ADAPTATION SYNDROME

From Big Medical Encyclopedia

ADAPTATION SYNDROME (late lat. adaptatio — adaptation) — set of the nonspecific changes arising in an organism of an animal or the person at action of any pathogenic irritant. The term is offered the Selye (see) in 1936.

On the Selye, Ampere-second. the stress reaction (see the Stress), always arising under any adverse conditions for an organism is clinical manifestation.

The Selye distinguishes the general, or a generalized, adaptation syndrome which heaviest manifestation is shock, and the local adaptation syndrome developing in the form of an inflammation. The syndrome is called the general (generalized) because it arises as reaction of all organism, and adaptation since its development promotes recovery.

Fig. Change of body weight of the growing rats at various stages of the general adaptation syndrome at the dosed electroirritation: I \stage of alarm (phase of mobilization); II \stage of resistance; III \stage of exhaustion.

In development of the general Ampere-second. consistently developing stages are noted. In the beginning, when the threat of disturbance of a homeostasis is created and there is a mobilization of protective forces of an organism, there is a stage of alarm (alarm — an appeal to mobilization). In the second phase of this stage there is a recovery of the broken balance and transition to a stage of resistance when the organism becomes steadier not only against action of this irritant, but also in relation to other pathogenic factors (cross resistance). When the organism but completely overcomes the continuing action of a pathogenic irritant, the stage of exhaustion develops. Death of an organism can occur in a stage of alarm or exhaustion.

One of the indicators defining stages of Ampere-second., change of overall balance of exchange can serve. In a stage of alarm and exhaustion the phenomena of a catabolism (dissimilation), and in a stage of resistance — anabolism (assimilation) prevail. At constantly growing animal (rats) of a stage of the general Ampere-second., e.g. at the daily dosed electroirritation, can be easily revealed on change of the weight (fig).

The most essential changes of an organism at the general Ampere-second.: a hypertrophy of bark of adrenal glands, an atrophy of timiko-lymphatic system and the bleeding stomach ulcers and a duodenum. The specified changes were known in literature and before works the Selye. The hypertrophy of bark of adrenal glands and increase in its activity at action of various factors were studied by A. A. Bogomolts (1909). Emergence of hemorrhages in a stomach and intestines as a standard form of dystrophy was described by A. D. Speransky (1935). Selye aimed to find origins of the general Ampere-second. and to define its biological essence. A part of this very complex challenge is successfully solved by it. It is established that many changes occurring at the general Ampere-second., depend on strengthening of hormonal activity of a front share of a hypophysis which, emitting adrenocorticotropic hormone (AKTG), stimulates secretory activity of bark of adrenal glands. By many researchers it is shown that reaction of a front share of a hypophysis and bark of adrenal glands arises very quickly (minutes and even seconds) and that in turn it depends on a hypothalamus, in Krom special substance — a rileasing-factor is produced (see. Hypothalamic neurohormones), stimulating secretion of a front share of a hypophysis. Thus, at the general Ampere-second. the system a hypothalamus a front share of a hypophysis - bark of adrenal glands reacts. It is necessary to refer release of adrenaline and noradrenaline which value, irrespective of works the Selye, was shown by Kennon (W. Cannon, 1932), and also L. A. Orbeli (1926 — 1935) in the doctrine about an adaptation and trophic role of a sympathetic nervous system to number of releasers of this system.

In experiments and in clinic it is fixed that at functional insufficiency of bark of adrenal glands resistance of an organism sharply goes down. Administration of steroid hormones (glucocorticoids) it is possible to recover resistance of an organism therefore the Selye considers them adaptive hormones. It carries AKTG, STG, adrenaline and noradrenaline as their action is connected with adrenal glands and adaptation to the same group. However in works the Selye is shown that some hormones and drugs (etilesternol, tyrosine, etc.) can increase resistance of an organism to toxicants, strengthening action of fermental systems of a liver. In this regard it is not necessary to consider that the condition of nonspecific resistance of an organism is defined only by direct effect of hormones on a pathogenic factor. The condition of nonspecific resistance depends on a number of processes. Here belongs influence of hormones on an inflammation, permeability of vessels, activity of enzymes, system of blood, etc.

It is a lot of not clear and in an explanation of origins of various symptoms of the general Ampere-second. In the beginning considered that the atrophy of timiko-lymphatic system results from disintegration of lymphoid cells under the influence of increase in blood of glucocorticoids which always takes place in an initial phase of development of the general Ampere-second. However it is established that disintegration of lymphoid cells is not so big and that a major factor of devastation of fabric is migration of lymphoid cells.

Formation of stomach ulcers and duodenum cannot be put into direct dependence on secretory activity of bark of adrenal glands. Developing of ulcers is more connected with influence of the autonomic nervous system on acidity and fermental activity of a gastric juice, secretion of slime, a tone of a muscular wall and pas change of microcirculation. For the purpose of specification of ulcerogenic mechanisms value of degranulation of mast cells, increases in a histamine (see) and serotonin was studied (see) and influence of microflora. However it is still not resolved an issue of what factor is decisive in development of ulcers and what role in these processes play corticosteroids. It is impossible to consider that formation of ulcers is adaptive process. Neither mechanisms of development, nor the biological importance of this phenomenon in a concept of the general Ampere-second. are not opened. However use of corticosteroids in big, not physiological, doses can cause development of stomach ulcers and a duodenum.

The Selye fairly believes that defense reactions of an organism are not always optimum therefore in many cases, in his opinion, there can be so-called adaptation diseases. The main reason for their development, on the Selye, is or the wrong ratio of hormones, at Krom the hormones strengthening reaction of an inflammation (STG of a hypophysis and a mineralokortikoida of bark of adrenal glands) while anti-inflammatory hormones (AKTG of a hypophysis and glucocorticoids of bark of adrenal glands) are not enough or the special reactivity of an organism caused by the adverse previous effects (a nephrectomy, excess loading I will merge, use of corticosteroids, etc.) prevail that creates predisposition (diathesis) to development of pathological processes. In experimental conditions a number of diseases like kollagenoz was succeeded to reproduce, arthritises, a nodular periarteritis, a nephrosclerosis, a hypertension, necroses of a myocardium, a scleroderma, a metaplasia of muscular tissue, etc. However yet there are no bases to consider that origins of these or those processes in an experiment are identical to the reasons of their emergence in a human body.

So, in clinic at the specified pathological processes increase in quantity of pro-inflammatory kortikoid (DOCK, Aldosteronum, STG) was not revealed that it was necessary to expect the Selye according to the concept. At many hron. diseases of the person there are no changes inherent to adaptation diseases. The critical analysis of some experiments allows to assume the Selye that sometimes the arising pathology is a consequence rather allergic manifestations, than hormonal frustration [Koup]. And if inadequate hormonal reactions take place, then they should be considered rather as display of pathology of the corresponding glands, than as adaptation diseases.

In works on studying of a local adaptation syndrome showed the Selye that depending on change of hormonal activity of a hypophysis and bark of adrenal glands the barrier role of an inflammation can change considerably.

The Selye considers the general Ampere-second. obligatory manifestation «just diseases». Therefore same picture of the general Ampere-second. is the general component at the most various diseases, on connected with specifics of action of a pathogenic factor. On this basis the Selye for many years propagandizes the idea of creation of the uniform theory of medicine, and it, undoubtedly, attracts great interest. However not all theoretical generalizations the Selye are generally recognized. In any nonspecific reaction there are always characteristic signs caused by action of this irritant therefore reactions are not unambiguous and development of the Ampere-second. it is not caused by the uniform mechanism of hormonal influences (e.g., stomach ulcer and a duodenum). Similarity of external manifestations of the general Ampere-second. at various diseases does not serve as the proof of a community of the etiological reasons therefore the idea the Selye about a plyurikauzalizm as to a basis of development of all diseases cannot be unconditionally accepted.

Bibliography: The horizons P. D. Rol of system a hypophysis — bark of adrenal glands in a pathogeny of extreme states. Vestn. USSR Academy of Medical Sciences, 7, page 23, 1969, bibliogr.; P. D. horizons iprota-with about in and T. N. A role of AKTG and corticosteroids in pathology (To a problem of a stress), M., 1968, bibliogr.; Selye of. Sketches about an adaptation syndrome, the lane with English. M, 1960; it, at the level of the whole organism, the lane with English. M, 1972; S.'s Litter of L. Adrenal steroids and disease, L. 1965, bibliogr.

P. D. Gorizontov.

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