MORPHOLOGICAL CHANGES IN MICE LIVER IN DYNAMICS OF CONCANAVALIN A - INDUCED HEPATITIS.

The injure of the liver tissue and its infiltration by cells of the innate and adaptive immunity in dynamics of Con A-induced hepatitis in mice was studied. The semiquantitative method of damage rate of microcirculation channel and liver parenchyma was used, leukocyte liver infiltration and cellular composition of infiltrates were investigated also. Primary liver reaction to the Con-A was the inflammatory changes in the vascular bed, followed by disturbances in the parenchyma.The sufficient increasing of leukocyte migration to the liver was revealed. Besides, the neutrophile infiltration was increased first with a maximum at 6 hours of the experiment (63,9 ±4,6%, p<0,001 to the control level) ,and then the lymphocyte infiltration was increased with creation of manycellular lymphocytemacrophage infiltrates (62% at 48 hours comparing to 6 hours of experiment) and sufficient quantity of plasma cells population (4,9%, p<0,05 comparing to 6 hours of experiment). The obtained data gives the base to suggest that the elevated infiltration of liver tissue by leukocytes, particularly by lymphocytes and monocytes, together with necrotic death increasing creats the conditions for effective intracellular interaction and immune response to autoantigenes. This can be the essential pathogenic mechanism of development of autoimmune liver deseases.

[Genotoxic stress and the pathways of thymus cell death and lymph nodes of mice in conditions of immunocomplex pathology].

There were performed the studies of genotoxic stress and the ways of immunocompetent cells death (apoptosis and necrosis) in the modeling of immune system damage by immunization of CBA mice with the bovine serum albumin. Immunofluorescence studies of immunized mice were established the fixation of immune complexes in liver tissue, spleen, kidney and the aorta. Histological studies of these organs showed vascular system affection and, to a lesser extent, parenchyma. It has been shown that DNA comets index increases in 1,4 time in the lymph node cells and in 1,5 time in the thymus cells in the presence of BSA immunization. We also observed an increase in the number of cells with maximum damage DNA thymus preparations (3.4 fold) and lymph nodes (3.3-fold), respectively, indicating strong genotoxic stress. There were shown the reduce of live ICC number and their death increase, including the pro-inflammatory and immunogenic necrotic way. In that way, data which were obtained on the experimental model is evidenced that generalized immunecomplex pathologic process leads to DNA damage and ICC death both central and peripheral organs of the immune system. ICC genotoxic stress and their death amplification by the necrotic way may play a significant role in the immunecomplex deseases development. These factors of peripheral blood lymphocytes can serve as a prospective test system for assessing the severity of autoimmune and immune complex diseases and their treatment effectiveness.

[Poly(ADP-ribose) polymerase (PARP): physiological and pathological roles].

PARPs are a large family of 18 enzymes found in most eukaryotes. PARP-1, the most abundant isoform, is activated by DNA breaks and catalyzes the post-translational modification of proteins. It forms polymers ofADP-ribose and attaches them to acceptor proteins, including histones, DNA repair proteins, transcription factors. PARP-1 is a key enzyme involved in a maintenance of genomic stability. Excessive activation of the enzyme has been shown to contribute to tissue injury and inflammatory disorders. PARP is a key mediator of cell death in oxidative stress, ischemia and DNA damage. It also promotes the activation ofproinflammatory gene expression. Inhibition of PARP-1 provides significant protection in animal models of cardiovascular, autoimmune and inflammatory diseases. PARP inhibitors have shown antitumor activity because they compromise ability of cancer cells to repair DNA. PARP-1 is a promising therapeutic target.

Effects of NF-κB blocker curcumin on oogenesis and immunocompetent organ cells in immune ovarian injury in mice.

Immunization of CBA mice with extracts from the ovaries of outbred albino mouse led to disorders in meiotic maturation of oocytes, enhanced death of immunocompetent cells in the thymus, spleen, and lymph nodes mainly by necrosis, and promoted the development of inflammatory reaction, as was shown by complete blood count. Treatment with activation inhibitor NF-κB curcumin against the background of immunization significantly reduced disorders in meiotic maturation of oocytes, decreased the number of cells dying by necrosis in immunocompetent organs, and attenuated the inflammatory reaction.

Effects of exogenous leukotrienes B4 and C4 on the viability of cultured rat hepatocytes.

Leukotrienes (LTs) are thought to be extensively involved in a liver damage in vivo through different mechanisms. In this study we used different doses (10(-7)-10(-12) M) of the dehydroxilated LTB4 and the cysteinyl LTC4 to estimate their direct injurious effects on cultured rat hepatocytes (HC). Our experiments demonstrated that exogenous LTB4 and LTC4 caused a rapid and transient increase in alanine aminotransferase release from HC and a slight, but significant decrease of mitochondrial electron transport chain activity in HC. Significant increases in ALT release were observed with LTs doses as low as 10(-12) M, but the loss of mitochondrial function was significant only at the two higher doses (10(-7) and 10(-8) M). HC were treated with the lipoxygenase inhibitor nordihydroguaiaretic acid (NDGA) to inhibit the possible synthesis of endogenous LTs. The effects of exogenous LTB4 and LTC4 on NDGA-treated HC tended to be similar to those indicated in the absence of inhibitor, but were more pronounced. These data suggest that LTs may be involved in the direct damage of liver cells under pathological conditions associated with enhanced LTs formation.

Effects of nordihydroguaiaretic acid and indomethacin on the viability and functional activities of normal and carbon tetrachioride-injured rat hepatocytes cultured alone and with Kupffer cells.

In order to study the contribution of eicosanoids to the regulation of the functions of normal and carbon tetrachloride (CCl4)-injured liver cells, primary cultures of hepatocytes (HC) either alone or in coculture with Kupffer cells (KC) were exposed for 4 and 24 h to lipoxygenase inhibitor (nordihydroguaiaretic acid-NDGA) or cyclooxygenase inhibitor (indomethacin-IND) in the presence and in the absence of CCl4. Treatment with CCl4 resulted in increased ALT release and a decreased mitochondrial respiration (MR) in HC and their cocultures with KC. The addition of NDGA decreased ALT levels and increased MR in control and CCL4-injured cells. Urea production (UP) was not significantly affected by NDGA. In contrast, addition of IND) decreased UP by HC (4 h), and did not alter ALT release and MR in control and CCl4-treated cells. These results indicate that arachidonic acid metabolites are involved in the regulation of HC flinctions. There is also evidence that a protective action of lipoxygenase inhibitors on CCl4-injured liver is mediated, at least partly, by their direct effects on HC and KC, in particular by increasing the mitochondrial respiration.

Effects of carbontetrachloride and chenodeoxycholic acid on hepatic monooxygenase system, lipid peroxidation and some immunologic parameters in rats.

The effect of chenodeoxycholic acid on liver monooxygenase system, lipid peroxidation, lymphocyte proliferation, and immune complexes formation was studied in carbontetrachloride-treated rats. Chenodeoxycholic acid increased the content of both cytochrome P-450 and cytochrome b5 and the rate of aminopyrine N-demethylation in liver microsomal fractions. It also normalized lipid peroxidation in the liver and the proliferative activity of blood lymphocytes activated by phytohemagglutinin. Soon after injection chenodeoxycholic acid caused disturbances of the liver histostructure and of the microcirculation followed by regenerative processes. Liver histostructure tended to return to normal. The level of serum immune complexes was increased. The relationship between the changes in monooxygenase system, lipid peroxidation and immunologic parameters is discussed.

[The effect of chenophalk on the liver function of intact animals and in experimental hepatitis]. / Vliianie khenofal'ka na sostoianie pecheni u intaktnykh zhivotnykh i pri éksperimental'nom gepatite.

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.

Xenogeneic antibodies against hepatocyte plasma membranes suppress bile secretion in rats.

The action of xenogeneic antibodies against rat hepatocyte plasma membranes which were injected into the portal vein in the dose of 40 mg of protein per kg of body mass on the bile secretion and on the ultrastructure of the liver were studied. It was shown that these antibodies suppressed the bile flow, the secretion of bile acids and cholesterol and decreased the bile salt-independent bile flow. The action of antibodies was accompanied by ultrastructural damage of sinusoidal and lateral plasma membranes of some hepatocytes and by a decrease in the Na+, K(+)-ATPase activity. It was concluded that the decrease of Na+, K(+)-ATPase activity in the plasma membranes was the most important mechanism responsible for a decrease in the bile flow.

[Oxygen-dependent processes in the liver and immunologic reactivity of rats in chronic liver damage induced by carbon tetrachloride]. / Kislorodzavisimye protsessy v pecheni i immunologicheskaia reaktivnost organizma krys pri khronicheskom porazhenii pecheni chetyrkhkhloristymuglerodom.

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.

[Analysis of hepatocyte cell membrane antigens in regenerating rat liver]. / Analiz antigenov plazmaticheskikh membran gepatotsitov regeneriruiushchei pecheni krys.

Antigens of plasma membranes in hepatocytes from regenerating rat liver were studied. Immunochemical investigation with polyvalent rabbits antiserum against plasma membrane proteins in hepatocytes from regenerating and normal rat liver have shown that liver regeneration processes are accompanied by the increase of proteins number with molecular weight of--80 kDa, 62 kDa, 40 kDa and 27 kDa. It is not excluded that protein with molecular weight of 27 kDa is the tissue-specific peripheral protein. The influence of antibodies against proteins of hepatocytes plasmatic membranes on histostructure of pathologically changed liver tissue has been studied. The data obtained testify to a possibility of participation of the above mentioned proteins in the regulation of rat liver regeneration processes.

[Possibility of directed changes in the surface activity of rat pulmonary surfactants by means of exposure to antibodies specific to them]. / Vozmozhnost' napravlennykh izmenenii poverkhnostnoi aktivnosti surfaktantov legkogo krys putem vozdeistviia spetsificheskimi k nim antitelami.

The experiments were performed on Wistar rats with weight of 150-200 g. Antibodies were prepared by immunization of rabbits with pure surfactants of rat lungs and were intravenously injected into rats three times within 3 days intervals. These antibodies were shown to influence the superficial activity of lung surfactants and the alveolar lung cells activity. The low doses of antibodies (0.06 micrograms of protein per 100 g of body mass) stimulated the superficial activity of lung surfactants, while higher doses (3 mg of protein per 100 g of body mass) inhibited it.

[An electron microscopic study of the structure of the rat liver under the action of antimembrane antibodies]. / Elektronno-mikroskopicheskoe izuchenie struktury pecheni krys pri deistvii antimembrannykh antitel.

Introduction of heteroantibodies (4 mg/100 g) to plasma membranes of hepatocytes into portal vein of the rat liver caused (already within 5 min) changes in the liver ultrastructure with their intensification by the 30th min. Specificity of the action of antimembrane antibodies (Am) was revealed as against the action of antibodies to summary antigens (As) of the liver. It is shown that Am change, mainly, sinusoidal and lateral regions of the hepatocyte membrane, not disturbing essentially structure of its cytoplasma, intracellular organelles and biliary canaliculi, endotheliocytes and stellate reticuloendotheliocytes, that is observed while introducing As to the liver. Membrane tracer--colloidal lanthanum has revealed that Am increases permeability of hepatocyte plasmalemma to a less degree than As of the liver.