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177 5′-Methylthioadenosine modulates the inflammatory response to bacterial lipopolysaccharide
58
Poster Sessions
of life was observed in 3/5 patients. LT in HIV-HCV coinfected patients is feasible and results in the short and medium term are good. Early and severe HCV recurrence occurred after LT.
175 ISCHEMIC PRECONDITIONING IMPROVES HEPATIC MICROCIRCULATION IN STEATOTIC LIVER AT THE LATE PHASE OF ISCHEMIA REPERFUSION INJURY
W. Yang, G.K. Glantzounis, M.C. Winslet, B.R. Davidson, A.M. Seifalian. University Department of Surgery, Royal Free and University College Medical School, Royal Free Hospital, London, UK Background/Aims: Impairment of hepatic microcirculation (HM) is a key event in the development of cell death during ischemia reperfusion injury (IRI). The present study investigated the effect of IPC on HM during late phase of IRI in steatotic liver. Methods: NZ female rabbits (3.0-3.5kg) were fed with high cholesterol (2%) diet for 8 weeks to induce moderate hepatic steatosis. Animals were subjected to 60 min liver lobar ischaemia followed by 7 hours of reperfusion with (IPC, n=6) or without IPC (IR, n=6). Control animals (n=5) underwent sham operation. Mean arterial pressure, oxygen saturation, heart rate and portal flow were monitored. HM was assessed by laser Doppler flowmeter. At the end of the reperfusion, indocyanine green (ICG, 0.5mg/kg) was administered intravenously and its uptake and clearance in the liver was measured directly by near infrared spectroscopy. Results: All animals with high cholesterol diet developed moderate steatosis. HM in IR group was significantly deteriorated at the end of reperfusion as compared with sham. HM in IPC group was significantly better than IR group at 7th hours of reperfusion (73.3 ± 3.3 vs.118.3 ± 16.2 flux unit, mean ±SEM, P=0.02, unpaired Student t test). AST and ALT levels were significantly lower in IPC group. ICG clearance was better in IPC as compared with IR group but the difference were not statistically significant (57.8 ± 13.5% vs. 44.4 ± 4.0%, P>0.05). Conclusions: IPC increases the tolerance of steatotic liver to the late phase of IRI through improvement of HM.
Category 2a: Cirrhosis and Complications: Pathophysiology
that in cirrhotic rats without ascites (12% vs 47%, p < 0.001). L-NIL had no effect on RSMA in rats without ascites and a little effect in rats with ascites which was of similar extent to that produced by L-NAME (15.5% vs 12%, p = N.S.). Western blot experiment showed a faint overexpression of NOS3 in the mesenteric artery of cirrhotic rats without and with ascites and a clear induction of NOS2 only in the mesenteric artery of rats with ascites. These results indicate that NO importantly contributes to the systemic circulatory dysfunction but that it only has a minor role in the maintenance of splanchnic arterial vasodilation in cirrhosis with ascites. 177 5 -METHYLTHIOADENOSINE MODULATES THE INFLAMMATORY RESPONSE TO BACTERIAL LIPOPOLYSACCHARIDE
H. Hevia 1 , M. Varela-Rey 1 , F.J. Corrales 1 , C. Berasain 1 , M.L. Martinez-Chantar 1 , M.U. Latasa 1 , S.C. Lu 2 , J.M. Mato 3 , E.R. Garcia-Trevijano 1 , M.A. Avila 1 . 1 Division De Hepatologia Y Terapia Genica, Universidad De Navarra, Pamplona, Spain; 2 Division of Gastroenterology and Liver Diseases, Usc Liver Disease Research Center, Usc School of Medicine, Los Angeles LA, USA; 3 Cic-Biogune, Vizcaya, Spain 5 -Methylthioadenosine (MTA) is a nucleoside generated from Sadenosylmethionine (AdoMet) during polyamine synthesis. Recent evidences indicate that AdoMet modulates in vivo the production of inflammatory mediators. We have evaluated the anti-inflammatory properties of MTA in bacterial lipopolysaccharide (LPS) challenged mice, murine macrophage RAW 264.7 cells and isolated rat hepatocytes treated with pro-inflammatory cytokines. MTA administration completely prevented LPS-induced lethality. The life-sparing effect of MTA was accompanied by the suppression of circulating tumor necrosis factor-α (TNF-α, inducible NO synthase (iNOS) expression, and by the stimulation of IL-10 synthesis. These responses to MTA were also observed in LPS-treated RAW 264.7 cells. MTA prevented the transcriptional activation of iNOS by proinflammatory cytokines in isolated hepatocytes, and the induction of cyclooxygenase 2 (COX2) in RAW 264.7 cells. MTA inhibited the activation of p38 mitogen-activated protein kinase (MAPK), c-jun phosphorylation, inhibitor kappa B alpha (IκBα) degradation and nuclear factor κB (NFκB) activation, all signaling pathways related to the generation of inflammatory mediators. These effects were independent from the metabolic conversion of MTA into AdoMet and the potential interaction of MTA with the cAMP signaling pathway, central to the anti-inflammatory actions of its structural analog adenosine. In conclusion, these observations demonstrate novel immunomodulatory properties for MTA that may be of value in the management of inflammatory diseases.
176 TEMPORAL RELATIONSHIP BETWEEN SYSTEMIC AND SPLANCNIC VASODILATATION, NOS ACTIVITY AND ASCITES FORMATION IN CIRRHOTIC RATS 1
1
2
1
P. Angeli , C. Cugini , G. Fernandez-Varo , V. Dalla-Libera , S. Fasolato 1 , V. Arroyo 2 , A. Sticca 1 , A. Gatta 1 , W. Jimenez 2 . 1 Department of Clinical and Experimental Medicine, University of Padua, Padua, Italy; 2 Hospital Clinic Universitari, University of Barcelona, Barcelona, Spain To investigate the role of NO in the pathogenesis of the splanchnic arterial vasodilation in cirrhosis, we analyzed the effect on mean arterial pressure (MAP), cardiac output (CO), total peripheral resistance (TPR), and resistance in the superior mesenteric artery (RSMA), before and after the administration of a unspecific nitric oxide synthase (NOS) inhibitor (L-NAME) and a specific NOS2 inhibitor (L-NIL) to cirrhotic rats without and with ascites and control rats. NOS2 and NOS3 protein expression was also assessed in systemic and splanchnic arteries of these animals. L-NAME in cirrhotic rats increased MAP, TPR and decreased CO. These effects were more pronounced in those with ascites. L-NIL had no effect on systemic haemodynamics in control and cirrhotic rats. The increase in RSMA induced by L-NAME in cirrhotic rats with ascites was lesser than
178 ACUTE MANIFESTATIONS OF PORTAL VEIN STENOSIS IN CD39/NTPDASE1 NULL MICE
A. Cardenas, X. Sun, K. Enjyoji, S.C. Robson, C. Thukral. Division of Gastroenterology and Hepatology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston Ma, USA Background: CD39/NTPDase1 is the major vascular ectonucleotidase that hydrolyzes ATP to adenosine. Nucleotide phosphohydrolytic cascades are disordered in the cd39-null mouse resulting in aberrant activation of purinergic/pyrimidinergic type-2 nucleotide receptors (P2) and failure to generate adenosine within the vasculature. Expression of CD39/NTPDase1 on the hepatosplanchnic endothelium may be a key element in the regulation of ATP (vasoconstrictor) to adenosine (vasodilator) levels and consequently of portal hemodynamics. Aim: Examine the role of cd39/NTPDase1in a murine model of portal hypertension. Methods and Results: Substantive cd39/NTPDase1 expression was observed on splanchnic and portal vein endothelium, whereas no expression on hepatic sinusoidal endothelial cells was observed (by immunopatho-
Poster Sessions
of life was observed in 3/5 patients. LT in HIV-HCV coinfected patients is feasible and results in the short and medium term are good. Early and severe HCV recurrence occurred after LT.
175 ISCHEMIC PRECONDITIONING IMPROVES HEPATIC MICROCIRCULATION IN STEATOTIC LIVER AT THE LATE PHASE OF ISCHEMIA REPERFUSION INJURY
W. Yang, G.K. Glantzounis, M.C. Winslet, B.R. Davidson, A.M. Seifalian. University Department of Surgery, Royal Free and University College Medical School, Royal Free Hospital, London, UK Background/Aims: Impairment of hepatic microcirculation (HM) is a key event in the development of cell death during ischemia reperfusion injury (IRI). The present study investigated the effect of IPC on HM during late phase of IRI in steatotic liver. Methods: NZ female rabbits (3.0-3.5kg) were fed with high cholesterol (2%) diet for 8 weeks to induce moderate hepatic steatosis. Animals were subjected to 60 min liver lobar ischaemia followed by 7 hours of reperfusion with (IPC, n=6) or without IPC (IR, n=6). Control animals (n=5) underwent sham operation. Mean arterial pressure, oxygen saturation, heart rate and portal flow were monitored. HM was assessed by laser Doppler flowmeter. At the end of the reperfusion, indocyanine green (ICG, 0.5mg/kg) was administered intravenously and its uptake and clearance in the liver was measured directly by near infrared spectroscopy. Results: All animals with high cholesterol diet developed moderate steatosis. HM in IR group was significantly deteriorated at the end of reperfusion as compared with sham. HM in IPC group was significantly better than IR group at 7th hours of reperfusion (73.3 ± 3.3 vs.118.3 ± 16.2 flux unit, mean ±SEM, P=0.02, unpaired Student t test). AST and ALT levels were significantly lower in IPC group. ICG clearance was better in IPC as compared with IR group but the difference were not statistically significant (57.8 ± 13.5% vs. 44.4 ± 4.0%, P>0.05). Conclusions: IPC increases the tolerance of steatotic liver to the late phase of IRI through improvement of HM.
Category 2a: Cirrhosis and Complications: Pathophysiology
that in cirrhotic rats without ascites (12% vs 47%, p < 0.001). L-NIL had no effect on RSMA in rats without ascites and a little effect in rats with ascites which was of similar extent to that produced by L-NAME (15.5% vs 12%, p = N.S.). Western blot experiment showed a faint overexpression of NOS3 in the mesenteric artery of cirrhotic rats without and with ascites and a clear induction of NOS2 only in the mesenteric artery of rats with ascites. These results indicate that NO importantly contributes to the systemic circulatory dysfunction but that it only has a minor role in the maintenance of splanchnic arterial vasodilation in cirrhosis with ascites. 177 5 -METHYLTHIOADENOSINE MODULATES THE INFLAMMATORY RESPONSE TO BACTERIAL LIPOPOLYSACCHARIDE
H. Hevia 1 , M. Varela-Rey 1 , F.J. Corrales 1 , C. Berasain 1 , M.L. Martinez-Chantar 1 , M.U. Latasa 1 , S.C. Lu 2 , J.M. Mato 3 , E.R. Garcia-Trevijano 1 , M.A. Avila 1 . 1 Division De Hepatologia Y Terapia Genica, Universidad De Navarra, Pamplona, Spain; 2 Division of Gastroenterology and Liver Diseases, Usc Liver Disease Research Center, Usc School of Medicine, Los Angeles LA, USA; 3 Cic-Biogune, Vizcaya, Spain 5 -Methylthioadenosine (MTA) is a nucleoside generated from Sadenosylmethionine (AdoMet) during polyamine synthesis. Recent evidences indicate that AdoMet modulates in vivo the production of inflammatory mediators. We have evaluated the anti-inflammatory properties of MTA in bacterial lipopolysaccharide (LPS) challenged mice, murine macrophage RAW 264.7 cells and isolated rat hepatocytes treated with pro-inflammatory cytokines. MTA administration completely prevented LPS-induced lethality. The life-sparing effect of MTA was accompanied by the suppression of circulating tumor necrosis factor-α (TNF-α, inducible NO synthase (iNOS) expression, and by the stimulation of IL-10 synthesis. These responses to MTA were also observed in LPS-treated RAW 264.7 cells. MTA prevented the transcriptional activation of iNOS by proinflammatory cytokines in isolated hepatocytes, and the induction of cyclooxygenase 2 (COX2) in RAW 264.7 cells. MTA inhibited the activation of p38 mitogen-activated protein kinase (MAPK), c-jun phosphorylation, inhibitor kappa B alpha (IκBα) degradation and nuclear factor κB (NFκB) activation, all signaling pathways related to the generation of inflammatory mediators. These effects were independent from the metabolic conversion of MTA into AdoMet and the potential interaction of MTA with the cAMP signaling pathway, central to the anti-inflammatory actions of its structural analog adenosine. In conclusion, these observations demonstrate novel immunomodulatory properties for MTA that may be of value in the management of inflammatory diseases.
176 TEMPORAL RELATIONSHIP BETWEEN SYSTEMIC AND SPLANCNIC VASODILATATION, NOS ACTIVITY AND ASCITES FORMATION IN CIRRHOTIC RATS 1
1
2
1
P. Angeli , C. Cugini , G. Fernandez-Varo , V. Dalla-Libera , S. Fasolato 1 , V. Arroyo 2 , A. Sticca 1 , A. Gatta 1 , W. Jimenez 2 . 1 Department of Clinical and Experimental Medicine, University of Padua, Padua, Italy; 2 Hospital Clinic Universitari, University of Barcelona, Barcelona, Spain To investigate the role of NO in the pathogenesis of the splanchnic arterial vasodilation in cirrhosis, we analyzed the effect on mean arterial pressure (MAP), cardiac output (CO), total peripheral resistance (TPR), and resistance in the superior mesenteric artery (RSMA), before and after the administration of a unspecific nitric oxide synthase (NOS) inhibitor (L-NAME) and a specific NOS2 inhibitor (L-NIL) to cirrhotic rats without and with ascites and control rats. NOS2 and NOS3 protein expression was also assessed in systemic and splanchnic arteries of these animals. L-NAME in cirrhotic rats increased MAP, TPR and decreased CO. These effects were more pronounced in those with ascites. L-NIL had no effect on systemic haemodynamics in control and cirrhotic rats. The increase in RSMA induced by L-NAME in cirrhotic rats with ascites was lesser than
178 ACUTE MANIFESTATIONS OF PORTAL VEIN STENOSIS IN CD39/NTPDASE1 NULL MICE
A. Cardenas, X. Sun, K. Enjyoji, S.C. Robson, C. Thukral. Division of Gastroenterology and Hepatology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston Ma, USA Background: CD39/NTPDase1 is the major vascular ectonucleotidase that hydrolyzes ATP to adenosine. Nucleotide phosphohydrolytic cascades are disordered in the cd39-null mouse resulting in aberrant activation of purinergic/pyrimidinergic type-2 nucleotide receptors (P2) and failure to generate adenosine within the vasculature. Expression of CD39/NTPDase1 on the hepatosplanchnic endothelium may be a key element in the regulation of ATP (vasoconstrictor) to adenosine (vasodilator) levels and consequently of portal hemodynamics. Aim: Examine the role of cd39/NTPDase1in a murine model of portal hypertension. Methods and Results: Substantive cd39/NTPDase1 expression was observed on splanchnic and portal vein endothelium, whereas no expression on hepatic sinusoidal endothelial cells was observed (by immunopatho-