[Catalase and glutathione-peroxidase: qualitatively different correlations with the rate of oxygen consumption]. / Katalaza i glutationperokxidaza: kachestvenno razlichnaia korreliatsiia so skorost'iu potrebleniia kisloroda.

Correlative relations of the liver supernatant enzymatic activity of catalase (CAT) and glutathione-peroxidase (GP) with the velocities of oxygen consumption (VO2) and carbon dioxide exhalation (VCO2) were analyzed by the two- and three-dimensional linear and non-linear statistical methods in mice. It is shown that despite the close functions, CAT and GP, nevertheless, exhibit opposite correlative and regressive links with the gaseous exchange indices. As was found by the pairwise linear method, the activity correlation with VO2 was positive for CAT, but negative for GP. The opposite patterns of correlation were also apparent under the three-dimensional non-linear analysis.

[Correlative links between superoxide dismutase, catalase and glutathione peroxidase activities in mouse liver]. / Korreliativnye sviazi mezhdu aktivnost'iu superoksiddismutazy, katalazy i glutationperoksidazy pecheni myshei.

Qualitative and quantitative differences in correlative and regressive links between superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase were assessed in the mice liver by two- and three-dimensional statistical methods. Paired linear correlation analysis indicated SOD-CAT tandem as the correlatively acting enzymatic pair. Three-dimensional analysis revealed uniform response surfaces which exhibited higher activities at disproportional values of the other two and lower activities at proportional activities of the other two enzymes. The direct effect of the enzymes on each other was positive [table: see text] while the effect of their product was always negative.

[Molecular and cellular aspects of radiation hormesis in Drosophila melanogaster]. / Molekuliarnye i kletochnye aspekty radiatsionnogo gormezisa u Drosophila melanogaster.

The long-term effects of the R-irradiation of D. melanogaster at the 1-hour egg stage with the dosages of 0.25, 0.50, 0.75, 1.0, 2.0 and 4.0 Gy were investigated. DNA samples were isolated from whole 5-6-days adult males. The aliquots of DNA were digested by S1-nuclease. Preimaginal stage lethality increased with irradiation dose increasing. At the same time, decrease in imaginal LS (life span) was observed after irradiation with the greatest dose (4 Gy) only. Moreover, hormesis by LS has revealed: in males irradiation with 0.25, 0.75 and 1 Gy increased the mean LS, and with 0.25 and 0.5 Gy caused the maximum LS; in females exposures with 0.25, 0.75 and 2 Gy increased the maximum LS. The densitometric assay of DNA electrophoregrams showed decrease by 39.2% of the part of high-molecular-weight DNA in control as a result of S1-nuclease action. Samples of DNA from the irradiated flies were more stable to enzyme action. The higher stability of DNA originated from the irradiated flies could be the result of reparation system activation. Ultrastructural changes induced at the egg stage by irradiation at the dose of 0.75 Gy testify the increased transcriptional activity of the brain cells.

[The vasoactive properties of different classes of blood lipoproteins in hypercholesterolemia and atherosclerosis]. / Vazoaktivnye svoistva raznykh klassov lipoproteinov krovi pri giperkholesterinemii i ateroskleroze.

Studies were made of the effects of various classes of lipoproteins (LP) from the blood of rabbits with experimental hypercholesterolemia and human subjects with pronounced atherosclerosis on the vascular tone of rat thoracic aorta specimens. In hypercholesterolemia, there was a considerable weakening of a vasodilatory action of atherogenic LP fractions--LDL and VLDL. A vasodilatory effect of HDLP was not changed. In subjects suffering from atherosclerosis vasodilatory effects of both atherogenic and antiatherogenic HDLP decreased significantly. The revealed changes were related to shifts in lipid and protein components of LP complexes manifesting in the development of dyslipoproteinemia and dysapoproteinemia. In atherosclerosis accompanied with more profound changes suppression of vasodilatory effects of LP is greater than in transient experimental hypercholesterolemia. Consequently, changes of lipid and apo composition of LP and weakening of their vasodilatory action play a considerable role in the vessel tone changes in atherogenic situation.

[The cytofluorimetric analysis of the nuclei in the regenerating rat liver in the late periods after x-ray irradiation]. / Tsitofliuorimetricheskii analiz iader regeneriruiushchei pecheni krys v otdalennye sroki posle rentgenovskogo oblucheniia.

The flow cytofluorimetric method allowed to show that intact liver nucleus population of adult (6 months) rats consists of discrete ploidy classes (2c, 4c, 8c and 16c+), from which the diploid class was approximately a half of the total nuclei. Thirty days after the wholebody X-ray irradiation with a dose of 2 Gy, the percentage frequency of each nuclear class was statistically unchanged. However, the polyploidization level of the total nuclear population increased. Partial hepatectomy induces an entering into mitotic cycle (maximum S-phase; 22 h after operation) of the most of the hepatocyte nuclei in both irradiated and unirradiated animals. With that the relative number of nuclei in S-phase decreases in geometric progression according to increasing of ploidy class. In regenerating liver of irradiated rats in comparison with that of unirradiated ones, the greater part of nuclei enters into the mitotic cycle at the expense of di- and especially tetraploid nuclei.

Effect of implantation of human apoAI gene on apoprotein composition and vasoactive properties of high-density lipoproteins in rats at different ages.

Transfer of human apoAI gene, within the molecular construction which provides its expression, to the liver of adult and aged rats resulted in the appearance of human protein in their blood, and was accompanied by changes in the content of high-density lipoproteins, as well as by the shifts in their protein and lipid composition. Administration of the human ApoAI gene was followed by changes of the vasoactive effects of HDL. Gene implantation is capable of enhancing the direct vasodilatory effects of HDL in old animals, being weakened by ageing, even against the background of normal age changes in the vascular wall tone.

Blood lipoproteins and their effect on contractile function of vessels in rats of different age.

Experiments on adult and old rats have shown that blood lipoproteins (LP) exert a dilatatory effect on isolated-segments of the thoracic aorta in animals of different age. In old versus adult animals, the sensitivity of vessels in all LP fractions (LDL, VLDL and HDL (low, very low and high density LP)) was lower as a result of age changes in the reactivity of vessels. The capacity of HDL to produce a vasodilatory effect decrease with age, which may be linked to changes in the lipid and apolipoprotein composition. The results revealed a decrease in the level of phospholipids and an increase in the amount of total cholesterol in HDL observed in old age. The capacities of LDL and VLDL to exert a vascular dilatatory action remained unchanged with age.