[Influence of the characteristics of lipids on the regulation of biochemical processes in animal liver and blood].

It has been established experimentally that the character and the scale of interrelations between various parameters of the phospholipid composition and their group-average values depend significantly on the characteristics of lipids (the antioxidative activity, quantity of peroxides, and antiperoxide activity) of animal liver and blood erythrocytes. It was shown that a single injection of low-toxicity Tween 80 and acetone at low doses modifies the intensity of lipid peroxidation in the liver and changes the physicochemical properties of lipids, and the interrelations between the parameters that are coordinated in norm, thereby causing the disturbance of biochemical functions of the liver.

[Modifying properties of 2,5-diphenyloxazole during low-dose X-ray exposure of mice].

The ability of 2,5-diphenyloxazole (DPO) to modify biological consequences of the X-rays irradiation of mice was studied with a dose of 16 cGy at the administration of the agent in a wide range of concentrations before or after irradiation was studied. It was shown that the administration of the agent in doses 9.9 x 10(-3)-9.8 mg/kg 35-60 min before irradiation causes a reliable decrease in the spleen mass within 1 month after the action; for the dose 1 mg/kg, it causes the tendency to decrease of the content of lipid peroxidation (LPO) products; the dose 9.8 mg/kg causes a decrease in the cell-free DNA amount in blood plasma of mice. The administration of DPO before irradiation causes changes in the scale and direction of the correlation between the DNA and LPO products contents in blood plasma of irradiated mice compared with the control. The administration of DPO 15-60 min after irradiation do not cause any reliable changes in the investigated parameters. The aviability of the study of the radioprotective properties of the DPO derivatives as agents with a nontraditional character of action is supposed.

[A new approach to assessment of biological consequences of exposure to low-dose radiation]. / Novye podkhody k otsenke biologicheskikh posledstvii vozdeistviia radiatsii v malykh dozakh.

A high sensitivity of characteristics of the lipid metabolism in erythrocytes to exposure to low doses of gamma- and X-rays was found; the changes in lipid peroxidation (LPO) of blood components were persistent, which substantially influenced the development of biological consequences of low doses of radiation. The effect of low doses of radiation on the interrelation between the LPO intensity in blood plasma and the lymphocyte DNA structural integrity or the cell-free DNA content in animal blood plasma was found. Different sensitivity of the examined parameters (neither normalization nor linear dependence on a dose rate was found) implies the transition of the LPO regulatory system to another level of functioning due to scale changes of interrelations between the examined parameters under influence of low doses of radiation. These findings make possible to assess biological consequences of radiation factor for animal groups by the scale changes of interrelations between the examined characteristics in blood plasma.

[Influence of the antioxidant status on the characteristics of lipids in tissues of animals after acute irradiation with sublethal doses]. / Vliianie antioksidantnogo statusa na kharakteristiki lipidov v tkaniakh zhivotnykh posle ostrogo oblucheniia v subletal'nykh dozakh.

The effect of the acute exposure to sublethal doses of X-rays on the interrelation between parameters of the lipid peroxidation regulatory system (lipid antioxidative activity, AOA; peroxide amount, lipid composition) was studied in liver, spleen and blood erythrocytes of CBA and SHK mice and rats within 1 month after irradiation. The reverse correlation between the lipid AOA values and the initial peroxide amount in lipids of the CBA mice spleen was found. The coefficient of the linear regression of this correlation for the exposed mice was 1.8-fold higher as compared with control. The correlative dependence between the ratio of the sums of the more readily to more poorly oxidizable phospholipid and the ratio of phosphatidyl choline to phosphatidyl ethanolamine content in phospholipids of liver and blood erythrocytes was revealed. The direction (the phospholipids of the rat liver) or the value of the linear regression coefficient of that correlation were different for groups of the exposed and control animals, especially in the blood erythrocytes. Thus, the different sensitivity of examined characteristics of lipids and the possibility of their normalization in the dependence on the lipid AOA value cause the conversion of the lipid peroxidation regulatory system in organs and blood erythrocytes of the exposed animals to the other scale of the functioning.

[The role of antioxidative status in development of the consequences of biological action under low dose and low intensity irradiation]. / Rol' antioksidantnogo statusa v formirovanii posledstvii biologicheskogo deistviia nizkointensivnogo izlucheniia v maloi doze.

The scale and direction of changes of a number of biophysical, biochemical and physiological parameters in SHK mice (male) tissues were studied depending on their initial values for mice control groups within 1 day after low intensity gamma-irradiation (15 cGy). The reciprocal dependences between the scales of the lipid antioxidative activity (AOA) in brain or the spleen mass changes and their values for mice control groups were found. The external dependences were revealed between the amounts of lipid peroxidation secondary products in spleen, liver and blood plasma of the control mice and a scale of their change after irradiation. The most substantial changes of this parameter were observed in blood plasma and the changes of the phospholipid content within the total lipid composition were found in spleen and blood erythrocytes of the irradiated mice, that is in the lipids of tissues, which had the lowest level of AOA for mice control groups. The experimental data obtained indicate that the initial antioxidant status of animal tissues plays the important role for the development of consequences of the biological action under low dose and low intensity irradiation.

[Radioprotective properties of phenoxane during low intensity low dose gamma irradiation]. / Protivoluchevye svoistva fenoksana pri nizkointensivnom gamma-obluchenii v maloi doze.

The effect of prophylactic and therapeutic administration of phenoxane on the parameters of lipid peroxidation (LPO) regulatory system in murine tissues under low intensity gamma-irradiation (15 cGy) over a wide range of the agent doses is studied in dynamics. The different pattern of the phenoxane effect depending on its dose as well as the time of administration (before or after irradiation) is revealed with physiological tests (the dynamics of leucocyte amount, the blood formula, the change in spleen mass per mouse), on biochemical level (the changes in the LPO products content in murine blood and tissues), in biophysical properties (the lipid antioxidant activity level, the rate of oxygen consumption under the initiated oxidation of ethylbenzene in the presence of lipids from the intact and experimental murine organs) and also by the analysis of variability of the biochemical and biophysical properties in tissues and blood leucocytic formula within groups of mice.