PubMed Health⌕ Search

Biomedical subjects

A V Alesenko

Publications and source records attributed to A V Alesenko.

At least 37 records · Page 2Linked to original sources
PubMed1981

[Changes in superoxide dismutase and glutathione peroxidase activities during the process of intensification of lipid peroxidation in hepatic ischemia].

A study was made of changes in the activity of superoxide dismutase and glutathione peroxidase, in the level of the antioxidant activity and lipid peroxides during development of liver ischemia. It was shown that the intensification of peroxidation in ischemia is determined by the impairment of the systems maintaining the constant low level of peroxide reactions in an intact cells. The level of antioxidants, glutathione peroxidase and superoxide dismutase drastically falls in liver ischemia.

Animals↗
PubMed1980

[Intensification of peroxidation and changes in lipid composition in ischemic liver homogenates and subcellular fractions].

Lipid peroxidation (hydroperoxides and antioxidant activity) and lipid composition in liver homogenates and in its mitochondrial, microsomal and nuclear fractions were studied after 15--120 minutes of liver warm ischemia. Pronounced enhancement of lipid peroxidation during ischemia was seen in all subcellular fractions, particularly in the mitochondrial one. The results are consistent with low resistance of the liver and specifically its mitochondria to ischemia. Activation of lipid peroxidation corresponded with changes in the lipid composition. Decrease in the level of total and readily oxidizable lipids (cardiolipin) and accumulation of poorly oxidizable phospholipids (sphingomyelin) and highly toxic lysophosphatides were recorded. The evidence obtained suggests a role for lipid peroxidation in the pathogenesis of ischemic injuries to the liver.

Animals↗
PubMed1978

[Stimulation of nuclear membrane components and DNA biosynthesis in rat liver cells after inhibition of translation with cycloheximide].

After a drastic inhibition of protein synthesis (95%) in rat liver by cycloheximide (0.2-0.4 mg/100 g of body weight) the recovery and subsequently prolonged marked stimulation of proteins, lipids and DNA were found. The correlation of nuclear membrane proteins and lipids synthesis was observed in a recovery and stimulation phases. Nuclear DNA synthesis increases after the stimulation biosynthesis of nuclear membrane components (36-40 hours after cycloheximide injection). The changes of a phospholipid composition and structure organisation of nuclear membrane hydrophobic zones (by spin probe) were found in stimulated DNA synthesis (48-60 hours).

Animals↗
PubMedDate not supplied

[Changes in the activity of neutral and acidic isoforms of sphingomyelinase in hepatoma-22, regenerating and ischemic liver].

Activity of neutral and acidic sphingomyelinases (N- and A-SMases) were studied in regenerating liver after partial hepatectomy (during 48 hrs after operation), in ischemic liver during 15, 30 min and 1 and 2 hrs ischemia and during following reperfusion (from 5 min up to 2 hrs), in hepatoma- 22 after 15 days of transplantation and in liver of tumor bearing animals. It was shown that activity of N-SMase is increased in hepatoma-22 and in regenerating liver and it is decreased in ischemic liver. Following reperfusion of ischemic liver area activity of enzyme was found to have returned to baseline in dependence on time of ischemia and reperfusion. Activity of A-SMase is decreased in tumor, is not changed in regenerating liver and increased after long time of ischemia. It was supposed that N-SMase is involved in cell proliferation, but A-SMase is connected with cell damage.

Animals↗
PubMedDate not supplied

[Changes in sphingomyelinase activity, tumor necrosis factor alpha level, and lipid peroxidation rate in the course of development of cholestatic liver injury].

Changes in sphingomyelinase activity, tumor necrosis factor alpha expression, and lipid peroxidation rate in the course of development of cholestatic liver injury have been studied. The same type phase shifts in the parameters analyzed were observed, which included a marked decrease at the early stages of cholestasis (days 3-6) and a pronounced increase at the later stages (days 12-16), i.e., under the conditions of developed pathology. There is a significant positive linear correlation between tumor necrosis factor alpha expression, sphingomyelinase activity, and lipid peroxidation rate during cholestatic injury. The changes detected may reflect balance between the effects of the two major bile components--bilirubin, which is accumulated in the liver at the early stages of cholestasis, and bile acids, whose influence dominates at the later stages of pathologic process. Our results indicate that tumor necrosis factor alpha overexpression, the sphingomyelin cycle activation, and lipid peroxidation intensification may cause apoptosis of hepatocytes at the late stages of cholestasis.

Animals↗
PubMedDate not supplied

[Expression of oncogenes in the rat liver under conditions of template biosynthesis uncoupling by sublethal doses of cycloheximide].

Injection of sublethal doses of cycloheximide (CHI) to rats allowed to reveal three stages in the dynamics of protein synthesis: 1) suppression stage (0-6 hrs), 2) regeneration stage (6-12 hrs), 3) stimulation stage (6-12 hrs). RNA-polymerases are activated when protein synthesis is inhibited. The stimulation stage precedes the activation of DNA replication. This model of DNA replication induced by CHI is specified by the expression of various cell oncogenes (c-fos, c-mys, p53, c-Ha-ras, c-sis, c-src). The investigated oncogenes may be divided into 4 groups according to the character of their expression. 1. Oncogenes (c-fos, c-myc) are switched on step-by-step 1 hour after CHI injection, the superexpression of the oncogenes being comparatively short. Maximum expression of c-fos and c-myc oncogenes is registered after 2-3 hours, respectively. 2./p53 oncogene expression increases within a few hours' after CHI injection and manifests itself at all three stages of protein synthesis till DNA replication. 3. c-Ha-ras oncogene is expressed at a high level in control and experimental animals. 4. Expression of c-sis and c-src oncogenes are absent both before and after CHI injection. Sublethal doses of CHI have the same effect on oncogene expression as the lethal ones.

Animals↗
PubMedDate not supplied

[Relation between the increase in the anti-oxidative activity of lipids and the activity of the blood coagulation system].

Relationship between alterations in the state of lipid antioxidative activity (AOA) and the patterns of blood coagulation system (content of fibrinogen, the rate of fibrinolytic activity and the period of blood coagulation) were studied after administration of a synthetic antioxidant ionol into animals and after partial hepatectomy and with Ehrlich ascites hepatoma. An increase in the lipid AOA in animal tissues correlated with a decrease in fibrinolytic activity and in the blood coagulation period. Concentration of fibrinogen was decreased similarly after hepatectomy and after the antioxidant administration. In the course of development of Ehrlich ascites hepatoma concentration of fibrinogen was increased. Interrelationship found between the alterations in lipid AOA and the patterns of blood coagulation as well as distinct impairment of these relations during malignant growth confirmed high importance of alterations in the rate of oxidative reactions for the processes of blood coagulation.

Animals↗