Protein composition of mixed human saliva: mechanisms of psychophysiological regulation. Does human saliva have medicinal properties Properties of human saliva

The liquid that is secreted by the salivary glands is a whole cocktail of proteins, vitamins, micro- and macroelements, although most of it, 98-99%, is water. The concentration of iodine, calcium, potassium, strontium in saliva is many times higher than in the blood. Microelements are also present in the salivary fluid: iron, copper, manganese, nickel, lithium, aluminum, sodium, calcium, manganese, zinc, potassium, chromium, silver, bismuth, lead.

Such a rich composition ensures the proper functioning of salivary enzymes, which begin digesting food in the mouth. One of the enzymes, lysozyme, has a significant bactericidal effect - and it is isolated for the preparation of certain drugs.

From ulcers to infections

An experienced doctor can judge the condition and functioning of certain organs by the nature of saliva, as well as identify certain diseases on the early stage. Yes, when infectious diseases the slightly alkaline reaction of saliva changes to acidic. With nephritis (inflammation of the kidneys), the amount of nitrogen in the saliva increases, the same thing happens with peptic ulcer stomach and duodenum. For diseases thyroid gland saliva becomes viscous and foamy. The composition of saliva also changes in some tumors, which makes it possible to detect the disease or confirm the diagnosis when clinical picture is not yet obvious.

As the body ages, the proportions of micro- and macroelements in saliva are disrupted, which leads to the deposition of tartar, increasing the likelihood of caries and inflammatory diseases periodontal

There is a change in the composition of saliva during fasting, as well as with certain hormonal imbalances.

So don't be surprised if your doctor prescribes a saliva test - you can really learn a lot from it.

Suspicious signs

Qualitative analysis of salivary fluid is performed in the laboratory using special reagents and instruments. But sometimes the changes in saliva are so strong that a person may suspect something is wrong without any examination. The following signs should alert you.

Change in saliva color - in some diseases digestive system it becomes yellowish (the same is observed in heavy smokers, which may signal some kind of internal pathology).

Lack of saliva constant dryness in the mouth and even a burning sensation, as well as thirst - this may be a sign of diabetes, hormonal imbalances, thyroid diseases.

Too much copious discharge saliva that is not associated with eating tasty food - this indicates a disorder and may be a sign of certain tumors or hormonal imbalances.

The bitter taste of saliva is a signal of liver or gallbladder pathology.

If any of these manifestations occur, it makes sense to consult a doctor so that he can prescribe additional research and identified the exact cause of the violations.

Saliva is a biological fluid secreted by three pairs of large salivary glands(parotid, submandibular and sublingual) and many minor salivary glands. The secretion of the salivary glands is supplemented by blood serum components, intact or destroyed cells of the mucous membranes, immune cells, as well as intact or destroyed microorganisms of the oral cavity. All this defines saliva as a complex mixture of various components. Saliva plays important role in the formation of acquired plaque on the surface of the teeth, and thanks to the lubricating effect, participates in maintaining the integrity of the oral mucosa and upper sections Gastrointestinal tract. Saliva also plays an important role in physicochemical defense, antimicrobial defense and oral wound healing. Many components of saliva and their interactions, including proteins, carbohydrates, lipids and ions, are finely regulated in performing the biological functions of saliva. Violation of the complex balanced composition of saliva leads to damage to the mucous membrane of the mouth and teeth.

Many changes physical and chemical properties saliva is of diagnostic interest and is used for screening and early diagnosis some local and systemic disorders.

Chemical composition of saliva

Inorganic components of saliva

Component	Saliva released between meals	Stimulated
		Within 8.0
Bicarbonates		Within 40-60 mmol/l
		Within 100 mM/l
		Within 70 mM/l

Water is the predominant component of saliva (~94%). The pH value of saliva at rest is slightly acidic, which varies between pH 5.75 and 7.05, with increasing saliva flow rate it rises to pH 8. In addition, pH also depends on the concentration of proteins, bicarbonate ions (HCO 3) and phosphate (PO 4 3-), which have significant buffer capacity. Bicarbonate concentration is ~5-10 mM/L at rest, and can increase to 40-60 mmol/L upon stimulation, whereas phosphate concentration is ~4-5 mM/L regardless of flow rate. In addition to bicarbonate and phosphate, other ions are present in saliva. In general, a slightly hypotonic salivary osmolarity is maintained. The most important ions are sodium (1-5 mM/L at rest and 100 mM/L with stimulation), chloride (5 mmol/L at rest and up to 70 mM/L with stimulation), potassium (15 mM/L at rest and 30-40 mmol/l with stimulation) and calcium (1.0 mmol/l at rest and 3-4 mmol/l with stimulation). The lower ones in saliva contain ammonium (NH 4 +), bromide, copper, fluoride, iodide, lithium, magnesium, nitrate (NO 3 -), perchlorate (ClO 4 -), thiocyanate (SCN-), etc.

Table 2 - Saliva proteins

Proteins secreted by glands	Whey proteins	Immune cell proteins	Bacterial, unknown and mixed
Alpha amylase	Albumen	Myeloperoxidase	Alpha1-macroglobulin
Blood group proteins	Alpha antitrypsin	Calprotectin	Cysteine ​​peptidase
Cytostatins	Clotting factors	Cathepsin G
Epidermal growth factor	Proteins of the fibrinolytic system	Defensins
		Elastase	Kallikrein
Histatin Lactoferrin Peroxidase Proline-rich proteins Statgerin		Immunoglobulins	Protease inhibitor Fibronectin Salivary chaperones Hsp70 Streptococcal inhibitor

Saliva enzymes:

• alpha amylase
• maltase
• lingual lipase
• lysozyme
• phosphatase
• carbonic anhydrase
• kallikrein
• RNase
• DNase
• Cysteine ​​peptidase
• Elastase
• Myeloperoxidase
• Proenzymes - blood coagulation factors and fibrinolysis systems

Saliva carbohydrates

Saliva contains a significant amount of glycoproteins. In the molecules of some proteins, the carbohydrate part is up to 80% - mucins, but usually - 10-40%. The most important components are amino sugars, galactose, mannose and sialic acids (N-acetylneuraminic acid). The carbohydrate chains of mucins predominantly contain acid sulfates and sialic acid residues; chains with the properties of blood group antigens contain approximately equal amounts of 6-deoxy galactose, glucosamine, galactosamine and galactose. Other common carbohydrate chain ingredients are N-acetylgalactosamine, N-acetylglucosamine and glucuronic acid. The total amount of carbohydrates contained in saliva is 300-400 pg/ml, of which the amount of sialic acid is usually about 50 pg/ml [up to 100 pg/ml].

Most important function carbohydrates in the composition of proteins - increasing the viscosity of saliva, preventing proteolysis, preventing the loss of acidic precipitation (acid-soluble antigens of blood groups, mucin).

Saliva lipids

Saliva contains from 10 to 100 μg/ml lipids. The most common lipids in saliva are glycolipids, neutral lipids (free fatty acid, cholesterol esters, triglycerides and cholesterol), slightly less phospholipids (phosphatidylethanolamine, phosphatidylcholine, sphingomyelin and phosphatidylserine). Salivary lipids are mainly of glandular origin, but some of them (such as cholesterol and some fatty acids) diffuse directly from the serum. The main sources of lipids are secretory vesicles, microsomes, lipid rafts and other plasma lipids and fragments of intracellular membranes of lysed cells and bacteria. Most of salivary lipids bind to proteins, especially high molecular weight glycoproteins (for example, mucin). Salivary lipids may play a role in the formation of dental plaque, salivary calculi and dental caries.

In the oral cavity there are a lot of small salivary glands located in the mucous membrane of the lips, cheeks, tongue, palate, etc. (Fig. No. 241). According to the nature of the secretion, they are divided into proteinaceous or serous (produce a secretion rich in protein and not containing mucus - mucin), mucous (produce a secretion rich in mucin) and mixed, or proteinaceous-mucous (produce a proteinaceous-mucous secretion). In addition to the small glands, the ducts of three pairs of large salivary glands located outside the oral cavity open into the oral cavity: parotid, submandibular and sublingual.

Parotid gland- the largest of the salivary glands. Its mass is 25 g. It is located in the retromaxillary fossa in front and below the external ear. Its excretory duct (stenon duct) opens in the vestibule of the mouth at the level of the second upper molar. It produces a serous secretion containing a lot of water, protein and salts.

Submandibular gland- the second largest salivary gland. Its mass is 15 g. It is located in the submandibular fossa. The excretory duct of this gland opens in the oral cavity under the tongue. Produces a protein-mucus secretion.

Sublingual gland- small, weighing about 5 g. It is located under the tongue on the mylohyoid muscle and covered by the mucous membrane of the oral cavity. There are several excretory ducts (10-12). The largest of them, the large sublingual duct, opens together with the submandibular duct under the tongue. Produces a protein-mucus secretion.

Each salivary gland receives dual innervation from the parasympathetic and sympathetic divisions vegetative nervous system. Parasympathetic nerves go to the glands as part of the facial (VII pair) and glossopharyngeal (IX pair) nerves, sympathetic - from the plexus around the external carotid artery. Subcortical centers of parasympathetic innervation of the salivary glands are located in the medulla oblongata, sympathetic - in the lateral horns of the II-VI thoracic segments spinal cord. When irritating the parasympathetic nerves salivary glands allocate a large number of liquid saliva, sympathetic - a small amount of thick, viscous saliva.

Saliva is a mixture of secretions of large and small salivary glands of the oral mucosa. This is the first digestive juice. Represents clear liquid, stretching into threads, weakly alkaline reaction

(pH - 7.2). The daily amount of saliva in an adult is from 0.5 to 2 liters.

The composition of saliva includes 98.5-99% water and 1-1.5% organic and inorganic substances. From inorganic substances saliva contains potassium, chlorine - 100 mg%, sodium - 40 mg%, calcium - 12 mg%, etc.

Of the organic substances in saliva there are:

1) mucin - a protein mucous substance that gives saliva viscosity, glues the food bolus and makes it slippery, facilitating the swallowing and passage of the bolus through the esophagus; a large amount of mucin in the oral cavity is secreted mainly by small salivary glands of the oral mucosa;

2) enzymes: amylase (ptialin), maltose, lysozyme.

Food does not remain in the oral cavity for long: 15-20-30 s.

Functions of saliva:

1) digestive;

2) excretory (excretory) - releases metabolic products, medicinal and other substances;

3) protective - washing away irritating substances that have entered the oral cavity;

4) bactericidal (lysozyme);

5) hemostatic - due to the presence of thromboplastic substances in it.

Human saliva is a colorless and transparent biological fluid of an alkaline reaction, which is secreted by three large salivary glands: submandibular, sublingual and parotid, and many small glands located in the oral cavity. Its main components are water (98.5%), trace elements and alkali metal cations, as well as acid salts. Wetting oral cavity, it helps free articulation, protects tooth enamel from mechanical, thermal and cold influences. Under the influence of salivary enzymes, it starts the process of digesting carbohydrates.

The protective function of saliva is manifested in the following:

• Protecting the oral mucosa from drying out.
• Neutralization of alkalis and acids.
• Due to the content of the protein substance lysozyme in saliva, which has a bacteriostatic effect, regeneration of the epithelium of the oral mucosa occurs.
• Nuclease enzymes, also found in saliva, help protect the body from viral infections.
• Saliva contains enzymes (antithrombins and antithrombinoplastins) that prevent blood clotting.
• Many immunoglobulins contained in saliva protect the body from the possibility of penetration of pathogenic microorganisms.

The digestive function of saliva is to wet the bolus of food and prepare it for swallowing and digestion. All this is facilitated by mucin, which is part of saliva, which glues food into a lump.

Food is present in the oral cavity for an average of about 20 seconds, but despite this, digestion, which begins in the oral cavity, significantly affects the further breakdown of food. After all, when saliva dissolves nutrients, it forms taste sensations and significantly affects the awakening of appetite.

Chemical processing of food also occurs in the oral cavity. Under the influence of amylase (an enzyme in saliva), polysaccharides (glycogen, starch) are broken down into maltose, and the next salivary enzyme, maltase, breaks down maltose into glucose.

Excretory function. Saliva has the ability to secrete metabolic products from the body. For example, some may be excreted in saliva. medications, uric acid, urea or mercury and lead salts. All of them leave the human body at the moment of spitting saliva.

Trophic function. Saliva is a biological medium that has direct contact with tooth enamel. It is the main source of zinc, phosphorus, calcium and other microelements necessary for the preservation and development of teeth.

Recently, the importance of saliva has become even greater - now it is used for diagnostics various diseases not only the oral cavity, but also the entire body. All that is needed for this is to collect a few drops of saliva on a cotton swab. Next, a test is performed that can reveal the presence of oral diseases, alcohol levels, the hormonal state of the body, the presence or absence of HIV and many other indicators of human health.

This test does not cause the patient any discomfort at all. Moreover, you can do the research at home by purchasing special kits at the pharmacy, which are designed for self-collection of saliva analysis. After that, all that remains is to send them to the laboratory and wait for the results.

• The process of salivation is divided into a conditioned reflex and an unconditioned reflex mechanism. The conditioned reflex process can be caused by any sight, smell of food, sounds associated with its preparation, or by talking and remembering food. The unconditional reflex process of salivation occurs already during the process of food entering the oral cavity.
• If there is not enough saliva, food debris is not completely washed out of the mouth, which leads to teeth staining yellow.
• The process of salivation decreases when fear or stress occurs, and stops altogether during sleep or under anesthesia.
• 0.5 - 2.5 liters is the amount of saliva secreted per day, which is necessary for normal life human body.
• If a person is in calm state, then the rate of saliva secretion does not exceed 0.24 ml/min, and during the process of chewing food it increases to 200 ml/min.
• In people over 55 years of age, salivation slows down.
• Insect bites are less painful and go away faster if they are moistened with saliva from time to time.
• To get rid of warts, boils and various types inflammation of the skin, up to ringworm, use saliva lotions.
• An increased dose of blood sugar negatively affects saliva production.

The quality of saliva and the presence in it useful properties, directly depends on general condition oral cavity, as well as the health of teeth and gums in particular. That's why

The excretory ducts of three pairs of large salivary glands open into the oral cavity: parotid, submandibular and sublingual. In addition to them, in the oral mucosa there are numerous small glands, which, according to their location, are called: labial, buccal, palatal and lingual. In the area of ​​the tongue there are: the anterior salivary gland on the lower surface of the tip of the tongue; at the root of the tongue there are glands, the ducts of which flow into the spaces between the foliate and villoid papillae. The excretory ducts of the labial and buccal glands open into the vestibule of the mouth, and the submandibular, sublingual, palatine and lingual glands open into the oral cavity proper. According to the nature of the secretion, the glands are divided into protein, mucous and mixed.

Saliva is a mixture of secretions from three major and many minor salivary glands. The secretions secreted in the oral cavity are mixed with epithelial cells, food particles, salivary bodies (neutrophil leukocytes, lymphocytes), mucus, and microorganisms.

Composition and properties of saliva.

The secretion of the salivary glands contains 98-99% water, and the rest is a solid residue, which includes mineral anions of chlorides, phosphates, bicarbonates, iodides, bromides, fluorides, and sulfates. Saliva contains sodium, potassium, calcium, magnesium cations and trace elements - iron, copper, nickel, lithium and others. The concentration of substances such as iodine, potassium, strontium is much higher than in the blood. Organic substances are represented mainly by proteins (albumin, globulins, enzymes), but in addition to them, saliva also contains nitrogen-containing components (urea, ammonia, creatinine, free amino acids, gamma aminoglutamate, taurine, phosphoethanolamine, hydroxyproline, vitamins). Some of these substances pass into saliva from the blood plasma without changes, and some (amylase, glycoproteins) are synthesized in the salivary glands.

The major and minor salivary glands normally secrete secretions of different composition and quantity. The parotid glands secrete liquid saliva containing large amounts of potassium and sodium chlorides, enzymes - catalase (hydrolyzes hydrogen peroxide to water and oxygen) and amylase. The latter contains calcium, without which it does not work. To perform its functions, amylase requires chlorine ions. Alkaline phosphatase there is no secret in this secret, but the activity of acid phosphatase is very high.

The submandibular glands secrete a product that contains a large amount of organic substances (mucin, amylase) and a small amount of potassium thiocyanate. From minerals The predominant salts are sodium chlorides, calcium chlorides, calcium phosphate, magnesium phosphate. Amylase is significantly less than in the secretion of the parotid gland.

The sublingual glands secrete mucin-rich saliva and have a strong alkaline reaction. The activity of alkaline and acid phosphatases in this saliva is very high. The consistency of saliva is viscous and sticky.

In the oral cavity, saliva performs a digestive function, as well as protective and trophic functions for tooth enamel. The digestive function is to prepare a portion of food for swallowing and digestion. Chewed food is mixed with saliva, which makes up 10-12% of its quantity. Mucin promotes bolus formation and swallowing; it is the most important organic component of saliva.

In the oral cavity, saliva acts as a digestive juice. It contains about 50 enzymes, which belong to the classes of hydrolases, oxyreductases, and transferases.

The protective function of saliva is that it protects the mucous membrane and teeth from drying out, physical and chemical damage from food, equalizes the temperature of food, binds acid as an amphoteric buffer and washes plaque from the teeth, promotes self-cleaning of the oral cavity and teeth; the presence of lysozyme, an enzyme-like protein that has bactericidal properties, gives it the ability to take part in defensive reactions the body and in the processes of epithelial regeneration in case of damage to the oral mucosa.

• Water (about 99% general composition saliva). Provides wetting and dissolution of food components for the emergence of a sense of taste and primary digestive reactions. Moisturizes the oral cavity. Promotes speech.
• Bicarbonates. Maintains a slightly alkaline reaction of saliva (pH: 5.25-8.0).
• Chlorides. Activate salivary amylase, an enzyme that breaks down starch.
• Immunoglobulin A (IgA) Component salivary antibacterial system.
• Lysozyme. Bactericidal enzyme, prevents caries, takes part in the processes of regeneration of the epithelium of the oral mucosa
• Mucin. A glycoprotein that promotes the formation of mucus and the formation of a food bolus.
• Slime. Participates in the formation of a food bolus. Promotes swallowing. Provides buffering properties of saliva.
• Phosphates. Maintains saliva pH.
• Salivary alpha-amylase (ptialin). Catalyzes the breakdown of polysaccharides into disaccharides
• Urea, uric acid. They do not perform a digestive function; are excretion products.
• Maltase (glucosidase). Breaks down maltose and sucrose into monosaccharides.