in the kidneys. Learn how to conduct and evaluate a biochemical analysis of urine.

The student must know:

1. The mechanism of urine formation: glomerular filtration, reabsorption and secretion.

2. Characteristics of the body's water compartments.

3. The main parameters of the liquid medium of the body.

4. What ensures the constancy of the parameters of the intracellular fluid?

5. Systems (organs, substances) that ensure the constancy of the extracellular fluid.

6. Factors (systems) that ensure the osmotic pressure of the extracellular fluid and its regulation.

7. Factors (systems) that ensure the constancy of the volume of extracellular fluid and its regulation.

8. Factors (systems) that ensure the constancy of the acid-base state of the extracellular fluid. The role of the kidneys in this process.

9. Features of metabolism in the kidneys: high metabolic activity, the initial stage of creatine synthesis, the role of intensive gluconeogenesis (isoenzymes), activation of vitamin D3.

10. General properties of urine (amount per day - diuresis, density, color, transparency), chemical composition of urine. Pathological components of urine.

The student must be able to:

1. Conduct a qualitative determination of the main components of urine.

2. Assess the biochemical analysis of urine.

The student must get an idea:

About some pathological conditions accompanied by changes in the biochemical parameters of urine (proteinuria, hematuria, glucosuria, ketonuria, bilirubinuria, porphyrinuria) .

Information from the basic disciplines necessary to study the topic:

1. The structure of the kidney, nephron.

2. Mechanisms of urine formation.

Tasks for self-training:

Study the material of the topic in accordance with the target questions (“the student needs to know”) and complete the following tasks in writing:

1. Refer to the course of histology. Remember the structure of the nephron. Note the proximal tubule, distal convoluted tubule, collecting duct, vascular glomerulus, juxtaglomerular apparatus.

2. Refer to the course of normal physiology. Remember the mechanism of urine formation: filtration in the glomeruli, reabsorption in the tubules with the formation of secondary urine and secretion.

3. The regulation of the osmotic pressure and volume of the extracellular fluid is associated with the regulation, mainly, of the content of sodium and water ions in the extracellular fluid.

Name the hormones involved in this regulation. Describe their effect according to the scheme: the cause of hormone secretion; target organ (cells); the mechanism of their action in these cells; the final effect of their action.

Test your knowledge:

A. Vasopressin(all correct except for one):

a. synthesized in the neurons of the hypothalamus; b. secreted with an increase in osmotic pressure; v. increases the rate of water reabsorption from primary urine in the renal tubules; g. increases reabsorption in the renal tubules of sodium ions; e. reduces osmotic pressure e. urine becomes more concentrated.

B. Aldosterone(all correct except for one):

a. synthesized in the adrenal cortex; b. secreted when the concentration of sodium ions in the blood decreases; v. in the renal tubules increases the reabsorption of sodium ions; d. urine becomes more concentrated.

e. The main mechanism for regulating secretion is the arenin-angiotensive system of the kidneys.

B. Natriuretic factor(all correct except for one):

a. synthesized in the bases of the cells of the atrium; b. secretion stimulus - increased blood pressure; v. enhances the filtering ability of the glomeruli; d. increases the formation of urine; e. Urine becomes less concentrated.

4. Draw a diagram illustrating the role of the renin-angiotensive system in the regulation of aldosterone and vasopressin secretion.

5. The constancy of the acid-base balance of the extracellular fluid is maintained by the buffer systems of the blood; a change in pulmonary ventilation and the rate of excretion of acids (H +) by the kidneys.

Remember the buffer systems of the blood (basic bicarbonate)!

Test your knowledge:

Food of animal origin is acidic in nature (mainly due to phosphates, in contrast to food of plant origin). How will the pH of urine change in a person who uses mainly food of animal origin:

a. closer to pH 7.0; b.pn about 5.; v. pH around 8.0.

6. Answer the questions:

A. How to explain the high proportion of oxygen consumed by the kidneys (10%);

B. High intensity of gluconeogenesis;

B. The role of the kidneys in calcium metabolism.

7. One of the main tasks of nephrons is to reabsorb useful substances from the blood in the right amount and remove metabolic end products from the blood.

Make a table Biochemical indicators of urine:

Auditorium work.

Laboratory work:

Carry out a series of qualitative reactions in urine samples from different patients. Make a conclusion about the state of metabolic processes based on the results of biochemical analysis.

pH determination.

Progress of work: 1-2 drops of urine are applied to the middle of the indicator paper, and by changing the color of one of the colored strips, which coincides with the color of the control strip, the pH of the urine under study is determined. Normal pH 4.6 - 7.0

2. Qualitative reaction to protein. Normal urine does not contain protein (trace amounts are not detected by normal reactions). In some pathological conditions, protein may appear in the urine - proteinuria.

Progress: To 1-2 ml of urine add 3-4 drops of freshly prepared 20% solution of sulfasalicylic acid. In the presence of protein, a white precipitate or turbidity appears.

3. Qualitative reaction for glucose (Fehling's reaction).

Progress of work: Add 10 drops of Fehling's reagent to 10 drops of urine. Heat to a boil. In the presence of glucose, a red color appears. Compare the results with the norm. Normally, trace amounts of glucose in the urine are not detected by qualitative reactions. Normally there is no glucose in the urine. In some pathological conditions, glucose appears in the urine. glycosuria.

The determination can be carried out using a test strip (indicator paper) /

Detection of ketone bodies

Progress of work: Apply a drop of urine, a drop of 10% sodium hydroxide solution and a drop of freshly prepared 10% sodium nitroprusside solution to a glass slide. A red color appears. Pour 3 drops of concentrated acetic acid - a cherry color appears.

Normally, ketone bodies are absent in the urine. In some pathological conditions, ketone bodies appear in the urine - ketonuria.

Solve problems on your own, answer questions:

1. The osmotic pressure of the extracellular fluid has increased. Describe, in diagrammatic form, the sequence of events that will lead to its decrease.

2. How will aldosterone production change if excessive production of vasopressin leads to a significant decrease in osmotic pressure.

3. Outline the sequence of events (in the form of a diagram) aimed at restoring homeostasis with a decrease in the concentration of sodium chloride in tissues.

4. The patient has diabetes mellitus, which is accompanied by ketonemia. How will the main blood buffer system - bicarbonate - respond to changes in acid-base balance? What is the role of the kidneys in the recovery of KOS? Whether the urine pH will change in this patient.

5. An athlete, preparing for a competition, undergoes intensive training. How to change the rate of gluconeogenesis in the kidneys (argue the answer)? Is it possible to change the pH of urine in an athlete; justify the answer)?

6. The patient has signs of a metabolic disorder in the bone tissue, which also affects the condition of the teeth. The level of calcitonin and parathyroid hormone is within the physiological norm. The patient receives vitamin D (cholecalciferol) in the required quantities. Make a guess about the possible cause of the metabolic disorder.

7. Consider the standard form "Complete urinalysis" (Tyumen State Medical Academy multidisciplinary clinic) and be able to explain the physiological role and diagnostic value of the biochemical components of urine determined in biochemical laboratories. Remember the biochemical parameters of urine are normal.

Department of Biochemistry

I approve

Head cafe prof., d.m.s.

Meshchaninov V.N.

______''_____________2006

LECTURE #25

Topic: Water-salt and mineral metabolism

Faculties: medical and preventive, medical and preventive, pediatric.

Water-salt exchange- exchange of water and basic electrolytes of the body (Na +, K +, Ca 2+, Mg 2+, Cl -, HCO 3 -, H 3 PO 4).

electrolytes- substances that dissociate in solution into anions and cations. They are measured in mol/l.

Non-electrolytes- substances that do not dissociate in solution (glucose, creatinine, urea). They are measured in g / l.

Mineral exchange- the exchange of any mineral components, including those that do not affect the main parameters of the liquid medium in the body.

Water- the main component of all body fluids.

The biological role of water

Water is a universal solvent for most organic (except lipids) and inorganic compounds.
Water and substances dissolved in it create the internal environment of the body.
Water provides the transport of substances and thermal energy throughout the body.
A significant part of the chemical reactions of the body takes place in the aqueous phase.
Water is involved in the reactions of hydrolysis, hydration, dehydration.
Determines the spatial structure and properties of hydrophobic and hydrophilic molecules.
In complex with GAG, water performs a structural function.

GENERAL PROPERTIES OF BODY LIQUIDS

All body fluids are characterized by common properties: volume, osmotic pressure and pH value.

Volume. In all terrestrial animals, fluid makes up about 70% of body weight.

The distribution of water in the body depends on age, gender, muscle mass, physique and fat content. The water content in various tissues is distributed as follows: lungs, heart and kidneys (80%), skeletal muscles and brain (75%), skin and liver (70%), bones (20%), adipose tissue (10%). In general, lean people have less fat and more water. In men, water accounts for 60%, in women - 50% of body weight. Older people have more fat and less muscle. On average, the body of men and women over 60 years of age contains 50% and 45% water, respectively.

With complete deprivation of water, death occurs after 6-8 days, when the amount of water in the body decreases by 12%.

All body fluid is divided into intracellular (67%) and extracellular (33%) pools.

extracellular pool(extracellular space) consists of:

1. Intravascular fluid;

2. Interstitial fluid (intercellular);

3. Transcellular fluid (fluid of the pleural, pericardial, peritoneal cavities and synovial space, cerebrospinal and intraocular fluid, secretion of sweat, salivary and lacrimal glands, secretion of the pancreas, liver, gallbladder, gastrointestinal tract and respiratory tract).

Between the pools, liquids are intensively exchanged. The movement of water from one sector to another occurs when the osmotic pressure changes.

Osmotic pressure - This is the pressure exerted by all the substances dissolved in water. The osmotic pressure of the extracellular fluid is determined mainly by the concentration of NaCl.

Extracellular and intracellular fluids differ significantly in composition and concentration of individual components, but the total total concentration of osmotically active substances is approximately the same.

pH is the negative decimal logarithm of the proton concentration. The pH value depends on the intensity of the formation of acids and bases in the body, their neutralization by buffer systems and removal from the body with urine, exhaled air, sweat and feces.

Depending on the characteristics of metabolism, the pH value can differ markedly both inside the cells of different tissues and in different compartments of the same cell (neutral acidity in the cytosol, strongly acidic in lysosomes and in the intermembrane space of mitochondria). In the intercellular fluid of various organs and tissues and blood plasma, the pH value, as well as the osmotic pressure, is a relatively constant value.

REGULATION OF THE WATER-SALT BALANCE OF THE BODY

In the body, the water-salt balance of the intracellular environment is maintained by the constancy of the extracellular fluid. In turn, the water-salt balance of the extracellular fluid is maintained through the blood plasma with the help of organs and is regulated by hormones.

Bodies regulating water-salt metabolism

The intake of water and salts into the body occurs through the gastrointestinal tract, this process is controlled by thirst and salt appetite. Removal of excess water and salts from the body is carried out by the kidneys. In addition, water is removed from the body by the skin, lungs and gastrointestinal tract.

Water balance in the body

For the gastrointestinal tract, skin and lungs, the excretion of water is a side process that occurs as a result of their main functions. For example, the gastrointestinal tract loses water when undigested substances, metabolic products and xenobiotics are excreted from the body. The lungs lose water during respiration, and the skin during thermoregulation.

Changes in the work of the kidneys, skin, lungs and gastrointestinal tract can lead to a violation of water-salt homeostasis. For example, in a hot climate, to maintain body temperature, the skin increases sweating, and in case of poisoning, vomiting or diarrhea occurs from the gastrointestinal tract. As a result of increased dehydration and loss of salts in the body, a violation of the water-salt balance occurs.

Hormones that regulate water-salt metabolism

Vasopressin

Antidiuretic hormone (ADH), or vasopressin- a peptide with a molecular weight of about 1100 D, containing 9 AAs connected by one disulfide bridge.

ADH is synthesized in the neurons of the hypothalamus and transported to the nerve endings of the posterior pituitary gland (neurohypophysis).

The high osmotic pressure of the extracellular fluid activates the osmoreceptors of the hypothalamus, resulting in nerve impulses that are transmitted to the posterior pituitary gland and cause the release of ADH into the bloodstream.

ADH acts through 2 types of receptors: V 1 and V 2 .

The main physiological effect of the hormone is realized by V 2 receptors, which are located on the cells of the distal tubules and collecting ducts, which are relatively impermeable to water molecules.

ADH through V 2 receptors stimulates the adenylate cyclase system, as a result, proteins are phosphorylated that stimulate the expression of the membrane protein gene - aquaporina-2 . Aquaporin-2 is embedded in the apical membrane of cells, forming water channels in it. Through these channels, water is reabsorbed by passive diffusion from the urine into the interstitial space and the urine is concentrated.

In the absence of ADH, urine is not concentrated (density<1010г/л) и может выделяться в очень больших количествах (>20l/day), which leads to dehydration of the body. This state is called diabetes insipidus .

The cause of ADH deficiency and diabetes insipidus are: genetic defects in the synthesis of prepro-ADH in the hypothalamus, defects in the processing and transport of proADH, damage to the hypothalamus or neurohypophysis (eg, as a result of traumatic brain injury, tumor, ischemia). Nephrogenic diabetes insipidus occurs due to a mutation in the type V 2 ADH receptor gene.

V 1 receptors are localized in the membranes of SMC vessels. ADH through V 1 receptors activates the inositol triphosphate system and stimulates the release of Ca 2+ from the ER, which stimulates the contraction of SMC vessels. The vasoconstrictive effect of ADH is seen at high concentrations of ADH.

Maintaining one of the sides of homeostasis - the water-electrolyte balance of the body is carried out with the help of neuroendocrine regulation. The highest vegetative center of thirst is located in the ventromedial hypothalamus. The regulation of the release of water and electrolytes is carried out mainly by neurohumoral control of kidney function. A special role in this system is played by two closely related neurohormonal mechanisms - the secretion of aldosterone and (ADH). The main direction of the regulatory action of aldosterone is its inhibitory effect on all pathways of sodium excretion and, above all, on the tubules of the kidneys (anti-natriuremic effect). ADH maintains fluid balance by directly inhibiting the excretion of water by the kidneys (antidiuretic action). Between the activity of aldosterone and antidiuretic mechanisms there is a constant, close relationship. The loss of fluids stimulates the secretion of aldosterone through volomoreceptors, resulting in sodium retention and an increase in the concentration of ADH. The effector organs of both systems are the kidneys.

The degree of water and sodium loss is determined by the mechanisms of humoral regulation of water-salt metabolism: the pituitary antidiuretic hormone, vasopressin and the adrenal hormone aldosterone, which act on the most important organ to confirm the constancy of the water-salt balance in the body, which are the kidneys. ADH is produced in the supraoptic and paraventricular nuclei of the hypothalamus. Through the portal system of the pituitary gland, this peptide enters the posterior lobe of the pituitary gland, concentrates there and is released into the blood under the influence of nerve impulses entering the pituitary gland. The target of ADH is the wall of the distal tubules of the kidneys, where it enhances the production of hyaluronidase, which depolymerizes hyaluronic acid, thereby increasing the permeability of the walls of blood vessels. As a result, water from the primary urine diffuses passively into the kidney cells due to the osmotic gradient between the hyperosmotic intercellular fluid of the body and the hypoosmolar urine. The kidneys pass about 1000 liters of blood through their vessels per day. 180 liters of primary urine is filtered through the glomeruli of the kidneys, but only 1% of the fluid filtered by the kidneys turns into urine, 6/7 of the fluid that makes up the primary urine undergoes mandatory reabsorption along with other substances dissolved in it in the proximal tubules. The rest of the primary urine water is reabsorbed in the distal tubules. In them, the formation of primary urine in terms of volume and composition is carried out.

In the extracellular fluid, osmotic pressure is regulated by the kidneys, which can excrete urine with sodium chloride concentrations ranging from trace to 340 mmol/L. With the release of urine poor in sodium chloride, the osmotic pressure will increase due to salt retention, and with the rapid release of salt, it will fall.

The concentration of urine is controlled by hormones: vasopressin (antidiuretic hormone), increasing the reverse absorption of water, increases the concentration of salt in the urine, aldosterone stimulates the reverse absorption of sodium. The production and secretion of these hormones depends on the osmotic pressure and sodium concentration in the extracellular fluid. With a decrease in plasma salt concentration, aldosterone production increases and sodium retention increases, with an increase, vasopressin production increases, and aldosterone production decreases. This increases water reabsorption and sodium loss, and helps to reduce osmotic pressure. In addition, an increase in osmotic pressure causes thirst, which increases water intake. Signals for the formation of vasopressin and the sensation of thirst initiate osmoreceptors in the hypothalamus.

The regulation of cell volume and the concentration of ions inside cells are energy-dependent processes, including the active transport of sodium and potassium through cell membranes. The source of energy for active transport systems, as in almost any cell energy expenditure, is ATP exchange. The leading enzyme, sodium-potassium ATPase, gives cells the ability to pump sodium and potassium. This enzyme requires magnesium, and in addition, the simultaneous presence of both sodium and potassium is required for maximum activity. One consequence of the existence of different concentrations of potassium and other ions on opposite sides of the cell membrane is the generation of electrical potential differences across the membrane.

To ensure the operation of the sodium pump, up to 1/3 of the total energy stored by skeletal muscle cells is consumed. With hypoxia or the intervention of any inhibitors in metabolism, the cell swells. The mechanism of swelling is the entry of sodium and chloride ions into the cell; this leads to an increase in intracellular osmolarity, which in turn increases the water content as it follows the solute. The simultaneous loss of potassium is not equivalent to the intake of sodium, and therefore the result will be an increase in water content.

The effective osmotic concentration (tonicity, osmolarity) of the extracellular fluid changes almost parallel to the concentration of sodium in it, which, together with its anions, provides at least 90% of its osmotic activity. Fluctuations (even under pathological conditions) of potassium and calcium do not exceed a few milliequivalents per 1 liter and do not significantly affect the osmotic pressure.

Hypoelectrolytemia (hypoosmia, hypoosmolarity, hypotonicity) of the extracellular fluid is a drop in osmotic concentration below 300 mosm / l. This corresponds to a decrease in the sodium concentration below 135 mmol/l. Hyperelectrolytemia (hyperosmolarity, hypertonicity) is the excess of the osmotic concentration of 330 mosm / l and the sodium concentration of 155 mmol / l.

Large fluctuations in fluid volumes in the sectors of the body are due to complex biological processes that obey physical and chemical laws. In this case, the principle of electrical neutrality is of great importance, which consists in the fact that the sum of positive charges in all water spaces is equal to the sum of negative charges. Constantly occurring changes in the concentration of electrolytes in aqueous media are accompanied by a change in electrical potentials with subsequent recovery. Under dynamic equilibrium, stable concentrations of cations and anions are formed on both sides of biological membranes. However, it should be noted that electrolytes are not the only osmotically active components of the liquid medium of the body that come with food. Oxidation of carbohydrates and fats usually leads to the formation of carbon dioxide and water, which can simply be excreted by the lungs. When amino acids are oxidized, ammonia and urea are formed. The conversion of ammonia to urea provides the human body with one of the detoxification mechanisms, but at the same time, volatile compounds, potentially removed by the lungs, are converted into non-volatile ones, which should already be excreted by the kidneys.

The exchange of water and electrolytes, nutrients, oxygen and carbon dioxide, and other end products of metabolism is mainly due to diffusion. Capillary water exchanges water with interstitial tissue several times per second. Due to lipid solubility, oxygen and carbon dioxide freely diffuse through all capillary membranes; at the same time, water and electrolytes are thought to pass through the smallest pores of the endothelial membrane.

7. Principles of classification and main types of disorders of water metabolism.

It should be noted that there is no single generally accepted classification of water and electrolyte balance disorders. All types of disorders, depending on the change in the volume of water, are usually divided: with an increase in the volume of extracellular fluid - the water balance is positive (hyperhydration and edema); with a decrease in the volume of extracellular fluid - a negative water balance (dehydration). Hamburger et al. (1952) proposed to subdivide each of these forms into extra- and intercellular. The excess and decrease in the total amount of water is always considered in connection with the concentration of sodium in the extracellular fluid (its osmolarity). Depending on the change in osmotic concentration, hyper- and dehydration is divided into three types: isoosmolar, hypoosmolar and hyperosmolar.

Excessive accumulation of water in the body (hyperhydration, hyperhydria).

Isotonic hyperhydration represents an increase in the extracellular fluid volume without disturbing the osmotic pressure. In this case, the redistribution of fluid between the intra- and extracellular sectors does not occur. The increase in the total volume of water in the body is due to the extracellular fluid. Such a condition may be the result of heart failure, hypoproteinemia in nephrotic syndrome, when the volume of circulating blood remains constant due to the movement of the liquid part into the interstitial segment (palpable edema of the extremities appears, pulmonary edema may develop). The latter can be a severe complication associated with parenteral fluid administration for therapeutic purposes, the infusion of large amounts of saline or Ringer's solution in the experiment or in patients in the postoperative period.

Hypoosmolar overhydration, or water poisoning, is caused by excess water accumulation without adequate electrolyte retention, impaired fluid excretion due to renal insufficiency, or inadequate secretion of antidiuretic hormone. In the experiment, this violation can be reproduced by peritoneal dialysis of a hypoosmotic solution. Water poisoning in animals also easily develops when loaded with water after the introduction of ADH or removal of the adrenal glands. In healthy animals, water intoxication occurred 4-6 hours after ingestion of water at a dose of 50 ml/kg every 30 minutes. Vomiting, tremor, clonic and tonic convulsions occur. The concentration of electrolytes, proteins and hemoglobin in the blood decreases sharply, the plasma volume increases, the blood reaction does not change. Continued infusion can lead to the development of a coma and death of animals.

With water poisoning, the osmotic concentration of the extracellular fluid decreases due to its dilution with excess water, hyponatremia occurs. The osmotic gradient between the "interstitium" and the cells causes the movement of part of the intercellular water into the cells and their swelling. The volume of cellular water can increase by 15%.

In clinical practice, water intoxication occurs when water intake exceeds the ability of the kidneys to excrete it. After the introduction of 5 or more liters of water per day to the patient, headaches, apathy, nausea and cramps in the calves occur. Water poisoning can occur with excessive consumption of water, when there is increased production of ADH and oliguria. After injuries, during major surgical operations, blood loss, the introduction of anesthetics, especially morphine, oliguria usually lasts at least 1-2 days. Water poisoning can occur as a result of intravenous infusion of large amounts of isotonic glucose solution, which is rapidly consumed by cells, and the concentration of the injected fluid drops. It is also dangerous to introduce large amounts of water with limited kidney function, which occurs with shock, kidney diseases with anuria and oliguria, treatment of diabetes insipidus with ADH drugs. The danger of water intoxication arises from the excessive introduction of water without salts during the treatment of toxicosis, due to diarrhea in infants. Excessive watering sometimes occurs with frequently repeated enemas.

Therapeutic effects in conditions of hypoosmolar hyperhydria should be aimed at eliminating excess water and restoring the osmotic concentration of extracellular fluid. If the excess was associated with excessively large administration of water to a patient with symptoms of anuria, the use of an artificial kidney gives a quick therapeutic effect. Restoring the normal level of osmotic pressure by introducing salt is permissible only with a decrease in the total amount of salt in the body and with obvious signs of water poisoning.

Hyperosomal overhydration manifested by an increase in the volume of fluid in the extracellular space with a simultaneous increase in osmotic pressure due to hypernatremia. The mechanism for the development of disorders is as follows: sodium retention is not accompanied by water retention in an adequate volume, the extracellular fluid turns out to be hypertonic, and water from the cells moves into the extracellular spaces until the moment of osmotic equilibrium. The causes of the violation are diverse: Cushing's or Kohn's syndrome, drinking sea water, traumatic brain injury. If the state of hyperosmolar hyperhydration persists for a long time, cell death of the central nervous system may occur.

Dehydration of cells under experimental conditions occurs with the introduction of hypertonic electrolyte solutions in volumes exceeding the possibility of a sufficiently rapid excretion by the kidneys. In humans, a similar disorder occurs when forced to drink sea water. There is a movement of water from the cells into the extracellular space, felt as a heavy feeling of thirst. In some cases, hyperosmolar hyperhydria accompanies the development of edema.

A decrease in the total volume of water (dehydration, hypohydria, dehydration, exsicosis) also occurs with a decrease or increase in the osmotic concentration of the extracellular fluid. The danger of dehydration is the threat of blood clots. Severe symptoms of dehydration occur after the loss of about one-third of extracellular water.

Hypoosmolar dehydration develops in those cases when the body loses a lot of fluid containing electrolytes, and compensation for the loss occurs with a smaller volume of water without the introduction of salt. This condition occurs with repeated vomiting, diarrhea, increased sweating, hypoaldosteronism, polyuria (diabetes insipidus and diabetes mellitus), if the loss of water (hypotonic solutions) is partially replenished by drinking without salt. From the hypoosmotic extracellular space, part of the fluid rushes into the cells. Thus, exsicosis, which develops as a result of salt deficiency, is accompanied by intracellular edema. There is no feeling of thirst. The loss of water in the blood is accompanied by an increase in hematocrit, an increase in the concentration of hemoglobin and proteins. The depletion of blood with water and the associated decrease in plasma volume and increase in viscosity significantly impair blood circulation and, sometimes, cause collapse and death. A decrease in minute volume also leads to renal failure. The filtration volume drops sharply and oliguria develops. Urine is practically devoid of sodium chloride, which is facilitated by increased secretion of aldosterone due to the excitation of bulk receptors. The content of residual nitrogen in the blood increases. There may be external signs of dehydration - a decrease in turgor and wrinkling of the skin. Often there are headaches, lack of appetite. In children with dehydration, apathy, lethargy, and muscle weakness quickly appear.

It is recommended to replace the deficiency of water and electrolytes during hypoosmolar hydration by introducing an iso-osmotic or hypoosmotic fluid containing various electrolytes. If sufficient oral water intake is not possible, the inevitable loss of water through the skin, lungs and kidneys should be compensated by intravenous infusion of 0.9% sodium chloride solution. With a deficiency that has already arisen, the injected volume is increased, not exceeding 3 liters per day. Hypertonic saline should be administered only in exceptional cases when there are adverse effects of a decrease in the concentration of electrolytes in the blood, if the kidneys do not retain sodium and much is lost in other ways, otherwise the administration of excess sodium may increase dehydration. To prevent hyperchloremic acidosis with a decrease in the excretory function of the kidneys, it is rational to introduce lactic acid salt instead of sodium chloride.

Hyperosmolar dehydration develops as a result of water loss exceeding its intake and endogenous formation without loss of sodium. Water loss in this form occurs with little loss of electrolytes. This can occur with increased sweating, hyperventilation, diarrhea, polyuria, if the lost fluid is not compensated by drinking. A large loss of water in the urine occurs with the so-called osmotic (or diluting) diuresis, when a lot of glucose, urea or other nitrogenous substances are excreted through the kidneys, increasing the concentration of primary urine and making it difficult to reabsorb water. The loss of water in such cases exceeds the loss of sodium. Limited administration of water in patients with swallowing disorders, as well as in the suppression of thirst in cases of brain diseases, in a coma, in the elderly, in premature newborns, infants with brain damage, etc. Newborns of the first day of life sometimes have hyperosmolar exicosis due to for low consumption of milk ("fever from thirst"). Hyperosmolar dehydration occurs much more easily in infants than in adults. In infancy, large amounts of water, almost without electrolytes, can be lost through the lungs in fever, mild acidosis, and other cases of hyperventilation. In infants, a mismatch between the balance of water and electrolytes can also occur as a result of an underdeveloped concentration ability of the kidneys. Electrolyte retention occurs much more easily in a child's body, especially with an overdose of hypertonic or isotonic solution. In infants, the minimum, mandatory excretion of water (through the kidneys, lungs, and skin) per unit area is approximately twice that of adults.

The predominance of water loss over the release of electrolytes leads to an increase in the osmotic concentration of the extracellular fluid and the movement of water from the cells into the extracellular space. Thus, blood clotting slows down. A decrease in the volume of the extracellular space stimulates the secretion of aldosterone. This maintains the hyperosmolarity of the internal environment and the restoration of fluid volume due to increased production of ADH, which limits the loss of water through the kidneys. The hyperosmolarity of the extracellular fluid also reduces the excretion of water by extrarenal routes. The adverse effect of hyperosmolarity is associated with cell dehydration, which causes an excruciating feeling of thirst, increased protein breakdown, and fever. Loss of nerve cells leads to mental disorders (clouding of consciousness), respiratory disorders. Dehydration of the hyperosmolar type is also accompanied by a decrease in body weight, dry skin and mucous membranes, oliguria, signs of blood clotting, and an increase in the osmotic concentration of blood. The inhibition of the mechanism of thirst and the development of moderate extracellular hyperosmolarity in the experiment was achieved by an injection into the suprooptic nuclei of the hypothalamus in cats and the ventromedial nuclei in rats. Restoration of water deficiency and isotonicity of the human body fluid is achieved mainly by the introduction of a hypotonic glucose solution containing basic electrolytes.

Isotonic dehydration can be observed with an abnormally increased excretion of sodium, most often with the secretion of the glands of the gastrointestinal tract (isoosmolar secretions, the daily volume of which is up to 65% of the volume of the entire extracellular fluid). The loss of these isotonic fluids does not lead to a change in intracellular volume (all losses are due to extracellular volume). Their causes are repeated vomiting, diarrhea, loss through the fistula, the formation of large transudates (ascites, pleural effusion), blood and plasma loss during burns, peritonitis, pancreatitis.

The student must know:

1. The mechanism of urine formation: glomerular filtration, reabsorption and secretion.

2. Characteristics of the body's water compartments.

3. The main parameters of the liquid medium of the body.

4. What ensures the constancy of the parameters of the intracellular fluid?

5. Systems (organs, substances) that ensure the constancy of the extracellular fluid.

6. Factors (systems) that ensure the osmotic pressure of the extracellular fluid and its regulation.

7. Factors (systems) that ensure the constancy of the volume of extracellular fluid and its regulation.

8. Factors (systems) that ensure the constancy of the acid-base state of the extracellular fluid. The role of the kidneys in this process.

9. Features of metabolism in the kidneys: high metabolic activity, the initial stage of creatine synthesis, the role of intensive gluconeogenesis (isoenzymes), activation of vitamin D3.

10. General properties of urine (amount per day - diuresis, density, color, transparency), chemical composition of urine. Pathological components of urine.

The student must be able to:

1. Conduct a qualitative determination of the main components of urine.

2. Assess the biochemical analysis of urine.

The student must be aware of: some pathological conditions accompanied by changes in the biochemical parameters of urine (proteinuria, hematuria, glucosuria, ketonuria, bilirubinuria, porphyrinuria); The principles of planning a laboratory study of urine and analysis of the results to make a preliminary conclusion about biochemical changes based on the results of a laboratory examination.

1. The structure of the kidney, nephron.

2. Mechanisms of urine formation.

Tasks for self-training:

1. Refer to the course of histology. Remember the structure of the nephron. Note the proximal tubule, distal convoluted tubule, collecting duct, vascular glomerulus, juxtaglomerular apparatus.

2. Refer to the course of normal physiology. Remember the mechanism of urine formation: filtration in the glomeruli, reabsorption in the tubules with the formation of secondary urine and secretion.

3. The regulation of the osmotic pressure and volume of the extracellular fluid is associated with the regulation, mainly, of the content of sodium and water ions in the extracellular fluid.

Test your knowledge:

A. Vasopressin(all correct except for one):

B. Aldosterone(all correct except for one):

e. The main mechanism for regulating secretion is the arenin-angiotensive system of the kidneys.

B. Natriuretic factor(all correct except for one):

4. Draw a diagram illustrating the role of the renin-angiotensive system in the regulation of aldosterone and vasopressin secretion.

Remember the buffer systems of the blood (basic bicarbonate)!

Test your knowledge:

Food of animal origin is acidic in nature (mainly due to phosphates, in contrast to food of plant origin). How will the pH of urine change in a person who uses mainly food of animal origin:

a. closer to pH 7.0; b.pn about 5.; v. pH around 8.0.

6. Answer the questions:

A. How to explain the high proportion of oxygen consumed by the kidneys (10%);

B. High intensity of gluconeogenesis;

B. The role of the kidneys in calcium metabolism.

7. One of the main tasks of nephrons is to reabsorb useful substances from the blood in the right amount and remove metabolic end products from the blood.

Make a table Biochemical indicators of urine:

Auditorium work.

Laboratory work:

Carry out a series of qualitative reactions in urine samples from different patients. Make a conclusion about the state of metabolic processes based on the results of biochemical analysis.

pH determination.

Progress: To 1-2 ml of urine add 3-4 drops of freshly prepared 20% solution of sulfasalicylic acid. In the presence of protein, a white precipitate or turbidity appears.

3. Qualitative reaction for glucose (Fehling's reaction).

The determination can be carried out using a test strip (indicator paper) /

Detection of ketone bodies

Normally, ketone bodies are absent in the urine. In some pathological conditions, ketone bodies appear in the urine - ketonuria.

Solve problems on your own, answer questions:

1. The osmotic pressure of the extracellular fluid has increased. Describe, in diagrammatic form, the sequence of events that will lead to its decrease.

2. How will aldosterone production change if excessive production of vasopressin leads to a significant decrease in osmotic pressure.

3. Outline the sequence of events (in the form of a diagram) aimed at restoring homeostasis with a decrease in the concentration of sodium chloride in tissues.

Lesson 27. Biochemistry of saliva.

Subject Meaning: Various tissues are combined in the oral cavity and microorganisms live. They are interconnected and a certain constancy. And in maintaining the homeostasis of the oral cavity, and the body as a whole, the most important role belongs to the oral fluid and, specifically, saliva. The oral cavity, as the initial section of the digestive tract, is the place of the first contact of the body with food, drugs and other xenobiotics, microorganisms . The formation, condition and functioning of the teeth and oral mucosa is also largely determined by the chemical composition of saliva.

Saliva performs several functions, determined by the physicochemical properties and composition of saliva. Knowledge of the chemical composition of saliva, functions, rate of salivation, the relationship of saliva with diseases of the oral cavity helps to identify the characteristics of pathological processes and the search for new effective means of preventing dental diseases.

Some biochemical parameters of pure saliva correlate with biochemical parameters of blood plasma; therefore, saliva analysis is a convenient non-invasive method used in recent years to diagnose dental and somatic diseases.

Purpose of the lesson: To study the physico-chemical properties, the constituent components of saliva, which determine its main physiological functions. Leading factors leading to the development of caries, the deposition of tartar.

The student must know:

1 . Glands that secrete saliva.

2. The structure of saliva (micellar structure).

3. Mineralizing function of saliva and factors causing and influencing this function: oversaturation of saliva; volume and speed of salvation; pH.

4. The protective function of saliva and the components of the system that determine this function.

5. Saliva buffer systems. The pH values are normal. Causes of violation of the acid-base state (acid-base state) in the oral cavity. Mechanisms of regulation of CBS in the oral cavity.

6. Mineral composition of saliva and in comparison with the mineral composition of blood plasma. The value of the components.

7. Characteristics of the organic components of saliva, saliva-specific components, their significance.

8. Digestive function and factors causing it.

9. Regulatory and excretory functions.

10. Leading factors leading to the development of caries, the deposition of tartar.

The student must be able to:

1. Distinguish between the concepts of "saliva itself or saliva", "gingival fluid", "oral fluid".

2. Be able to explain the degree of change in resistance to caries with a change in the pH of saliva, the reasons for the change in the pH of saliva.

3. Collect mixed saliva for analysis and analyze the chemical composition of saliva.

The student must be proficient in: information about modern ideas about saliva as an object of non-invasive biochemical research in clinical practice.

Information from the basic disciplines necessary to study the topic:

1. Anatomy and histology of the salivary glands; mechanisms of salivation and its regulation.

Tasks for self-training:

Study the material of the topic in accordance with the target questions (“the student needs to know”) and complete the following tasks in writing:

1. Write down the factors that determine the regulation of salivation.

2. Sketch a saliva micelle.

3. Make a table: The mineral composition of saliva and blood plasma in comparison.

Learn the meaning of the listed substances. Write down other inorganic substances contained in saliva.

4. Make a table: The main organic components of saliva and their importance.

6. Write down the factors leading to a decrease and increase in resistance

(respectively) to caries.

Classroom work

Laboratory work: Qualitative analysis of the chemical composition of saliva

MODULE 5

WATER-SALT AND MINERAL METABOLISM.

BIOCHEMISTRY OF BLOOD AND URINE. TISSUE BIOCHEMISTRY.

ACTIVITY 1

Topic: Water-salt and mineral metabolism. Regulation. Violation.

Relevance. The concepts of water-salt and mineral metabolism are ambiguous. Speaking of water-salt metabolism, they mean the exchange of basic mineral electrolytes and, above all, the exchange of water and NaCl. Water and mineral salts dissolved in it constitute the internal environment of the human body, creating conditions for the occurrence of biochemical reactions. In maintaining water-salt homeostasis, an important role is played by the kidneys and hormones that regulate their function (vasopressin, aldosterone, atrial natriuretic factor, renin-angiotensin system). The main parameters of the liquid medium of the body are osmotic pressure, pH and volume. The osmotic pressure and pH of the intercellular fluid and blood plasma are practically the same, and the pH value of cells of different tissues can be different. Maintaining homeostasis is ensured by the constancy of osmotic pressure, pH and volume of intercellular fluid and blood plasma. Knowledge of water-salt metabolism and methods for correcting the main parameters of the body's fluid medium is necessary for the diagnosis, treatment and prognosis of such disorders as tissue dehydration or edema, increased or decreased blood pressure, shock, acidosis, alkalosis.

Mineral metabolism is the exchange of any mineral components of the body, including those that do not affect the main parameters of the liquid medium, but perform various functions associated with catalysis, regulation, transport and storage of substances, structuring of macromolecules, etc. Knowledge of mineral metabolism and methods of its study is necessary for the diagnosis, treatment and prognosis of exogenous (primary) and endogenous (secondary) disorders.

Target. To get acquainted with the functions of water in the processes of life, which are due to the peculiarities of its physical and chemical properties and chemical structure; to learn the content and distribution of water in the body, tissues, cells; water condition; water exchange. Have an idea about the water pool (the ways in which water enters and leaves the body); endogenous and exogenous water, content in the body, daily requirement, age characteristics. To get acquainted with the regulation of the total volume of water in the body and its movement between individual fluid spaces, possible violations. To learn and be able to characterize macro-, oligo-, micro- and ultramicrobiogenic elements, their general and specific functions; electrolyte composition of the body; the biological role of the main cations and anions; the role of sodium and potassium. To get acquainted with phosphate-calcium metabolism, its regulation and violation. Determine the role and metabolism of iron, copper, cobalt, zinc, iodine, fluorine, strontium, selenium and other biogenic elements. To learn the daily need of the body for minerals, their absorption and excretion from the body, the possibility and forms of deposition, violations. To get acquainted with the methods of quantitative determination of calcium and phosphorus in blood serum and their clinical and biochemical significance.

THEORETICAL QUESTIONS

1. The biological significance of water, its content, the daily need of the body. Water is exogenous and endogenous.

2. Properties and biochemical functions of water. Distribution and condition of water in the body.

3. Water exchange in the body, age characteristics, regulation.

4. Water balance of the body and its types.

5. The role of the gastrointestinal tract in the exchange of water.

6. Functions of mineral salts in the body.

7. Neurohumoral regulation of water-salt metabolism.

8. Electrolyte composition of body fluids, its regulation.

9. Mineral substances of the human body, their content, role.

10. Classification of biogenic elements, their role.

11. Functions and metabolism of sodium, potassium, chlorine.

12. Functions and metabolism of iron, copper, cobalt, iodine.

13. Phosphate-calcium metabolism, the role of hormones and vitamins in its regulation. Mineral and organic phosphates. Urine phosphates.

14. The role of hormones and vitamins in the regulation of mineral metabolism.

15. Pathological conditions associated with impaired metabolism of mineral substances.

1. In a patient, less water is excreted from the body per day than it enters. What disease can lead to such a condition?

2. The occurrence of Addison-Birmer disease (malignant hyperchromic anemia) is associated with vitamin B12 deficiency. Select the metal that is part of this vitamin:

A. Zink. V. Cobalt. C. Molybdenum. D. Magnesium. E. Iron.

3. Calcium ions are secondary messengers in cells. They activate glycogen catabolism by interacting with:

4. In a patient, the content of potassium in the blood plasma is 8 mmol/l (the norm is 3.6-5.3 mmol/l). In this condition, there is:

5. What electrolyte creates 85% of the osmotic pressure of the blood?

A. Potassium. B. Calcium. C. Magnesium. D. Zinc. E. Sodium.

6. Specify the hormone that affects the content of sodium and potassium in the blood?

A. Calcitonin. B. Histamine. C. Aldosterone. D. Thyroxine. E. Parathirin

7. Which of the listed elements are macrobiogenic?

8. With a significant weakening of cardiac activity, edema occurs. Indicate what will be the water balance of the body in this case.

A. Positive. B. Negative. C. Dynamic balance.

9. Endogenous water is formed in the body as a result of reactions:

10. The patient went to the doctor with complaints of polyuria and thirst. When analyzing urine, it was found that the daily diuresis is 10 liters, the relative density of urine is 1.001 (the norm is 1.012-1.024). For what disease such indicators are characteristic?

11. Specify what indicators characterize the normal content of calcium in the blood (mmol/l)?

14. The daily water requirement for an adult is:

A. 30-50 ml/kg. B. 75-100 ml/kg. C. 75-80 ml/kg. D. 100-120 ml/kg.

15. A 27-year-old patient has pathological changes in the liver and brain. There is a sharp decrease in the blood plasma, and an increase in the content of copper in the urine. The previous diagnosis was Konovalov-Wilson's disease. Which enzyme activity should be tested to confirm the diagnosis?

16. It is known that endemic goiter is a common disease in some biogeochemical zones. Deficiency of what element is the cause of this disease? A. Iron. V. Yoda. S. Zinc. D. Copper. E. Cobalt.

17. How many ml of endogenous water is formed in the human body per day with a balanced diet?

A. 50-75. V. 100-120. pp. 150-250. D. 300-400. E. 500-700.

PRACTICAL WORK

Quantification of calcium and inorganic phosphorus

In the blood serum

Exercise 1. Determine the calcium content in the blood serum.

Principle. Serum calcium is precipitated with a saturated solution of ammonium oxalate [(NH 4) 2 C 2 O 4 ] in the form of calcium oxalate (CaC 2 O 4). The latter is converted with sulfate acid into oxalic acid (H 2 C 2 O 4), which is titrated with a solution of KMnO 4 .

Chemistry. 1. CaCl 2 + (NH 4) 2 C 2 O 4 ® CaC 2 O 4 ¯ + 2NH 4 Cl

2. CaC 2 O 4 + H 2 SO 4 ®H 2 C 2 O 4 + CaSO 4

3. 5H 2 C 2 O 4 + 2KMnO 4 + 3H 2 SO 4 ® 10CO 2 + 2MnSO 4 + 8H 2 O

Progress. 1 ml of blood serum and 1 ml of [(NH 4) 2 C 2 O 4] solution are poured into a centrifuge tube. Leave to stand for 30 minutes and centrifuge. The crystalline precipitate of calcium oxalate is collected at the bottom of the test tube. The clear liquid is poured over the precipitate. Add 1-2 ml of distilled water to the sediment, mix with a glass rod and centrifuge again. After centrifugation, the liquid above the precipitate is discarded. Add 1 ml1n H 2 SO 4 to the test tube with the precipitate, mix the precipitate well with a glass rod and put the test tube in a water bath at a temperature of 50-70 0 C. The precipitate dissolves. The content of the test tube is titrated hot with 0.01 N KMnO 4 solution until a pink color appears, which does not disappear for 30 s. Each milliliter of KMnO 4 corresponds to 0.2 mg Ca. The content of calcium (X) in mg% in blood serum is calculated by the formula: X = 0.2 × A × 100, where A is the volume of KMnO 4 that went for titration. The content of calcium in blood serum in mmol / l - content in mg% × 0.2495.

Normally, the concentration of calcium in the blood serum is 2.25-2.75 mmol / l (9-11 mg%). An increase in the concentration of calcium in the blood serum (hypercalcemia) is observed with hypervitaminosis D, hyperparathyroidism, osteoporosis. Decreased calcium concentration (hypocalcemia) - with hypovitaminosis D (rickets), hypoparathyroidism, chronic renal failure.

Task 2. Determine the content of inorganic phosphorus in blood serum.

Principle. Inorganic phosphorus, interacting with molybdenum reagent in the presence of ascorbic acid, forms molybdenum blue, the color intensity of which is proportional to the content of inorganic phosphorus.

Progress. 2 ml of blood serum, 2 ml of a 5% solution of trichloroacetic acid are poured into a test tube, mixed and left for 10 minutes to precipitate proteins, after which it is filtered. Then 2 ml of the resulting filtrate is measured into a test tube, which corresponds to 1 ml of blood serum, 1.2 ml of molybdenum reagent, 1 ml of 0.15% ascorbic acid solution are added and topped up with water to 10 ml (5.8 ml). Mix thoroughly and leave for 10 minutes for color development. Colorimetric on FEC with a red light filter. The amount of inorganic phosphorus is found from the calibration curve and its content (B) in the sample is calculated in mmol / l according to the formula: B \u003d (A × 1000) / 31, where A is the content of inorganic phosphorus in 1 ml of blood serum (found from the calibration curve) ; 31 - molecular weight of phosphorus; 1000 - conversion factor per liter.

Clinical and diagnostic value. Normally, the concentration of phosphorus in the blood serum is 0.8-1.48 mmol / l (2-5 mg%). An increase in the concentration of phosphorus in the blood serum (hyperphosphatemia) is observed with renal failure, hypoparathyroidism, an overdose of vitamin D. A decrease in the concentration of phosphorus (hypophosphatemia) - in violation of its absorption in the intestine, galactosemia, rickets.

LITERATURE

1. Gubsky Yu.I. Biological chemistry. Assistant. - Kiev-Vinnitsa: New book, 2007. - S. 545-557.

2. Gonsky Ya.I., Maksimchuk T.P., Kalinsky M.I. Biochemistry of people: Pdruchnik. - Ternopil: Ukrmedkniga, 2002. - S. 507-529.

3. Biochemistry: Textbook / Ed. E.S. Severin. - M.: GEOTAR-MED, 2003. - S. 597-609.

4. Workshop on biological chemistry / Boykiv D.P., Ivankiv O.L., Kobilyanska L.I. that in./ For red. O.Ya. Sklyarova. - K .: Health, 2002. - S. 275-280.

ACTIVITY 2

Topic: Functions of the blood. Physical and chemical properties and chemical composition of blood. Buffer systems, mechanism of action and role in maintaining the acid-base state of the body. Plasma proteins and their role. Quantitative determination of total protein in blood serum.

Relevance. Blood is a liquid tissue consisting of cells (shaped elements) and an intercellular liquid medium - plasma. Blood performs transport, osmoregulatory, buffer, neutralizing, protective, regulatory, homeostatic and other functions. The composition of blood plasma is a mirror of metabolism - changes in the concentration of metabolites in cells are reflected in their concentration in the blood; the composition of blood plasma also changes when the permeability of cell membranes is disturbed. In this regard, as well as the availability of blood samples for analysis, its study is widely used to diagnose diseases and monitor the effectiveness of treatment. Quantitative and qualitative study of plasma proteins, in addition to specific nosological information, gives an idea of the state of protein metabolism in general. The concentration of hydrogen ions in the blood (pH) is one of the most stringent chemical constants in the body. It reflects the state of metabolic processes, depends on the functioning of many organs and systems. Violation of the acid-base state of the blood is observed in numerous pathological processes, diseases and is the cause of severe disorders of the body. Therefore, timely correction of disorders of the acid-base state is a necessary component of therapeutic measures.

Target. To get acquainted with the functions, physical and chemical properties of blood; acid-base state and its main indicators. To learn the buffer systems of blood and the mechanism of their action; violation of the acid-base state of the body (acidosis, alkalosis), its forms and types. To form an idea of the protein composition of blood plasma, to characterize protein fractions and individual proteins, their role, disorders and methods of determination. Familiarize yourself with the methods of quantitative determination of total protein in blood serum, individual fractions of proteins and their clinical and diagnostic significance.

TASKS FOR INDEPENDENT WORK

THEORETICAL QUESTIONS

1. The functions of blood in the life of the body.

2. Physical and chemical properties of blood, serum, lymph: pH, osmotic and oncotic pressure, relative density, viscosity.

3. Acid-base state of the blood, its regulation. The main indicators reflecting its violation. Modern methods for determining the acid-base state of the blood.

4. Buffer systems of blood. Their role in maintaining the acid-base balance.

5. Acidosis: types, causes, mechanisms of development.

6. Alkalosis: types, causes, mechanisms of development.

7. Blood proteins: content, functions, changes in content in pathological conditions.

8. Main fractions of blood plasma proteins. Research methods.

9. Albumins, physical and chemical properties, role.

10. Globulins, physical and chemical properties, role.

11. Blood immunoglobulins, structure, functions.

12. Hyper-, hypo-, dis- and paraproteinemias, causes.

13. Acute phase proteins. Clinical and diagnostic value of the definition.

TESTS FOR SELF-CHECKING

1. Which of the following pH values is normal for arterial blood? A. 7.25-7.31. B. 7.40-7.55. S. 7.35-7.45. D. 6.59-7.0. E. 4.8-5.7.

2. What mechanisms ensure the constancy of blood pH?

3. What is the reason for the development of metabolic acidosis?

A. Increase in production, decrease in oxidation and resynthesis of ketone bodies.

B. Increase in production, decrease in lactate oxidation and resynthesis.

C. Loss of grounds.

D. Inefficient secretion of hydrogen ions, acid retention.

E. All of the above.

4. What is the cause of metabolic alkalosis?

5. Significant loss of gastric juice due to vomiting causes the development of:

6. Significant circulatory disorders due to shock cause the development of:

7. Inhibition of the respiratory center of the brain with narcotic drugs leads to:

8. The pH value of the blood changed in a patient with diabetes mellitus to 7.3 mmol/l. What buffer system components are used to diagnose acid-base balance disorders?

9. The patient has an obstruction of the respiratory tract with sputum. What disorder of the acid-base balance can be determined in the blood?

10. A patient with a severe injury was connected to an artificial respiration apparatus. After repeated determinations of indicators of the acid-base state, a decrease in the content of carbon dioxide in the blood and an increase in its excretion were revealed. What acid-base disorder is characterized by such changes?

11. Name the buffer system of the blood, which is of the greatest importance in the regulation of acid-base homeostasis?

12. What buffer system of the blood plays an important role in maintaining the pH of urine?

A. Phosphate. B. Hemoglobin. C. Hydrocarbonate. D. Protein.

13. What physical and chemical properties of blood are provided by the electrolytes present in it?

14. Examination of the patient revealed hyperglycemia, glucosuria, hyperketonemia and ketonuria, polyuria. What type of acid-base state is observed in this case?

15. A person at rest forces himself to breathe often and deeply for 3-4 minutes. How will this affect the acid-base balance of the body?

16. What blood plasma protein binds and transports copper?

17. In the patient's blood plasma, the content of total protein is within the normal range. Which of the following indicators (g/l) characterize the physiological norm? A. 35-45. V. 50-60. pp. 55-70. D. 65-85. E. 85-95.

18. What fraction of blood globulins provides humoral immunity, acting as antibodies?

19. A patient who had hepatitis C and constantly consumed alcohol developed signs of liver cirrhosis with ascites and edema of the lower extremities. What changes in the composition of the blood played a major role in the development of edema?

20. On what physicochemical properties of proteins is the method for determining the electrophoretic spectrum of blood proteins based?

PRACTICAL WORK

Quantitative determination of total protein in blood serum

biuret method

Exercise 1. Determine the content of total protein in blood serum.

Principle. The protein reacts in an alkaline environment with a copper sulfate solution containing sodium potassium tartrate, NaI and KI (biuret reagent) to form a violet-blue complex. The optical density of this complex is proportional to the protein concentration in the sample.

Progress. Add 25 µl of blood serum (without hemolysis), 1 ml of biuret reagent containing: 15 mmol/l potassium sodium tartrate, 100 mmol/l sodium iodide, 15 mmol/l potassium iodide and 5 mmol/l copper sulfate to the experimental sample . Add 25 µl of total protein standard (70 g/l) and 1 ml of biuret reagent to the standard sample. Add 1 ml of biuret reagent to the third tube. Mix all tubes well and incubate for 15 minutes at 30-37°C. Leave for 5 minutes at room temperature. Measure the absorbance of the sample and standard against the biuret reagent at 540 nm. Calculate the total protein concentration (X) in g/l using the formula: X=(Cst×Apr)/Ast, where Cst is the concentration of total protein in the standard sample (g/l); Apr is the optical density of the sample; Ast - optical density of the standard sample.

Clinical and diagnostic value. The content of total protein in the blood plasma of adults is 65-85 g/l; due to fibrinogen, the protein in the blood plasma is 2-4 g / l more than in the serum. In newborns, the amount of blood plasma proteins is 50-60 g / l and during the first month it slightly decreases, and at three years it reaches the level of adults. An increase or decrease in the content of total plasma protein and individual fractions can be due to many reasons. These changes are not specific, but reflect the general pathological process (inflammation, necrosis, neoplasm), dynamics, and severity of the disease. With their help, you can evaluate the effectiveness of treatment. Changes in protein content can manifest as hyper, hypo- and dysproteinemia. Hypoproteinemia is observed when there is insufficient intake of proteins in the body; insufficiency of digestion and absorption of food proteins; violation of protein synthesis in the liver; kidney disease with nephrotic syndrome. Hyperproteinemia is observed in violation of hemodynamics and thickening of the blood, fluid loss during dehydration (diarrhea, vomiting, diabetes insipidus), in the first days of severe burns, in the postoperative period, etc. Noteworthy is not only hypo- or hyperproteinemia, but also changes such as dysproteinemia ( the ratio of albumin and globulins changes with a constant content of total protein) and paraproteinemia (the appearance of abnormal proteins - C-reactive protein, cryoglobulin) in acute infectious diseases, inflammatory processes, etc.

LITERATURE

1. Gubsky Yu.I. Biological chemistry. - Kiev-Ternopil: Ukrmedkniga, 2000. - S. 418-429.

2. Gubsky Yu.I. Biological chemistry. Assistant. - Kiev-Vinnitsa: New book, 2007. - S. 502-514.

3. Gonsky Ya.I., Maksimchuk T.P., Kalinsky M.I. Biochemistry of people: Pdruchnik. - Ternopil: Ukrmedkniga, 2002. - S. 546-553, 566-574.

4. Voronina L.M. that in. Biological chemistry. - Kharkiv: Osnova, 2000. - S. 522-532.

5. Berezov T.T., Korovkin B.F. Biological chemistry. - M.: Medicine, 1998. - S. 567-578, 586-598.

6. Biochemistry: Textbook / Ed. E.S. Severin. - M.: GEOTAR-MED, 2003. - S. 682-686.

7. Workshop on biological chemistry / Boykiv D.P., Ivankiv O.L., Kobilyanska L.I. that in./ For red. O.Ya. Sklyarova. - K .: Health, 2002. - S. 236-249.

ACTIVITY 3

Topic: Biochemical composition of blood in normal and pathological conditions. Enzymes in blood plasma. Non-protein organic substances of blood plasma are nitrogen-containing and nitrogen-free. Inorganic components of blood plasma. Kallikrein-kinin system. Determination of residual nitrogen in blood plasma.

Relevance. When formed elements are removed from the blood, plasma remains, and when fibrinogen is removed from it, serum remains. Blood plasma is a complex system. It contains more than 200 proteins, which differ in physicochemical and functional properties. Among them are proenzymes, enzymes, enzyme inhibitors, hormones, transport proteins, coagulation and anticoagulation factors, antibodies, antitoxins and others. In addition, blood plasma contains non-protein organic substances and inorganic components. Most pathological conditions, the influence of external and internal environmental factors, the use of pharmacological drugs are usually accompanied by a change in the content of individual components of blood plasma. Based on the results of a blood test, one can characterize the state of human health, the course of adaptation processes, etc.

Target. Familiarize yourself with the biochemical composition of blood in normal and pathological conditions. To characterize blood enzymes: the origin and significance of activity determination for the diagnosis of pathological conditions. Determine what substances make up the total and residual nitrogen of the blood. Familiarize yourself with nitrogen-free blood components, their content, clinical significance of quantitative determination. Consider the kallikrein-kinin system of the blood, its components and role in the body. Familiarize yourself with the method of quantitative determination of residual blood nitrogen and its clinical and diagnostic significance.

TASKS FOR INDEPENDENT WORK

THEORETICAL QUESTIONS

1. Blood enzymes, their origin, clinical and diagnostic significance of the determination.

2. Non-protein nitrogen-containing substances: formulas, content, clinical significance of the definition.

3. Total and residual blood nitrogen. Clinical significance of the definition.

4. Azotemia: types, causes, methods of determination.

5. Non-protein nitrogen-free blood components: content, role, clinical significance of the determination.

6. Inorganic blood components.

7. Kallikrein-kinin system, its role in the body. The use of drugs - kallikrein and inhibitors of kinin formation.

TESTS FOR SELF-CHECKING

1. In the patient's blood, the content of residual nitrogen is 48 mmol/l, urea - 15.3 mmol/l. What organ disease do these results indicate?

A. Spleen. B. Liver. C. Stomach. D. Kidney. E. Pancreas.

2. What indicators of residual nitrogen are typical for adults?

A.14.3-25 mmol / l. B.25-38 mmol / l. C.42.8-71.4 mmol / l. D.70-90 mmol/l.

3. Specify the component of blood that is nitrogen-free.

A. ATP. B. Thiamine. C. Ascorbic acid. D. Creatine. E. Glutamine.

4. What type of azotemia develops when the body is dehydrated?

5. What effect does bradykinin have on blood vessels?

6. A patient with hepatic insufficiency showed a decrease in the level of residual nitrogen in the blood. Due to what component did the non-protein nitrogen of the blood decrease?

7. The patient complains of frequent vomiting, general weakness. The content of residual nitrogen in the blood is 35 mmol/l, kidney function is not impaired. What type of azotemia has arisen?

A. Relative. B. Renal. C. Retention. D. Production.

8. What components of the fraction of residual nitrogen predominate in the blood in case of productive azotemia?

9. C-reactive protein is found in the blood serum:

10. Konovalov-Wilson disease (hepatocerebral degeneration) is accompanied by a decrease in the concentration of free copper in the blood serum, as well as the level of:

11. Lymphocytes and other cells of the body, when interacting with viruses, synthesize interferons. These substances block the reproduction of the virus in the infected cell, inhibiting the synthesis of viral:

A. Lipids. B. Belkov. C. Vitamins. D. Biogenic amines. E. Nucleotides.

12. A 62-year-old woman complains of frequent pain in the retrosternal region and spine, rib fractures. The doctor suggests multiple myeloma (plasmocytoma). Which of the following indicators has the greatest diagnostic value?

PRACTICAL WORK

LITERATURE

1. Gubsky Yu.I. Biological chemistry. - Kiev-Ternopil: Ukrmedkniga, 2000. - S. 429-431.

2. Gubsky Yu.I. Biological chemistry. Assistant. - Kiev-Vinnitsa: New book, 2007. - S. 514-517.

3. Berezov T.T., Korovkin B.F. Biological chemistry. - M.: Medicine, 1998. - S. 579-585.

4. Workshop on biological chemistry / Boykiv D.P., Ivankiv O.L., Kobilyanska L.I. that in./ For red. O.Ya. Sklyarova. - K .: Health, 2002. - S. 236-249.

ACTIVITY 4

Topic: Biochemistry of the coagulation, anticoagulation and fibrinolytic systems of the body. Biochemistry of immune processes. Mechanisms of development of immunodeficiency states.

Relevance. One of the most important functions of blood is hemostatic, in its implementation the coagulation, anticoagulation and fibrinolytic systems take part. Coagulation is a physiological and biochemical process, as a result of which blood loses its fluidity and blood clots form. The existence of a liquid state of blood under normal physiological conditions is due to the work of the anticoagulant system. With the formation of blood clots on the walls of blood vessels, the fibrinolytic system is activated, the work of which leads to their splitting.

Immunity (from Latin immunitas - liberation, salvation) - is a protective reaction of the body; This is the ability of a cell or organism to protect itself from living bodies or substances that carry signs of alien information, while maintaining its integrity and biological individuality. Organs and tissues, as well as certain types of cells and their metabolic products, which provide recognition, binding and destruction of antigens using cellular and humoral mechanisms, are called the immune system. . This system exercises immune surveillance - control over the genetic constancy of the internal environment of the body. Violation of immune surveillance leads to a weakening of the body's antimicrobial resistance, inhibition of antitumor protection, autoimmune disorders and immunodeficiency states.

Target. To get acquainted with the functional and biochemical characteristics of the hemostasis system in the human body; coagulation and vascular-platelet hemostasis; blood coagulation system: characteristics of individual components (factors) of coagulation; mechanisms of activation and functioning of the cascade system of blood coagulation; internal and external ways of coagulation; the role of vitamin K in coagulation reactions, drugs - agonists and antagonists of vitamin K; hereditary disorders of the blood coagulation process; anticoagulant blood system, functional characteristics of anticoagulants - heparin, antithrombin III, citric acid, prostacyclin; the role of the vascular endothelium; changes in blood biochemical parameters with prolonged administration of heparin; fibrinolytic blood system: stages and components of fibrinolysis; drugs that affect the processes of fibrinolysis; plasminogen activators and plasmin inhibitors; blood sedimentation, thrombosis and fibrinolysis in atherosclerosis and hypertension.

To get acquainted with the general characteristics of the immune system, cellular and biochemical components; immunoglobulins: structure, biological functions, mechanisms of regulation of synthesis, characteristics of individual classes of human immunoglobulins; mediators and hormones of the immune system; cytokines (interleukins, interferons, protein-peptide factors regulating cell growth and proliferation); biochemical components of the human complement system; classical and alternative activation mechanisms; the development of immunodeficiency states: primary (hereditary) and secondary immunodeficiencies; human acquired immunodeficiency syndrome.

TASKS FOR INDEPENDENT WORK

THEORETICAL QUESTIONS

1. The concept of hemostasis. The main phases of hemostasis.

2. Mechanisms of activation and functioning of the cascade system