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Biomedical subjects

G V Idova

Publications and source records attributed to G V Idova.

At least 19 recordsLinked to original sources

Significance of initial emotional state for neuroimmunomodulation in conditions of activation and blockade of 5-HT(1A) receptors.

Experiments performed on male CBA mice immunized with sheep erythrocytes at a dose of 5 x 10(8) cells showed that the selective agonist of serotonin 5-HT(1A) receptors 8-OH-DPAT (1 mg/kg) suppresses the immune response in aggressive animals. In mice demonstrating the submissive type of behavior, formed during 10 days of experience of defeats, activation of 5-HT(1A) receptors with 8-OH-DPAT had no effect on the immune response. However, treatment with the selective 5-HT(1A) receptor blocker WAY-100635 stimulated the immune response, but only in submissive mice. These data lead to the conclusion that activation and blockade of 5-HT(1A) receptors have different effects on the immune response in CBA mice depending on the initial emotional state of the animals, due to different activities of neurotransmitter systems, particularly the serotoninergic, in aggressive and submissive mice.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

[Differential contribution of dopamine D1 and D2 receptors in the mu-opioidergic immunomodulation].

The study has shown that activation of mu-opioid receptors by a highly selective agonist DAGO (100 microg/kg) results in a significant increase of the immune response to antigen (SRBC, 5% 10(8)) in CBA mice. Haloperidol (2 mg/kg), a selective antagonist of the postsynaptic dopamine (DA) receptors, prevented immunostimulating effect of DAGO. In contrast, selective D1--antagonist SCH 23390 (1 mg/kg) did not affect on DAGO-induced enhancing of immune reactivity. At the same time, the blockade of both types of DA receptors (D1 and D2) caused similar immunosuppressing effects. These data suggest a possible differential role for D1 and D2 receptors in mu-opioidergic immunomodulation.

Analgesics, Opioid↗

[Effect of the activation and blockade of D2 dopamine receptors on the immune response in mice with different types of social behavior].

Activation of D2 dopamine receptors with a selective agonist quinpirol in C57BL/6J mice was found to induce increase in the immune response regardless of the initial psychoemotional state of animals, e. g. in aggressive mice, submissive mice, and mice without victory or defeat experience (control). However, the immune response level in aggressive and submissive mice was significantly higher than that of control animals. At the same time, the blockade of D2 dopamine receptors with haloperidol suppressed immunogenesis in aggressive and control mice, whereas the immune reactions in submissive mice were unchanged. Thus, the effect of activation and blockade of D2 dopamine receptors on immune function is dependent on the initial psychoemotional status of animals which to a greater extent might be provided by the neuromediator pattern of the brain and activity of DA receptors.

Animals↗

Effect of dexamethasone on immune response of mice with different behavioral types.

Experiments on a model of paired sensory contact showed that dexamethasone effectively suppressing the response to ACTH not only prevented immunosuppression in male C57Bl/6J mice with submissive behavior formed during different periods of confrontation testing (days 10 and 20), but also stimulated the immune response in comparison with the control. Immune response in aggressive animals after 20-day confrontations was higher than in controls and submissive mice and did not change after dexamethasone injection. The authors conclude that the immunosuppressive effect in submissive animals is realized through ACTH, which little contributes into immunomodulation in aggressive mice.

Adrenocorticotropic Hormone↗

Stimulation of the immune response during activation of the dopaminergic system in mice with opposite types of behavior.

Studies reported here demonstrated that activation of the dopaminergic system induces increases in the immune response regardless of the type of behavior in mice (line CBA), i.e., in aggressive mice, submissive mice, and mice lacking experience of victory or defeat (controls). Changes in the activity of the dopaminergic system were induced with SKF-38393, a selective agonist of dopamine D1 receptors, and with p-chlorophenylalanine (PCPA), which we have previously shown to activate D2 receptors. In the aggressive form of behavior, which was characterized by strong (compared with controls) immune responses, SKF-38393 and PCPA led to further increases in the immune response. In submissive mice, activation of the dopaminergic system altered the nature of the immune response, with immunostimulation, as in aggression. It is suggested that activation of the dopaminergic system in conditions of defined psychoemotional status fixed by acquisition of opposite types of behavior, induces the formation of a new neurochemical pattern--the dopaminergic set--which led to changes in the nature and intensity of the immune response.

Aggression↗

Nature of the distribution of serotonin and a serotonin metabolite in brain structures and the development of immunosuppression in submissive mice.

Studies of C57BL/6J mice with acquired submissive behavior in a sensory contact model demonstrated increases in serotonin (5-HT) levels in the amygdaloid complex, hippocampus, the dopaminergic nuclei A11, A10, and A9, and in the caudate nucleus and hypothalamus, compared with controls, after 10 and 20 days of confrontations. Levels of the 5-HT metabolite 5-hydroxyindoleacetic acid (5-HIAA) in most structures were significantly higher after 20 days of confrontations than after 10 days. Increases in the 5-HIAA/5-HT ratio in the cervical nuclei of the midbrain, nucleus accumbens, A9, and hypothalamus as compared with controls were seen in mice with 10 and 20 days of confrontations. Immunization of mice on days 10 and 20 of confrontations showed suppression of immune responses as compared with controls, while immune measures reached control values by 40 days of experience of defeat. Thus, experience of 10 days of defeat led to immunosuppression on a background of activation of the 5-HT system in a series of brain structures: the cervical nuclei of the midbrain, the nucleus accumbens, and A9. As confrontations continued, there were decreases in the 5-HIAA/5-HT ratio on these structures, along with a tendency for immune responses to increase.

Animals↗

[Distribution of serotonin and its metabolites in the brain structures and immunosuppression in submissive mice].

The development of submissive behaviour in C57BL/6J mice in the sensory contact model was associated with an increase in the content of serotonin (5-HT) in the amygdala, hippocampus, dopaminergic nuclei A11, A10, A9, as well as in the caudate nucleus and hypothalamus after 10 and 20 days of confrontations compared to the controls. The level of 5-HT metabolite 5-hydroxyindolacetic acid (5-HIAA) was significantly higher in the most structures examined after 20 daily encounters as compared to animals with experience of 10 confrontations. The time course of submission over 10 or 20 days resulted in an increase of 5-HIAA/5-HT ratio in the midbrain nucleus raphe, nucleus accumbens, A9 and hypothalamus. In mice immunised on the 10th or 20th day of confrontations, the immune response inhibition was observed while its level remained unchanged after more prolonged confrontations (40 days). Thus, the experience of defeats during 10 days shown to be accompanied with an activation of 5-HT system in a number of the brain structures, produced immunosuppression. With increasing number of confrontations the ratio 5-HIAA/5-HT was decreased in the same structures and a tendency to the immune response elevation appeared.

Animals↗

[Activation of dopaminergic system stimulates an immune response in mice with opposite type of behaviour].

It was shown that activation of dopaminergic (Daergic) system induced an increase of the immune responsiveness independent of the CBA mice behaviour typeanimals without experience of victories and defeats (control), with aggression and submission. Administration of SKF-38393, a selective agonist of DA D1-receptors, resulted in enhanced immune response as tested by plaque-forming cells and rosette-forming cells number. Similar immunostimulation was observed after injection of p-chlorophenylalanine realizing its influence on the immune response through DA D2-receptors as shown by us elsewhere. It was suggested that activation of Da-ergic system produces a new neurochemical pattern (Daergic neurochemical set) which are responsible for character and intensity changes of the immune response in mice with alternative form of social behaviour.

Aggression↗

Effects of type 1A serotonin receptor agonist 8-OH-DPAT on immune response.

The selective agonist of type 1 A serotonin receptors 8-hydroxy-2-(di-n-propyl-amino)tetra-lin (8-OH-DPAT) suppressed the immune response. Intraperitoneal administration of 1 mg/kg 8-OH-DPAT to Wistar rats over 2 days after immunization decreased the count of plaque- and rosette-forming cells on day 5. Our results indicate that type 1A serotonin receptors are involved in the realization of the immunosuppressive effects of the serotoninergic system.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

Brain content of 5-hydroxytryptamine and 5-hydroxyindoleacetic acid and immune response in aggressive C57bl/6J mice.

Catabolism of 5-hydroxytryptamine in the midbrain raphe nuclei of aggressive C57Bl/6J mice increased after 10 and 20 days of confrontations. Both catabolism and concentration of 5-hydroxytryptamine increased in the dopaminergic nuclei A11, A10, A9, and in the amygdala. The level of 5-hydroxyindoleacetic acid in the A9 and raphe nuclei decreased after 20 days of confrontations, which coincided with manifestation of the immune response.

Aggression↗

[Effect of opioid peptides on immunomodulation].

Activation of the opioid receptors by delta-agonist DSLET and by kappa-agonist rimorphin led to a significant inhibition of plaque-forming and rosette-forming cells in the CBA mice. On the other hand, mu-agonist DAGO stimulated the immune response on the 4th and 5th days after immunization with SRBC (5 x 10(8)). Lesion of the hypothalamo-hypophyseal connection prevented immuno-stimulating as well as immuno-depressive effects. The latter seems to be due to an interaction with the serotoninergic system, whereas immuno-stimulating effect involves the dopaminergic system.

Animals↗

[The neurochemical set of the brain--an extra-immune mechanism of psychoneuroimmunomodulation].

The present study provides evidence for involvement of brain neurotransmitters in the control of an immune response. The extra-immune mechanism of immunomodulation is considered by analyzing drug-induced changes in the brain neurotransmitter systems, brain destruction, altered activity of brain regions due to psychoemotional stress, including mental disease. It is suggested that the pattern of neurotransmitter activity with its prevalence in certain brain regions determines the neurochemical set-up of the brain for psychoneuroimmunomodulation, i.e. its extra-immune mechanism.

Animals↗

[The serotonin-dependent suppression of the immune response by kappa-opiate receptors].

The modulating effect of the kappa-opiate agonist, rimorphin, on the immune response was studied. This opioid in all the doses tested (1, 10 and 100 mkg/kg) was found to cause inhibition of the immune reaction as compared to the control CBA mice which received saline only. The dissection of the pituitary stalk prevented the inhibitory effect of rimorphin on the immunity. The opioid-induced immunosuppression was shown to be due to interaction with the serotoninergic system since it had no effect after preliminary blockade of S-2 serotonin postsynaptic receptors with cyproheptadine.

Animals↗

[The participation of the delta opioid receptors in immunomodulation].

The delta-receptors agonist DSLET inhibited immune responses in the CBA mice. The immunosuppression was shown to be due to an interaction with the serotoninergic system. No immunostimulating effect of the delta-opioid receptors antagonist ICI 174,864 occurred in the animals with dissection of the pituitary stalk. The immunostimulation was shown to be realised via the thymus and prevented by a preliminary haloperidol blockade of the D-2 dopaminergic receptors. The cerebral delta-opioid receptors seem to participate in neuro-immunomodulation through the interaction with the serotonin and dopamine neurotransmitter systems.

Animals↗