Volume 110, Nº 7 (2024)

As a result of a literature search, the physiological aspects of the gonadotropin-releasing hormone (GnRH) influence on immune organs, such as red bone marrow, thymus, spleen and lymph nodes, were considered. The use of GnRH drugs leads to the replacement of red bone marrow with yellow one with an increase in the content of lymphoid and myeloid progenitor cells. In parallel, processes of osteoporosis occur due to increased bone resorption with corresponding changes in calcium metabolism and a decrease in the density of various bone tissues. At the same time, there are papers reporting no effect of GnRH on bone density and changes in calcium metabolism. GnRH acts on the thymus during embryonic development, and in postnatal ontogenesis, and during inflammation and age-related involution processes. Not only GnRH causes changes in the thymus; the thymus may also influence on the GnRH system. A direct effect of GnRH on spleen cells had not been detected, but the weight of the organ changed as a result of active immunization against GnRH in experiment. Unfortunately, very few articles demonstrate the physiological mechanisms of immunomodulation in such conditions. In any case, the obvious insufficiency and contradictory of publications on each aspect of GnRH effects indicates that they have been poorly studied, and it’s advisabile of further continuing not only applied research, but also fundamental investigations, due to its possible high prospects for creating immune control systems.

Hyperglycemia is a symptom and damaging factor of diabetes mellitus (DM) that leads to systemic complications in the body, including macro- and microangiopathies of the brain, impaired blood supply, the appearance of foci of neurodegeneration and might be a trigger of neuroinflammation. Nervous tissue is characterized by a high level of energy consumption and is highly sensitive to fluctuations in the level of metabolic substrates. Therefore, it is extremely important to study the effect of high glucose levels on the functional state of the central nervous system. This review attempts to comprehensively assess the effects of hyperglycemia on brain cells. Analysis of experimental data obtained in in vivo and in vitro models of diabetes on the morphofunctional state of neurons, microglia and astrocytes showed that the direct and indirect effects of glucose in high concentrations depends on the cell type. Receptors and intracellular signaling cascades of astrocytes and microglia, that mediate the effects of hyperglycemia and the development of neuroinflammation, can act as therapeutic targets for the correction for the consequences of diabetes. Thus, finding ways to modulate the functional activity of glial cells may be an effective strategy to reduce the severity of the consequences of CNS damage.

Peripheral cytokines may influence psychoemotional behavior, but the role of interleukin-1beta (IL-1beta) in altering anxiety and motor activity in response to inflammatory activation remains unclear. To clarify this issue, correlations between behavioral parameters in the elevated plus maze (EPM) test and plasma levels of IL-1beta after administration of the proinflammatory stimulus lipopolysaccharide (LPS) in different modes were analyzed in adult male rats. LPS in doses of 0.5 or 5 mg/kg, as well as physiological solution (control), were administered to rats intraperitoneally. The most pronounced behavioral effect 24 hours after a single injection was an endotoxin dose-dependent inhibition of the animals’ motor activity. After a dose of 5 mg/kg, increased anxious behavior was also noted every other day. The behavioral changes caused by the high dose of endotoxin were completely normalized after a week. The behavior of the animals one day after the end of repeated injections of LPS at a lower dose for a week (0.5 mg/kg; once every two days) also did not differ from the control. The inhibition of motor activity after LPS could be due to an increase in the level of IL-1beta in the blood plasma, as indicated by the identified significant negative correlations between IL-1beta and the corresponding behavioral parameters. No significant correlation was found between the peripheral level of IL-1beta and such a classic indicator of anxiety as the percentage of entries into the open arms of the maze. In general, the obtained results allow us to conclude that IL-1beta is an undoubted participant in the mechanism of the transient inhibitory effect of LPS on motor activity.

Non-invasive study of blood rheology is relevant, but quite complex issue. When systemic blood viscosity and hematocrit levels deviate, blood flow indicators in different parts of microvasculature change. Purpose of the study – research of blood flow characteristics in skin microcirculatory bloodstream of rats obtained by high-frequency ultrasound Dopplerography (HFUD) with given changes in rheological blood indicators. The studies were carried out on pubescent male Wistar rats. 3 experimental groups were formed. Group 1 (n = 21) “Hemodilution” – viscosity 1.99 ± 0.02 mPa*s, hematocrit 31.48 ± 0.31%. Group 2 (n = 32) “Reference values” – animals with unchanged blood levels – viscosity 2.84 ± 0.03 mPa*s, hematocrit 41.60 ± 0.3%. Group 3 (n = 32) “Erythrocytosis” – viscosity 3.95 ± 0.04 mPa*s, hematocrit 54.56 ± 0.23%. Dynamic blood viscosity in vitro studies were carried out on oscillatory viscometer. In order to evaluate hematocrit level heparinized whole blood was centrifuged in glass capillaries using; hematocrit values were assessed taking into account sedimentation of formed elements column using a hematocrit reader card. Blood flow in skin microcirculatory bloodstream of rats` left thigh area was estimated by HFUD method using Minimax-Doppler-K hardware and software system, with ultrasound transducer (frequency 20 MHz). Statistical analysis showed the models are correct. Blood indicators of the animals in three experimental groups differed statistically and significantly in terms of blood viscosity and hematocrit. Discriminant analysis was used to determine the relations between rheological blood parameters and characteristics of blood velocity in microcirculatory bloodstream which made it possible to identify the most significant characteristics of blood flow that tend to change depending on altered blood composition. These include: mean systolic velocity Vas (p < 0.01), mean velocity Vam (p < 0.001), mean volume velocity Qam (p < 0.001), vascular resistance index RI (p < 0.01) and the percentage of blood cells moving in low-speed H' (p = 0.03). The reliability of selected characteristics was checked with one-way analysis of variance; and their significance in determining membership in “Hemodilution”, “Reference values” or “Erythrocytosis” groups according to HFUD data was confirmed. Based on this analysis classification functions were generated for non-invasive dynamic blood viscosity determination according to ultrasound Dopplerography data.

The reaction of cortical structures of different significance (associated with delusions and hallucination and neutral ones) was studied. The work was conducted in patients with paranoid schizophrenia and normal control (24 patients with paranoid schizophrenia, 15 controls). In patients in frontal areas paradox effect (PE) in AEPs with the increase of both parameters of N170 component was revealed. In central and temporal areas PEs were found in N170 component with the decrease of both parameters of this component. These results point to the “conflict” between the processes of excitation and inhibition in schizophrenia. In schizophrenia patients Pes were revealed in auditory and visual modalities (EVPs and VEPs) on the N170 wave with the unidirectional shifts (increase and decrease) of both parameters in the same cortical areas in AEPs and VEPs. It is supposed that ERP disturbances revealed in patients with schizophrenia are due to the pathology of the synaptic pruning causing the imbalance of excitation-inhibition and leading to the psychosis onset.