[Effect of vitamin D2 on the monooxygenase activity of the rat liver]. / Vliianie vitamina D2 na aktivnost' monooksigenaz pecheni krys.

Stimulation of lipid peroxidation in the liver microsomal fraction and alteration in the xenobiotic metabolism were found within twelve hrs after a single vitamin D2 administration (960,000 MU/kg) into male rats. The effects observed appear to occur due to the vitamin D2 prooxidative properties.

[Stabilizing action of alpha-tocopherol in postischemic damage to the hydroxylating system of the endoplasmic reticulum membranes of the rat liver]. / Stabiliziruiushchee deistvie al'fa-tokoferola pri postishmicheskom povrezhdenii gidroksiliruiushchei sistemy membran éndoplazmaticheskogo retikuluma pecheni krys.

Administration of alpha-tocopherol (50 mg/kg) as an oily emulsion into male rat stomach every 12 hours 2 days before and 3 days after local disturbance in liver circulation prevents postischemia (72 hours after resumption of circulation) repression of amidopyrine-N-demethylation, aniline-hydroxylation, NADP H-neotetrazolium reductase, NADP H oxidase, a decrease in the cytochrome P-450 level, as well as intensification of ascorbate-dependent lipid peroxidation of hepatocyte endoplasmic reticulum membranes. The protective effect of alpha-tocopherol is suggested to be due to its antioxidative and membrane-stabilizing properties.

[Effect of alpha-tocopherol on the hydroxylating system and lipid peroxidation in membranes of endoplasmic reticulum from ischemic rat liver]. / Vliianie alpha-tokoferola na gidroksiliruiushchuiu sistemu i perekisnoe okislenie lipidov membran éndoplazmaticheskogo retikuluma ishemizirovannoi pecheni krys.

If 60 min long ischemia of a liver tissue lobe occurred after feeding of rats with oil emulsion of alpha-tocopherol at a dose of 50 mg/kg within 12 hrs during 2 days, the "ischemic" decrease in metabolism of amidopyrine and aniline, in content of cytochrome P-450 and activity of initial and middle steps of NADPH-dependent redox chain as well as intensification of ascorbate-dependent peroxidation of membrane lipids were prevented in endoplasmic reticulum of hepatocytes. The protective effect of alpha-tocopherol on these xenobiotics metabolism is apparently related to an increase in catalytic activity of cytochrome P-450, to the enzyme antioxidant and membrane-stabilizing properties.

[Enzyme activity of microsomal oxidation in ischemic and intact lobes of the rat liver after resumption of the liver blood circulation]. / Aktivnost' fermentov mikrosomal'nogo okisleniia v ishemizirovannykh i intaktnykh doliakh pecheni krys posle vozobnovleniia pechenochnogo krovoobrashcheniia.

Forty-minute lobular ischemia of the rat liver produces no considerable changes in the activity of the enzymes of the hydroxylation system of the hepatocyte endoplasmic reticulum. After resumption of circulation in the microsomes of ischemized and intact lobes of the liver the activity of hydroxylases appreciably decreases, reaching the minimum level by the 72nd hour of the postischemic period. During this time lipid peroxidation increases.

[Changes in the enzyme activity of the hydroxylating system of the rat liver endoplasmic reticulum in ischemia]. / Izmenenie aktivnosti fermentov gidroksiliruiushchei sistemy éndoplazaticheskogo retikuluma pecheni krys pri ishemii.

Local disturbance of liver circulation for 40 minutes did not lead to any substantial changes in the hydroxylation system of microsomes of the ischemized area. 60-, 120- and 180-minute circulation distress causes a progressing decrease in amidopyrine and aniline metabolism, diminution of the content of cytochrome P-450 in the microsomes, and of the activity of NADP.H-ferricytochrome-c-reductase, NADP.H-neotetrazolium-reductase and NADP.H-oxidase. After 120-minute ischemia hydrophobic properties of the microsomal membranes were found to be decreased.