Background/aims: Lipopolysaccharide (LPS) induces liver injury which is associated with upregulated endothelin (ET)-1 production. The aim of this study was to investigate the effects of tezosentan, a nonselective ETA and ETB receptor antagonist, in LPS challenged rats with cirrhosis.Methods: Rats with cirrhosis received LPS and then tezosentan or placebo one hour later. Four hours after LPS administration, rats were killed to measure serum transaminase activity and plasma tumour necrosis factor alpha (TNF-alpha) levels. Hepatic inducible nitric oxide synthase (iNOS), myeloperoxidase (MPO), a marker of neutrophil infiltration, and cyclooxygenase (COX)-2 expression were also measured.Results: LPS administration significantly decreased arterial pressure and significantly increased plasma endothelin levels. Following LPS and tezosentan administration, serum aspartate aminotransferase and alanine aminotransferase activities were similar to those in the control group while they were increased by more than 700% with LPS alone. Plasma TNF-alpha levels were significantly lower in rats receiving LPS and tezosentan (182 (38) pg/ml) compared with those receiving LPS alone (821 (212) pg/ml). Tezosentan significantly decreased hepatic MPO activity and hepatic neutrophils but had no effect on LPS induced iNOS or COX-2. Survival rate was significantly higher in rats receiving LPS plus tezosentan (80%) than in rats receiving LPS alone (50%).Conclusion: In LPS challenged cirrhotic rats, tezosentan administration prevents LPS induced liver injury by decreasing intrahepatic neutrophil infiltration. In addition, tezosentan increases survival in these rats.
Background and Aim: Hypoxemia is common in patients with cirrhosis but the natural history of this syndrome is unknown. The aim of this study was to follow a series of patients with cirrhosis and to compare patients with and without hypoxemia to determine their risk of complications and survival rate.
In cirrhosis, lipopolysaccharide (LPS, a product of Gram-negative bacteria) in the blood may cause septic shock. LPS-elicited induction of arterial inducible nitric oxide synthase (iNOS) results in nitric oxide (NO)-induced vasodilation, which causes arterial hypotension and hyporeactivity to alpha(1)-adrenergic constrictors. In vitro studies have suggested that vasopressin inhibits iNOS expression in cultured vascular smooth muscle cells exposed to LPS. Thus, the aim of this study was to investigate the effects of terlipressin administration (a vasopressin analog) on in vivo LPS-induced aortic iNOS in rats with cirrhosis. LPS (1 mg/kg, intravenously) was administered followed by the intravenous administration of terlipressin (0.05 mg/kg, intravenously) or placebo 1 hour later. Arterial pressure was measured, and contractions to phenylephrine (an alpha(1)-adrenoceptor agonist), iNOS activity, and iNOS expressions (mRNA and protein) were investigated in isolated aortas. LPS-induced arterial hypotension and aortic hyporeactivity to phenylephrine were abolished in rats that received terlipressin. LPS-induced aortic iNOS activity and expression were suppressed in terlipressin-treated rats. In conclusion, in LPS-challenged rats with cirrhosis, terlipressin administration inhibits in vivo LPS-induced aortic iNOS expression. Terlipressin administration may be a novel approach for the treatment of arterial hypotension and hyporeactivity to alpha(1)-adrenergic constrictors in patients with cirrhosis and septic shock.
BACKGROUND Although nitric oxide (NO) overproduction and protein kinase C (PKC) alterations may play a role in systemic haemodynamic changes in cirrhotic rat aortas, the relationship between NO synthase (NOS) hyperactivation and PKC hypoactivation is unknown. Therefore, the relationships between NOS and PKC activities were studied in cirrhotic rat aortas. METHODS The effects of NOS inhibition by Nw-nitro-L-arginine (LNNA) on the contractile response to phorbol myristate acetate (PMA), a PKC activator, were studied. The effects of NOS inhibition and those of S-nitroso-N acetyl-DL-penicillamine (SNAP), an NO donor, on PKC activity were also evaluated. The effects of PKC activation and inhibition on total NOS and inducible NOS (iNOS) activities were measured. Nitric oxide synthase inhibition caused an increase in PMA-induced contraction and an increase in PKC activity in cirrhotic rat aortas. S-nitroso-N acetyl-DL-penicillamine induced downregulation of PKC activity. Total basal aortic NOS activity was significantly higher in cirrhotic rats than in control rats and activation of PKC by PMA induced a decrease in total aortic NOS activity. Protein kinase C downregulation caused an increase in both total aortic NOS and iNOS activities only in control rats, whereas only iNOS activity increased in cirrhotic rats. CONCLUSION In cirrhotic rat aortas, NO overproduction plays a role in the decreased PKC activation that leads to reduced aortic contraction. Overactivation of aortic NOS in cirrhotic rats may be because of, in part, the reduced PKC activity.
BACKGROUND & AIMSIn rats with portal vein stenosis, the initial cause of aortic nitric oxide (NO) overproduction might be overactivation of endothelial NO synthase (eNOS) related to increased shear stress. Cardiac output is higher in cirrhosis than in extrahepatic portal hypertension. The aims of this study were to evaluate the role of shear stress, vascular endothelial growth factor (VEGF), and cytokines in aortic eNOS up-regulation in rats with biliary cirrhosis and to compare these results with those in rats with portal vein stenosis.METHODSNOS activities, NOS protein, heat shock protein (Hsp) 90, and VEGF expressions were studied in rat aortas. Propranolol was administered to rats with cirrhosis to reduce cardiac output and thus shear stress.RESULTSIn cirrhotic rats, the aortic eNOS protein was 3.0 and 1.7 times higher than in control and portal vein-stenosed rats, respectively. In cirrhotic rats, the Hsp90 content was 3.2 and 2.2 times higher than in control and portal vein-stenosed rats, respectively. Propranolol decreased NOS activity by 47% and eNOS and Hsp90 expression by 75% and 72%, respectively. Aortic VEGF expression was decreased in cirrhotic rats. VEGF-induced stimulation of NOS activity was greater in aortas from control rats than in aortas from portal vein-stenosed or cirrhotic rat aortas. eNOS expression was up-regulated after VEGF incubation. After lipopolysaccharide administration, eNOS expression did not change in portal vein-stenosed or cirrhotic rats.CONCLUSIONSThis study shows that in aortas from rats with biliary cirrhosis, systemic vasodilation depends mainly on eNOS up-regulation related to shear stress.
Abstract Background and Aim: Terlipressin has been proposed to treat renal failure in patients with type 1 hepatorenal syndrome (HRS). However, the predictive factors for improved renal function and survival are unknown in patients with type 1 HRS treated with terlipressin. The aim of the present retrospective study was to investigate the predictive factors and prognosis of patients with type 1 HRS treated with terlipressin.
Objective In patients with cirrhosis, the relationships between haemodynamic alterations and the development of ascites or the occurrence of refractory ascites are unknown. The aim of the present study was to compare haemodynamic measurements obtained in patients with non-refractory ascites to haemodynamic measurements obtained in patients without ascites and in patients with refractory ascites.Methods A cohort of 121 patients was prospectively studied, of whom 29 patients did not have ascites, 45 had non-refractory ascites and 47 had refractory ascites. Splanchnic, renal and systemic haemodynamics were measured in all patients.Results The hepatic venous pressure gradient was significantly higher in patients with non-refractory ascites than in patients without ascites (18.5 +/- 0.8 mmHg versus 15.8 +/- 0.7 mmHg). Renal and systemic haemodynamics did not significantly differ between patients with nonrefractory ascites and patients without ascites. The glomerular filtration rate and renal blood flow were significantly lower in patients with refractory ascites than in patients with non-refractory ascites (77 +/- 4 versus 107 +/- 5 ml/min and 867 +/- 62 versus 1008 +/- 68 ml/min, respectively). Splanchnic and systemic haemodynamics did not significantly differ between patients with refractory ascites and patients with non-refractory ascites.Conclusions In patients with cirrhosis, an increase in portal hypertension was the sole haemodynamic alteration related to the development of ascites. Renal vasoconstriction (and subsequent renal hypoperfusion and hypofiltration) was the only haemodynamic alteration related to the occurrence of refractory ascites. The development of ascites or refractory ascites was not associated with any alteration in systemic haemodynamics. Eur J Gastroenterol Hepatol 13:251-256 (C) 2001 Lippincott Williams & Wilkins.
Background/Aims: In vitro studies have shown, that cirrhotic aortas are hyporeactive to the contractile effect of vasoconstrictors because upregulated endothelial nitric oxide-synthase (NOS) overproduces nitric oxide (NO). Although stimulation of endothelial small-conductance Ca2+-dependent K+ (SKCa) channels may elicit vasorelaxation in normal arteries, the role of these channels in cirrhosis-induced hyporeactivity is unknown. Thus, the aim of the present study was to investigate the role of endothelial SKCa channels in cirrhosis-induced, NO-mediated, in vitro aortic hyporeactivity to alpha (1)-adrenergic vasoconstrictors.Methods: Isolated thoracic aortas from cirrhotic and normal rats were used. The effects of apamin, a selective SKCa channel blocker, were measured on the vascular reactivity to phenylephrine. In addition, SKCa channel protein expression was studied. The effects of iberiotoxin and charybdotoxin, blockers of other K-Ca channels, were also studied in cirrhotic aortas.Results: Apamin suppressed cirrhosis-induced aortic hyporeactivity to phenylephrine in an endothelium-dependent, NOS-inhibitor-sensitive manner. SKCa channel protein was overexpressed in cirrhotic aortic walls. Iberiotoxin abolished cirrhosis-induced aortic hyporeactivity to phenylephrine in an endothelium-dependent but NOS-inhibitor-resistant manner. Charybdotoxin did not induce any significant increase in phenylephrine-elicited contraction.Conclusions: In cirrhotic aortas, the overexpression and overactivity of endothelial SKCa channels contributes to in vitro NO-mediated hyporeactivity to the contractile action of alpha (1)-adrenergic agonists. (C) 2001 European Association for the Study of the Liver. Published by Elsevier Science B.V. All rights reserved.
We report the case of a 40-year-old-man who developed febrile cytolysis as the presenting sign of hemorragic fever with renal syndrome (HFRS). On admission, he had fever (40 degrees C) and epigastric pain. The AST level was at 2N, the ALT at 3N. There was a thrombocytopenia (61 000/mm(3)) without anemia or hyperleukocytosis. Three days after admission, the platelet count decreased to 40 000/mm(3), serum urea and creatinine increased from normal rate to 10.8mmol/l, 204.0 micromol/l, respectively. The HIV, HBV, HCV, leptospirosis antibodies were negative. The Hantavirus serology was positive (Ig G: 1/512). This case suggests that HFRS should be entertained as a possible cause of cytolysis with thrombocytopenia in patients with fever and no initial sign of renal involvement in North-Eastern France.