Anaphylaxis - a state of heightened sensitivity to the re-introduction of the organism alien protein antigen. This protein (anaphylactoid), entering the body for the first time, causes the formation of specific antibody, which leads to sensitization sensitivity) of the body of this protein. Most often this occurs with the introduction of various types of antigens as medical means [for example, anti-tetanus serum, and some medications (antibiotics) and others]. When introduced into the body of antibodies from the blood serum already sensitised donor occurs passive sensitization.
With the reintroduction of the antigens (anaphylactogenic) interact with antibodies with the formation of toxic substances - anaphylatoxins that cause anaphylactic shock. It develops immediately after the re-introduction of anaphylactogenic and occurs with shortness of breath and the subsequent development of asthma, seizures, a sharp rise in blood pressure at the beginning and so sharp then by his fall. At this time there are blood clots and slowing its coagulation. In blood detect biologically active substances (gistamina, serotonin and others), the change of leukocyte formula with a shift to the left, eosinophilia, increased number of globulins. In anaphylactic shock there are significant abnormalities in the Central nervous system and increase the tone of the autonomic nervous system.
To mitigate anaphylactic shock to use drugs and sedatives, antispasmodic, antihistamines drugs, etc.
If anaphylactic shock does not end with death, after its termination occurs desensitization, or indianapolise,is a condition in which the body does not react to the introduction of anaphylactogenic. This phenomenon is often used to prevent the development of shock. The antigen is injected in small amounts, causing mild form of anaphylactic shock followed by desensitization, then re-introduction of alien protein is already not dangerous for the body. Based on this principle the introduction of various serums on Besedka: first enter a small part of serum, and then the rest of the amount (see Besedki method).

Anaphylaxis (from the Greek. ana - against and phylaxis protection) is a pathological process that develops when introducing antigen ("anaphylactogenic") and manifested in the form of increased sensitivity with repeated administration. The term proposed richer (G. R. Richet) and Porter (P. Portier) in 1902 in a typical form of anaphylaxis is reproduced in all mammals and humans. Birds anaphylaxis described only in pigeons, chickens, geese. In reptiles, amphibians and fish in typical form of anaphylaxis cannot be obtained. The most important condition playback anaphylaxis in animals and man is the sensitization, or sensitivity to the re ("allowing") introduction of alien protein (anaphylactogenic"). Distinguish between active and passive sensitization (Fig). In Guinea-pig state of the active sensitization, such as horse serum, occurs in 15-20 days after the primary (sensitizing) parenteral introduction. For sensitization enough of the small number of foreign protein (hundredths or even thousandths of shares milligrams).
The sensitization in Guinea-pig with immunologically very specific: sensitization to one type of protein, such as horse, causes anaphylaxis only to this type of protein; protein animal of another species (bovine, sheep and so on) anaphylaxis in this case will not cause. This allows the use of anaphylaxis in Guinea pigs as a very sensitive biological reaction to a particular alien protein. In other species of animals and humans reaction is anaphylaxis somewhat less specific than in the Guinea pig.
The most important change, occurring in the body after the initial introduction of alien protein, is the process of development of antibodies against this protein. Antibodies are produced by the same system of "immunologically competent cells (see Immunity), which produce antibodies in response to stimulation by antigens on any immunization. In the period of sensitization antibodies found in liquid fabric environments (lymph, blood)and the cells of the body ("sessile" antibodies). The latter depends either primary education antibodies in the cells ("immunologically competent cells of the lymph nodes and other organs)or secondary fixation on the cells of antibodies from a liquid tissue environments. When passive sensitization fixation anaphylactic antibodies in the cells is played by introducing healthy, desencibilizirutee Guinea pig intraperitoneally or intravenous serum actively sensitized Guinea pigs at the height of the development status of sensitization. Through 12-24 hours. after the introduction of serum sensitised mumps antibodies are fixed on the healthy cells of animal and create a state of sensitization, quite similar to that from the initial introduction of small doses of a foreign protein. Passive sensitization can be played also by introducing anaphylactic antibodies produced in the body of the animal of another species.
In laboratory studies on anaphylaxis is now used mainly by the method of passive sensitization, as it allows you to accurately measure the amount of antibody bound by the body or private body.

Again, allow the introduction of alien protein Guinea pig common causes the reaction, anaphylactic shock, the most important expression of which in Guinea-pig is shortness of breath, passing into a state of asphyxia, cramps, involuntary urination and defecation; in a few minutes death from paralysis of the respiratory center. Light died from anaphylactic shock animal vzduchu and almost completely closed heart, staying in diastole and full of dark blood rich CO2; in the abdominal cavity sometimes there light stagnation. In anaphylactic shock in Guinea pigs are thickening of the blood, an increase in the content of globulins, eosinophils and basophils, sharp decrease of neutrophilic leukocytes and blood platelets, slow blood clotting, the fall of the content of complement (N. N. Sirotinin). The blood of an animal during anaphylactic shock and after it acquires the toxic properties due to the presence in it is not hypothetical "anaphylatoxin", and of a number of substances (histamine, serotonin, peptides and other). Blood pressure in anaphylactic shock at first increases due to asphyxia and catastrophically falls before his death.
In the Central nervous system are observed phase changes (excitation braking, which extends from the highest areas of the brain stem and the scope of the respiratory center. Anaphylactic shock is accompanied by violations of the tone of vegetative nervous system; initially marked increase the tone of the sympathetic, further develops parasympathicotonia. If the Guinea pig has not perished during anaphylactic shock, it develops resistance to allow subsequent impacts of alien protein to which it has been sensitized. Consequently, the sensitization after a previous anaphylactic shock disappears. Develops desensitization, or indianapolise (A. M. Besedka)that can be called, if you enter sensitised mumps an hour before the resolution injection specific antigen parenteral (subcutaneously, intravenously), a small amount of a specific antigen. In this case, mumps transfers anaphylactic shock in the form of light, which means it develops desensitization.
Method-specific desensitization was proposed A. M Bezrodnoy (see Besedki methods) not only for the Guinea pig, but also to humans. Immunological mechanism specific desensitization is the binding of the antigen specific antibody-sensitized animal and activate the enhanced their products. The method is based on specific desensitization is the process of braking immunological stage of development anaphylacticski shock. As methods of counteraction pathogenically stage in the development anaphylacticski shock apply the introduction of various antihistamines, antiserotoninic drugs inhibitors active peptides, drugs, sealing the vascular wall. Development pathophysiological stages of shock prevent techniques of non-specific desensitization, consisting in the use of drugs that cause Central nervous system inhibition (drugs, sedatives), sealing cell membranes and reduces permeability of blood capillaries, and spasmolytic, soothing bronchospasm and other smooth muscle bodies. Methods of non-specific desensitization widely used in people with various manifestations of anaphylactic shock (see Serum sickness) and allergic reactions. Cm. also Allergic.

Active and passive sensitization (scheme).