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L I Aleksiuk

Publications and source records attributed to L I Aleksiuk.

16 recordsLinked to original sources
PubMed2005

[The role of nitric oxide in the development of humoral immune response in mice].

The immune response in CBA mice was evoked by injection of sheep erythrocytes. The number of antibody-producing cells in the spleen, as well as nitric oxide production, oxygen-dependent metabolism and 5"-nucleotidase activity of peritoneal macrophages and lymphocytes were studied on days 1-5-14 after immunization. It was shown that during the inductive phase of the immune response (day 1), the peritoneal cells increased nitric oxide production, while later their functional activity increased and NO level became normal. The use of NO-synthase inhibitors (non-selective L-NNA and iNOS inhibitors SMT and dexamethasone) increased the immune response and decreased the macrophage functional activity. The use of NO-donator SNP resulted in reverse effect: decrease of the immune response and stimulation of peritoneal cells functional activity. The data obtained indicate that nitric oxide participates in the immune response regulation, in particular, through the suppressive effect of macrophages.

5'-Nucleotidase↗
PubMed2003

[Effect of inhibitors of cyclooxygenase and lypoxygenase pathway of metabolism of arachidonic acid on the development and suppression of the immune response in mice].

The influence of indomethacin (IM) and nordihydroguaiaretic acid (NDGA) as inhibitors of cyclooxygenase and lypoxygenase pathways of arachidonic acid metabolism, accordingly, on the development of the immune response (IR) to sheep red blood cells (SRBC), as well as on the formation and functional activity of the antigen-induced (by the tolerogenous dose of SRBC) T-suppressors (AITs) was studied. Investigation was carried out on mice of line CBA. The IR was estimated by quantity of antibody-forming cells in the mouse spleen. The functional activity of AITs was determined in the transfer adopting system by the intensity of IR suppression in mice--recipients. The data obtained have demonstrated, that both inhibitors mainly stimulated the IR which was more expressed at NDGA application and depended on a phase of the IR. The stimulation of the IR was related with a suppression of AITs and a decrease in their functional activity.

Animals↗
PubMed2002

[Exogenous L-arginine modulates mitochondrial and microsomal oxidation in acute and intermittent normobaric hypoxia].

It is known that protective effects of adaptation to intermittent hypoxia are mediated partly by stimulating of some mitochondrial and microsomal enzymes activity. Our objective was to investigate whether exogenous NO (L-arginine) or NO blocker (L-NNA) modulate mitochondrial and microsomal oxidation during acute hypoxia (AH) and intermittent hypoxic training (IHT). In control rats AH (inhalation of 7% O2, 30 min) provoked a decrease of ADP-stimulated liver mitochondrial respiration. However, the pattern of oxidation substrates was different from normoxic controls. In the presence of succinate, an increase of the Chance respiratory coefficient and the phosphorylation rate and a decrease of O2 uptake efficacy with simultaneous activation of aspartate aminotransferase activity were observed. Simultaneously, oxidation of a-ketoglutarate, an NAD-dependent substrate, was inhibited. IHT caused reorganization of mitochondrial energy metabolism favoring NAD-dependent oxidation and improving the protection against acute hypoxia. After 14 days of normobaric IHT (10% O2, 15-min sessions with 15 min rest intervals, 5 times daily), in comparison to controls acute hypoxic challenge in the presence of succinate resulted in an increase of the Chance respiratory coefficient, the ADP/O ratio and the phosphorylation rate, in activation of both aspartate and alanine aminotranferases, and in less lipid peroxidation. The microsomal oxidation was not changed under AH per se but significantly decreased (by 37%) during acute hypoxic test after ITH. These findings indicated a more efficient use of oxygen under hypoxic conditions after IHT pre-conditioning. The combination of IHT with L-arginine treatment (600 mg/kg intraperitoneally, daily before IHT sessions) provoked more pronounced decrease of tissue oxygen consumption and microsomal oxidative processes in comparison with IHT animals. L-arginine effects were abolished by the NO-synthase blocker L-NNA. We conclude that the combination of IHT with NO-donor treatment provokes a decrease in aerobic link of energy regulation thereby increasing the tolerance to episodes of acute hypoxia.

Adaptation, Physiological↗
PubMed2001

[Effect of inhibitors of cyclooxygenase and lipoxygenase pathways of arachidonic acid oxidation on the immune response and the activity of the monoxygenase system and lipid peroxidation in the spleen and liver in mice].

In experiments on CBA mice we studied an immune response (IR) to sheep red blood cells, the activity of monooxygenase system and lipid peroxidation (LP) in a spleen and a liver after administration of indomethacin (IND) and nordihydroguaiaretic acid (NDGA) as the inhibitors of cyclooxygenase and lypoxygenase pathways of oxydation of arachidonic acid consequently. We have found that the both inhibitors changed differently the intensity of IR during its development. IND and NDGA activate the accumulation of antibody-forming cells in the mouse spleen in a dose-dependent fashion at both the inductive and fading phases of IR. At the productive phase these changes are less expressed and they are different depending on the dose of NDGA: the smaller dose increases the immune response and the bigger one decreases it a bit. Changes in the activity of the monooxygenase system in spleen and liver, affected with the both inhibitors, independing on the dose, were of different direction: after IND administration the activity increased, but after NDGA administration it decreased at all the terms of investigation, excluding the term of the 5-th day (productive phase of IR). In these conditions changes in the activity of IR were of opposite direction as compared to the changes in the monooxygenase system.

Animals↗
PubMedDate not supplied

[The effect of antimembrane testicular antibodies on Na+, K(+)-ATPase activity in the testicles of rats of different ages].

The effect of large and small doses of rabbit antibodies specific to plasma membranes of the rat testicle cells has been studied in the experiments on Wistar rats of three age groups (preadolescent--aged 20 days, puberal--aged 5-7 months and old--aged 24-26 months). It is stated that incubation of plasma membranes by IgG fraction isolated from antimembrane testicular serum (IgG-ATCSm) in a large dose (43 g of protein G per 125 g of protein of membrane fraction) caused statistically reliable inhibition of Na+, K(+)-ATPase activity in the membranes of testicle cells of puberal and old rats. Preadolescent rats exhibit only a tendency to decrease the activity of this enzyme. Incubation of plasma membranes of testicle cells in rats of different age by small doses of IgG-ATCSm (0.43 g of protein G per 125 g of membrane protein) induced a statistically reliable increase of Na+, K(+)-ATPase activity in puberal and old animals and its slight increase in preadolescent rats. The IgG fraction isolated from normal rabbit serum (IgG-NRS) exerted a less pronounced effect on Na+, K(+)-ATPase activity parallel with retention of a tendency to a decrease of activity under the influence of large doses of the drug and to an increase with introduction of small doses.

Aging↗
PubMedDate not supplied

[Effect of antibodies specific to sarcolemma of cardiomyocytes in activity of 5-nucleotidase in rats].

Rabbit antibodies specific to sarcolemma of cardiomyocytes have been studied for their effect on activity of 5'-nucleotidase ecto-enzyme of the Wistar rat cardiomyocytes. It is shown that incubation of isolated plasma membranes of cardiomyocytes of rats (100 micrograms of protein) with the gamma-globulin fraction of antisarcolemmal cardial serum (gamma-ASCS, 20 micrograms protein) and with the gamma-globulin fraction of normal rabbit serum (gamma-NRS, 0.20 micrograms protein) promotes a decrease of the enzyme activity. An inhibiting effect was greatly pronounced in incubation with gamma-NRS and did not depend on the dose of antibodies and duration of their action. An assumption is made that inhibiting action of antibodies on activity of ecto-5'-nucleotidase may change adenosine concentration and may be one of elements in the mechanism promoting an increase of the intracellular calcium concentration.

5'-Nucleotidase↗
PubMedDate not supplied

[The effect of chenophalk on the liver function of intact animals and in experimental hepatitis].

Chenophalk (chenodeoxycholeic acid) was given to Wistar rats, including intact animals and those with chronic toxic hepatitis, in daily oral dose of 15 mg/kg body weight during 11 days. Chronic toxic hepatitis was induced by 7 subcutaneous injections of carbon tetrachloride (0.3 ml of 50% oil solution per kg body weight) each three days. Chenophalk was shown to impair bile crystallization. It enhanced demethylase activity, elevated the levels of cytochromes P-450 and b5 in the liver microsomal fraction, and decreased lipid peroxidation just after injection. The agent normalized oxygen tension in the liver tissue, which had been reduced by carbon tetrachloride. Chenophalk caused disturbances in the structure of the liver and in microcirculation early after injection, showing a tendency to normalize the histostructure of the liver.

Animals↗
PubMedDate not supplied

[Oxygen-dependent processes in the liver and immunologic reactivity of rats in chronic liver damage induced by carbon tetrachloride].

The chronic hepatitis in Wistar rats was induced by seven subcutaneous injections of carbon tetrachloride (0.3 ml of 50% oil solution per 1 kg of body mass) made each third day. It was shown that cytochromes P-450 and b5 content, demethylase activity in the liver microsomal fraction as well as the oxygen tension in the liver tissue were decreased, while lipid peroxidation was intensified. The PHA-induced blood lymphocyte blastogenesis was inhibited and concentration of circulating immune complexes in the blood was higher than that in intact animals.

Animals↗