[Properties of liposomes adsorbed by montmorillonite]. / Svoistva liposom, adsorbirovannykh montmorillonitom.

Adsorption of phosphatidylcholine liposomes by montmorillonite was studied for its effect on peroxidation of phospholipids and structure of the bilayer. The UV spectroscopy has shown that adsorption decreases peroxidation of lipids. A parameter is suggested for estimating an oxidation degree of lipids at the stage of the intensive formation of secondary products of their peroxidation. Fluorescent probes (1-anilinonaphthalene-8-sulphonate and pyrene) are used to establish that structural changes of the bilayer take place in adsorbed liposomes being followed by a decrease in the mobility of surface zones of phospholipid "heads" and by an increase in the polarity of hydrophobic parts of the bilayer.

[Complexing of bovine serum albumin with phosphatidyl choline liposomes]. / Kompleksoobrazovanie bych'ego syvorotochnogo al'bumina s fosfatidilkholinovymi liposomami.

Thermodynamic parameters of the bovine serum albumin interaction with phosphatidyl choline liposomes have been determined. It is shown that the bovine serum albumin is adsorbed on the liposomal surface without change of the globule conformation, the polar interactions making dominant contribution in immobilization. The complexing is characterized by a binding constant and a great number of binding sites.

[Effect of the conditions of ultrasonic treatment on the characteristics of forming liposomes]. / Vliianie uslovii ul'trazvukovoi obrabotki na kharakteristiki formiruiushchikhsia liposom.

The conformity of the ultrasonic treatment influence on characteristics of the forming liposomes from phosphatidylcholine water dispersion has been studied by means of spectrophotometry, atomic absorption spectrometry, thin layer and gel chromatography and electron microscopy. Optimal treatment conditions which allow attaining relatively homogeneous suspension of small unilamellar vesicles with the low peroxidation level and minimal lysophospholipid contents have been determined.

[Structural rearrangement in leukocyte membranes under the effect of quercetin and linoleic acid hydroxamate]. / [Strukturnye perestroiki v membranakh leikotsitov pri deistvii kvertsetina i gidroksamata linolevoi kisloty.

The character of structural rearrangements in leukocyte membranes affected by 5-lipoxygenase inhibitors: quercetin and linoleic acid hydroxamate, has been investigated. Quercetin has been shown to induce the translocation of tryptophanyls and tyrosyls from membrane protein inner regions to their surface. Linoleic acid hydroxamate produces the analogous transition of tyrosine residues only. Quercetin brings out disturbances of surface membrane proteins as was registered by ANS fluorescent parameters. It is likely able to arise from the increase of protein hydration. The linoleic acid hydroxamate elevates the quantity of ANS binding sites on the membrane surfaces without any change in their structural features. This effect is likely induced by the surface charge modification of the leukocyte membranes. The linoleic acid hydroxamate increases the level of protein descent into the lipid matrix and decreases the polarity and microviscosity of hydrophobic regions of the latter.

[Structural changes in membranes of proliferating leukocytes L-41 as affected by low doses of ionizing radiation]. / Strukturnye izmeneniia v membranakh proliferiruiushchikh leikotsitov L-41 pod deistviem nizkikh doz ioniziruiushchego izlucheniia.

The dose-dependent effects of gamma-radiation on the leucocyte cultures L-41 has been investigated. Irradiation by the dose of 0.25 Gy stimulates the cell proliferation while that by the doses of 1.0 and 2.0 Gy inhibits this process. In this dose range the radiohormesis effects characterizing structural organization of the probed membranes have been also registered for fluorescence parameters. The zone of qualitative transition of response of the cell membranes to radiation is individual for various effects. The action of radiation in the doses of 0.25 and 0.50 Gy induces a decrease of ANS fluorescence intensity and a decrease of membrane protein immersion in the lipid bilayer of leukocyte membranes. The values of these parameters rise at the doses of 1.0 and 2.0 Gy that reflects different directions of structural changes in various membrane regions. The irradiation in the range of 0.25-1.0 Gy induces the increase of microviscosity in deep regions of membrane lipid matrix while at the dose 2.0 Gy it causes its decrease. Radioactive radiation does not change the membrane protein conformation of leukocytes and polarity of lipid bilayer hydrophobic zones as recorded by fluorescent methods used.

[Effect of 1,8-ANS on structural characteristics of cardiomyocytes sarcolemma]. / Vliianie sufana na strukturnye svoistva plazmaticheskoi membrany kardiomiotsitov.

The effect of sufan on structure properties of the rat cardiomyocyte sarcolemma was investigated. Fluorescence methods involving the probing with 1-anilino-8-naphthalene-sulfonate or pyrene and the self-fluorescence of membrane proteins was used. Effect of sufan on the cardiomyocyte sarcolemma structure has been determined to provoke the conformational disturbances. These are the compaction of membrane proteins and translocation of their tryptophanyls from the surface to the interior of macromolecules. This process was accompanied by the increase of a protein plunge into the lipid matrix. Sufan induces a decrease of the microviscosity without a change of the polarity index in hydrophobic region of the lipid bilayer. These mechanisms have been supposed to be significant for the exhibition of sufan cardioactive properties.

[Interaction of liposomes with erythrocytes in the process of their lysis]. / Vzaimodeistvie liposom s éritrotsitami v protsess ikh lizisa.

Interaction of phosphatidyl choline liposomes with erythrocytes during spontaneous lysis of the latter has been studied. It is shown that hemoglobin which is released during the lysis of erythrocytes is found by liposomes which in their turn are absorbed on the external erythrocyte surface. In this case the binding of hemoglobin by liposomes takes place with a greater speed than its release during erythrocyte lysis and is accompanied by a change in its conformation. Possibilities of the microcalorimetry methods for studying the interaction of liposomes with erythrocytes under the conditions mentioned above are considered.

[Structural effects in membranes after exposure to methyl (embiquin) and metaxylyl derivatives of chloroalkylamines]. / Strukturnye éffekty v membranakh pri vozdeistvii metil'nogo (émbikhin) i metaksil'nogo proizvodnykh khloralkilaminov.

Chloroaklylamine derivatives are studied for their effect on the structural organization of mitochondrion and microsome membranes of the cattle liver. The antitumoural preparation--embiquin is shown to increase microviscosity of hydrophobic zones of a lipid matrix of mitochondrial membranes and to decrease the quantity of immobilized cytochrome C, whereas it has no effect on microsomal membranes. It is established that the replacement of a methyl substituent in the nitrogen atom of chloroalkylamines by the metaxylyl one evokes no qualitative differences in the character of disturbances of the structural properties of mitochondrial membranes, however it induces structural perturbations in the microsomal membranes.

[Structural effects in the sarcolemma of the cardiomyocytes under the action of modulators of the polyphosphoinositide system]. / Strukturnye éffekty v sarkolemme kardiomiotsitov pri deistvii moduliatorov polifosfoinozitidnoi sistemy.

The influence of activators (Ca(2+)-channels stimulator BAY K 8644 and phospholipase C stimulator fMLP) and inhibitors (Ca(2+)-channels blocker verapamil and alpha 1-adrenoceptors blocker prazosin) of the polyphosphoinositide system on cardiomyocytes sarcolemma, was studied. The structural effects of the PPI modifiers seem to be one of the mechanisms of the PPI physiological activity at the membrane level.

Character of structural disturbances caused by chloroalkylamines in the model and erythrocyte membranes.

beta, beta-Dichlorodiethylamine is proved not to induce structural disturbances in phosphatidylcholine liposomes and erythrocyte membranes which is registered by fluorescence methods. Methyl-beta, beta-dichlorodiethylamine and metaxylyl-beta, beta-dichlorodiethylamine cause the increase in microviscosity of lipid bilayer hydrophobic areas in both erythrocyte membranes and liposomes. Besides, polarity of the latter also decreases, and the metaxylyl derivative alkylates nucleophilic centers of phospholipid phosphate groups in liposomes. Erythrocyte membranes, being treated by beta, beta-dichlorodiethylamine derivatives, the increase in the membrane protein hydrophobicity is registered as well as the decrease in their immersion in the lipid bilayer.