[Isoenzymic spectrum of lactate dehydrogenase in rat liver and myocardium as affected by polychlorocamphene]. / Izofermentnyi spektr laktatdegidrogenazy v tkaniakh pecheni i miokarda krys pri deistvii polikhlorkamfena.

In rats, which were administered daily during four months polychlorocamphene, the lactate dehydrogenase activity rises in the myocardium independently of the method of the preparation application and in the liver it increases only with a simultaneous peroral and epicutaneous administration. Under the effect of the pesticide administered by all the methods the content of LDG5 decreases and that of LDC1 increases in the liver, in the myocardium the amount of LDG1 lowers and that of LDG3 and LDG4 rises.

[Succinate dehydrogenase and cytochrome oxidase activity in rat liver tissue under the influence of valexon]. / Suktsinatdegidrogenaznaia i tsitokhromoksidaznaia aktivnosti v tkani Pecheni krys pri deistvii valeksona.

The cytochrome oxidase and succinate dehydrogenase activities were studied in the liver supernatant fraction and homogenate of rats whom different amounts of valexon, organophosphoric pesticide with a hepatotoxic effect, were administered to. A significant increase in the enzymic activity in the supernatant fraction and the resulted rise in the value of the ratio of the activity in the supernatant fraction to that in the homogenate were found five days after a single administration of the preparation in a dose of 310 mg per 1 kg of body weight and after its three-month administration in a dose of 31 mg/kg. These changes may be believed to result from disturbances of the structural-functional state of the mitochondria due to penetration of valexon and its accumulation in them.

[Activity of NADPH-dependent monooxygenase hydroxylating system of rat liver under the effect of tetramethylthiuramdisulfide]. / Aktivnost' NADPH-zavisimoi monooksigenaznoi gidroksiliruiushchei sistemy pecheni krys pri vozdeistvii tetrametiltiuramdisul'fida.

Changes in the activity of a NADPH-dependent monooxygenase system of the rat liver are studied under the effect of tetramethylthiuramdisulphide. Under these conditions aniline hydroxylation is shown to be inhibited to a higher extent than amidopyrine demethylation. Besides a decrease in the level of cytochrome P-450, the central component of the microsomal system of hydroxylation, there appears cytochrome P-420--an inactivated form of cytochrome P-450.

[Activity of the indicator enzymes of liver subcellular structures with the prolonged administration of Valexon]. / Aktivnost' indikatornykh fermentov subkletochnykh struktur pecheni pri dlitel'nom vvedenii valeksona.

The free and unprecipitated activity of succindehydrogenase and glucose-6-phosphatase, as well as of that of glucose-6-phosphate-dehydrogenase in the rats liver was determined. The animals received for a long time (1--3 and 6 months) a new organophosphorus pesticide valexon (0.0-diethyl thiophosphoryl-oxyiminophenylnitryle acetate) by mouth in doses of 31 mg/kg and 3.1 mg/kg which corresponds to 1/20 and 1/200 LD50. The earliest changes (after 1 month) include: falling activity of hexokinase and a rise in that of glucose-6-phosphatase and succindehydrogenase, pointing to the damage of microsomes and mitochondria supervenes in 1 and 6 months time after introduction, respectively. The role of an early injury of microsomes and of disturbed first stages of glucose metabolism in the mechanism of the valexon action is suggested.