[Permeability of isolated rat hepatocyte plasma membranes for molecules of dimethyl sulfoxide].

We have studied permeability of isolated rat hepatocyte membranes for molecules of dimethyl sulfoxide (DMSO) at different hypertonicity of a cryoprotective medium. The permeability coefficient of hepatocyte membranes κ1 for DMSO molecules was shown to be the differential function of osmotic pressure between a cell and an extracellular medium. Ten-fold augmentation of DMSO concentration in the cryoprotective medium causes the decrease of permeability coefficients κ1 probably associated with the increased viscosity in membrane-adjacent liquid layers as well as partial limitations appeared as a result of change in cell membrane shape after hepatocyte dehydration. We have found out that in aqueous solutions of NaCl (2246 mOsm/l) and DMSO (2250 mOsm/l) the filtration coefficient L(p) in the presence of a penetrating cryoprotectant (L(pDMSO) = (4.45 ± 0.04) x 10(-14) m3/Ns) is 3 orders lower compared to the case with electrolyte (L(pNaCl) = (2.25 ± 0.25) x 10(-11) m3/Ns). This phenomenon is stipulated by the cross impact of flows of a cryoprotectant and water at the stage of cell dehydration. Pronounced lipophilicity of DMSO, geometric parameters of its molecule as well as the presence of large aqueous pores in rat hepatocyte membranes allow of suggesting the availability of two ways of penetrating this cryoprotectant into the cells by non-specific diffusion through membrane lipid areas and hydrophilic channels.

The use of nanocomposite coatings with various physicochemical properties in tissue engineering.

We studied the effect of nanocomposite coatings with various physicochemical properties on the structural and functional properties (adhesion potential, phenotype, gene expression) of mesenchymal stem cells. Of all tested nanocoatings (Al2O3, ZrO2, Ta2O5), oxide coating Al2O3 enriched in vitro monolayer bone marrow cell culture with cells carrying mesenchymal stem cells phenotype markers and stimulated expression of ido gene, which can confer new therapeutic potencies to these cells and extend their application in clinical practice.

The physico-mathematical theory of human erythrocyte hypotonic hemolysis phenomenon.

A physico-mathematical model of human erythrocyte hypotonic hemolysis has been developed in this work. It quantitatively describes the kinetics of the phenomenon occurring when cells are suspended in a hypertonic aqueous solution of permeable non-electrolyte.

[Reaction of cells to hypertonic effects by cryoprotection]. / Reaktsiia kletok na gipertonicheskie vozdeistviia pri krioprotektsii.

Kinetics of volume changes in cells caused by hypertonic solutions has been investigated theoretically using an apparatus of the non-equilibrium thermodynamics. Analytical expressions for relaxation times of the two-stage process studied have been found. The reaction of mouse peritoneal exudate cells to hypertonic solutions of glycerol. PEO-400 or PEO-1500 has been studied experimentally. An agreement has been obtained between theoretical calculations and experimental results. Possible mechanism of cell injury caused by hypertony is discussed.

[Ontogenic differences of glutamate decarboxylase, GABA-aminotransferase, monoamine oxidase activities of cerebral cortex mitochondria and hypothalamic cerebral area]. / Ontogeneticheskie razlichiia glutamatdekarboksilaznoi, GAMK-aminotransferaznoi, monoaminoksidaznoi aktivnostei mitokhondrii kory bol'shikh polusharii i gipotalamicheskoi oblastimozga.

It is shown that the glutamate decarboxylase activity in the initial mitochondrial fraction of "light" and "heavy" synaptosomes of cerebral hemispheres changes on the 14th, 21st day, 1st, 3d, 12th and 24th months of rat development: in the hypothalamus area it lowers in the initial mitochondria in the 21-day animals, and in the fraction of "heavy" synaptosomes--in the 24 day animals as compared to the adult ones. The GABA-aminotransferase activity in the cortex synaptosome fraction rises in the period between the 14th and 21st day after birthday and in the initial mitochondrial fraction of the hypothalamus area--between the 14th day and the first month of life. In adult rats the glutamate decarboxylase and GABA-aminotransferase activities in the "heavy" synaptosome fraction are higher than in the "light" synaptosome one. The amine oxidase activity of the subcellular fractions which is determined with serotonin as a substrate (form A) is stable during the whole developmental period of studies. The intensity of benzylamine (amine oxidase B) desamination in the cortex fraction and hypothalamus area rises sharply in the second half of ontogenesis.