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Biomedical subjects

V N Vitvitskiĭ

Publications and source records attributed to V N Vitvitskiĭ.

At least 19 recordsLinked to original sources
PubMed1990

[The short-term and long-lasting changes in DNA and RNA synthesis in the cerebral cortex cells of animals subjected to hypoxia and nerve tissue transplantation].

The DNA and RNA synthesis in the cells of the brain cortex of intact rats and animals subjected to hypoxia, hypoxia with subsequent transplantation or by the local brain injury has been investigated. The DNA synthesis changes insignificantly in the case of hypoxia, it enhances slightly in the area of the injury and increases much more after transplantation. The RNA synthesis decreases considerably immediately after hypoxia and decreases much more 120 days later. Using the ultracentrifuge method it has been found that under the effect of hypoxia the number of nervous cells decreases, the number of glial cells does not change. The local injury in the nervous tissue enhances abruptly the synthesis in neurons and glial cells in the hypoxia-exposed animals, the embryonic nervous tissue transplantation normalizes the number of neurons in the specimens under study and the RNA synthesis in the neurons and glial cells.

Animals↗
PubMed1986

[Isolation and study of the properties of a protein factor activating proliferative processes in nerve tissue].

The method of isolation and some properties of the neutral protein activator of proliferation processes are described. The protein obtained is characterized by high lability and easily destroys treated with proteolytic enzymes and stored under any conditions. It loses the greater part of activity. Peptides formed differ in their properties from the proliferation peptide activators studied earlier and are not able to stimulate the proliferation processes in the brain tissue cells.

Animals↗
PubMed1985

[2 methodological approaches to the problem of the tissue specificity of transcription].

The determination of genome transcription level in different tissues or structures of organism is carried out at present by the method of DNA--RNA-hybridization in solutions using labeled unique DNA sequences and significant RNA excess. Similar results may be probably obtained by a more simple method--numerously repeated recycles of RNA passage through the columns with denaturated DNA polymerized in agarose gel. Hybridization of single-stranded DNAs with each other is excluded and it is possible to separate RNA into fractions specific for different tissues and organs.

Brain↗
PubMed1985

[Study of DNA synthesis stimulators in nerve tissue cells].

Ontogenetic changes in DNA synthesis in different divisions and regions of the brain occur via different mechanisms, which is conditioned by changes in the composition and properties of corresponding mediators. Tissue extracts obtained from the parts of brain characterized by intensive cell division (cortex of 15-17-day-old embryos or cerebellum of 8-10-day-old animals) can stimulate the incorporation of labeled precursors into brain cell DNA in both neonatal and adult rats. Using desalting at increasing concentrations of ammonium sulfate, gel filtration on sephadexes and isoelectrofocusing, three fractions of DNA synthesis stimulators whose isoelectric points lie at acidic, neutral and alkaline regions of pH, were isolated. A method is described, which can be employed for isolation in a pure state and determination of some physico-chemical properties of an acid activator. The latter is a low molecular weight peptide causing marked stimulation of [3H]thymidine incorporation into nervous tissue cell DNA in an in vitro system, when taken at a concentration of about 1 microgram/ml.

Aging↗
PubMed1983

[Chromatin protein metabolism and phosphorylation in the cells of different parts of the brain and liver in rats under normal conditions and under motor load].

The relationship of intensive motional load with quantitative changes of the synthesis processes and phosphorylation in chromatin peptide fractions of varied polyacrylamide gel electrophoretic mobility from different rat brain structures and liver has been investigated. It has been established that the functional influences change not only the velocity of metabolism and phosphorylation but also the pattern of chromatin protein distribution. The new low molecular peptides differing in their electrophoretical mobility appear in chromatin of liver and neocortical neurons. The changes of the synthesis processes and phosphorylation typical of some fractions of the cerebral chromatin are variable and not so important as in the case of cytoplasmic proteins. The velocity of synthesis of the most proteins studied and the phosphorylation rate of some proteins increase in the neocortical neurones. The phosphorylation rate of separate low molecular peptides increases in the glial cells.

Animals↗
PubMed1982

[Characteristics of the biosynthesis and phosphorylation of cytoplasmic proteins from different parts of brain and liver of rats under functional influences].

The biosynthesis and phosphorylation of peptide fractions from rat liver cytoplasm and from different divisions of rat brain differing in their electrophoretic mobilities during polyacrylamide gel electrophoresis with Na-DS were studied under normal conditions and at intensive locomotor exercise. In brain trunk the incorporation of [14C]methionine into nearly all peptide fractions and the phosphorylation were found to be considerably decreased. In neocortical preparations the changes in biosynthesis were different depending on the nature of protein fractions, which can partly be due to the oppositely directed types of [14C]methionine incorporation into the neurons and glyal cells, i. e. decrease and considerable increase, respectively. The level of phosphorylation of neuronal proteins was significantly decreased in the cytoplasm and considerably increased in the glyal cells. The rate of biosynthesis in all the peptide fractions and the phosphorylation were considerably increased in cerebellar preparations, which was not the case in other brain divisions and in the liver.

Animals↗
PubMed1982

[Effect of a physiological load on the metabolism and phosphorylation of cell membrane proteins in the rat brain].

The effect of intense motor activity (swimming) followed by signs of physiological stress, on biosynthesis and phosphorylation of membrane proteins from different brain cells (neurons, glia) and sections (cerebellum, brain stem) as well as from liver, involved a significant decrease of 14C-methionine and 32P-phosphate incorporation related, probably, to inhibition of the physiological function, in all the electrophoretic fractions of proteins. In membrane proteins of cortical cells (particularly neurons), on the contrary, there was an increase of biosynthesis and phosphorylation in all the fractions. This seems to reflect an activation of cortical neurons for adaptation purposes.

Animals↗
PubMed1982

[Biosynthesis and phosphorylation of chromatin, cytoplasmic and cell membrane proteins of the rat neocortical neurons and glial cells in a normal state and during various functions].

Intensive motor activity strongly changes the biosynthesis and enzymatic modification of proteins (phosphorylation) in the rat brain neocortex cells. For different groups of neuronal and glial cell proteins, this change is different. For proteins of the neuron cytoplasm, under the above functional influences a decrease of biosynthesis and phosphorylation occurs in the majority of the fractions examined, having different polyacrylamide gel electrophoretic mobility. In the glial cytoplasm proteins, the situation is reverse. In contrast to the cytoplasmic proteins, the cell membrane proteins of neocortical neurones displayed a high increase in the biosynthesic rate and phosphorylaion. These changes in glial cells were much less and not homogeneous. The functional influences were shown to change not only the velocity of metabolism and phosphorylation, but also the pattern of chromatin protein distribution. Under the functional influences, some new peptide fractions appear in preparations of neocortical neurons.

Animals↗