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Biomedical subjects

M A Chebotareva

Publications and source records attributed to M A Chebotareva.

At least 19 recordsLinked to original sources

Phospholipids and their fatty acids in mitochondria, synaptosomes and myelin from the liver and brain of trout and rat: a new view on the role of fatty acids in membranes.

The content of different phospholipids (PL) and their fatty acid (FA) composition in subcellular fractions from the liver and brain of rat (Rattus rattus) and trout (Salmo irideus) were estimated. It was shown that despite higher content of unsaturated fatty acids in myelin compared to synaptosomes, the unsaturation index of the latter is equal or higher than that of myelin. The total content of PL polyunsaturated fatty acids (PUFA) was shown to be higher in membrane structures with more active ion transport (mitochondria). This feature seemed to be characteristic of membranes from both representatives of homoiotherms and poikilotherms studied. A possible role for PUFA information within the lipid monolayer of areas with different capacity to accept electrons and transport them along a sort of intermolecular 'tunnel' is discussed. The double bonds of PUFA in this area seem to be able to produce bonds similar to conjugated bonds.

Animals↗

Comparative investigation of lipid and fatty acid composition of fish gills and mammalian lungs. A model of the membrane lipid component areas.

The lipid and fatty acid composition of gills and lungs were studied in 18 fish species and seven mammalian species. Different relationships among individual phospholipids and different molar ratios between phospholipids and cholesterol (2:1 in fish and 3:1 in mammals) were found. Conformational analysis of the main phospholipid and cholesterol molecules was carried out using a molecular mechanics method. The model of "one unit fragment of the membrane lipid component" accommodates 19 lipid molecules in fish and 42 in mammals. The areas of the molecule projections of the main phospholipids do not differ from each other by more than 2-3%. It may be suggested that the closely packed lipids in membranes of the aerohaematic barrier protect the organism of mammals from the high oxygen content in the environment.

Animals↗

[Lipids of the bone tissue in bodies of thoracic vertebrae in scoliosis in rabbits].

The content of total lipids, triglycerides, cholesterol and phospholipids in the bone tissue of the bodies of the thoracic vertebrae was investigated in 4.5-, 7- and 12 month old rabbity. The development of scoliosis in two month old animals was induced by the one-sided blockade of the afferent links of the innervation in thoracic region at the extent of four segments (TH6-9). In: experimental scoliosis there were important alternations in the content of the total lipids comparing with the control which are observed only on the level of the primary and of the anterior compensatory curves in 12 months old animals. The content of triglycerides changed even at early stages of the development of scoliosis. A decrease of triglycerides content was observed at the level of the primary curve in rabbits of all ages with experimental scoliosis. Probably it is due to the alteration of neurotrophic processes in the bone tissue. There were similar age-related changes of triglyceride content in both groups of animals. Phospholipids have absolutely another than triglycerides dynamics of the content changes during the scoliosis development. Time-course of phospholipid changes in scoliosis differed from that of triglycerides. In older rabbits with experimental scoliosis the cholesterol content in the bone tissue of vertebral bodies was reduced by 1.5-2 times while in normal animals it remained almost unchanged. The most substantial changes in cholesterol content of the vertebral bone tissue in rabbits with the experimental scoliosis occur in early age (4.5 months) on the level of the primary curve and the posterior compensatory curve. This may be considered as one of the biochemical indicators of the progressing scoliosis.

Aging↗

[Combined effect of environmental temperature and trematodes on fatty acids composition of lipids of Littorina saxatilis (Olivi 1792) (Gastropoda, Prosobranchia)].

An effect of environmental temperatures and invasion by helminthes larvae on fatty acids composition of digestive gland lipids of marine littoral gastropod Littorina saxatilis from White Sea and Barents Sea was investigated. We have compared gastropods from boreal and subarctic populations. It was found that gastropods from waters of lower temperature have increased omega3/omega6 fatty acids ratio. However, saturation index of individual membrane phospholipids was not affected. Also, content of eicosenoic acid (20:1) in individual phospholipids was not affected by temperature. Invasion increases the omega3/omega6 ratio of common lipids but not the omega3/omega6 ratio of common and individual phospholipids with the exception of phosphatidilcholine of cold water mollusks from Barents Sea that had this ratio doubled. In contrast to temperature, invasion affects the content of eicosenoic acid that was increased in the investigated organs. Adaptability of these effects is discussed regarding parasite-host system.

Animals↗

[Respiratory organ lipids in fishes and mammals. A model representation of the area of the lipid component].

Studies have been made on lipid composition of the gills in 19 species of fishes and of the lungs in 8 mammalian species. It was shown that the arbitrary "unit fragment" of the lipid component of the respiratory organs in all the investigated animals exhibits similar qualitative composition, but contains different quantity of lipid molecules, i. e. approximately 19 in fishes and 42 in mammals. Theoretical conformational analysis revealed predominant conformations of phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, sphingomyelin and cholesterol; projections of these molecules on the surface which is parallel to membrane surface were composed. It was shown that projectional areas for the main phospholipid molecules differ only by 2-3%. These data indicate that the surface of a model of the lipid component in the membranes of respiratory organs in mammals is twice larger than in fishes. These differences presumably account for more effective oxygen transfer in mammals.

Animals↗

[Brain cholesterol in representatives of different vertebrate classes].

Studies have been made on the cholesterol content of the brain in 73 species of vertebrates. Cholesterol content increases in both aquatic and terrestrial animals in evolutionary row. Significant variations in cholesterol content were noted within the same class. Comparative studies revealed correlation between changes in phospholipids and cholesterol on one hand and various glycolipids on the other. It is suggested that cholesterol content of the brain in vertebrates depends on ecological factors rather than on taxonomic position of animals.

Animals↗

[Lipid composition of spinal bone tissue in rabbits of different ages].

Studies have been made on the lipid composition of total lipids, triglycerides and their fatty acids, cholesterol and phospholipids in the vertebral column of young and adult rabbits. It was shown that the content of total lipids and triglycerides increases, whereas that of cholesterol and phospholipids decreases with age. The content of total lipids in the vertebral column is 10 times higher as compared to that in the bones of the extremities. Mid-thoracic part of the vertebral column exhibits higher lipid content than other thoracic parts of the column. Lipid content of the vertebral processes is lower than that of the vertebral bodies. These data indicate lipid specificity and heterogeneity of bone tissue of the vertebral column. The main fatty acids of vertebral triglycerides are presented by those with 14-18 carbon atoms (90%), no acids with 22 atoms were found. Higher content of the linoleic acid (19%) and higher total unsaturation of triglycerides were found in the bone tissue of rabbits in comparison with those of man.

Aging↗

[Cholesterol in the brain of cartilaginous and bony fish].

Data are presented on the content of cholesterol in the brain of 23 fish species with different phylogenetic position and ecology. Stable and lower cholesterol content (mean level 10.6 mg/g wet tissue) in the brain of 11 species of Chondrichtyes was shown together with variable and higher (mean level 13 mg/g wet tissue) one in the brain of 12 species of Teleostei. The data obtained are discussed in relation to phylogenetic position of the species investigated and ecological factors (depth and temperature). The ratio of cholesterol to phospholipids in the brain of fishes is lower than that in mammals.

Animals↗

[The possible role of fatty acids and their conformation in the realization of the respiratory function and in the adaptations of fish gill membranes and of mammalian lungs].

Fatty acid composition of major phospholipids has been studied in 12 fish and 7 mammalian species. Projections of the fatty acid pairs of these molecules on the plane parallel to the membrane surface have been computed. The projection area of two saturated acids was shown to look like the projection area of its "head", while substitution of one or two saturated acids to unsaturated ones increases the projection area 25%.

Adaptation, Physiological↗

[Thiamine content and enzyme activity in blood cells in leukemia].

Content of thiamine and activities of two enzymes were studied in blood cells of patients with various types of leukosis. In patients with acute leukemia content of thiamin was decreased in leucocytes and blood plasma. Content of vitamin B1 was increased in erythroid cells of peripheric blood in erythroleukosis. Administration of thiamin into some patients caused a distinct increase in its content in blood cells. The guanosine phosphorylase activity was higher in blood cells in leukosis as compared with control. The transketolase activity was not distinctly altered.

Acute Disease↗