[MORPHOLOGICAL CHANGES IN THE LIVER OF MICE WITH ANTIPHOSPHOLIPID SYNDROME AND ADMINISTRATION OF NITRIC OXIDE SYNTHESIS MODULATORS]

The aim of the research is to study the effect of L-arginine, the precursor of nitric oxide, and aminoguanidine, the inhibitor of inducible nitric oxide synthase, on morpho-functional changes in the liver of BALB/c mice with antiphospholipid syndrome. The study was carried out on 50 female BALB/c mice modelled with antiphospholipid syndrome. L-arginine (25 mg/kg) and aminoguanidine (10 mg/kg) were used for its correction. The material for microscopic study was taken by the method of Horalsky. The liver tissue samples were stained with hematoxylin and eosin. Significant hemodynamic disorders with manifestations of thrombosis in the liver in cases of antiphospholipid syndrome followed by destructive-degenerative changes of the stoma and parenchyma have been established. Administration of L-arginine in antiphospholipid syndrome caused restoration of the lobular and beam organization of the liver. The maximum effect on the morphological state of the liver was observed in using a combination of L-arginine and aminoguanidine. The protective effect of L-arginine and aminoguanidine on the microcirculation has been proved that evidences liver function restoration in mice with antiphospholipid syndrome.

[NEUROPROTECTIVE EFFECT OF AMINOGUANIDINE IN EXPERIMENTAL OBSTETRIC ANTIPHOSPHOLIPID SYNDROME]

The aim of the research was to investigate the effect of aminoguanidine on the content of autoantibodies in the serum, nitric oxide synthesis (NO), glial fibrillary acidic protein (GFAP) content and indicators of free radical oxidation in the cerebral hemispheres of BALB/c mice with antiphospholipid syndrome (APS) on the 18th day of pregnancy. An increase in the content of autoantibodies to brain proteins (120 kDa, 150 kDa, and >170 kDa) was detected in the serum of BALB/c mice with APS on the 18th day of pregnancy. An increase in the content of GFAP (total), GFAP (49-37 kDa), NO2¯, NO3¯ and prooxidant-antioxidant system imbalance in the cerebral hemispheres of pregnant mice with APS was established. With administration of aminoguanidine into the pregnant mice with APS, a decrease in the content of autoantibodies to brain proteins (120 kDa and 150 kDa) in serum was proved. With the introduction of aminoguanidine, a selective inhibitor of inducible NO synthase on the 18th day of pregnancy the increase in GFAP (49-37 kDa) in the cerebral hemispheres of APS mice was established, and the GFAP (total), NO2¯ and NO3¯ content did not change significantly, relative to the indicators of pregnant animals with APS. With introduction of aminoguanidine in cases of APS on the 18th day of pregnancy lesser manifestations of oxidative stress in the cerebral hemispheres, a decrease in the activity of lipid peroxidation processes, an increase in the activity and content of the antioxidant system components was evidenced. Thus, aminoguanidine has a neuroprotective effect in obstetric antiphospholipid syndrome in the BALB/c mice.

[PRODUCTION OF REACTIVE OXYGEN SPECIES AND DEVELOPMENT OF APOPTOSIS IN BLOOD LEUKOCYTES IN EXPERIMENTAL ANTIPHOSPHOLIPID SYNDROME]

The aim of the study is to investigate the processes of apoptosis and the level of formation of reactive oxygen species (ROS) in blood cells of BALB/c female mice in experimental antiphospholipid syndrome (APS). The content of living, apoptotic and necrotic cells in blood leukocytes was evaluated. Apoptosis in cells was detected using Annexin V conjugated to GFP and propidium iodide. ROS in blood leukocytes were detected using 2',7'-dichlorofluorescein diacetate. The redistribution between the leukocytes populations was assessed by the magnitude of direct (FS) and lateral (SS) light scattering on the flow cytofluorimeter. It was established that the APS reduced the viability of blood leukocytes compare to the control. It is likely that their death is due partly to the activation of apoptosis. In the animals with APS a redistribution between the two main types of leukocytes (granulocytes and agranulocytes) was found out. An increase in the number of granulocytes in the blood was evidenced in cases of APS. It was established that the basal level of ROS production in granulocytes reduced by 27% and in agranulocytes - by 19% compare to the control. Thus, taking into account the attained results it can be argued that in the pathobiochemical mechanisms of APS development the enhanced activation of apoptosis and deficient formation of ROS is significant.

CORRELATION BETWEEN CONNECTIVE TISSUE METABOLISM AND THYROID DYSFUNCTION IN RATS WITH PERIODONTITIS

The aim of the study was to clarify mechanisms of the periodontitis development in rats with thyroid dysfunction based on a comparative analysis of the correlations between the connective tissue metabolism indices and the concentration of thyroid stimulating hormone, free thyroxine and free triiodothyronine in blood serum. 12-14-week-old inbred white male rats (n=48) were included to the experiment. They were randomly divided into the following groups: control; animals with a model of periodontitis; animals with periodontitis in a setting of hyperthyroidism; animals with periodontitis in a setting of hypothyroidism. Concentrations of free thyroxine, free triiodothyronine and thyroid stimulating hormone were assayed with ELISA method. Collagenolytic activity, content of glycosaminoglycans, free hydroxyproline, fucose, unbound with proteins were determined by the spectrophotometric method. The linkages between the studied indices were established on the basis of the results of the correlation analysis using the Pearson correlation coefficient. Our research has found different interconnections between the indices of connective tissue metabolism and free triiodothyronine, free thyroxine and thyroid stimulating hormone concentrations in case of experimental periodontitis combined with thyroid dysfunction, indicating that thyroid gland has regulatory influence on connective tissue metabolism. In hypothyroid rats more correlations have been established compared to the hyperthyroid rats.

CHANGES OF CYTOLYSIS INDICATORS IN RATS' BLOOD RESULTED FROM SIMULTANEOUS INTOXICATION WITH TOBACCO SMOKE AND SODIUM NITRITE AFTER USING MILDRONATE

The article is devoted to an experimental study of the effect of tobacco smoke and the effect of sodium nitrite on the background of tobacco intoxication on the body of rats of different age groups and to identify violations caused by these toxicants. It has been established that under the conditions of nitrite-tobacco intoxication, a more pronounced cytolysis of the cells takes place, which leads to a change in the permeability of the plasma membranes than in case of poisoning with only tobacco smoke. Immature rats were the most sensitive to the action of toxicants, in which the activity of membrane-dependent enzymes was more statistically significant (ALT activity in the serum increased 7,7 times, AST - 5 times, GGTP - 4,1 times, LDH - 1,8 times; p ≤ 0.05) at the end of the study. In the same group of rats, the highest percentage of permeability of the erythrocyte membrane was revealed, as indicated by its index (55,6% higher than normal, in mature animals 38% EII was higher than in intact control animals, in old ones - 54%). When using an antihypoxant, it was noted that mildronate significantly (p≤0.05) reduced the activity of indicator enzymes in the blood serum of rats during the whole experiment, and also led to a decrease in the erythrocyte index of intoxication in the blood of rats of all age groups. To confirm the obtained results, morphological studies of the organs of rats of different age groups were carried out after sodium was damaged by nitrite against the background of tobacco intoxication and the effect of the metabolic action of mildronate on them. The membrane-protective properties of mildronate have been proven, which makes it possible to use it in various pathologies accompanied by the development of cytolytic syndrome.

THE SPECIFIC FEATURES OF CELL DEATH OF CIRCULATING NEUTROPHILS IN A SETTING OF EXPERIMENTALLY INDUCED CRUSH SYNDROME

Although the overall incidence of trauma-induced crush syndrome (CS) is as low as 0.1 per 10,000 of population, which makes it one of the least common traumatic injuries, the hazard of CS lies in the high incidence of hemodynamic and metabolic complications, which call for an early diagnosis of this syndrome. This paper reports the specific features of cell death of neutrophils in rat blood as they changed with time using the model of endogenous toxemia formed in a setting of crush syndrome. To assess apoptosis/necrosis in neutrophils ANNEXIN V FITC assay kit (manufactured by Beckmann Coulter, USA) was used. The results obtained in this study suggest an increase in apoptotic and necrotic processes in a setting of CS from the first day of the experiment through the end of observation. Also we have found a significant impact of reactive oxygen species generation on neutrophils death in a setting of CS. However, other mechanisms to launch apoptosis/necrosis in case of experimental crush syndrome should not be neglected.

THE INFLUENCE OF MONOSODIUM GLUTAMATE ADMINISTRATION ON GENERATION OF REACTIVE OXYGEN SPECIES AND APOPTOSIS OF BLOOD LEUKOCYTES IN RATS

The use of food additives in food manufacturing has been a public health issue for many years. Currently, more than 3000 food additives have been approved and estimates has shown that each person may consume 3.6 to 4.5 kg of food additives per year on average. One of the most common food additives in Ukraine and in Europe is monosodium glutamate (MSG). This paper reports the effect of monosodium glutamate administration at "safe" (allowed) doses on the generation of reactive oxygen species and apoptosis in leukocyte blood suspension of rats. Experimental studies were conducted on 32 non-linear, male, white rats weighing 180-200 g. The experimental animals were administered MSG (Sigma-Aldrich, USA) at a dose of 15, 30 and 45 mg/kg body weight. Control group of animals received normal saline. We have found that consumption of MSG at low dosage was associated with development of excessive reactive oxygen species generation and apoptotic processes in blood leukocytes of rats. Therefore it is advisable not only to investigate the established dangerous doses of E621, but also to study the molecular mechanisms of the "safe" (allowed) doses of MSG effect on a living organism.

[EVALUATION OF THE COMPARATIVE TOXICITY OF VARIOUS MATERIALS FOR DENTAL PROSTHETICS ON CELL CULTURE MODELS]

Difficulties in repairing the defects of the teeth are related with allergic-inflammatory, traumatic and dystrophic complications arising from the interaction of the foreign body with the mucous tissues of the oral cavity after the patient's prosthesis is established. The aim of our study was to establish the toxic pro-inflammatory activity of materials used for the manufacturing of bases of removable dentures - plastics based on polymethylmethacrylate prosthetic complexes Prothyl Hot, Ftorax and Perflex Flexi Nylon on the model of human leukemia transformed T cells (Jurkat cells) and MDCK cells. For the cells simulation Jurkat and MDCK cells was incubated with the components of prosthetic materials, Prothyl Hot, Ftorax and Perflex Flexi Nylon/ Prosthetic materials were added to the incubation medium at the doses used in practice (calculated at 106 cells); duration of incubation was 24 hours. A comparative assessment of the toxicity of prosthetic materials was determined by the MTT test (activity of mitochondrial dehydrogenases). Statistical analysis was carried out using the package (SPSS version 11.0). The statistical reliability of the difference between the indices was evaluated by the Student t test (the P <0.05 level was considered reliable). The results of the conducted studies testify to the absence of toxicity of the complexes Prothyl Hot, Ftorax and Perflex Flexi Nylon, used as a basis of circuit prostheses, on intact Jurkat and MDCK cells, as evidenced by the stability of their mitochondrial dehydrogenases. Based on the analysis of the conducted studies, it can be concluded, that as Jurkat and MDCK cells are used as models of immune and epithelial cells, the materials used for manufacturing of removable prostheses, the polymethylmethacrylate-based plastics (Prothyl Hot and Ftorax) and elastic thermoplastic polymer material Perflex Flexi Nylon, are not toxic. Studied materials, with the high probability, are not capable to cause massive death of immune cells, development of allergic or inflammatory damages, which in turn can stat cause the development of stomatitis and gingivitis, the destruction of the paradental tissue.