MORPHOFUNCTIONAL CHARACTERISTICS OF MITOCHONDRIA AND IMMUNOHISTOCHEMICAL APPROACHES TO THEIR STUDY

Violation of the functions of mitochondria is accompanied by any disease, so further study of the functional characteristics of mitochondria in various pathologies in the clinic and experiment, as well as the search for new diagnostic markers is promising and relevant. The purpose of this review is to summarize and systematize the literature data on morphofunctional characteristics and molecular immunohistochemical markers used to assess the function of mitochondria. The most characteristic feature of these organelles is the presence of a large number of enzymes involved in oxidative phosphorylation and energy supply to the cell. Also, the aim was to allocate so-called mitochondrial diseases associated with genetic, structural, biochemical defects of mitochondria, including those leading to energy deficiency of cells. Mitochondrial diseases are transmitted through the female line, since only the ovum contains mitochondria. Hereditary mitochondrial diseases associated with mutations in the genes encoding the synthesis of mitochondrial proteins – Bart’s syndrome, Kearns – Sayre syndrome, Pearson’s syndrome, and others are known. In addition, mitochondria are involved in the storage and transmission of hereditary information, apoptosis and plastic processes. There are a number of molecular markers, the use of which allows a detailed study of the activity of mitochondria under various experimental effects. The nearly thousand mitochondrial markers are known, but this review encloses the main ones

Morphological features of parietal cortex and hippocampus neuron of rats following subtotal cerebral ischemia associated with omega-3 polyunsaturated fatty acids injection

Aim of the study was to investigate the morphological features of neurons of the parietal cortex and hippocampus of rats with subtotal cerebral ischemia (SACI) during administration of omega-3 polyunsaturated fatty acids (omega-3 PUFA). Materials and methods. The experiments were performed on 24 white outbred male rats. Surgical interventions were carried out under conditions of intravenous thiopental anesthesia (40–50 mg/kg). Acute SACI was modeled by bilateral ligation of the common carotid arteries. The animals of the main group (n = 6, SACI + omega-3 PUFA) received intragastric injections of omega-3 PUFA preparation at a dose of 5 mg/kg body weight prior to ischemia for a week. In the comparison group (n = 6, SACI), the drug was not used; the control (n = 6) was sham operated animals, which were incised without skin ligation. Animals were decapitated after 60 minutes of ischemia. In rats, morphological changes in the neurons of the parietal cortex and the CA1 field of the hippocampus were studied. For morphometric and histochemical studies, animals were quickly removed after decapitation of the brain, pieces of the anterior cortex of the cerebral hemispheres were fixed in Carnoy fluid. Serial paraffin sections were stained with 0.1 % toluidine blue according to the Nissl method. Statistical hypothesis testing was performed using the Kruskal-Wallis ANOVA test. Results and discussion. The morphological and functional disorders in the parietal cortex and hippocampus have been revealed in animals of both experimental groups. The appointment of omega-3 did not significantly affect the size and shape of neurons in both the parietal cortex and the hippocampus. In the hippocampus, the administration of omega-3 polyunsaturated fatty acids resulted in a decrease in the number of hyperchromic shriveled neurons (by 20%) and an increase in hyperchromic neurons by 31 %. The number of shadow cells in this section did not differ from the indices of the control group. In the parietal cortex, no corrective effect was noted. Conclusions. Thus, subtotal cerebral ischemia leads to the development of morphofunctional disorders of the cerebral cortex. Administration of omega-3 had a positive effect on the state of rat hippocampal neurons, reducing the number of degenerative forms of neurons. The data obtained can serve as the basis for the search for new approaches to the treatment of acute ischemic stroke, which is one of the urgent problems of experimental and clinical neurology

Levels of Free Amino Acids and their Derivatives in the Brain Cortex of Rats During Unilateral Ischemia

amino acids, brain, ischemia.The efficiency of treatment of ischemic brain damage depends upon integrity of sofisticated conceptions of its pathogenesis. One of the prospective approaches in the development of most comprehensive treatment can be the study of the pool of free amino acids (AAs) as a possible target for the correction in such pathology. Available information does not provide a complete view on the changes of their content under ischemia of various severity. The aim of the study was to evaluate changes in the content of free amino acids and their derivatives in the frontal cortex of the cerebral hemispheres of rats at different terms of unilateral ischemia. Materials and methods: The changes of pool of A As and their derivatives in the frontal cortex of the cerebral hemispheres at different duration of unilateral cerebral ischemia (UCI) (1 hour, 3 hours, 1 day) were studied in 18 rats. The analyses of the levels of AAs and their derivatives were carried out in the supernatant of protein-free tissue homogenates by reversed-phase liquid chromatography using chromatograph Agilent 1100. Results: Shifts of AAs content after 3 h of UCI observed included the raise of lysine, branched chain AAs (BCAA) – valine and leucine, depletion of the aromatic AAs (AAA) — tyrosine and tryptophan with the doubled ratio of BCAA/AAA. Moreover, we observed the decrease in the content of asparagine and essential/nonessential AAs and glycogenic/ketogenic AAs ratios. These changes were disappeared after 1 day of UCI. Conclusions: These results show possible mechanisms of development of the energy and neurotransmitter imbalances and their implications in the function of the brain with pathology studied. It is feasible that limitation on BCAA in this pathology will reduce consequences of mediator disturbancies caused by the deficiency of the precursors of biogenic amines – tyrosine and tryptophan

Development of fever under combined administration of substrate and inhibitor of inducible NO-syntase in experimental peritonitis

The purpose of the study was to study the development of fever under combined administration of a substrate and an inhibitor of inducible NO-synthase in experimental peritonitis.Цель исследования – изучение развития лихорадки в условиях сочетанного введения субстрата и ингибитора индуцируемой NO-синтазы при экспериментальном перитоните

Изменения аминокислотного пула в теменной доле и гиппокампе крыс при неполной церебральной ишемии

Introduction. Amino acids and their derivatives are involved in synaptic transmission as neurotransmitters and neuromodulators, and some of them are involved in the formation of neurotransmitters of the nervous system. Therefore, the study of the state of the amino acid pool in incomplete cerebral ischemia plays a significant role.The objective was to assess the nature of changes in amino acid pool and evaluate their participation in oxidative processes in rats with incomplete cerebral ischemia.Methods and materials. The experiments were carried out on 16 male outbred white rats weighing 260±20 g in compliance with the requirements of the Directive of the European Parliament and of the Council No. 2010/63/EU of September 22, 2010 on the protection of animals used for scientific purposes.Results. Compared with the indicators in the control group, rats with an ischemic period of 1 hour in the parietal lobe had a decrease in the content of sulfur-containing amino acids: methionine by 12 % and cysteate by 28 %. In addition, there was an increase of L-arginine in the parietal lobe by 39 %, and in the hippocampus – by 56 %.Conclusions. The following changes are characteristic for one-hour incomplete cerebral ischemia: a decrease in the content of sulfur-containing amino acids, with a decrease in both methionine and an increase in the content of L-arginine. Changes in the parietal lobe and hippocampus had a similar nature, except for the absence of a drop in the level of cysteate in the hippocampus, as a reflection of the higher sensitivity of the parietal lobe to oxygen deficiency, compared with the hippocampus.Введение. Аминокислоты и их дериваты принимают участие в синаптической передаче как нейротрансмиттеры и нейромодуляторы, а некоторые из них участвуют в образовании медиаторов нервной системы. Поэтому изучение состояния аминокислотного пула при неполной ишемии головного мозга играет значимую роль.Цель – оценить характер изменения пула аминокислот и оценить их участие в оксидативных процессах у крыс с неполной ИГМ.Методы и материалы. Опыты выполнялись на 16 самцах беспородных белых крыс массой 260±20 г с соблюдением требований Директивы Европейского Парламента и Совета № 2010/63/EU от 22.09.2010 г. о защите животных, использующихся для научных целей.Результаты. По сравнению с показателями в группе «контроль» у крыс с продолжительностью ишемического периода 1 час в теменной доле происходило уменьшение содержания серосодержащих аминокислот: метионина на 12 % и цистеата на 28 %. Наряду с этим отмечалось увеличение L-аргинина в теменной доле на 39 %, а в гиппокампе – на 56 %.Выводы. Для одночасовой неполной ишемии головного мозга характерны следующие изменения: уменьшение содержания серосодержащих аминокислот со снижением метионина и повышение содержания L-аргинина. Изменения в теменной доле и гиппокампе носили аналогичный характер, за исключением отсутствия падения уровня цистеата в гиппокампе, как отражение более высокой чувствительности теменной доли к дефициту кислорода по сравнению с гиппокампом

HISTOLOGICAL CHANGES IN THE PARIETAL CORTEX AND HIPPOCAMPUS OF RATS AFTER INCOMPLETE CEREBRAL ISCHEMIA

Background. Cerebrovascular diseases, including stroke, take a leading position in the structure of morbidity and mortality worldwide. Solving the problem of stroke requires an in-depth study of its pathogenesis, for which it is necessary to identify morphofunctional changes in the brain at the cellular, subcellular and molecular levels. Purpose: To study histological disorders of neurons in parietal cortex and hippocampus of rats after incomplete cerebral ischemia. Material and methods. The experiments were performed on female white rats weighing 230 ± 20 g. The use of rats as experimental animals was due to the similarity of angio-architectonics and morphology of the cerebral cortex in rats and humans. Incomplete cerebral ischemia was modeled by ligation of both common carotid arteries under intravenous thiopental anesthesia (40-50 mg / kg). Results. Incomplete cerebral ischemia leads to histological changes in the neurons of the parietal cortex and hippocampus. There is a decrease in the number of normochromic and an increase in the number of pathological forms of neurons, their size and shape change significantly. Conclusions. Incomplete ischemia of the brain leads to significant histological changes in the neurons of the parietal cortex and hippocampus of rats. The disorders are similar, but they are more pronounced in the parietal cortex, the neurons of which are more sensitive to lack of oxygen

THE ROLE OF NEUROGLOBIN IN CEREBRAL ISCHEMIA / HYPOXIA AND OTHER NEUROPATHOLOGY

The aim of the study was to summarize literature data on the localization, functions and role of neuroglobin in ischemia / hypoxia of the brain and neuropathology of different genesis. Results: neuroglobin is a representative of the globin family of the nervous system proteins, involved in maintaining of gas homeostasis of nerve cells. It serves for the deposition and transfer of oxygen to the mitochondria of neurons, and in the presence of pathology it can prevent neurodegeneration through antioxidant and anti-apoptotic mechanisms. Neuroglobin is involved in the binding and neutralizing of active forms of oxygen and nitrogen, the amount of which increases with the development of cerebral ischemia / hypoxia; it supports ion homeostasis and energy metabolism of the cell, acting as a neuroprotector and regulator of cellular respiration. Studying of the changes in neuroglobin expression in ischemia / hypoxia of the brain and other neuropathology is an actual task, since the violation of its neuroprotective mechanisms serves as a pathogenetic mechanism of neurodegenerative diseases

Changes in the parameters of pro-oxidant–antioxidant balance in the brain of rats with stepwise incomplete cerebral ischemia

Objective: to evaluate the activity of oxidative stress in rats with stepwise incomplete cerebral ischemia (SICI). Material and methods. Experiments were performed on 24 male outbred rats weighing 260±20 g, allocated into 3 subgroups (6 animals in each) based on time of ligation of both common carotid arteries (CCA). The control group comprised of shamoperated rats of the same sex and similar weights (n=6). To identify the pro-oxidant–antioxidant state of the brain based on its homogenates, the activity of lipid peroxidation processes, the content of thiobarbituric acid reactive substances (TBARS), the concentration of reduced glutathione (GSH), total thiol groups (TSH), and the activity of glutathione peroxidase were determined. Results. SICI with ligation interval of both CCAs of 1 day and 3 days led to a significant decrease in the total SH groups of proteins and glutathione by 30% (p=0.038) and 46% (p=0.044), respectively, TBARS concentration by 29% (p=0.038) and 31% (p=0.043), respectively. SICI with the maximum interval between CCA ligations was manifested by less pronounced changes in the pro-oxidant–antioxidant state of the brain. Conclusion. In SICI with ligation of both CCAs 7 days apart, at which histological changes were the least pronounced, changes in the pro-oxidant–antioxidant balance were insignificant. The most pronounced disorders of the pro-oxidant–antioxidant balance in the brain were observed in the subgroup with the minimum interval between CCA ligations, which implied the highest activity of oxidative stress