[Effect of lipid hydroperoxides on the yield of chromosome aberrations in irradiated cells].

The combined effect of linoleic acid hydroperoxide and gamma-radiation on Ehrlich ascites tumor cells was not additive with regard to the formation of chromosome aberrations. When cells were preincubated in the presence of a subliminal hydroperoxide dose of 2.10(-5) M the number of aberrant cells increased after irradiation.

[Correlation of the membrane and genetic effects of lipid peroxidation].

Linoleic acid hydroperoxides delivered to Ehrlich ascites tumor cells in vitro in a concentration reaching a threshold one (approximately 10(-5) M) sharply decrease their ionic permeability and the value of membrane capacity. With suprathreshold hydroperoxide concentrations (greater than 10(-5) M), the specific yield of chromosome aberrations and the share of aberrant cells increase while the mitotic index decreases. The correlation between general regularities and the equality of the threshold concentrations, with a reference to membrane and genetic effects of hydroperoxides, is thought to be an indication of a close relationship between membrane lesions caused by the development of induced lipid peroxidation and injury to genetic apparatus of the cell.

[Damage of cell membranes by linoleic acid hydroperoxide].

It has been shown on Ehrlich ascite carcinoma cells that under the effect of linoleic acid hydroperoxides in vitro ionic permeability and membrane capacity of the cells sharply decrease after some threshold concentration of hydroperoxides (greater than 10(-5) M), while the threshold value decreases with the increase of the time of cell incubation in the presence of hydroperoxides. Interrelationship between the development of induced POL processes in the cell membranes and disturbance of their functional-structural state in the living cell is discussed.

[Relation of K+-dependent cellular swelling to the state of cellular membranes].

It has been shown that after heating of ACE cells for 15 min at temperature 46 degrees C inhibition of K+-dependent swelling and a sharp decrease of cell resistance and capacity are observed. Changes of the parameters studied were of a threshold pattern, the threshold temperature proved to be uniform and equaled 46 degrees C. It is believed that the temperature relationships obtained point to an important role of barrier functions of cellular membranes in K+-dependent cell swelling.

[Dose relationship of the electric conductivity of liver cells at early periods after gamma-radiation].

The dependence of electroconductivity and electric capacity of isolated liver cells, irradiated in vitro, upon radiation dose (within 100 Gy) was described by an extreme curve characterized by the presence of a "critical" dose (25 Gy) at which the effect was maximum. The kinetics of changes in the electric parameters, which were measured at early times following irradiation (up to 4 h), has an opposite direction. The possibility is discussed that peroxidation and repair processes in membrane lipids are involved in the effects observed.