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Aim. To characterize iNOS expression indicators in the basal magnocellular nucleus of rats during early pathogenetic correction of neurodegeneration induced by intracerebroventricular colchicine administration. Materials and methods. The study was conducted using 50 male Wistar rats aged 10–11 months, which were divided into 5 experimental groups (n = 10). The control animals (group 1) were administered a 0.9 % NaCl solution intracerebroventricularly, while the other experimental group rats (groups 2–5) received a colchicine solution in the same manner. The following day, the animals from groups 3–5 were initiated early pathogenetic correction with citicoline (group 3), thiocetam (group 4), and HSF-1 (group 5) lasting 14 days. All the experimental animals (groups 1–5) were then euthanized with sodium thiopental, and their brains were extracted for histochemical, immunofluorescent, and biochemical examinations. Results. The study has demonstrated that intracerebroventricular administration of colchicine to rats was accompanied by morphological signs of neurodegeneration in the basal magnocellular nucleus and characterized by a significantly smaller area of chromaffin substance in the neurons of this structure by 39 % as compared to the control animals. At the same time, early pathogenetic correction of colchicine-induced neurodegeneration was associated with significantly larger values of Nissl substance area of the basal magnocellular nucleus neurons compared to the corresponding values in animals that did not receive the correction. Additionally, the nitrite level in the brain homogenates of rats administered colchicine without correction (group 2) exceeded the control (group 1) by almost 7 times, while the indicators in experimental groups 3, 4, and 5 exceeded it by 3.5, 2.9, and 3.8 times, respectively. However, no statistical differences were found between the control group and the correction groups in terms of nitrite content. Evaluating the expression of iNOS (the area of immunopositive cells and corrected total cell fluorescence, CTCF) in the basal magnocellular nucleus of the experimental rats it has been shown that the area was most affected in group 5 (HSF-1 correction), exceeding the control parameter by 18.9 %, group 3 (citicoline correction) by 14.7 %, and group 4 (thiocetam correction) by 17.1 %, with no statistical differences compared to group 2 (colchicine administration without correction). Meanwhile, the CTCF of iNOS+-cells in the basal magnocellular nucleus of the experimental animals was the highest in group 2 significantly exceeding the corresponding parameters in the control and correction groups. No significant differences were found between the control and correction groups in this parameter. Additionally, it is noteworthy that intracerebroventricular administration of colchicine to rats, compared to control animals, was associated with a significant double the number of iNOS+ cells in the basal magnocellular nucleus. However, early pathogenetic correction in groups 3-5 did not significantly affect the number of iNOS+ cells in the studied structure, as this parameter did not statistically differ from group 2, although significantly exceeding the corresponding parameter in the control group (group 1). Conclusions. Early pathogenetically substantiated correction with citicoline, thiocetam, and HSF-1 in colchicine-induced neurodegeneration in the basal magnocellular nucleus of experimental rats is accompanied by an increase in the area of chromaffin substance compared to rats that received intracerebroventricular colchicine without correction, as well as a reduction in nitrite levels in brain homogenates to the control level (sham-operated animals). In the basal magnocellular nucleus of experimental rats, under the influence of early pathogenetically substantiated correction of experimental neurodegeneration, iNOS expression indicators (area of immunopositive cells and CTCF) vary depending on the neuroprotectant used. The number of iNOS+ cells in the basal magnocellular nucleus of experimental rats in the correction groups does not change compared to the group that received intracerebroventricular colchicine without correction and is statistically higher than the corresponding indicator in the control rats.

Aim. To characterize the features of iNOS expression in neurons of the basal magnocellular nucleus against the background of nitrosative stress during experimental colchicine-induced neurodegeneration. Materials and methods. The study was conducted on 30 male Wistar rats. At the first stage of the experiment, cognitive impairments were modeled in rats (n = 10) by intracerebroventricular injection of colchicine, and compared with sham-operated and intact animal groups, the validity of the model was demonstrated using an 8-arm radial maze LE760 (PanLab Harvard Apparatus, Spain). Subsequently, the animals were euthanized with sodium thiopental, and the brain was removed for histological, immunofluorescence, and biochemical analyses. Results. It was found that intracerebroventricular injection of colchicine compared to intact and sham-operated animals leads to disruption of histoarchitecture in the basal magnocellular nucleus of rats with a significant decrease in the Nissl substance area in neurons by 47.3 % and 35.9 %, respectively. At the same time, the level of nitrites in the brain homogenates of animals with experimental neurodegeneration exceeded the comparison groups almost 10 times (intact) and 7 times (sham-operated rats). Meanwhile, immunofluorescence investigation of iNOS expression in the basal magnocellular nucleus of rats with intracerebroventricular colchicine administration, compared to intact and sham-operated animals, revealed a significantly higher value of corrected total cell fluorescence by 22.7 % and 45.3 %, respectively. Simultaneously, it was established that experimental colchicine-induced neurodegeneration is accompanied by a significantly greater number of iNOS+ cells in the basal magnocellular nucleus compared to control groups. Conclusions. Intracerebroventricular injection of colchicine to experimental rats is accompanied by morphological signs of neurodestruction in the basal magnocellular nucleus against the background of nitrosative stress. iNOS expression in rats after intracerebroventricular colchicine administration in the cells of the basal magnocellular nucleus is characterized by a higher enzyme content compared to intact and sham-operated animals. The area of immunopositive cells between experimental groups does not change statistically. Intracerebroventricular administration of colchicine to experimental rats is accompanied by an increase in the number of immunopositive cells for iNOS in the basal magnocellular nucleus.

Mechanisms of beta-endocrinocyte differentiation involving c-kit may be associated with a number of processes, including signaling pathways and regulatory mechanisms. Such factors as activation of the c-kit signaling pathway, an increase or decrease in cell proliferation and survival, regulation of differentiation gene programs and stem cells are important in controlling self-preservation and regulating the cellular number and types, that are differentiated being impacted by intermittent hypoxic hypoxia, hypertension and diabetes mellitus. The aim of the work is to determine the dynamics of c-kit proliferative factor in beta cells under an exogenous influence (intermittent hypoxic hypoxia) and endogenous pathology (arterial hypertension and diabetes mellitus). Materials and methods. The study was conducted using 15 white Wistar rats and 5 spontaneously hypertensive rats (SHR), which were divided into 4 groups of 5 animals each. Group 1 – control (intact) rats, group 2 – animals with experimental diabetes mellitus, group 3 – rats with hereditary arterial hypertension (SHR), group 4 – animals exposed to the effect of intermittent hypoxic hypoxia. At the end of the experiment, the animals were euthanized, organs were harvested and processed, serial histological pancreatic sections 5 µm thick were deparaffinized and retrieved. Insulin and c-kit+ beta progenitor cells were detected by the immunofluorescence method using antibodies. Immunofluorescent reactions were studied using an AxioImager-M2 fluorescence microscope. Results. The quantitative indicator of beta cells was almost 6 times decreased in rats with diabetes mellitus. Concentrations of insulin in animals of this group were increased compared to intact animals and the marker of proliferative activity was decreased without changes in the percentage of c-kit-immunopositive beta cells. The course of hereditary arterial hypertension in SHR was accompanied by an 8-fold decrease in the number of beta cells per 1 cm2, an increase in insulin in beta cells as compared to the animals of both intact and experimental diabetes groups. Regarding the c-kit expression in beta cells, it was significantly reduced only in the group of intact animals and the number of c-kit-immunopositive beta cells was almost 2.8 times decreased. In the experimental group of animals exposed to hypoxic hypoxia, the number of beta cells per measurement unit was significantly increased, the concentration of insulin in beta cells was increased as compared to the intact animals, but lower than that in rats with diabetes and hypertension. The marker of proliferative activity c-kit was decreased compared to both intact and diabetic animals. As for the number of c-kit-immunopositive beta cells, it did not differ statistically from that in intact and diabetic animals, but was higher than that in SHR. Conclusions. The development of experimental diabetes in Wistar rats and hereditary hypertension in SHR results in a significant decrease in the specific density of beta cells in the pancreas in contrast to the effect of multiple-day hypoxic training, which stimulates an increase in the density of insulin-synthesizing endocrinocytes. Experimental conditions, diabetes mellitus, hypertension and adaptation to hypoxia, are accompanied by an increase in insulin and a decrease in the c-kit expression in beta cells. However, the number of c-kit-immunopositive beta cells in the pancreatic islets significantly decreases only with the development of hereditary arterial hypertension.

In modern medical science great attention is paid to the clarification of the molecular mechanisms, which are the basis of adaptation to environmental factors of unusual origin and/or extraordinary strength. The aim of the study is to determine the features of a group of genes with low expression level, associated with hypoxia in the pancreas of Wistar rats under conditions of intermittent hypoxia. Materials and methods. The study was conducted on 10 white, sexually mature Wistar rats, which were divided into 2 groups (5 animals in each). Animals of group 1 were part of the control (intact) group. The animals of the 2nd group were subjected to hypoxic training according to the following scheme: for 15 days, 6 hours daily, namely on days 1–5 they simulated an ascent to a height of one to five kilometers above sea level under the conditions of a barometer, and the last 10 days 6 km above the sea level. To analyze gene expression, we used the polymerase chain reaction method with real-time reverse transcription (PCR) CFX-96 Touch™ (Bio-Rad, USA) and the RT2 Profiler™ PCR Array Rat Hypoxia Signaling Pathway kit (QIAGEN, Germany), where 84 genes were the subject of research in experimental animals. Results. According to the results of the PCR study of genes in the pancreas samples of intact animals and animals exposed to hypoxic training, it was established that out of 84 genes associated with hypoxia, a group of 5 genes with a low expression level (∆∆Ct < 30) was found. This pattern includes Bhlhe40 genes, Ctsa, Hif1a, Lox, and Slc16a3, the expression of which is statistically reduced. Thus, compared to the level of their expression in intact animals, the expression of Bhlhe40 decreased by 2.59 times, Ctsa by 6.02 times, Hif1a by 3.85 times, Lox by 3.01 times, and Slc16a3 by 2.40 times. Conclusions. Intermittent hypoxia reduces the expression of the Bhlhe40 gene by 2.59 times, which can be considered as an element of adaptation of cells to a low level of oxygen and modulation of genetic programs. The decrease in Ctsa gene expression by 6.02, Hif1a by 3.85, and Lox by 3.01 times during intermittent hypoxia demonstrates, that these effects can be used as sanogenic factors in insulin resistance and type 2 diabetes. The 2.40-fold decreased expression level of Slc16a3 is probably an element of metabolic adaptation and adaptation of the metabolic pathway of cells to hypoxia conditions.

Intermittent hypoxia affects a variety of pathological conditions in the body and is used in medicine to reproduce the sanogenic therapeutic effect. Intermittent hypoxia is used for clinical indications to improve lung function; increase the body’s adaptive capacity; in obstructive sleep apnoea syndrome; in anaemia, diabetes mellitus. In cancer radiotherapy, intermittent hypoxic training helps to increase the sensitivity of the tumour to treatment. Intermittent hypoxia is useful in rehabilitation medicine to improve the physical recovery of patients after surgery or injury to improve the body’s functional capabilities. However, to date, the activity of regulatory genes, that activate the molecular mechanisms of the above-mentioned sanogenic effects of intermittent hypoxia has not been sufficiently studied. The aim of the study: to determine the expression of hypoxia-related genes in pancreas of Wistar rats under intermittent hypoxia. Materials and methods. The CFX-96 Touch™ real-time reverse transcription polymerase chain reaction (PCR) (Bio-Rad, USA) and the RT2 Profiler™ PCR Array Rat Hypoxia Signalling Pathway kit (QIAGEN, Germany) were used to analyse gene expression in experimental animals, where 84 genes involved in the hypoxia signalling pathway identified in the pancreas were studied. Results. According to the results of PCR analysis of pancreatic samples from intact animals and animals exposed to hypoxic training, the activity of the gene panel can be distributed as follows: genes with high expression compared to the intact group of animals, genes with low expression compared to the intact group of animals and genes in which no significant changes were detected in the samples compared to the intact group of animals. We have found, that the genes Cops5, F10, Jmjd6, Lgals3, Rbpjl, Vegfa have high expression activity compared to the intact group of animals. Conclusions. The increase in the expression of Cops5 by 10.29 times, Lgals3 by 2.94 times and Rbpjl by 5.73 times as a result of intermittent hypoxia can be regarded as an activating factor for the increase in the proliferation of endocrine and exocrine pancreatic cells and the growth of their antiapoptotic potential. The 3.20-fold increase in Jmjd6 gene expression under intermittent hypoxia can be interpreted as a regulatory effect through protein dehydroxylation and promotion of antiapoptotic protein activity in endocrine and exocrine pancreatic cells. The 5.99-fold increased level of Vegfa expression may promote angiogenesis in the pancreas under intermittent hypoxia.

The aim of the work was to define the nature of changes in morpho-densitometric parameters of magnocellular neurons of the hypothalamic paraventricular nucleus in rats at 6, 15 and 21 weeks of restricted living space. Materials and methods. A total of 55 male Wistar rats aged 6-10 months were used and divided into 4 groups (1 – intact control, 10 rats; 2, 3 and 4 – experimental groups of 15 rats each, which were in conditions of restricted environmental space for 6, 15 and 21 weeks, respectively). Morpho-densitometric analysis of 5-μm-thick rat brain sections was performed after preliminary standard histological processing and 48 hours of halocyanine-chrome staining by Einarson using an AxioImager-M2 microscope (Carl Zeiss, Germany). Images of magnocellular neurons of the hypothalamic paraventricular nuclei (PVN), which were topographically identified according to the stereotaxic atlas of the rat brain, were captured using a highly sensitive AxioCam-ERc 5s video camera (Carl Zeiss, Germany) and recorded as a computer file using AxioVision 40 V 4.8.2.0 software (license number 3005339). Quantitative data on the area of neurons, their nuclei and nucleoli, the content of heterogeneous DNA and RNA in the cell cytoplasm, nuclei and nucleoli were obtained in a semi-automatic mode using the open source software ImageJ (National Institutes of Health, USA). Results. Chronic stress condition modelled in rats for 6, 15, and 21 weeks (limited living space, inactivity, and complicated communications) resulted in a decrease in the area of cytoplasm and nuclei of magnocellular neurons of the hypothalamic PVN. The decrease was directly proportional to restrain stress duration: cytoplasm and nuclei by 18 % and 9 % at week 6 and by 40 % and 25 % at week 21, respectively, and only cytoplasm by 23 % at 15 weeks. On the contrary, the area of neuronal nuclei was increased by 31 % at 6 weeks of stress and 33 % at 15 weeks, and by 15 % at 21 weeks of stress compared to the control. The content of nucleic acids in the cytoplasm of magnocellular neurons of the hypothalamic PVN in the group of rats with 6-week restriction was 39 % less than in the control group, 34 % less than that in the group with 15-week restriction, and 42 % less than that in the group of 21-week restrain stress. In the nuclei of cells after 6 and 15 weeks of restriction, the content was decreased approximately equally by 37 % and 35 %, respectively, and long-term restriction (21 weeks) contributed to a 41 % decrease. In the neuron nucleoli, the content of nucleic acids was changed similarly: in the group of 6 weeks, a decrease of 40 % was characteristic, after 15 weeks – by 39 %, and after 21 weeks – by 43 %. Conclusions. Changes in the morphometric parameters of magnocellular neurons of the hypothalamic PVN in rats with long-term limitation of living space are characterized by time dependence and multidirectionality, which is related to the functional features of the neuron structural components (cytoplasm, nucleus and nucleoli). There is a progressive decrease in the cytoplasmic area of PVN neurons and their nuclei, while the nucleolar area increases with increasing length of living space limitation. The content of nucleic acids in the studied structures of the hypothalamic PVN magnocellular neurons after prolonged stress at each time point (6, 15, 21 weeks) becomes less than the control values by more than a third. Comparison of nucleic acid content in the neuron cytoplasm, nuclei, and nucleoli shows a narrow range of variations in the parameters of the experimental group rats between different periods.

Aim of the study was to characterize the locomotor and cognitive aspects of the behavior of experimental rats under intracerebroventricular colchicine administration in the open field test and the 8-arm radial maze, as well as identify a set of behavioral features of experimental animals that emerged during the study. Materials and methods. The study was conducted in two stages on 20 male Wistar rats aged 10–11 months. The first stage involved assessment of initial locomotor activity and cognitive functions in all intact rats. At the next stage, the rats were divided into two experimental groups (n = 10): the first group with intracerebroventricular injection of physiological NaCl solution, and the second group with intracerebroventricular injection of colchicine. In 14 days after the surgery, repeated recording of locomotive and cognitive activity indicators was performed. Results. The locomotor activity characteristics did not statistically differ between the animals before the surgical procedures and the rats of the first group. However, in the second group, the activity indicators were significantly higher than in the respective pre-surgery rats. In the intergroup comparison of the rats that entered the second stage of the experiment, it was found that among all the investigated parameters, only the indicator of high activity duration was significantly higher in the second group compared to the first group. At the same time, the animals in the second group showed significant cognitive impairments compared to the first group, as indicated by significantly lower memory index values, the number of correct entries into the maze arms, and a significantly longer time to make the first correct entry into the maze arm. Conclusions. Intracerebroventricular administration of colchicine to experimental rats is accompanied by increased locomotor activity and impairment of cognitive functions. The administration of a physiological solution is not accompanied by a statistically significant increase in locomotor activity, but it demonstrates a clear tendency to increase, which may indicate a certain influence of the procedure itself. The applied pharmacological model of neurodegeneration with subsequent comprehensive assessment of animal behavior in an open field and an 8-arm radial maze is legitimate and can be used to study the early development of neuroinflammation, neuroapoptosis, and synaptogenesis disorders in the experiment.

The aim of the work was to define the pattern of changes and pathogenetic mechanisms of glycemic curve shape during a glucose tolerance test in rats at 6, 15, and 21 weeks of environmental space restriction. Materials and methods. A total of 55 male Wistar rats aged 6–10 months were used and divided into 4 groups (1 – intact control, 10 rats; 2, 3 and 4 of 15 rats each, which were in conditions of restricted environmental space for 6, 15 and 21 weeks, respectively). Fasting plasma levels of glucose (test strips Test Strip II on a Glucocard glucometer (ARKRAY Inc., Japan)), insulin and corticosterone (by an immunoenzymatic method using commercial kits for rats from Monobind, USA) were measured, glucose tolerance tests (GTT) were performed, the HOMA index and the insulin/corticosterone ratio were calculated. Results. The 6-week environmental space restriction, immobility and complex communication relations resulted in a hypoinsulinemic-hypoglycemic type of the glycemic curve with high tissue glucose sensitivity in animals which were in the conditions described (the HOMA index was significantly decreased to 0.21 versus 0.55 in the control), the characteristic delayed hyperglycemic peak at the 30th min of the test slowly returned to the euglycemic level by only the 90th min against the 30th min in the controls. The 15-week restriction caused a hypoinsulinemic curve with preserved tissue glucose sensitivity (the HOMA index 0.33 versus 0.55 in the controls). Alterations in postprandial glucose absorption were manifested by the highest glucose concentration at the 15th min of the test, a very slow decrease in the glucose level in the post-absorption period not being restored to baseline values by the 90th min. The 21-week restriction shaped a diabetic type of the glycemic curve, impaired tissue glucose sensitivity (a substantial and significant increase in the calculated HOMA index from 0.55 in the controls to 0.95) and resulted in the development of insulin resistance. Conclusions. The environmental space restriction, immobility and complex communication relations gradually induce a range of disorders in animals and change the glycemic response shape to glucose load, impair prandial insulin secretion, augment hyperglycemic effects of counterinsular hormones (corticosterone), and realize dysfunctional manifestations of prandial/postprandial glycemia. 6 weeks of restrictions and challenges shape the hypoinsulinemic-hypoglycemic type of the glycemic curve with high tissue glucose sensitivity, while 15 weeks result in the hypoinsulinemic curve with preserved tissue glucose sensitivity. 21 weeks show the diabetic type of the glycemic curve with impaired tissue glucose sensitivity and the development of insulin resistance.

The aim of the work is to ascertain the character of changes in the hormonal profile (concentrations of corticosterone, insulin, and adrenocorticotropic hormone) in conjunction with metabolic alterations and elevated blood pressure, which are induced in rats by restraint stress at 6th, 15th and 21st weeks of environmental space restriction. Materials and methods. A total of 55 normotensive male Wistar rats, aged 6–10 months, were assigned into 4 experimental groups (1 – intact control (10 rats); 2, 3 and 4 (15 rats each exposed to restricted space allowance)). All the animals were subjected to blood pressure (BP), blood glucose level and body weight measurements twice: at the stage of forming groups and at the 6th, 15th and 21st weeks. Plasma hormone concentrations (insulin, corticosterone, and ACTH) were examined by the immunoenzymatic method using commercial kits (Monobind, USA). Results. The body weight of the animals was significantly reduced by 20.72 % after 6 weeks of space allowance restriction, it was restored to baselines by the 15th week and exceeded control values by 26.1 % at the 21st week. BP levels showed an increasing trend, a dynamic increase in systolic pressure by 7 %, 17 % and 26 % was detected, respectively, as well as diastolic from the 15th week to the 21st week by 21.4 % and 37.0 %, respectively. Glucose concentration was within the euglycemic range. Changes in the hormonal profile showed an increase in the concentration of ACTH by more than 50 % and a decrease in insulin – by 34 % at the 6th week with a subsequent twofold decrease in the insulin concentration (at week 15) and a further more than twofold increase in ACTH at the 21st week. As for changes in the concentration of corticosterone, a peak increase of 3.77 times was noticed at the 15th week, followed by a decrease and restoration to the normative values by the 21st week. Conclusions. Even minor and unremarkable continuously acting stressors, which cannot be coped, become important triggers for hormonal profile and carbohydrate metabolism alterations as well as for a persistent increase in blood pressure, which manifest first by hypoinsulinemia, an increase in the level of ACTH, and a constant concentration of corticosterone. Long-term stress exposure contributes to a transient “peak” increase in the corticosterone level, a significant increase in insulin and a sustained increase in ACTH. Multidirectional changes in the levels of the studied hormones occur amidst a gradual increase in blood pressure and a stable increase in the level of glycemia.

Intermittent hypoxia has been studied for many years as a promising non-pharmacological method of cardiovascular disease prevention. Hypoxic effects are accompanied by structural and functional changes in the myocardium. There is a direct link between the duration of hypoxic exposures and the severity of left ventricular myocardial remodeling. A range of histochemical markers of myocardial remodeling (cardiotrophin-1, titin, collagen type 1, annexin V) characterizing parenchymal-stromal relationships in the myocardium has shown high informativeness and prognostic value. The aim of the study was to examine cardiotrophin-1, titin, collagen type 1, annexin V and the morphofunctional state of the left ventricle of the heart in experimental rats exposed to intermittent 15-day (IH15) and 60-day hypoxia (IH60). Materials and methods. Intermittent hypoxia was modeled using 30 normotensive male Wistar rats, 7–8 months old, which were randomly assigned to 3 experimental groups of 10 animals each: 1) INT – a control group – intact animals (196.3 ± 6.8 g); 2) IH15 – 15-day hypoxia (205.6 ± 4.1 g); 3) IH60 – 60-day hypoxia (201.1 ± 5.5 g). The study compared the effects of intermittent hypoxia of varying duration: 15-day and 60-day hypoxia. Experimental modeling of intermittent hypoxia of 2 terms revealed a number of differences between the effects dependent on this factor duration through functional (blood pressure measurement, echocardiography) and immunofluorescent studies. Results. Blood pressure in rats of both groups was in the normotensive range, but an increase in systolic by 10 % and diastolic by 19 % was found in IH60 group compared to IH15 group (p < 0.05). In IH15 group, there was a significant decrease in end-diastolic dimension by 20 %, end-systolic dimension by 22 %, an increase in the thickness of left ventricular posterior wall by 44 % and interventricular septum by 33 % as well as left ventricular mass by 12 %, indicating concentric remodeling of the left ventricle, the development of which was confirmed by a 76 % increase in relative wall thickness compared to that in the control group (p < 0.05). Along with these changes, a decrease in end-diastolic volume by 47 %, end-systolic volume by 48 %, stroke volume by 49 % and cardiac output by 50 % with preserved ejection fraction was revealed (p < 0.05). While the parameters of IH60 rats were characterized by an increase in the thickness of interventricular septum by 33 % and left ventricular posterior wall by 17 %, as well as left ventricle mass by 23 %, relative left ventricular wall thickness was 15 % higher than the control value (p < 0.05). At the same time, diastolic volume was 9 % decreased and systolic volume was 24 % increased (p < 0.05). Also, cardiac output was increased by 58 % compared to that in 15-day hypoxic rats with an 8 % decrease in ejection fraction (p < 0.05). The concentrations of markers in IH60 group exceeded those in IH15, namely: cardiotrophin-1 by 39 %, titin by 70 %, collagen type 1 by 60 % and annexin V by 130 % (p < 0.05). Conclusions. 15-day hypoxia forms concentric left ventricular hypertrophy according to echocardiography findings; the study of marker profile of myocardial remodeling has revealed the development of moderate hypertrophy with increased resilient-elastic properties and decreased intensity of cardiomyocyte death. Remodeling caused by 60-day hypoxia is characterized by the eccentric pattern of changes with severe hypertrophy, significant fibrosis associated with apoptosis of cardiomyocytes. Such morphofunctional state of the myocardium may indicate the initial stages of maladaptation, increasing the risk of heart failure development.

Myocardial remodeling is considered as a three-component complex process, including cardiomyocyte hypertrophy, their apoptosis, interstitial and perivascular fibrosis. At the same time, the nature of remodeling and the direction of restructuring in the myocardium depend on the prevalence of one of these processes, the degree of their severity and the impact duration. Therefore, to understand the effect of short- and long-term intermittent hypoxia on the direction of myocardial remodeling and its type, the aim of this study was to determine the pathogenetic features of the morphodensitometric characteristics of cardiomyocytes and the marker profile of left ventricular myocardial remodeling in the rats with experimental intermittent hypoxia durated 15 and 60 days.Material and methods. A total of 30 male Wistar rats aging 6-10 months were used for the experiment and assigned to 3 experimental groups of 10 animals each: control; rats exposed to 15-day hypoxia; rats exposed to 60-day hypoxia. The object of the study was the left ventricular myocardium. The number of nuclei in an image, their average linear size and density (the ratio of the total area of nuclei to the area of the cytoplasm), and the concentration of RNA in the nucleus and cytoplasm were measured in the sections stained by Einarson via morphodensitometric method. An immunofluorescence method was used to study the content of immunoreactive material to markers of remodeling (cardiotrophin-1, type I collagen, titin, annexin V). As a result of the study, it was found that intermittent hypoxia led to a decrease in the number of nuclei in cardiomyocytes in both experimental groups compared to the control. Such changes in the number of nuclei were accompanied by significantly larger nuclear size compared to the control (in rats with 15-day hypoxia by 52.9 %, in rats with 60-day hypoxia - by 153.4 %) and a decrease in the density of nuclei in relation to the cytoplasm by 19.5 % and 21.2 %, respectively. In both groups, a significantly lower control concentration of RNA in the nuclei of cardiomyocytes was found alongside with an increase in their area. Such changes were accompanied by a significantly higher concentration of RNA by 23.2 % in the cytoplasm in case of long-term intermittent hypoxia. The marker profile of remodeling parameters in rats exposed to 15-day hypoxia was characterized by a higher content of cardiotrophin-1 and titin by 11.5 % and 23.1 %, respectively, as compared to the control. The content of type I collagen was 19.9 % higher, while the content of annexin V did not change significantly. In rats with long-term 60-day hypoxia, the content of cardiotrophin-1 was higher by 73.6 %, titin - by 124.9 %, type I collagen - by 41.9 %, and annexin V - by 95.9 % in comparison to the control. When calculating the titin / collagen ratio in rats based on their content, a significant increase in myocardial stiffness was determined in the 60-day hypoxia group which was 1.44, while it was0.91 in the control, and in rats with 15-day short-term hypoxia – 0.93.Conclusions. Intermittent hypoxic effects, regardless of duration, result in morpho-structural rearrangements of the myocardium, are characterized by an increase in viscoelastic mechanical properties and the development of hypertrophy, but with an increase in the duration of exposure (60 days) – by an additional formation of interstitial fibrosis and apoptosis of cardiomyocytes. Short-term hypoxia forms a hypertrophic type of myocardial remodeling with a decrease in the number of nuclei alongside with an increase in their size and a moderate decrease in RNA concentration. The marker profile of remodeling changes in a physiological manner and is characterized by an increase in the content of cardiotrophin-1, type I collagen and titin, while maintaining the titin / collagen ratio and normal apoptotic rate. Long-term hypoxia causes a fibro-apoptotic type of pathological myocardial remodeling including an almost two-fold decrease in the number of nuclei with an increase in their size and a decrease in RNA concentration. The marker profile of remodeling is characterized by an increase in all 4 components, a significant increase in the titin / collagen ratio and high apoptotic rate of cardiomyocytes.

The aim was to determine the morphodensitometric parameters of cardiomyocytes and features of the marker profile of remodeling in the left ventricular myocardium of rats with experimental hypertension of different etiopathogenetic forms. Materials and methods. The experiment was conducted on 20 male Wistar rats and 10 SHR which were divided into two groups of 10 animals each: the 1st –control; the 2nd – rats of the SHR line (EAH); the 3rd – 10 male Wistar rats with endocrine-salt arterial hypertension. Systolic and diastolic BP levels were measured in all the rats using the system of non-invasive arterial pressure measurement BP-2000. The objects of the study were myocardial sections in which the content of immunoreactive material to remodeling markers (cardiotrophin-1, titin, collagen type I, annexin V) was determined by the immunofluorescent method, titin / collagen ratio was calculated, the average linear size of cardiomyocyte nuclei, their density, RNA concentrations in the nucleus and cytoplasm were determined by morphodensitometric method. Results. Arterial hypertension, regardless of its etiopathogenetic form, is characterized by an increase in the number of cardiomyocyte nuclei with an increase in their size, decrease in the density and decrease in their RNA concentration against increase in the cytoplasm. In rats with EAH, the content of cardiotrophin-1 was higher than the control by 27 %, and in ESAH by 80 %. Titin levels were 12% higher in EAH and 46 % in ESAH. The collagen type I content of EAH was higher than the control by 49 %, while in the group with ESAH by 68 %. EAH rats had a higher annexin V content by 58 %, while ESAH – 64 %. The ratio of the content of titin and type I collagen in control rats was 1.01, in rats with EAH decreased to 0.76, while in rats ESAH it was 1.3. Conclusions. The formation of arterial hypertension, regardless of its etiopathogenetic form, leads to the development of pathological myocardial remodeling, as indicated by increased heart mass and specific gravity, changes in the cytoarchitectonics of cardiomyocytes, the development of polymorphism of their nuclei with increasing size against increasing of its number with nuclear dysfunction. The marker profile of myocardial remodeling in rats with essential hypertension is characterized by a moderate increase in cardiotrophin-1 and titin, with a significant increase in collagen type I and annexin V, which in combination with a low ratio of titin / collagen type indicates fibrosis with increased myocardial stiffness and the development of hypertrophic-fibrous type of myocardial remodeling with moderate apoptosis. In rats with endocrine-salt arterial hypertension, the marker profile of myocardial remodeling is characterized by a significant increase in all 4 immunohistochemical markers of remodeling, moderate fibrosis and an increase in the titin / collagen ratio, which is characteristic of hypertrophic-apoptotic type of pathological remodeling.

The aim was to determine the features of the NO system status in the left ventricular myocardium in the rats with intermittent hypoxic hypobaric hypoxia during 15 and 60 days. Material and methods. The study was conducted on the 30 Wistar male rats, which were divided into 3 experimental groups: the 1st – control, the 2nd – rats exposed to intermittent hypoxia during 15 days and the 3rd group – the rats exposed to intermittent hypoxia during 60 days. Blood pressure was measured in all the rats. The objects and methods of the study were blood plasma (nitrotyrosine detection with immunoassay) and the myocardium of the left ventricle (concentration of nitrites by Griess nitrite test and content of immunoreactive material to the nitric oxide synthase isoforms by immunofluorescence method). mRNA expression of NOS isoforms was determined by PCR-RT method in the myocardium. Results. In the rats with 15-day hypoxia there was an increase in systolic pressure compared to control, and in 60-day hypoxia, there was also an increase in diastolic pressure although this changes were within the normotensive range. mRNA to all the myocardial NOS isoforms was characterized by an increase in both hypoxia groups. At the same time, the indices of the immunoreactive material content to the NOS isoforms were dependent on the hypoxia term. The concentration of the nitrotyrosine increased in both hypoxic groups, but in the long term it occurred along with a decrease in the level of nitrite, which indicates the possibility of nitro-oxidative stress. Conclusions. The 15-day intermittent hypoxia changes the myocardial NO system: an increase in the expression of all 3 isoforms, an increase in the nitrite and the nitrotyrosine content. iNOS becomes the predominant form of the enzyme in the myocardium with the increasing its mRNA. In 60-day hypoxia, the profile of the NOS enzyme is characterized by increased expression of the constitutive isoforms and decreased inducible NOS expression that was accompanied with significant increase in mRNA of all three forms. The level of terminal metabolites of NO was characterized by a decrease in the nitrite while the content of the nitrotyrosine increased.

The aim was to determine the morpho-functional parameters of the left ventricular myocardium NO system in the rats with essential hypertension (SHR line). Material and methods. We used a combination of modern highly informative methods, namely: research of NOS isoform profie (nNOS, iNOS eNOS) in the myocardial slices along with an assessment of their synthesis and expression of the corresponding mRNA; NO derived nitrites level determination directly in the myocardium homogenates and concentration of nitrotyrosine in blood plasma of rats. The results of the performed studies have shown that high blood pressure in the SHR was accompanied by a signifiant increase in the concentrations of all three NOS isoforms in the myocardium and increased expression of their mRNA. Higher concentration of nitrites by 18.8 % was detected in the SHR group compared with the control animals. The concentration of nitrotyrosine in blood plasma of rats with essential hypertension was also increased by 25 %. Conclusions. The predominance of IRM to constitutive isoforms of NOS with low IRM content to iNOS was noted in the myocardium of the control group rats while in SHR rats higher IRM values were marked for all NOS isoforms. The formation of hypertension is accompanied by high content of NO end metabolites and the development of systemic nitroso-oxidative stress with the increase of nitrotyrosine concentration.

The vasopressinergic system of the hypothalamus occupies an important place in the neuroendocrine mechanisms of maintaining homeostasis, controlling autonomic reactions and the processes of adaptation of the organism to the acute and chronic stressors. The main portion of the magnocellular vasopressin-synthesizing neurons is localized in the supraoptic nucleus (SON) and in the lateral part of the posterior magnocellular subnuclei of the paraventricular nucleus (PVNpml). The aim of study was to establish the features of the vasopressinergic neurons of the hypothalamus magnocellular nuclei functional state under the inflence of prolonged intermittent hypoxic hypoxia and in the post-hypoxic period. Materials and methods. The research was carried out on 30 male Wistar rats. Intermittent hypoxia was modeled by daily 6 hour stay of rats at the simulated altitude of 6000 m (pO2 = 9.8 %) for 15 days, the post-hypoxic period lasted 10 days. The distribution of [Arg8]-vasopressin (AVP), cFos, HIF-1α, and HIF-3α proteins was investigated by quantitative immunoflorescence methods in serial frontal sections of hypothalamus. Results. The hypoxic hypoxia action led to SON neurons degeneration, inhibition of AVP synthesis in SON by 40 %, decrease of cFos protein content by 56 %, and the failure of reaction to hypoxia from the HIF-proteins family. In PVNpml neurons, intermittent hypoxia stimulated 6-fold increase in the AVP content along with cFos-protein increase by 80%. The response of PVNpml neurons to hypoxia was accompanied by 3-times increase of the HIF family proteins content. In the post-hypoxic ially restored in SON neurons, but decrease of cFos-protein synthesis indicated inhibition of secretory activity in SON. In the post-hypoxic period the content of the AVP and the HIF-proteins decreased signifiantly in PVNpml neurons, but the level of all proteins remained higher than in the control group. At the same time, the level of cFos secretory activity did not change signifiantly as compared with the hypoxic period. These data indicate the stability of the high level of functional activity of the PVNpml asopressinergic neurons during the 10-day post-hypoxic period. Conclusions. Intermittent hypoxia stimulates the functional activity of the PVNpml that manifests as an increase of vasopressin, cFos, HIF-1α, and HIF-3α proteins synthesis in magnocellular neurons. In the post-hypoxic period, a slight decrease in the synthesis of vasopressin, HIF-1α and HIF-3α proteins is observed without a decrease in the cFos protein content in PVNpml. Intermittent hypoxia inhibits the functional activity of SON neurons, which is partially restored in the post-hypoxic period.

Modern biomedical research conducted in scientific laboratories is a basis not only for studying the pathogenetic mechanisms of diseases formation and progression, today they are widely used for highly informative diagnostic methods development, new medicines creation, and the study of newly developed pharmaceutical compounds influence on the organism with their potential effectiveness assessment. The article highlights new approaches and possibilities for the functional state of small laboratory animals assessing, taking into account modern international requirements for research conduction and findings interpretation.

Alpha cells of pancreatic islets constitute the second largest population of pancreatic endocrinocytes, and the glucagon synthesized in them plays an important role in the regulation of glucose homeostasis. At the same time, glucagon-suppressive therapy is defined as the strategically main source of success of therapy for patients with type 2 diabetes mellitus. In clinical practice, diabetes is often associated with hypertension in the metabolic syndrome, which causes interest in the pathophysiology of α-endocrinocytes. The aim of the study was to investigate the distribution parameters of α-cells in the pancreatic islets of SHR and to characterize the morphological and functional state of glucagon-synthesizing endocrinocytes Materials and methods. In the histological sections of the pancreas, glucagon was detected by the immunofluorescence method; the area of pancreatic islets, as well as the number of α-cells in them, the concentration of immunoreactive glucagon in these cells, the specific indices of the distribution of islets, α-cells and glucagon per unit area of the gland. The results were processed with a package of statistical programs, to assess the reliability of the differences in the groups, the Student’s t-test and the Wilcoxon W-test were used. Results. In normoglycemic SHR, the number of islets containing glucagon-synthesizing α-cells was 10% more (p

Abstract In is known, that one of the main regulators of the blood pressure (BP) is hypothalamus. The efficiency of the BP regulation in a changeable environment is dependable on its coherence and coordination. This intrahypothalamic coordinator is an arcuate nucleus. One of the main conditions of the proper neuronal function is combination of their functional stability and plasticity, which is strictly dependable on adequate blood supply, metabolic and trophic processes. One of the key regulators of the above mentioned features is nitric oxide (NO). The purpose was to establish the pathogenetic link of NO synthases isoforms imbalance in Arc of hypothalamus with formation of hypertension in etiologically different models of essential hypertension (SHR) and endocrine-saline model (ESM). Materials and methods. Study was conducted on 48 mature male rats with weight of 250–270 gram and age of 13–14 months, which were allocated into 3 experimental groups of 16 animals: the 1st group was control with Wistar rats; the 2nd group comprised of Wistar rats with ESM and the 3rd was made of SHR. Results. Formation of the hypertension in ESM and SHR rats led to similar changes of the pattern of NOS isoforms expression. We found the significant increase of the IRM content to nNOS and iNOS, but decrease to eNOS. In the same time, the constitutive isoforms concentration (nNOS and eNOS) was significantly lower compared with control group, and iNOS concentration in both groups with hypertension was higher than in control group (6 % and 9 %, p < 0.05, respectively). Conclusions: In rats with normal BP in Arc, the most expressed NOS isoform was the endothelial one. We found the typical changes in the pattern of the NOS isoforms allocation. We also found the increase of the content of all isoforms with the decrease of the concentration of constitutional ones (nNOS and eNOS), but the increase of the iNOS concentration.

The control of b-cells pool in patients with hypertension is an actual problem, as it is possible that the hereditary genetic defects of arterial hypertension formation may affect the mechanisms of endocrine cell mass maintenance in pancreas and cause disruption of glucose metabolism and diabetes. In addition, violation of cytoarchitectonics of pancreatic islets may affect the adequate insulin secretion by the pancreas. This could be provoked by regional blood flow violations in patients with hypertension. The aim of our study was to assess the parameters of the allocation of pancreatic islets and characterize the b-cells morphofunctional state in SHR. Materials and methods. We assessed the amount of b-cells in islets, the concentration of immunoreactive material in them, specific indexes of allocation of islets, b-cells and insulin per unit area using immunohistochemical assay. Results were processed by statistical application package. We used Student’s t-test and Wilcoxon’s w-test when appropriate. Results and discussion. In normoglycemic SHR about 80 % of pancreatic islets are small islets, whereas in normotensive Wistar rats the portion of small islets is less than 45 %. In SHR rats we found the 1/3 decrease of b-cells in islets with area less than 1500 µm2, and 2-fold decrease in islets with area 3500–7500 µm2; decrease of specific amount of b-cells (12,4 % compared with Wistar) and insulin contain (3-fold compared with Wistar). Conclusions: Formation of hereditary hypertension in SHR is accompanied by remodeling of the insular apparatus of pancreas with prevailing of small and middle-sized islets, 2-fold decrease of amount of pancreatic islets and 8-fold decrease of b-cells cell amount. In normoglycemic SHR we found a middle b-cells hypertrophy and increased concentration of insulin. Herewith the specific insulin contain is 3-fold less in hypertensive compared with normotensive rats due to decrease of b-cells cell pool.

The aim of our study was to find out the features of the nitric oxide synthase (NOS) isoforms expression in longitudinal and transversal layers of the myocardium of the left ventricle in male rats of 3 months, which are descendants of female rats with experimental gestational diabetes (EGD). Materials and methods. Study was carried out on 10 male rats descendants of female rats with normal course of pregnancy and 10 descendants of female rats with EGD. We evaluated the expression of neuronal, endothelial and inducible isoforms of NOS in histological sections both of transversal and longitudinal layers of the myocardium of left ventricle. With the aim to analyze the pattern of the NOS isoforms expression in 5 um histological slices of left ventricle myocardium we have carried out a complex of histochemical assays. Slices were allocated to 3 groups: 1st one was incubated with rabbit IgG to neuronal NOS (Santa Cruz Biotechnology, USA) in dilution of 1:200; 2nd group underwent the incubation with rabbit IgG to endothelial NOS (eNos) (Santa Cruz Biotechnology, USA) in dilution 1:200; 3rd group was incubated with mice IgG to inducible NOS (iNos) conjugated with FITC (Santa Cruz Biotechnology, USA) in dilution of 1:200. The analysis of images was carried out with VIDAS-2.5 application package (Kontron Elektronik, Germany). Microimages of the left ventricle myocardium obtained with AxioScope (Carl Zeiss, Germany) and COHU 4922 (COHU Inc., USA) camera were processed in the system of digital image analysis VIDAS-386 (Kontron Elektronik, Germany). Results. In the study we have found that prenatal hyperglycaemia leads to the significant changes of the expression of NOS isoforms in the myocardium of left ventricle in male rats descendants of females with EGD, and the contain and the allocation of these enzymes are dependent both on type of the enzyme and its location in muscular layers. For eNOS the increase of the expression and the allocation in both transversal and longitudinal layers was typical, and for nNOS and iNOS we have found the significant decrease of the expression in transversal layers and the significant increase in longitudinal layers. Conclusion.We believe, the glucose homeostasis violation in foetus during the last trimester of the pregnancy changes the ratio of the NOS isoforms expression in the left ventricle myocardium and affects the balance of them in different layers, which could be a reason of the cardiovascular pathology development in adulthood.

The regulation of the paraventricular (PVN) and supraoptic (SON) nuclei’s activity is carried out with a great amount of different neurotransmitters, in particular, with nitric oxide. In order to get clear understanding of the local NO effects in hypothalamus in normal condition and different models of hypertension it is necessary to study all isoforms of NOS in PVN and SON. Our purpose was to find out the features of the inducible nitric oxide synthase (iNOS) expression in magnocellular SON and PVN in SHR and endocrine-saline model of hypertension in rats. Materials and methods. For all rats the mean blood pressure (mBP) was measured. In Wistar rats mBP was stable during the experiment. In SHR mBP was higher than normal. In animals of the 3rd group with ESM the first measurement (before the modelling) demonstrated normal rates of mBP. Since the 7th day of modelling mBP started increase and became steadily increased from the 21st day. We obtained the frontal slices of hypothalamus and performed the assessment of iNOS expression using immunofluorescence assay. The results showed the presence of the constitutive expression of iNOS in the magnocellular neurons of hypothalamus in Wistar rats as well as in both groups of experimental hypertension. The level of iNOS expression in magnocellular nuclei was dependent both on type of hypertension and topography of magnocellular neurons in hypothalamus. In SHR there was high expression of iNOS in PVN and low one in SON, whereas in endocrine-saline model there was high expression in SON and there were no substantial changes of the iNOS expression in PVN. Conclusions. We believe the alteration of iNOS expression in magnocellular nuclei of hypothalamus could participate in development and/or adaptation to hypertension.

Background. Diabetes mellitus (DM) became a major problem of the healthcare in Ukraine. The rapid increase in the incidence was noticed especially in recent decade. The treatment of diabetes and its complications become a difficult task. From this standpoint the experimental modeling of diabetes is rather essential. Using the experimental models gives the possibility to assess the significance of the activity of pharmacological substances or to find out new mechanism in the action of medicaments. The aim of this review is to light up the most studied and common experimental models of diabetes mellitus type 2 (T2DM) in small rodents and find out their drawbacks. It is known the background of T2DM is the violation of the insulin homeostasis such as the resistance of peripheral tissues to insulin as well as the dysfunction of the pancreatic beta-cells, which both lead to appearance of such phenomena as the glucosetoxicity and the lipotoxicity. In the end they both could result in life threatening vascular complications. Considering the steady growth of T2DM patients, the development both of the drug and non-drug methods of its treatment with the high therapeutically efficiency and the perfect safety profile becomes essential. The most important stage of the search of new ways of influence on pathogenetic links of T2DM is the preclinical stage. From this standpoint the usage of experimental models of T2DM has a huge importance. There are a lot of models of T2DM developed by different scientists. These models could be spontaneous or be induced by different chemical diabetogenic substances, diet or surgical interventions or be a combination of methods listed above. Conclusions. We should underline the adequate modeling of DM2T is the necessary basis for the pre-clinical study of drug-based and not-drug methods of correction of the hyperglycemic states. Using different models makes it possible for infer the obtained experimental results to the society, which suffers from DM2T.

The aim was to study patterns of the nNOS, iNOS and eNOS expression in pancreatic islets in prepubescent male offsprings of female rats with experimental gestational diabetes mellitus. Materials and methods. The study was carried out in 10 prepubescent male offsprings of female rats with normal pregnancy and in 10 prepubescent male offsprings of female rats with experimental gestational diabetes mellitus. The expression of nNOS, iNOS and eNOS was evaluated in histological slices of pancreatic islets. Results. It was found that the largest area of enzyme expression of eNOS was detected in control animals. On the other hand the immunoreactive material enzyme was maximal for iNOS. Chronic fetal hyperglycaemia affects the allocation of NOS isoforms in pancreatic islets. Higher immunoreactive material enzyme and nNOS contain, increase of iNOS area and the most significant increase of contain and area of fluorescence of eNOS compared with other expression indexes were detected. We believe the affection of glucose homeostasis in fetus during the last trimester of the pregnancy changes the relation of patterns of the expression of NOS isoforms, and it can lead to the formation of metabolic violation in adults.

Aim. The purpose was to evaluate the features of the neuronal and endothelial nitric oxide synthase expression pattern in supraoptic and magnocellular part of paraventricular nuclei of the hypothalamus in different models of hypertension. Materials and methods. The study was carried out on 20 Wistar male rats and 10 SHR male rats. There were two experimental models of hypertension used: the genetically predisposed to age-related hypertension SHR and rats with endocrine-saline model of hypertension (ESM). The object was the hypothalamus of rats. The immunohystochemical assay was used to determine the expression of NOS isoforms. Results showed the imbalance of constitutive NOS isoforms in SON and PVN of hypothalamus in both of SHR and ESM. The eNOS and nNOS expression pattern is dependent on etiological factor, topographical peculiarities of the nuclei and their functions. Conclusions. We believe the imbalance of constitutive NOS isoforms take part in the hypertension development, its progression and the formation of complications.