[Changes in cerebral vessels during experimental hyperlipidemia].
Explore the source record for details and available documents.
Blood↗
Biomedical subjects
G I Shaposhnikova
Publications and source records attributed to G I Shaposhnikova.
[Study of anti-amnesic activity of amiridin in a model of amnesic syndrome].
The model of amnestic syndrome obtained by treatment with scopolamine during 20 days in rats was used to study anti-amnesic activity of amiridin in comparison with that of tacrine, physostigmine and piracetam. Multiple injection of Sc resulted in significant deterioration of rats, performance in passive avoidance test. Behavioral disorders were accompanied by such changes in lipid composition of brain synaptosomes which indicated a decreased membrane fluidity. Amiridin and tacrine as well as piracetam showed anti-amnesic action which in the course of treatment correlated with their normalizing effect on lipid content of synaptosomes. The diverse effect of amiridin and tacrine with respect to physostigmine implies that the former drugs can't be attributed to anticholinesterase preparations which are traditionally used in the treatment of Alzheimer disease.
Acetylcholinesterase↗
Changes of glycolipids dependent on cell density of Ehrlich ascites carcinoma cells.
The glycolipid composition of Ehrlich ascites carcinoma cells was found to depend strongly on the cell density of the suspension. The general trend observed upon dilution of the cell suspension was a reduction of the less complex gangliosides GM3 and GM2 with concomitant increase of the more complex gangliosides, especially GM1. The increase of the content of ganglioside GM1 upon dilution was accompanied by a comparable decrease of the content of its immediate precursor, asialo-GM1, whereas the content of other neutral glycosphingolipids did not change very much. When the cell suspension was diluted with medium conditioned by dense cells the ganglioside profile of the diluted suspension remained similar to that of the dense cell suspension. It is postulated that the medium conditioned with dense cells contains a transferable factor inhibiting sialylation of asialo-GM1.
Animals↗
Shedding of gangliosides from tumor cells depends on cell density.
The ganglioside composition of mouse ascites hepatoma ( MAH ) cells, the ascites fluid and cell-conditioned media were determined and found to be qualitatively identical, but quantitatively different. The ganglioside content of the ascites fluid and the medium conditioned by MAH -cells at the native cell concentration (10(8) cells/ml) comprised respectively 74.9% and 23% of the cell-associated gangliosides. When incubated at lower cell-density (10(6) cells/ml) the cells were found to be release about three-times higher amounts of ganglioside per cell than during incubation at the native concentration. Centrifugation of the dense-cell-conditioned medium revealed the major part of the released gangliosides to be associated with a 150000 X g pellet that probably contains shed plasma membrane fragments. In the 150000 X g pellet of the extracellular fluids the relative content of the most polar cell ganglioside corresponding chromatographically to GT1b was about ten-times higher than in the cells. The possibility is raised that the more intense shedding of gangliosides from less crowded MAH cells may play a role in the self protection of the tumor from host immune rejection during initial stages of growth.
Animals↗
[Neutral glycosphingolipids in Ehrlich ascites carcinoma cells].
The structure of the neutral glycosphingolipids of the Ehrlich ascite carcinoma (EAC) cells was studied. The main four components were identified as glycosylceramide, lastosylceramide, N-acetylgalactosyllactosylceramide and galactosyl-N-acetyllactosylceramide (asialo-GM1). The neutral glycolipid pattern of the cells was found to depend on their density. Dilution of the cell suspension resulted in an increased content of asia-lo-GM1, whereas the content of the other neutral glycolipids remained unchanged. The possible connection between these changes and the earlier disclosed cell density dependence of the gangliosides in EAC cells is discussed.
Animals↗
Role of gangliosides in reception of influenza virus.
The ganglioside composition of Ehrlich ascites carcinoma (EAC) cells and the role of the individual gangliosides in binding and penetration into the cell of influenza virus were determined. EAC gangliosides identical with or close to GM3, GM2, GM1, GT1a and GT1b were characterized by thin-layer chromarography, compositional analyses, methylation analysis and mass-spectrometry. The ganglioside uptake capacity of native and neuraminidase-treated EAC cells was studied with tritium-labeled gangliosides of definite structure and the binding of influenza virus to cells was determinated by using [3H]uridine-labeled virus and by hemagglutination studies. Treatment of the cells with Vibrio cholerae neuraminidase largely decreased binding of the virus. Exogenous gangliosides with a terminal galactose unit or a penultimate galactose masked by neuraminic acid were able to restore the virus-binding capacity of neuraminidase-treated cells, however, the main ganglioside of EAC cells, GM2, which carbohydrate chain is terminated by N-acetylgalactosamine, was completely ineffective. The common carbohydrate sequence of the gangliosides showing binding activity (formula; see text) is proposed to be the main recognition structure of the influenza virus receptor on the surface of EAC cells. Penetration of labeled influenza virus into the nuclei of EAC cells was evaluated by measuring the radioactivity of the nuclei of neuraminidase-treated ganglioside-loaded cells after exposition to the labeled virus. Of all gangliosides tested only trisialogangliosides of the GT1b type were able to induce increased entry of the virus into the cells and accumulation of its radioactive component into the nuclei. It is suggested that GT1b gangliosides react specifically with the virus protein responsible for membrane fusion (apparently the hemagglutinin HA2 subunit) and thus are involved in virus penetration and delivery of the virus genome to the nuclei.
Animals↗
[Role of gangliosides in influenza virus reception and penetration into the cell].
Explore the source record for details and available documents.
Adsorption↗
[Effect of gangliosides secreted by ascites hepatoma 22a cells on intensity of protein synthesis and sensitivity of cells to indocarb].
Explore the source record for details and available documents.
Animals↗
[Gangliosides of mouse liver and ascites hepatoma 22a].
The ganglioside composition of the ascite hepatoma 22a and that of mouse liver was compared. GM2 was shown to be the main ganglioside in both tissues; however, the gangliosides of the hepatoma differed from liver gangliosides by a higher amount of disialoganglioside GD1a and by contents of monosialoganglioside GM1 and disialoganglioside GD1b which are absent in normal mouse liver. Trisialogangliosides which are characteristic for normal liver cells were not detected in the hepatoma. The liver and hepatoma gangliosides differed also by the type of sialic acids. In the liver the individual ganglioside fractions belong to either the N-glycolyl- or the N-acetylneuraminyl series, whereas the ganglioside fractions of the hepatoma are characterized by simultaneous presence of both sialic acid types.
Animals↗
[Relationship between the ganglioside composition of Ehrlich ascitic carcinoma and cell population density].
The ganglioside composition of Ehrlich ascite carcinoma cells changes drastically with changes in density of the cell population. Upon 30-fold dilution of the native cell suspension and subsequent incubation for 2 h the amount of total gangliosides per cell doubles the quantities of a monosialoganglioside and of a disialoganglioside increase ten- and five-fold, respectively, whereas the other cell gangliosides do not change. The decrease of cell density is supposed to be accompanied by induction on the cell surface of a sialytransferase activity, which appears to be depressed in the dense suspension.
Animals↗
[Structural-functional changes in biomembranes during complications of diabetes mellitus and their pharmacological correction].
The decrease of sorbitol dehyidrogenase activity and the increase both of aldoso reductase activity and sorbitol concentration in aorta or eye lens under experimental diabetic angiopathy have been shown. The structural and functional alterations in erythrocytes membranes under angiopathy studied by spin- and luminesoense probes confirm the hypothesis on the major role of membrane pathology processes in the pathogenesis of diabetic mellitus. Pharmacological correction of diabetic angiopathy by glucophag or new antioxidant LBK-78 normalized the studied diversions on the membranes level.
Animals↗
[Gangliosides--specific receptors for the influenza virus].
The capacity of two gangliosides, GD1a and GT1b isolated from bovine brain to function as specific receptors of influenza virus was determined. A primary chick fibroblast culture was treated with neuraminidase to destroy natural receptors, the cells were loaded with gangliosides GD1a and GT1b, inoculated with 3H-uridine-labeled virus, and virus adsorption and penetration into the cell nucleus were determined. Both gangliosides were shown to restore virus adsorption to the cell surface and penetration of viral structures into the cell, GT1b facilitating more effective transportation of viral structures into the nuclei than GD1a and inducing penetration into the nuclei nearly 1.5-fold as much amount of viral structures as in native cells. The same ganglioside partially restored virus-induced hemolysis upon loading it on erythrocytes pre-treated with neuraminidase. It is concluded that ganglioside GT1b is a specific receptor for influenza virus. 3.9% of this ganglioside was found in chick fibroblast lipids.
Adsorption↗
[The hormone-metabolic changes in the diabetic angiopathy].
Biochemical, morphological and electron-microscopic readings of blood serum, liver, aorta and brain vessels, and in crystalline lens were investigated in intact and experimental animals during the process of experimental diabetes mellitus formation. The experimental diabetes mellitus was induced by L-adrenaline implementation and atherogenous load. Characteristics of lipid metabolism, peroxide lipid oxidation, sorbitol way of glucose metabolism, glucose and insulin levels conform to diabetes mellitus. Diabetic lipid metabolism impairments were accompanied with changes in microcirculation--a cause of diabetes mellitus complications. These data were supported by morphological and electron-microscopic readings. The results of the study confirm the hormone hypothesis of diabetic complications and stress (high adrenaline level) factors of Diabetes Mellitus pathogenesis.
Animals↗