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T V Potapova

Publications and source records attributed to T V Potapova.

8 recordsLinked to original sources
PubMed1979

[Changes in intercellular exchange intensity in an L cell culture].

Intercellular junctions permeable to fluorescein Na were studied with the aid of intracellular glass microelectrodes in the cultures of transformed mouse-embryo cells (L-strain). The degree of coupling was correlated with the cell culture density. In addition, the degree of coupling increased after short-time incubated of the cells with 1mM lanthanum. Such an incubation did not influence other features of cells: the value of the membrane potential, the character of growth or the inclusion of the vital dye neutral red. Some other factors stimulated cellular aggregation (concanavalin A, protamine, decreasing the pH) but did not influence the degree of coupling.

Animals↗
PubMed1979

[Ultrastructure of the specialized intercellular contacts in an L-cell culture treated with low concentrations of lanthanum].

The electron microscope study of L-cells treated with 1 mM lanthanum has shown an increased amount of gap-like junctions and a decreased number of tight junctions compared to the norm. No damage in the plasma membrane structure and other cell organoids was observed. This may suggest that following the above treatment, the amplified intercellular exchange is associated with the increase in the quantity of intercellular highly permeable junctions. In this case lanthanum may serve as a membrane structure modificator. This effect must be taken into account when the electron microscopists use the lanthanum label for studying specialized intercellular junctions.

Animals↗
PubMed1976

[Highly permeable contacts between epithelial cells in culture].

Cultured epithelial cells producing monolayered sheets were used to study intercellular contacts permeable to sodium fluorescein. Cells in dense cultures were more capable of forming permeable junctions than cells of sparse cultures. In addition, the standard microelectrode technique revealed some differences in cellular membrane potentials in dense and sparse cultures. A possible correlation is discussed between intercellular contact formation and other features of cells depending on cell culture density.

Cell Line↗
PubMed1976

[Cultivation of embryonic mouse liver epithelium].

Mouse embryo liver epithelial cells maintained in vitro were connected with each other by highly permeable cell-to-cell contacts, synthesized alpha-fetoprotein and possessed the property of contact inhibition of phagocytosis. Methods of cultivation of these cells are presented in this paper.

Animals↗
PubMed1975

The effect of non-ionic detergent tween 80 on colcemid-resistant transformed mouse cells in vitro.

The effect of the non-ionic detergent tween 80 on one colcemid-resistant and one sensitive subline of mouse L cells has been studied. The colcemid-resistant subline was also resistant to colchicine and Vinca alkaloids. Tween 80 at concentrations of 0.01% (v/v) or higher increased the sensitivity of drug-resistant cells to the antimitotic effect of colcemid, colchicine and vinblastine. Tween 80 also potentiated the initial rate and the maximal level of the (3-H)-cholchicine uptake by both sensitive and resistant cells. However, the detergent at concentrations of up to 1% had no effect on (3-H)-colchicine binding by cell homogenates. Thus it appears that the effects of tween 80 were due to an increase in cell membrane permeability to the drugs. The effect was completely reversible. The cells did not become adapted to the sensitizing action of tween 80 even after prolonged incubation in medium containing the detergent. A considerable increase in the permeability to the drug was obtained with doses of tween 80 which were non-toxic and which had no effect on cell proliferation, morphology and locomotion. The increase in membrane permeability caused by tween 80 at these concentrations was selective, the membrane permeability to ions and to (3-H)-2-deowy-D-glucose being, in fact, unchanged.

Animals↗
PubMed1975

[Electrical characteristics of normal and transformed fibroblasts in tissue culture].

The two-electrode method of input resistance measuring was shown to give lower values of resistance compared with the one-electrode balance method. Gradual growth of estimates of input resistance and membrane potential in the cause of experiment is associated with decrease in the shunting effect of the electrode puncture. The mean values of steady Rin of sparse and confluent culture did not differ when the cells were electrically disconnected (38 plus or minus 1.2 MO and 41 plus or minus 1.8 MO respectively) and differed in electrically coupled fibroblasts (54 plus or minus 4.9 MO --sparse; 29 plus or minus 2.2 MO -- confluent culture). This difference is thought to be associated with shunting effect of electrical connections. The specific resistance of membrane was estimated in normal and transformed fibroblasts.

Animals↗
PubMed1975

[Highly permeable intercellular junctions in normal and transformed fibroblast cultures].

Intercellular junctions permeable to ions and fluorescein Na were studied with the aid of intracellular microelectrodes in the cultures of normal and transformed mouse-embryo and hamster-embryo fibroblast-like cells. Normal cells were effectively coupled by the highly permeable junctions. In cultures of 7 types of transformed cells, 3 types of coupling were detected: effective, decreased, and fully reduced couplings. The degree of uncoupling was not correlated with morphological patterns of malignization and tumorogeneity of transformed cultures. The decrease of permeability of intercellular junctions to ions and small molecules is concluded not to be necessary for malignization.

Animals↗