Stress and infections

SO THAT WE RELATED STRESS TO THE INFECTIONS?

The networks psico-neuro-inmuno-endocrinas

During many years, one has known that the attitudes and mental stress influence in the resistance of some diseases. For example, the animals that undergo confinement or social stress (distance, abandonment) show a depressed immune activity.
From old, clinical observations existed that they indicated that certain psycho-social factors could influence in the susceptibility of an organism to infectious diseases or autoinmunes.
It is possible that many of the effects of stress on the immune system must to the actions of hormones neuroendocrinas.
The cells of the immune system have receivers for opioides peptides. During stress neuropéptidos are freed, like encefalinas and endorfinas. These can be united to the lymphocytes and be influenced in their activity. Thus, the generation of cytotoxic cells T is favored by [met] - encefalina and beta endorfinas.
The alpha-endorfina suppresses the formation of antibodies and the endorfina beta reverts east effect suppresor.
A other neuropéptidos that they have influence on the system includes the ACTH, oxitocina, vasoactivo intestinal peptide (VIP), somatostatina, prolactose, substance P and noradrenaline. The VIP and the somatostatina tend to inhibit the function of cells T whereas the substance P is mainly estimuladora.
Certain sites of the brain, in special the hypothalamus, prosencéfalo límbico and the cerebral stem, have influence on the immune function when controlling the neurotrasmisora function or the independent nervous system.
The pituitaria has influence on the immune function, since the hormone of the growth increases the concentration of timulina in the thymus in the dogs. The estimuladora hormone of alpha-melanocitos inhibits the fever, the answer of acute phase and the inflammation, when modulating the effects on the interleukina -1
The central nervous system can influence in several forms the immune response:
1. The likeable activity can directly affect certain populations of lymphocytes, or indirectly influence the linfocitario transit by lymph or blood, when modifying the provision of blood to the linfoides organs.
2. Some pituitarias hormones (GH, endorfinas and encefalinas) can act directly on inmunocompetentes cells, like monocitos/macrophages and lymphocytes.
3. The ACTH influences the suprarrenal crust, inducing the production and liberation of corticoids, that can depress the immune system.
4. The nervous system independent, specially the likeable one, inerva to primary linfoides organs (estroma of the bony marrow, crust and marrow of the thymus) and secondary (areas T of bazo and ganglia).
The likeable nervous system also influences the immune reactivity.
The thymus, the esplénica white pulp and the lymphatic ganglia are inervados by nonadrenérgicos nerves. These influence the sanguineous flow, the vascular permeability and the linfocitarias migration and the differentiation.
If the likeable activity in bazo by surgery is annulled or drugs, increase the production of antibodies and can induce changes in the distribution of the linfocitarias subpopulations.
Also, the central nervous system can act on the endocrino system:
Before a stress situation (fear, hunger, physical damage, etc) the hypothalamus causes that the previous hipófisis releases hormone ACTH, which acts on the crust of the suprarrenales capsules so that they release glucocorticoids as well (like hidrocortisona).
These glucocorticoids have inmunosupresor effect (inhibiting to collaborating lymphocytes T of class 1 and the macrophages)
Apparently, the estrogens cause that the females are more active in their immune response that the males (produce better levels of antibodies and the infections resist better), but however, are more susceptible to the diseases autoinmunes.

How can influence the immune system the nervous function?
A recent study demonstrated that some individuals that suffer of serious depression present/display autoanticuerpos, that went directed against the beta-endorfina. When blocking the activity of this molecule that regulates sensations of pleasing, the autoanticuerpos presumably collaborate with the depressive sensation.
In addition, interleukina- 1 derived from macrophages stimulates the synthesis of the factor of nervisoso growth in inflamed areas and with it they promote ka inervación and the reestablecimiento of the nerves.
Interleukina -1 stimulates the somatostatina synthesis, which as well depresses the hormone of the growth and the estimuladora hormone of the thyroid.
Due to its complexity, the interrelation of the immunity with neurology and the endocrinology not yet completely is included/understood, but solid evidences of the tridirectional communication between the immune systems exist, nervous and endocrino.
Some of them can be:
* Mice that have been put under daily confinement, during 1 hour, in a small box, are incapable to recover to sublethal virales inoculations for normal mice.
* Separated monkeys of their families or companions experience a severe diminution of the answers of linfocitaria activation before antigenic stimuli.
* Those same answers are observed decreased in most of the species, including the man, during periods of stress (emotional, environmental, physiological, of relation, etc)

The recent study of the psychological factors that agree on the immune responses, lays a way towards a new specialty, the Psicoinmunología.

Author: Lidia Mariana Gogorza.
Lawyer in Health Animal and Veterinary Doctor
Graduated as the Face of Cs Veterinary of the National University of Center of the Pcia of Buenos Aires. At the moment she exerts like educational and investigating in the mentioned House, in the Dpto de Sanidad Animal and Preventive Medicine
She participates like attached Professor in courses of Inmunología (basic and special), and in Virology.
She develops his Doctoral Thesis in the immunity to the bovine viral Diarrea (BVDV).
She participates in the management of the UNCPBA like Superior Advisor.
www.lidiagogorza.mascotia.com
to gogorzalidia@ciudad.com.ar

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