[State of the monooxygenase system of the rat liver during ontogenesis under the action of polychlorinated diphenyls]. / Sostoianie monooksigenaznoi sistemy pecheni krys v ontogeneze pri vozdeistvii polikhlorivovannykh difenilov.

Perinatal action of polychlorinated diphenyls on rat liver monooxygenase system in ontogenesis was studied. Significant modifications in the development of cytochrome P-450 system were noted.

[Liver lipid peroxidation in the ontogeny of rats during perinatal exposure to polychlorinated biphenyls]. / Izuchenie perekisnogo okisleniia lipidov pecheni v ontogeneze u krys pri perinatal'nom vozdeistvii polikhlorirovannymi difenilami.

We studied the activity of NADPH-cytochrome P-450 reductase, NADPH- and ascorbate-dependent systems of lipid peroxidation in liver microsomes, the activity of superoxide dismutase in the supernatant and the level of malonic acid dialdehyde in liver tissue of rats of various age. The activity of lipid peroxidation system and the malonic dialdehyde content in the early postnatal period increased to the adult level. The NADPH-cytochrome P-450 reductase activity increased during the first four months of animals life while that of superoxide dismutase increased until the animals were seven months old. A single administration of polychlorinated diphenyls at a dose of 500 mg/kg (1/10 LD50) to pregnant rats drastically stimulated and changed the pattern of the studied activities in their offspring. The role of lipid peroxidation in modification of microsomal membranes after the monooxygenase system induction by polychlorinated diphenyls in early ontogenesis is discussed.

[The effect of a lipid food component on enzymatic activity of rat liver endoplasmic reticulum upon the action of polychlorinated biphenyls]. / Izuchenie vliianiia lipidnogo komponenta pishchi na aktivnost' fermentov éndoplazmaticheskogo retikulum pechenia krys pri vozdelstvii polikhlorirovannykh difenilov.

The authors have studied the character of changes in the content of cytochrome P450 and b5, in the oxidation rate of amidopyrine, dimethyl-aniline and aniline, in the NADPH- and ascorbate-dependent lipid peroxidation systems, as well as in glucose-6-phosphatase and acetylesterase activities in the liver microsomes of the rats on semisynthetic diets, including 50% (according to calorific value) of butter or sunflower oil, or receiving fat-free diet (0.5% of sunflower oil) in different terms (4 and 70 days) after a single intragastric administration of a mixture of polychlorinated diphenyls, chlorinated biphenyl (500 mg/kg). It is shown that the degree and character of the microsomal enzymes studied, as well as the changes in the liver structure under the action of chlorinated biphenyl depend, to a certain extent, on the quality and quantity of fat in the diet.

[Reinduction of the cytochrome P-450 system of the liver in rats exposed to polychlorinated biphenyls during starvation]. / Reinduktsiia sistemy tsitokhroma P-450 pecheni krys pod deistviem polikhlorirovannykh difenilov pri golodanii.

Contents of cytochrome P-450 and b5, rates of oxidation of aniline, amidopyrine and dimethylaniline as well as activities of NADP-H- and ascorbate-dependent systems of lipid peroxidation (LPO) in rat liver microsomes five months after single administration of the mixture of polychlorinated diphenyls (PCD) significantly exceeded the control level. Starvation of the animals for 120 hours led to an additional increase of cytochrome P-450 content and LPO activation. The rat liver monooxygenase system retained the ability to respond to the inducing action of the mixture of PCD (500 mg/kg) during starvation.

[Monooxygenase system activity and rate of lipid peroxidation in rat liver microsomes in reinduction with polychlorinated biphenyls]. / Aktivnost' monooksigenaznoi sistemy i skorost' perekisnogo okisleniia lipidov v mikrosomakh pecheni krys pri reinduktsii poliklorirovannymi difenilami.

Single oral administration of sovol (mixture of polychlorinated diphenyls) caused a significant induction of the liver monooxygenase system (MOS) in rats. The inducing effect persisted for 5 months. Liver MOS responses were similar in repeated and primary sovol administrations. Differences in the morphological liver changes have been detected following single and repeated administrations of sovol.

[Effect of different doses of dichlorodiphenyl on the cytochrome P-450 level and lipid peroxidation rate in the rat liver]. / Izuchenie vliianiia razlichnykh doz dikhlordifenila na uroven' tsitokhroma P-450 i skorost' perekisnogo okisleniia lipidov v pecheni krys.

A single administration of increasing doses of dichlorodiphenyl (60-2400 mg/kg) leads to an increase in the content of cytochrome P-450 in rat liver. Initially, the increase rate is high whereupon, within the dose ranges of 800-1600 mg/kg, it does not virtually change, constituting 270-290%. A higher dose, 2400 mg/kg, produces an increase in the hemoprotein level only in individual animals. When given in cytochrome P-450-induction doses, dichlorodiphenyl has a stimulant action on the non-enzymatic system of lipid peroxidation in rat liver.

[Enzyme characteristics of the rat liver in ontogeny in chronic alcohol intoxication]. / Fermentnaia kharakteristika pecheni krys v ontogeneze pri khronicheskoi alkogol'noi intoksikatsii.

Chronic alcohol intoxication led to an increase in activity of alcohol dehydrogenase and to decrease -- of aldehyde dehydrogenase and the microsomal ethanol oxidizing system (MEOS) with simultaneous activation of cytochrome P-450 in liver tissue of rats during ontogenesis. Ethanol, which did not affect the enzymatic status of lysosomes within ontogenesis (alpha- and beta-glucosidases, alpha- and beta-galactosidases, alpha-mannosidase, beta-N-acetylglucosaminidase, beta-xylosidase, beta-glucuronidase, beta-N-acetyl galactosaminidase acid RNAase, arylsulfatases A and B, cathepsin D), activated the majority of hydrolases in both embryonal and postnatal periods of development. Distinct increase in lipoperoxidation was detected under conditions of chronic alcohol intoxication.