Standard Vivarium Conditions Research Articles

Structural changes in the organs of the lymphoid system in terms of induced carcinogenesis

Colorectal cancer is the third most common cancer in the world. Despite recent therapeutic advances, it causes more than 500,000 deaths each year. The immune system plays a crucial role in protecting the body from cancer. However, cancer cells are able to evade immune detection and destruction. For example, they can downregulate antigen expression, produce immunosuppressive molecules, or recruit immune cells that perform regulatory or inhibitory functions. Understanding the complex interactions between the immune system and carcinogenesis is crucial for developing effective cancer treatments. The study aimed to determine the morphological changes in the thymus, spleen, and lymph nodes under N,N-dimethylhydrazine-induced carcinogenesis. The study was performed on 77 male outbred albino rats weighing 190-230 g, kept in standard vivarium conditions. Colon adenocarcinoma was modeled by administration of N,N-dimethylhydrazine hydrochloride for 30 weeks. To study the peculiarities of morphological and functional changes in lymphoid organs in the dynamics of colon tumor lesions, animals were withdrawn from the experiment every 30 days. Paraffin sections of the thymus, spleen, and lymph nodes 5-6 μm thick were made on a rotary microtome and stained with hematoxylin and eosin. The experimental investigation unveiled the character and extent of histological alterations within the lymphoid system organs under conditions of N,N-dimethylhydrazine-induced colon adenocarcinomatosis. As the experiment progressed, there was a noticeable escalation in the severity of detrimental and degenerative modifications observed in the thymus, spleen, and lymph nodes. These modifications were evident in the disruption of blood circulation within the examined organs, leading to vascular wall impairment and hemorrhaging, the disarray of morphofunctional elements and the development of fibrosis. Given the significant role played by the thymus, spleen, and lymph nodes in regulating carcinogenesis and maintaining immune balance, it is extremely important to delve into understanding the changes in their structure and function. Obtained results indicate that carcinogenesis is accompanied by pronounced morphological changes in the structural components of the lymphoid system organs, the degree of which increases in direct proportion to the duration of exposure to the oncogenic factor.

Pathomorphological characteristics of heat stress in the experiment.

The purpose of this research was to explore some morphological, physiological, and biochemical changes in female and fetal Wistar rats under heat stress. The experiment involved 30 animals, including two experimental groups (pregnant and nonpregnant females) kept under heat stress at 32°C and one control group consisting of healthy individuals kept in standard vivarium conditions. After dissection, fixation, dehydration, and primary processing, tissue samples were embedded in a mixture of paraffin and lanolin to obtain material for sections. Sections were made using a freezing and angular microtome and stained with hematoxylin and fuchsine solutions. Changes in morphology were assessed by microscopy using a Leitz DIAPLAN system. As a result of heat stress, an increase in linear cell size, capillary network area, and adrenal mass was observed; adipocytes lost lipid vacuoles; prismatic thyroid cells were replaced by flat cells; hypothyroidism; an increase in the number of osteocyte lacunae; and increased osteoclast activity in bone tissue; interstitial and intracellular oedema and caryopycnosis of ventricular cardiomyocytes; reduction in the diameter of skeletal muscle fibers and replacement of tissue with collagen fibers; water loss in the structure of myofibrils; destructive local changes, hyperchromatosis and caryopycnosis of the hippocampus. The data obtained allows predicting the possible consequences of prolonged overheating of tissues of other vertebrates and the human body.

Adaptogenic correction of free radical processes in liver tissue under the exposure to coal-rock dust on the body (experimental study)

Introduction. Damage to the liver under the conditions of long-term exposure to coal-rock dust on the body leads to significant impairment of its metabolic, detoxification, synthetic, and other functions. In this regard, it is relevant to search for early methods of prevention and correction of developing pathological changes in this organ. The purpose of the study is to experimentally study the effect of a complex drug with dihydroquercetin on the activity of free radical processes in the liver of laboratory rats over the dynamics of long-term exposure to coal-rock dust. Materials and methods. The work was carried out on male white rats weighing 200–250 g. The control group was kept under the standard vivarium conditions. The experimental group included rats that inhaled coal-rock dust in a priming chamber daily for 4 hours for 1, 3, 6, and 9 weeks and rats that received a daily complex drug with dihydroquercetin immediately before dust exposure. In the liver tissue, the activity of free radical oxidation and antioxidant defense enzymes (superoxide dismutase and catalase) was determined. Results. Priming rats with coal-rock dust for three weeks led to the gain in the intensity of free radical processes in the liver tissue: the initial level of accumulation of TBA-active oxidation products reliably raised by almost 2 times over the 1st week and 3 times over the 3rd week of the experiment compared to the control. An increase in the intensity of free radical oxidation was accompanied by activation of antioxidant defense enzymes - catalase - by 2.4 times at the 1st week and 1.6 times at the 3rd week of dust exposure. Raising the period of priming with dust up to 9 weeks led to multidirectional changes in oxidative metabolism in the liver tissue: at week 6, a decrease in the activity of superoxide dismutase was almost 3 times; at week 9, to a slight activation of antioxidant enzymes: superoxide dismutase by 55% and catalase by 36%.The most effective use of a complex drug with dihydroquercetin had been shown in short-term mode for three weeks, but not long-term (more than 6 weeks). The maximum antioxidant defense effect of dihydroquercetin was detected at the 3rd week of dust exposure – the level of free radical products decreased by 2 times and the activity of superoxide dismutase increased by 4 times. Limitations. Since the issue of organ-specific effects and the optimal duration of use of dihydroquercetin to increase resistance to free radical damage has been little elaborated, this imposes certain restrictions on its use for the correction and prevention of occupational diseases. Conclusion. The results obtained should be taken into account with long-term use of exogenous antioxidants in the correction and prevention of occupational diseases to support the level of endogenous antioxidant systems in the cell and the protective effect of dihydroquercetin for tissues most sensitive to the action of free radical processes.

Effect of metal nanoparticles usage on oxidative stress indicators and endotoxemia parameters under DMH-induced carcinogenesis

One of the properties of nanoparticles is their ability to correct manifestations of oxidative stress and endotoxemia, which are critical factors in cancer development. Therefore, the work aimed to investigate the effect of the usage of Au/Ag/Fe nanoparticles on oxidative stress indicators and endotoxemia parameters in experimental colon carcinogenesis. The study was performed on 90 white male rats kept in standard vivarium conditions. The division into groups: I – intact animals; II – intact animals with 21 days NPs administration; III – animals injected with N,N-dimethylhydrazine dihydrochloride for 30 weeks; ІV – animals to which Au/Ag/Fe nanoparticles were intragastrically administered daily for 21 days after induced adenocarcinoma. According­ to our results, the concentration of oxidative stress indicators significantly increases under DMH-induced carcinogenesis conditions. It was established that the 21-day intragastric administration of NP Au/Ag/Fe composition caused a significant (P < 0.001) decrease in the concentration of TBARS in the blood serum by 1.33 times, in the content of diene and triene conjugates by 1.63 and 1.98 times, respectively compared to the third experimental group. The introduction of NPs in the fourth experimental group reduces the concentration of the Schiff bases by 1.34 times (P < 0.001), decreases the content of POMP370 and POMP430 by 1.25 (P < 0.001) and 1.37 times (P < 0.001), respectively, compared to the third experimental group. We also observed the reduction of endotoxemia levels in a fourth experimental animal group based on a significant decrease in MMM indexis and EII percentage. Keywords: Au/Ag/Fe nanoparticles, endotoxemia, induced colon carcinogenesis, N‚N-dimethylhydrazine dihydrochloride, oxidative stress

Dynamics of changes in the content of proteoglycans in the tissues of the cerebellum of rats under the influence of hypokinesia

The article reflects the dynamics of changes in the content of proteoglycans in preparations that were taken from the cerebellum of experimental animals after modeling hypokinesia. Laboratory animals were removed from the experiment at different time intervals (3, 7, 14, 21 and 30 days of simulated hypokinesia) to identify the dynamics of changes in proteoglycan content using histochemical studies. The experiment was carried out on laboratory rats of the Vistar breed. The animals were divided into two groups: control and experimental. All laboratory rats were kept under standard vivarium conditions. The experiment is based on the model of hypokinesia proposed by E. A. Kovalenko. Complex studies showed the dynamics of changes in the content of proteoglycans, which were not homogeneous at different stages of the experiment. However, despite the different trends in the dynamics of the content of various fractional components of proteoglycans, one can note a general trend towards a decrease in proteoglycans. This indicates a negative effect of hypokinesia on the productive function of cerebellar tissue in experimental animals.

SIX-DAYS DYNAMICS ANXIETY INDEX OF FEMALE RATS WITH HIGH LEVEL OF ANXIETY IN BLOCKADE OF MAO-B

Notoriously that motor and research activities are gradually oppressed up to complete suppression during the daily testing of animals. Generally, an animal stops researching the test space and demonstrates the passive behavior. In the past studies on female rats we have found out that the blockade of monoamine oxidase B (MAO-B) doesn’t prevent of the suppression of animal’s behavior activity during the daily testing. Also, according to the cumulative result it was supposed, that the increasing of anxiety can’t to be the main reason of motor deprivation. But the last statement required of experimental confirmation. According to the said statement the purpose of this work was formulated the following way: to find out the dependence of behavior activity oppression of female rats during the daily testing of anxiety level in normal conditions and in blockade of MAO-B one.
 Methods: the research work was carried out on 48 white female rats line Wistar aged 7 months, contained in standard conditions of vivarium. All of the animals were homogenous sample with the middle level of motor activity and high level of anxiety (the index of anxiety (IA) were more than 0,7 of conventional units).
 The rats were divided into four groups of 12 animal units in each one, lately -2 control sets and 2 experimental one (blockade of MAO-B). The animal behavioral reactions were researched in two tests: “Open field” (circular, diameter 1m) and elevated plus-maze (EPM, standard sized for rats). The residence time of each rat in both test setting was 5 minutes. This period of time is recorded by high definition camcorder; video recording is analyzed automatically by the program complex Noldus EthoVision 12.
 It was found out, that the increasing the level anxiety cannot be the only reason of motor activity oppression of high-anxiety female rats in “Open field” and elevated plus-maze tests. The blockade of MAO-B decreases the index of anxiety of animals, that, possible, indicates on directly dopaminergic system and the central dopamine participation in the emotional state regulation along with other monoamines. Also the EPM test is more indicative for analyzing of dynamic of the anxiety index compared with “Open field” test.

Modulating Effect of Extremely High-Frequency Low-Intensity Electromagnetic Radiation on Tissue Oxidative Metabolism and Skin Microhemodynamics

We set out to examine the indicators of microhemodynamics and tissue oxidative metabolism in rats after their tenfold exposure to extremely high-frequency low-intensity electromagnetic radiation (EHF EMR). The aim was to elucidate the specifics of skin microcirculation and tissue oxidative metabolism following exposure to tenfold electromagnetic radiation of extremely high frequency. The experiment was carried out on 40 mature male Wistar rats weighing 200–220 g, which were kept in standard vivarium conditions under natural light regimen. The animals were divided into two groups with 20 rats each. The animals in the first group were biological controls and were exposed to false EHF EMR (placebo); the animals in the second group were exposed to mm-exposure in the morning, 10 sessions daily. On the 10th day of EMR exposure, the indicators of skin tissue fluorescence on the tail base were recorded. Tenfold exposure to low-intensity EHF EMR was shown to increase the concentration and intensity of NADH fluorescence, as well as the FAD and redox ratio. This indicates an increased cellular demand for ATP and the predominance of oxidative phosphorylation over other processes, thus demonstrating the activation of the respiratory chain. At the same time, an increase in endothelium-dependent vasodilation, a decrease in peripheral resistance, an increase in blood flow to the nutritive microvascular bed, and an improvement in venular outflow were observed in the microcirculatory bed. The conclusion is made that the modulating effect of EHF EMR is manifested in the rearrangements of correlations. Thus, the coefficient of variation comes to the fore – the final calculated indicator of microcirculation, which has strong negative associations with all indicators of tissue metabolism (FAD, NADH, RR). In addition, the amplitudes of endothelial rhythms associated with periodic releasing of nitric oxide by the endothelium show a strong negative association with FAD.

Experimental study of the effectiveness of ademethionine and inosine glycyl-cysteinyl-glutamate disodium in the treatment of dichloroethane-induced toxic hepatitis

Introduction. Currently, in the search for drugs for the toxic liver damage treatment, considerable attention is paid to glutathione preparations and its metabolic precursors. There are separate reports in the literature on the hepatoprotective and antifibrotic effects of glutathione disulfide in viral liver lesions, which gives grounds for their additional study when exposed to hepatotropic substances.
 Material and methods. Performing a comparative assessment of the hepatoprotective effect of inosine glycyl-cysteinyl-glutamate disodium and ademetionine on the model of dichloroethane-induced toxic hepatitis in rats was carried out with the formation of the following experimental groups of animals: no treatment; with the introduction of physiological saline; with the introduction of inosine glycyl-cysteinyl-glutamate disodium; with the introduction of ademetionine, as well as a group of intact animals. The study drugs were administered intraperitoneally for 10 days. In the course of the study, biochemical indicators of cytolytic and cholestatic syndromes of liver damage were determined, the activity of its detoxification system and plastic function were assessed.
 Results. In groups that did not receive treatment, but received physiological saline, the lethality of experimental animals by the 20th day of observation was 40%, in the group treated with ademetionine – 
 10%. In the group treated with inosine glycyl-cysteinyl-glutamate disodium, no death of animals was observed. The use of inosine glycyl-cysteinyl-glutamate disodium led to a more significant decrease in the indicators of cytolytic and cholestatic syndromes, as well as normalization of the functional activity of the liver (restoration of the content of glutathione in the liver tissue) and its plastic function (restoration 
 of the level of total blood serum protein and glycogen content in the liver parenchyma) to a greater extent than with ademetionine.
 limitation. The experimental study was carried out on outbred male rats weighing 180–220 g, kept under standard vivarium conditions in one cage, no more than 6 individuals, divided into groups by randomization with the exclusion of weakened and sick animals from the study.
 Conclusion. The study provided an experimental justification for further study of the hepatoprotective effect of inosine glycylcysteinylglutamate disodium in toxic liver damage.

The corrective effect of Au/Ag/Fe nanoparticles on oxidative stress in terms induced colon adenocarcinoma

ABSTRACT. Studying biological markers of oxidative stress is crucial and relevant, as this process can trigger the transition from an organ's "normal state" to a "malignant lesion". The use of metal nanoparticles to correct oxidative stress manifestations in oncology is one of the most popular subjects of modern science and is actively being introduced into modern medicine. Practically all possible types of nanoparticles have found their use in solving different problems in oncology. Therefore, our study aimed to investigate the possibility of Au/Ag/Fe nanoparticles use for the correction of redox balance disorders of the antioxidant system under the conditions of induced colon adenocarcinoma. Materials and methods. The study was performed on 150 white male rats. Animals were kept in standard vivarium conditions. Division of experimental rats into groups: I - control intact group (40 individuals); II - experimental group (70 individuals) with N,N-dimethylhydrazine hydrochloride administration once a week for 30 weeks; ІІІ – an experimental group (40 animals) with daily intragastric administration of Au/Ag/Fe nanoparticles. Oxidative stress was assessed in colon tissue homogenate by changes in the concentrations of 8-iso-prostaglandin F2α (8-iso-PGF2α), TBC-active products, diene and triene conjugates, Schiff bases, as well as by the activities of catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, and reduced glutathione. Results. Due to this research, we established that Au/Ag/Fe nanoparticles use leads to a decrease in the concentration of 8-iso-prostaglandin F2α (8-iso-PGF2α), TBC-active substances, diene, triene conjugates, Schiff bases. As a result of the above, we observed a reduction of manifestations of oxidative stress and restoration of enzymes of the antioxidant system and its biological mediators of a non-enzymatic nature. The activity of catalase, superoxide dismutase, glutathione peroxidase, and the concentration of reduced glutathione was restored to control indicators. Conclusions. Therefore, the use of Au/Ag/Fe nanoparticles leads to the restoration of the balance of redox equilibrium, improving the antioxidant system with induced adenocarcinoma of the large intestine.

Study of changes in catalase activity in blood and liver of rats with experimentally induced dyslipoproteinemia against the background of mechanical damage to skeletal muscle

Purpose : to study the dynamics of catalase activity in the blood and liver liver tissues with oxidative stress caused by the modeling of dyslipoproteinemia with the subsequent mechanical trauma of the skeletal muscle. Materials and methods . The study was conducted on white, unconventional sexual healthy rags of six months of age, weighing 200-230 grams, in the amount of 120 pieces contained in standard conditions of vivarium. All animals were divided into four groups, 30 animals in each group. Animals of the first group are intact rats to which no effects were applied. Animals of the second group (regeneration control) had a mechanical dissection in the area of the middle third of the calf muscle of the posterior limb. Animals of 1 and 2 groups were on the standard diet of Vivaria and had free access to water and food. The animals of the third and fourth groups were first modeled by dyslipoprotein for 63 days. All this time, animals received a high -carb and high -fat diet with a weight of dry substances increased up to 30 % and replacement of drinking water with a 20 % fructose solution. After the specified time, the animals of the fourth group were injured by the middle third of the calf muscle of the posterior limb. The activity of catalase was investigated in animals before the start of the experiment, as well as on 1, 3, 5, 14, 21 days of experience according to the standard methodology of Queen M. A. The capture of the material and the removal of rats from the experiment was carried out with accurate observance of all ethical norms applicable to laboratory animals . Under etheric anesthesia, a blood fence was made, and then the liver fence, which was washed with physiological solution and frozen. Then, by mechanical grinding of fabrics weighing 1 g and mixing with 9 ml of Tris Bufer (pH 7.4), homogenates were prepared in an automatic homogen at a speed of 5,000 rpm in a vessel with double walls, constantly cooled by running water. Results . The mechanical trauma of the calf muscle and dyslipoprotemia contributed to the intensification of oxidative processes at the local and systemic levels of the body, but the combination of these facts was characterized by extremely intense oxidative stress and led to a decrease in the activity of catalase in the blood and liver tissues.

Study of changes in the activity of glutathione system enzymes in the blood and liver in experimentally induced dyslipoproteinemia on the background of mechanical damage to the skeletal muscle in rats of different age groups

Currently, there is a steady increase in morbidity and mortality from acute cerebrovascular conditions, which are based on vascular ischemic manifestations, which are systemic in nature. At the heart of the root cause of any ischemic process – heart attack, stroke, hypertension – is atherosclerosis and dyslipoproteinemia. One of the biomarkers of this pathological process is oxidative stress.The purpose of the study: to analyze the dynamics of the activity of glutathione peroxidase and glutathione reductase in the blood and liver of rats of different ages under oxidative stress caused by modeling dyslipoproteinemia followed by mechanical injury to the skeletal muscle.Materials and methods. The study was conducted on outbred healthy male rats, divided into two groups according to age: the first group (c) – 24-month-old (old) rats, weighing 230–250 grams in the amount of 120 pieces and the second group (m) – 6-month-old (young) rats, weighing 190–210 grams in the amount of 120 pieces, kept under standard vivarium conditions. All rats were divided into four subgroups within their group, 30 animals each. Animals of the first subgroup in each group (1s, 1m) are intact (old and young) animals, to which no effects were applied. Animals of the second subgroup (2c, 2m) (regeneration control, old and young) had a mechanical dissection in the region of the middle third of the gastrocnemius muscle of the hind limb. Animals of the first and second subgroups were on a standard vivarium diet and had free access to water and food. Animals of the third (3s, 3m) and fourth (4s, 4m) subgroups of each group were subjected to dyslipoproteinemia modeling for 63 days and received a high-carbohydrate and high-fat diet with an increased fat content of up to 30% by weight of dry matter and replacement of drinking water with a 20% fructose solution. After the specified time, the animals of the fourth subgroups of both groups were injured in the middle third of the gastrocnemius muscle of the hind limb.Conclusions. Against the background of dyslipoproteinemia, oxidative stress occurs in the tissues of young and old rats, which is reflected by a decrease in the activity of enzymes of the glutathione system. Mechanical injury of the calf muscle in combination with dyslipoproteinemia aggravates oxidative processes against the background of inflammation and leads to an even more intense decrease in the activity of glutathione peroxidase and glutathione reductase in the liver and blood tissues of rats, and in old animals these processes are more pronounced than in young ones.

Homology in Structural and Functional Organization of the Fibrous Framework of the Derma and Paraneural Connective Tissue Components

Background: The recent increase in hostilities throughout the globe is one of the main factors that damage both the skin and peripheral nerves (PN), mainly of the upper and lower extremities. The duration of treatment of the injured limb and the rate of recovery of its functions are directly related to the structural integrity of the connective tissue (CT) sheath apparatus of the PN, which further actualizes the study of its micromorphological components. The structural integrity of the peripheral nerve includes not only the preservation of its conductive component but also the membranes surrounding it, providing complete morphofunctional unity. Thus, the study of the features of their tissue organization, vascularization and innervation, with the obligatory comparison of data with homologous tissue of different topography and possible extrapolation of data, determined the purpose of this work. The aim of this study was to analyze the dynamics of changes in the fibrous components of the paraneurium and dermis in onto- and phylogenesis under the influence of various factors and to compare the data obtained for their further extrapolation. Methods and Results: The study was conducted on mature male Wistar rats under standard vivarium conditions. The material for the study was the CT sheaths of the PN of the extremities and skin areas, 1x1 cm in size, to the depth of the subcutaneous fascia of animals. The cadaver material was taken on Days 1, 3, 7, 10, and 28 of ontogeny. The resulting biomaterial was fixed in a 10% buffered neutral formalin solution and embedded in paraffin, according to the standard method. Microtomized, the resulting histological sections were stained with hematoxylin and eosin, according to the method of Mallory and Van Gieson. A comprehensive morphological study was performed using light and electron microscopy. The study revealed the presence of two stages in the ontogeny of the CT, forming the dermis of the skin and paraneural CT structures of PN. In the first stage, structural elements are formed, considering the topography of the CT; in the second, they are differentiated, leading to a qualitative-quantitative transformation due to the appearance of a number of additional functions, an active period of body growth, and taking into account the action of various environmental factors. At earlier stages of ontogenesis, thin, flattened fibrous structures without a clear organization are observed in the field of view in the dermis of the skin. In the paraneurium, the components that form it are not sufficiently expressed. At later periods, the shape and architectonics of the fibrous component change, structurization and an increase in the thickness of the fibers occur and pronounced heterogeneity of the cellular component is observed.

Preclinical Substantiation of the Use of Implants for Osteosynthesis from Carbon-Carbon Composite Material

Background. Metals used for the manufacture of various implants for traumatology have all the necessary mechanical properties, but these materials are able to oxidize. In comparison, carbon has excellent biocompatibility. Carbon-carbon composite material (CCCM) is 2-4 times lighter than a similar metal implant, has a stiffness and modulus of elasticity close to similar indicators of a human bone, not prone to the effect of fatigue stress, and is characterized by chemical resistance in the body and high biocompatibility.
 Objective. The purpose of this work was to evaluate the features of bone regeneration according to pathomorphological analysis in an experiment on animals.
 Material and Methods. Carbon-carbon composite material for intromedular osteosynthesis after experimental fracture on white outbred male Wistar rats (n=18) was used in the experiment. A stainless steel rod (n=18) was used for control. Subsequently, rats of both groups were kept in standard vivarium conditions.
 Results. Histological examination revealed that the use of implants with CCCM did not disrupt vascularization and angiogenesis in the fracture zones. During the analysis of the contact of bone tissue and implant material, it was determined that in the larger area of ​​the perimeter of the pin with CCCM, a newly formed bone was located directly on its surface, filling its irregularities. In the case of the use of stainless steel rods, a significant number of lymphocytes were accumulated around the newly formed blood vessels directly adjacent to small hemorrhages, which were always observed at the fracture site.
 Conclusions. Regeneration of an experimental rat femur fracture after osteosynthesis with carbon-carbon composite implants did not differ significantly from fracture fusion after osteosynthesis with a stainless steel implant.

PECULIARITIES OF PRENATAL INFLUENCE OF A NUTRITIONAL FACTOR ON THE STRUCTURAL AND FUNCTIONAL STATE OF THE LIVER OF NEWBORN RATS

Disease of the digestive system occupies one of the first places in the structure of morbidity and mortality in the population of Ukraine and EU countries. The alimentary factor (diet with an excess or deficiency of nutrients) is of leading importance Among the factors that cause liver damage in the mother-fetus system. The purpose of this study was to establish the effect of excess or insufficient content of nutrients in the mother's diet on the structural and functional state of the liver of newborn rats. Materials and Methods. To achieve this goal, 20 female rats of the WAG population were used; they were divided into 3 groups: group 1 (control) - rats were in standard vivarium conditions and received a basic diet; animals of the 2nd group received a diet with excess nutrients; rats of the 3rd group received a nutrient deficient diet. The offspring of rats were hatched from experiment through decapitation straightaway after birth. Was a complex of morphological and biochemical studies of liver tissue was carried out. Results. When analysing micro preparations of liver tissue, a similarity in the nature of the induced changes in the organ rats of the 2nd and 3rd groups in the form of moderately pronounced discomplexation of beamed-radiary structure and expansion sinusoids were revealed. The difference was that in rats of the 2nd group, mainly around the zone of portal tracts, small extramedullary hematopoiesis foci; and in rats of the 3rd group, multiple small extramedullary hematopoiesis foci that indicated more pronounced hypoxia were determined. Thus, it can be noted that the greatest damage to the fetus liver was caused by nutritional deficiency in the mother's diet. When studying the fractional composition of lipids in liver homogenates of newborn rats, the following dynamics of changes was discovered: in animals of the 2nd group - an increase of cholesterol and triglycerides levels, with a decrease of PL level, and in rats of the 3rd group, a decrease in almost all fractions of lipids cholesterol, triglycerides, and NEF A (nonesterified fatty acid). The obtained data suggested that, most likely, such dynamics of changes in lipid metabolism parameters is associated with the inclusion of epigenetic programming mechanisms in the mother-fetus complex. Conclusions. Therefore, based on conducted research, we can do conclusion about the negative impact of the alimentary factor (nutrient deficiency) on the structural and functional state of the liver of newborn offspring of rats.

MELATONIN PREVENTS OXIDATIVE STRESS IN RATS EXPOSED TO ETHANOL INTOXICATION, ITS COMBINATION WITH CAFFEINE AND LIGHT EXPOSURE

The аim of the research – to investigate the effects of melatonin on oxidative stressbiomarkers malonic dialdehyde (MDA) and oxidatively modified proteins (OMP) inblood, liver and kidneys of rats exposed to subacute alcohol intoxication, its combinationwith constant light exposure, and caffeine intake.Materials and methods. Experiments were performed on 42 male rats weighing180-200 g kept under standard conditions of vivarium and artificial equinox. Subacutealcohol intoxication was induced by intragastric administration of 40 % ethanol at a doseof 7 ml/kg of body weight for 7 days. Caffeine was administered by gavage at a doseof 30 mg/kg of body weight.Results. Ethanol poisoning results in increase in MDA and OMB, and liver was the mostaffected (90 % and 42 % higher than control). The combination of ethanol with caffeinereduced the intensity of oxidative stress in the blood but increased the toxic effectsof ethanol on the liver (MDA and OMP were 116 % and 60 % above control range).The most significant increase in MDA was in the liver and kidneys under combinationof alcohol intoxication with exposure to constant light (139 % and 33 % respectively).There was a decrease in OMB level along with elevation of MDA level in kidneys of allgroups of alcoholized animals.Administration of 5 mg/kg melatonin for 7 days limited the rise in MDA in the bloodand liver of animals and changes in OMB content in the blood liver and kidneys of animalsexposed to ethanol and constant lighting. Melatonin showed to be less effective in theliver and kidneys of rats treated with a combination of ethanol and caffeine.Conclusion. The data obtained are evidence of the pronounced antioxidant melatoninaction and its capacity to prevent toxic effects of ethanol and its combination withconstant lighting and caffeine introduction into organism.

Morphofunctional characteristics of the mucous membrane of the masticatory apparatus in experimental carcinogenesis

BACKGROUND: Diseases of the gastrointestinal tract are often accompanied by changes in the oral cavity. This is largely due to the morphological and functional unity of the oral mucosa and the entire digestive tract. Therefore, the role of a dentist is important in early oncological alertness for detecting malignant neoplasms at an early stage of their development.
 AIM: Present the results of a morphological study of the mucous membrane of the mouth of an animal during experimental carcinogenesis.
 MATERIAL AND METHODS: The study was carried out on 168 sexually mature outbred white male rats kept under standard vivarium conditions. The animals were divided into the following groups: control 84 individuals and experimental 84 animals with simulated colon adenocarcinomatosis. Every 30 days of the experiment, 12 animals were withdrawn from the control and experimental groups. Carcinogenesis was modeled by the introduction of 1,2-dimethylhydrazine dihydrochloride, previously diluted with isotonic sodium chloride solution. Using a histological study, the mucous membrane of the mouth was studied in animals of both examined groups.
 RESULTS: The dynamics of morphological changes in the mucous membrane of the animals mouth was revealed against the background of the development of adenocarcinomatosis of the large intestine; the development of destructive-degenerative and sclerotic changes in the mucous membrane of the mouth of animals with simulated adenocarcinomatosis of the large intestine, the severity of which increased in accordance with the period of development of the neoplasm, was established.
 CONCLUSION: The revealed changes in the large intestine and the mucous membrane of the animals mouth, caused by a simulated chemical carcinogen, indicate a high risk of developing a malignant tumor with spread to all parts of the gastrointestinal tract.

THE IMPACT OF BLAST-INDUSED TRAUMATIC BRAIN INJURY ON PASSIVE AVOIDANCE RESPONSE

Among military personnel participating in armed confl icts around the world, blast- induced traumatic brain injury is common. Mild blast- induced traumatic brain injury is characterized by clinical signs in the form of impaired cognitive functions, including memory. In this regard, the objective is to study the features of the infl uence of an blast-i nduced traumatic brain injury on conditioned refl ex activity in the experiment. The studies were carried out on 18 white male Wistar rats aged 5-7 months, weighing 180.0-220.0 g, which were kept under standard vivarium conditions of Dnipro State Medical University. Selected rats were divided into three groups: I group – experimental (n=6), whose animals were anesthetized with halothane (Halothan Hoechst AG, Germany), fi xed and simulated blast-i nduced traumatic brain injury by generating a baroacoustic wave with an excess pressure of 26.4±3.6 kPa on your own manufactured device. II group – sham (n=6), the animals of which were subjected only to inhalation anesthesia with halothane and fi xation in a horizontal position, and III group – intact (n=6). The passive avoidance response was reproduced according to the standard method in a light-dark chamber with an electrifi ed fl oor in a dark chamber. The latent period of entry into the dark chamber was determined in rats that had undergone preliminary training.As a result of the data analysis obtained during the experiment, it was found that a mild blast- induced traumatic brain injury leads to a violation of passive avoidance response on the 3rd day after the injury (lengthening of the latent time by 28-31%, p˃0.05), which progressed by 21 (100-79%, p˃0.05) and 28 (100-96%, p<0.05) days of the post-traumatic period. Taking into previous studies, the changes which we obtained are indicate signifi cant secondary damage by biologically active substances, which lead to the launch of neurodegenerative processes and, as a result, memory impairment.

AGE FEATURES OF THE STRUCTURE OF THE BLOOD VESSELS OF THE SOME DIGESTIVE GLANDS AND ITS RESTRUCTURING IN THE INITIAL STAGES OF EXPERIMENTAL DIABETES MELLITUS

The aim: The purpose of the work was to study the peculiarities of blood supply the pancreatic islet of the 24-month-old rat, and its restructuring during the initial periods of experimental diabetes mellitus. Materials and methods: The work was performed on 20 white outbred rats - males weighing 340-420g. 24 months of age, kept in standard vivarium conditions in compliance with all accepted ethical rules. Experimental streptozotocin diabetes mellitus was simulated in 16 animals. The material was taken on the 14th and 28th day of the experiment. Results: Reorganization of the endocrine part of the pancreas in the early stages of experimental diabetes is characterized by a decrease in the number and area of pancreatic islets, a decrease in the diameter of the lumen of arterioles, precapillaries, postcapillaries compared to the control group of animals by 7% and 5%. The diameter of the capillaries decreases by 16% and reaches 3.8 ± 0.62 μm2, and the diameter of the venules increases by 12%. In some blood vessels there are phenomena of desolation and edema of perivascular connective tissue, which is manifested by a decrease in optical density and stratification of collagen fibers. Conclusions: Thus, the reorganization of the circulatory system of the endocrine part of the pancreas of 24-month-old rats in the early stages of experimental diabetes mellitus is characterized by a decrease in the number and area of pancreatic islets.

Сравнение эффективности препаратов метиленового синего для визуализации путей лимфооттока в эксперименте

Objective. To compare and evaluate the effectiveness of using methylene blue solutions to visualize lymph drainage pathways in laboratory animals (outbred rat). Materials and methods. In the experiment, 16 female outbred rats aged about 40 days, with an initial body weight of 180-220 g, kept in standard vivarium conditions, were used. Zolazepam (Zoletil®100) was used for anesthesia. Animals were randomized into 2 groups ― 8 in each. The first group was injected subcutaneously in the left thigh with a 1% aqueous solution of methylene blue, the second group ― solution of methylene blue with human serum albumin. Depending on the time of exposure, animals were divided randomly into 4 subgroups ― 15, 30, 45 and 60 minutes. There was evaluated the effectiveness of marking the lymph drainage pathways from the injection site. Results. The study demonstrated that the use of a 1% aqueous solution of methylene blue solution allows visualizing of the lymph drainage pathways when the preparation is exposed for 30 minutes. Staining of the lymph nodes of the next order occurs with an increase in exposure time. A solution of methylene blue in combination with human serum albumin stains the first node in the lymph drainage path 30 minutes after administration. The preparation is characterized by slow migration from the first-order lymph nodes (>60 minutes). Conclusion. The use of methylene blue solution in combination with serum albumin is characterized by slow migration from the first-order lymph nodes, which makes its use preferable for surgical interventions.

СТРЕССПРОТЕКТИВНОЕ ДЕЙСТВИЕ СУКЦИНАТСОДЕРЖАЩЕГО ПРЕПАРАТА НА ЛЕЙКОЦИТАРНЫЙ СОСТАВ КРОВИ КРЫС ПРИ ВОЗДЕЙСТВИИ ГИПОКСИИ

The study of the dynamics of white blood cells in male rats under the conditions of normoxia and in the simulation of hypoxia before and after the use of the succinate-containing drug Cytoflavin ®was carried out. The animals were divided into three groups: two control groups of animals: group 1 – intact rats kept in standard vivarium conditions, and group 2, which were subjected to hourly hypoxic exposure, and group 3 - experimental animals subjected to daily training in a hypoxicator (O2-14%) and received the drug immediately before training. The multidirectional shifts characterizing the morphofunctional state of the white blood of rats under experimental conditions were determined. In group 2 animals, compared to group 3, there was a decrease in the number of white blood cells due to an increase in the pool of granulocyte cells, and an unchanged level of agranlocytes with a tendency to reduce the number of lymphocytes. In-group 2, compared with group 3, the change in the number of white blood cells and their subpopulation composition significantly differed from the control group 1, intact rats, and there was a decrease in the number of phagocytic mononuclears and an increase in granulocyte cells. The differences in the cellular composition of blood in group 2 animals from the data of group 3 are considered as the effect of the succinate-containing drug Cytoflavin ® on the preparation of the body for the implementation of the protective function under the influence of extreme factors and the stress of the body's resistance to load, since the nature of the redistribution of the leukocyte composition of blood in group 2 has a significant similarity in indicators with animals in group 3. The practical significance of the research is related to the search for new biologically active substances that optimally affect the ability of the animal body to adapt to conditions of low oxygen content. New data on the mechanism of redistribution of animal blood, which is realized under the action of the succinate-containing drug Cytoflavin ® in conditions of oxygen deficiency, can be used to study the regularities of the manifestation of an urgent adaptive effect.