[The effect of cholesterol and dicetylphosphate on the physical parameters of liposomes]. / Vliianie kholesterina i ditsetilfosfata na fizicheskie parametry liposom.

The physical parameters of liposomes from phosphatidylcholine with cholesterol or dicetylphosphate were investigated. The sizes, electrophoretic mobility, surface density charges of these liposomes were estimated. It has been shown that dicetylphosphate, as well as cholesterol increases the thickness of bilayer of the lecithin liposomes and at the same time the area occupied by one lipid molecule has not been changed by dicetylphosphate in contrast to cholesterol.

[The composition and physicochemical properties of the blood lipoproteins in rats exposed to external gamma irradiation]. / Sostav i nekotorye fiziko-khimicheskie svoistva lipoproteinov krovi krys pri vozdeistvii vneshnego gamma-oblucheniia.

Content of lipids, character of chemiluminescence of blood plasma and certain classes of lipoproteins have been studied. Geometrical parameters, nature and quantity of charged groups of lipoprotein particles accessible for titration have been determined 1 and 30 days after a single external gamma irradiation of rats in a dose of 3 Gy. The used irradiation dose exerts an expressed hyperlipidemic effect retained for one month after irradiation. The disturbances in the spectrum of blood lipids and lipoproteins are of hyper-beta and hyper-prebeta lipoproteinemia character. Considerable disturbances of physicochemical properties of different classes of lipoproteins have been detected. They are exhibited in changes of the pattern of free-radical processes, state of the charge of surface ionogenic groups and geometrical parameters of lipoprotein particles. Changes registered by the methods of potentiometric titration and correlation spectroscopy are most expressed in lipoproteins of very low density and those of low density.

[Interaction of very low density lipoproteins (VLDL) with macrophages and their triboluminescence in hypercholesterolemia]. / Vzaimodeistvie lipoproteinov ochen' nizkoi plotnosti (LONP) s makrofagami i ikh triboliuminestsentsiia pri giperkholesterinemia.

Accumulation of cholesterol esters and triglycerides in peritoneal mice macrophages in the course of their interaction with lipoproteins of very low density (VLDL) is shown to grow considerably under conditions of hypercholesterolemia. A decrease of triboluminescence intensity characterizing the surface charge has been revealed at hypercholesterolemia both in VLDL and in the blood plasma. It is supposed that the triboluminescence method may be used for testing of the atherosclerotic process development.

[Composition and physical structure of atherogenic lipoproteins in ischemic heart disease]. / Osobennosti sostava i fizicheskoi struktury aterogennykh lipoproteinov pri ishemicheskoi bolezni serdtsa.

The results of comparative studies in atherogenic lipoproteins of blood plasma under heart ischemic disease (HID) which is accompanied by hypercholesterinemia or proceeds without disturbances in the lipid metabolism, evidence for considerable differences in the composition and physical structure of very low-density lipoproteins (VIDL) and low-density ones (LDP) under the investigated states. The decrease in the surface charge density and in sizes of VLDL, as compared to normal, which are least expressed at HID and an increase in the surface charge density with certain increase of LDL radii under this pathologic state are revealed.

[Structural-functional changes in plasma lipoproteins during vitamin D-deficient rickets in children]. / Strukturno-funktsional'nye izmeneniia lipoproteinov plazmy krovi pri vitamin-D-defitsitnom rakhite u detei.

The lipid composition and structure of low- and high-density lipoproteins (LDL and HDL) have been studied in children with the vitamin D-deficient rachitis. An increase of the cholesterol content in the atherogenic LDL against a background of its decrease in the antiatherogenic HDL has been revealed, that is analogous to the observed changes under the atherosclerosis development in adults. Due to the studies in the amino acidic composition and determination of the nature and quantity of the charged groups of lipoprotein particles accessible for titration definite, certain disturbance in the structure of lipoproteins are observed as such that may cause disturbances in their functional activity.

[Structural organization of blood plasma lipoproteins and their interaction with the cell]. / Strukturnaia organizatsiia lipoproteinov plazmy krovi i ikh vzaimodeistvie s kletkoi.

Up-to-date information on the structural organization of basic blood plasma lipoproteins and their interaction with a cell is presented. Different types of lipoprotein modifications which make changes in lipoprotein interactions with the receptors of macrophages, fibroblasts and other cells are shown. The participation of different types of receptors in the process of interaction with native and modified lipoproteins is emphasized.

[Structural properties and lipid-binding characteristics of plasma fibrinogen and gamma-globulins in vitamin D-deficient rickets]. / Strukturnye osobennosti i lipidsviazyvaiushchaia sposobnost' fibrinogena i gamma-globulinov plazmy krovi pri vitamin-D-defitsitnom rakhite.

Structure properties and lipid-binding ability of fibrinogen and gamma-globulins were studied in blood plasma of children with rickets. Content of cholesterol and its esters, developing complexes with fibrinogen, was found to increase simultaneously with a decrease in the phospholipids, containing in the protein fraction, under conditions of the disease. Surface charge of the proteins studied, especially of fibrinogen, was altered, thus demonstrating the distinct impairments of their structure and functions. Lipid environment appears to be of importance in functional activity of these proteins.

[Changes in geometric parameters of liposomes and plasma lipoproteins during enrichment with cholesterol]. / Izmenenie geometricheskikh parametrov liposom i lipoproteinov plazmy krovi pri ikh obogashchenii kholesterinom.

Geometrical parameters of liposomes and lipoproteins of human blood plasma with different content of cholesterol are determined by the methods of radiationless energy transfer between fluorescence probes and by spectroscopy of the optical shift. The bilayer thickness of liposomes containing 33% (mol.) cholesterol is 48 +/- 3A, that of liposomes of pure phosphatidyl choline--32 +/- 2 A. The surface area is equal to (0.41 +/- 0.02).10(3) m2/g of lipid and (0.47 +/- 0.01).10(3) m2/g of lipid, respectively. The radii of lipoproteins of very low density were 13.9 and 25.5 nm, those of the low density--10.0 and 9.5 nm and those of high density--5.3 and 7.8 nm by the data of radiationless energy transfer and optical mixing, respectively. In case of hyper cholesternemia these values are equal to 20.7 and 31.9 nm, 12.7 and 11.1 nm, 5.2 and 5.9 nm, respectively. The results obtained are compared with data of other methods.

[Surface charge of erythrocyte membrane during disorders of lipid metabolism from the data of microelectrophoresis, H+-titration and fluorescence studies]. / Poverkhnostnyi zariad membran éritrotsitov pri narusheniiakh lipidnogo obmena po dannym mikroélektroforeza, H+-titrovaniia i fluorestsentnykh issledovanii.

The surface charges and the isoelectric points (pI) as well as changes in these values depending on the lipid composition are determined for erythrocyte membranes of rat, rabbit, bull and man under conditions of hypercholesterinemia, atherosclerosis, D-hypovitaminosis and in experiments in vitro using the techniques of microelectrophoresis and positive charged ligands (proton, probe astraphloxin) binding. The ionogenic groups forming charge and essential differences in their nature (pK) and quantity depending on the erythrocyte type are found. Inverse correlation between the content of cholesterol and cholesterol ethers and the value of erythrocyte membrane surface charges was established for each sample examined. A comparative evaluation of the methods used was conducted.

[Surface properties and size of very low and low density lipoproteins in human plasma in normal states and in hypercholesterolemia]. / Poverkhnostnye svoistva i razmery lipoproteinov ochen' nizkoi i nizkoi plotnosti plazmy krovi cheloveka v norme i pri giperkholesterinemii.

Dimensions and density of surface charge of very low (VLDL) and low density lipoproteins (LDL) from hyman blood plasma under conditions of normal state and hypercholesterolemia were evaluated by means of radiation-free energy transition between fluorescent probes and potentiometric titration. Radia of VLDL constituted 13.9 +/- 0.6 nm and 20.7 +/- 1.2 nm and those of LDL--10.0 +/- 0.5 nm and 12 +/- 0.4 nm, respectively, in normal state and under the pathological conditions, while the density of surface charge of VLDL was equal to 0.5 X X 10(-2)K/m2 and 0.3.10(-2)K/m2; those of LDL--0.2.10(-2)K/m2 and 0.05.10(-2)K/m2, respectively. These alterations appear to facilitate the unspecific interaction between atherogenic lipoproteins and vascular cells in hypercholesterolemia.

[Surface charge of plasma lipoproteins from the data of potentiometric studies]. / Poverkhnostnyi zariad lipoproteinov plazmy krovi po dannym potentsiometricheskikh issledovanii.

The method of potentiometric titration is used to measure a surface very low, low- and high-density charge of the human blood plasma lipoproteins. Density of the surface charges is -0.5 X 10(-2); -0.2 X 10(-2); -3.4 X 10(-2) K/m2, respectively. The surface area of the lipoproteins determined by the method of radiation-free energy transfer between fluorescent probes amounts to 185.9; 241.7 and 426.8 m2 per 1 g of lipoprotein, respectively. Results of the experiments satisfactorily coincide with the data, obtained by other methods.

[Structural characteristics of integral protein-3 of rat erythrocyte membranes in hypovitaminosis D]. / Strukturnye osobennosti integral'nogo belka-3 membran érytrotsitov krys pri D-gipovitaminoze.

The amino acid composition, lipid-binding ability, the values of pK and binding capacity of negatively charged sites of the integral protein-3 from erythrocyte membranes are determined for rats in norm and under conditions of D-hypovitaminosis. Protein-3 binding of phosphatidyl choline and sphingomyelin considerably decreases, while that of cholesterol and lanosterol increases with the unchanged amino acid composition under conditions of D-hypovitaminosis. This leads to the enhancement of the protein electro-negativity as its carboxylic groups and histidine imidazole become more accessible for titration. An increase of the negative charge of protein-3 with D-hypovitaminosis is supposed to be responsible for inhibition of the anionic transport realized by it through the forces of electrostatic repulsion.