UMLS:C0023890 - FACTA Search

Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Target Concepts:

Query: UMLS:C0023890 (cirrhosis)
42,195 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The aim of the present study was to analyze the hepatic endothelin system and its regulation in liver cirrhosis due to bile duct obstruction. Wistar rats were subjected for 6 weeks to: 1) sham operation; 2) bile duct obstruction; 3) bile duct obstruction and the selective oral endothelin A receptor antagonist LU 135252; 4) bile duct obstruction and oral silymarin, a hepatoprotective and antifibrotic compound. We determined tissue concentrations of endothelin-1 and big-endothelin-1 by ELISA and the density of both endothelin receptor subtypes in plasma membrane fractions by Scatchard analysis. The hepatic endothelin system in liver cirrhosis due to chronic bile duct obstruction is characterized by a simultaneous up-regulation of both endothelin-1 tissue concentration (7.2 fold compared to sham operation; p<0.001) as well as the density of both endothelin receptor subtypes (ET(A) 7.4-fold, ET(B) 4.9-fold, p<0.001, respectively) suggesting a synergistic activation of the hepatic endothelin system in this rat model of non-inflammatory cirrhosis. Treatment with proven antifibrotic agents such as silymarin or a selective endothelin-A-receptor blocker (LU 135252) did not reduce the activity of the hepatic endothelin system, suggesting that the hepatic endothelin system is not activated by the fibrotic process itself.
...
PMID:Regulation of the hepatic endothelin system in advanced biliary fibrosis in rats. 1098 98

Plasma concentrations of endothelin-1 (ET-1) and nitrite/nitrate of patients with portal hypertension were measured. Sixteen patients with liver cirrhosis (the LC group) and 14 patients with idiopathic portal hypertension (the IPH group) and 12 healthy subjects (normal controls) were included in this study. The peripheral venous plasma concentration of ET-1 was significantly higher in the LC group (6.69+/-2.44 pg/ml) than in the IPH group (3.07+/-0.84 pg/ml) and normal controls (1.79+/-0.36 pg/ml), while the value in the IPH group was also significantly higher than that in normal controls. The peripheral venous plasma concentration of nitrite/nitrate was significantly higher in the LC group (67.7+/-38.9 &mgr;Mol/l) than in the IPH group (32.3+/-24.4 &mgr;Mol/l) and normal controls (26.1+/-9.8 &mgr;Mol/l). Hepatic venous plasma concentrations of ET-1 and nitrite/nitrate were measured in 8 patients from the LC group and 10 patients from the IPH group. The plasma concentration of ET-1 in the hepatic vein was significantly higher than that in the peripheral vein in both the LC and the IPH groups. The plasma concentration of nitrite/nitrate in the hepatic vein was significantly higher than that in the peripheral vein in the LC group. We also investigated the localization of ET-1, endothelin receptor (ET receptor) and nitric oxide synthase (NOS) in the liver tissue of LC patients (n=10), IPH patients (n=10) and normal controls (n=10). The expressions of ET-1, ET A receptors, ET B receptors, and inducive NOS (iNOS) were detected in patients with LC, and the labeling index (LI) was significantly higher than that in patients with IPH and normal controls. The expressions of ET-1, ET A receptors, and ET B receptors were found in patients with IPH, and the LI was significantly higher than that in normal controls. The expression of endothelial NOS (eNOS) was scarce in both LC and IPH patients. From these results, overproduction of ET-1 in the liver was regarded as one of the causes of the high plasma concentration of ET-1 in patients with LC and IPH. One of the causes of the high plasma concentration of nitrite/nitrate in LC was considered to be overproduction of nitric oxide (NO) in the liver. And we suggested that ET-1 is at a relatively higher density than NO in the hepatic sinusoid in LC and IPH.
...
PMID:Clinical investigation of endothelin-1 and nitric oxide in patients with portal hypertension focusing on plasma levels and immunohistological staining of liver tissues. 1147 Jun 27

Recurrent hepatitis C is a common problem after liver transplantation that can progress to liver cirrhosis of the graft. Preliminary reports of combination treatment with interferon (IFN) and ribavirin have been promising, but long-term follow-up data are not yet available. We report our experience with 1 year of combination therapy with IFN (3 million units thrice weekly) and low-dose ribavirin (600 mg/d), followed by long-term ribavirin monotherapy in 18 patients with moderate to severe recurrent hepatitis C and a median follow-up of 32 months after the completion of combined therapy. All patients were followed up clinically and histologically at regular intervals. Overall, in an intention-to-treat analysis, 15 patients had normal alanine aminotransferase levels (biochemical end-treatment response [ETR], 83%), and 8 patients were also hepatitis C virus RNA negative in serum (virological ETR, 44%) at the end of combined treatment. At last follow-up after the completion of combined therapy (median, 32 months; range, 18 to 73 months), 13 patients were biochemical responders (biochemical long term-sustained response [LT-SR], 72%), and 5 patients also maintained viral clearance (virological LT-SR, 27%). Comparison of liver biopsy specimens before and after 12 months of combined therapy showed improvement in grading scores of at least two points in the majority of the patients (73%). Notably, a trend toward fibrotic progression was only noted in nonresponders. Regarding side effects, despite the low dose of ribavirn, almost half the patients developed hemolytic anemia requiring dose reductions. In addition, long-term ribavirin monotherapy was not associated with iron accumulation. We conclude that combined therapy with low-dose ribavirin followed by long-term ribavirin monotherapy can be recommended because it favorably modifies the natural history of recurrent hepatitis C in most patients and possibly halts histological disease progression without causing iron accumulation.
...
PMID:Combined therapy with interferon and low-dose ribavirin in posttransplantation recurrent hepatitis C: a pragmatic study. 1167 85

Endothelin (ET) has been implicated in the regulation of hepatic microcirculation and development of portal hypertension, but the role of ET in cirrhosis of the liver has not yet been elucidated. We present here the application of peptide nucleic acid (PNA) probes in a fast and sensitive in situ hybridization (ISH) method for localizing the mRNA of endothelin receptor subtypes in formalin-fixed, paraffin-embedded sections of normal and cirrhotic human liver. The results of ISH using synthetic FITC-labeled PNA probes combined with the catalyzed signal amplification (CSA) system were compared with those using the standard detection system. It was indicated that the CSA-ISH protocol is more sensitive for the detection of mRNA target than the standard ISH protocol. Our results with CSA-ISH showed that the expression of mRNA for the endothelin B receptor was significantly upregulated in hepatic sinusoidal lining cells in cirrhotic human liver tissues compared to control normal liver tissue. Therefore, the CSA detection system may facilitate and enhance the use of in situ hybridization protocols, and CSA-ISH will be used as an important diagnostic technique in the future.
...
PMID:Signal detection of endothelin receptor subtypes in human cirrhotic liver by a new in situ hybridization method. 1181 Apr 78

The dual endothelin receptor antagonist bosentan has been approved in several countries for pulmonary arterial hypertension, and patients with portopulmonary hypertension (PPHTN) have not specifically been excluded. However, no data have been published on the efficacy and safety of bosentan in this patient population. Here, the first clinical experiences with bosentan in patients with Child A cirrhosis and severe PPHTN are reported. In total, 11 consecutive patients with cirrhosis and severe PPHTN in New York Heart Association Functional Classes III and IV were treated for >1 yr with bosentan. After 1 yr of treatment with bosentan, all patients showed improved symptoms and exercise capacity. The 6-min walking distance increased from 310+/-102 m at baseline to 388+/-81 m at 1 yr. Cardiopulmonary exercise testing disclosed a significant increase in peak oxygen uptake, from 12.6+/-3.5 to 16.6+/-2.8 mL.min(-1).kg(-1). Pulmonary vascular resistance fell from 944+/-519 to 635+/-321 dynes.s.L(-1). The medication was well tolerated by all patients, and there was no evidence of drug-related liver injury. In conclusion, bosentan proved to be efficacious and safe in a small number of patients with portopulmonary hypertension.
...
PMID:Bosentan therapy for portopulmonary hypertension. 1573 95

Novel treatments, such as prostanoids or endothelin receptor antagonists, have been introduced for various forms of pulmonary arterial hypertension, but the long-term effects of these treatments on portopulmonary hypertension (PPHT) are unknown. In a retrospective analysis, the present authors assessed the safety and efficacy of inhaled iloprost, a prostacyclin analogue, and bosentan, an endothelin receptor antagonist, in patients with PPHT. In total, 31 consecutive patients with Child class A or B cirrhosis and severe PPHT were treated for up to 3 yrs with either inhaled iloprost (n = 13) or bosentan (n = 18), and the effects on exercise capacity, haemodynamics and survival were evaluated. In the iloprost group, the survival rates at 1, 2 and 3 yrs were 77, 62 and 46%, respectively. In the bosentan group, the respective survival rates were 94, 89 and 89%. Event-free survival rates, i.e. survival without transplantation, right heart failure or clinical worsening requiring the introduction of a new treatment for pulmonary hypertension, was also significantly better in the bosentan group. Bosentan had significantly better effects than inhaled iloprost on exercise capacity, as determined by the 6-min walk test, as well as on haemodynamics. Both treatments proved to be safe, especially in regards of liver function. In the present series of patients with well-preserved liver function and severe portopulmonary hypertension, treatment with both inhaled iloprost and bosentan appeared to be safe. Patients treated with bosentan had higher survival rates, but prospective controlled studies are required to confirm these findings.
...
PMID:Experience with inhaled iloprost and bosentan in portopulmonary hypertension. 1805 1

Endothelin-1 (ET-1), a potent vasoactive peptide, plays an important role in the pathogenesis of liver disease and portal hypertension. Two major endothelin receptors (ET-A and ET-B) mediate biological effects, largely on the basis of their known downstream signaling pathways. We hypothesized that the different receptors are likely to mediate divergent effects in portal hypertensive mice. Liver fibrosis and cirrhosis and portal hypertension were induced in 8-wk-old male BALB/c mice by gavage with carbon tetrachloride (CCl4). Portal pressure was recorded acutely during intravenous infusion of endothelin receptor antagonists in normal or portal hypertensive mice. In vivo microscopy was used to monitor sinusoidal dynamics. Additionally, the effect of chronic exposure to endothelin antagonists was assessed in mice during induction of fibrosis and cirrhosis with CCl4 for 8 wk. Intravenous infusion of ET-A receptor antagonists into normal and cirrhotic mice reduced portal pressure whereas ET-B receptor antagonism increased portal pressure. A mixed endothelin receptor antagonist also significantly reduced portal pressure. Additionally, the ET-A receptor antagonist caused sinusoidal dilation, whereas the ET-B receptor antagonist caused sinusoidal constriction. Chronic administration of each the endothelin receptor antagonists during the induction of fibrosis and portal hypertension led to reduced fibrosis, a significant reduction in portal pressure, and altered sinusoidal dynamics relative to controls. Acute effects of endothelin receptor antagonists are likely directly on the hepatic and sinusoidal vasculature, whereas chronic endothelin receptor antagonism appears to be more complicated, likely affecting fibrogenesis and the hepatic microcirculation. The data imply a relationship between hepatic fibrogenesis or fibrosis and vasomotor responses.
...
PMID:Endothelin antagonism in portal hypertensive mice: implications for endothelin receptor-specific signaling in liver disease. 1929 80

Chronic alcohol consumption leads to inflammation and cirrhosis of the liver. In this study, we observed that liver sinusoidal endothelial cells (LSEC) derived from ethanol-fed rats showed several fold increases in the mRNA expression of endothelin-1 (ET-1), hypoxia-inducible factor-1alpha (HIF-1alpha), and inflammatory cytochemokines compared with control rat LSEC. We also observed the same results in acute ethanol-treated LSEC from control rats and human dermal microvascular endothelial cells. Ethanol-mediated ET-1 expression involved NADPH oxidase and HIF-1alpha activation. Furthermore, ethanol increased the expression of the ET-1 cognate receptor ET-BR in Kupffer cells and THP-1 monocytic cells, which also involved HIF-1alpha activation. Promoter analysis and chromatin immunoprecipitation showed that hypoxia response element sites in the proximal promoter of ET-1 and ET-BR were required for the binding of HIF-1alpha to up-regulate their expression. We showed that microRNAs, miR-199 among several microRNAs, attenuated HIF-1alpha and ET-1 expression, while anti-miR-199 reversed the effects, suggesting that ethanol-induced miR-199 down-regulation may contribute to augmented HIF-1alpha and ET-1 expression. Our studies, for the first time to our knowledge, show that ethanol-mediated ET-1 and ET-BR expression involve HIF-1alpha, independent of hypoxia. Additionally, ethanol-induced ET-1 expression in rat LSEC is regulated by miR-199, while in human endothelial cells, ET-1 expression is regulated by miR-199 and miR-155, indicating that these microRNAs may function as novel negative regulators to control ET-1 transcription and, thus, homeostatic levels of ET-1 to maintain microcirculatory tone.
...
PMID:Ethanol-induced expression of ET-1 and ET-BR in liver sinusoidal endothelial cells and human endothelial cells involves hypoxia-inducible factor-1alpha and microrNA-199. 1978 78

Portopulmonary hypertension (PoPH) is an underrecognized complication of portal hypertension, related to cirrhosis and noncirrhotic portal hypertension. PoPH has been found in 5-6% of patients with decompensated liver disease and may adversely affect outcome after liver transplantation. The prevalence of PoPH is unrelated to the severity of liver disease but associated with female sex and underlying autoimmune liver disease. Diagnosis of PoPH is based on screening with Doppler echocardiography and confirmation by right-heart catheterization. Treatment options with proven efficacy in idiopathic pulmonary hypertension include endothelin receptor antagonists, prostanoids, and sildenafil. In PoPH, such targeted treatment was found to be safe in small uncontrolled studies but randomized trials demonstrating its benefit are lacking.
...
PMID:Portopulmonary hypertension: short review. 1990 38

Hepatopulmonary syndrome, portopulmonary hypertension and hepatic hydrothorax are typical pulmonary complications in patients with liver cirrhosis. Whereas hepatopulmonary syndrome and portopulmonary hypertension represent pulmonary vascular diseases, the development of hepatic hydrothorax is associated with the presence of ascites and phrenic lesions. For severe hepatopulmonary syndrome and refractory hepatic hydrothorax, liver transplantation is the treatment of choice. In severe portopulmonary hypertension specific medical treatment is indicated. In selected patients, beside intravenous prostanoids, oral endothelin receptor antagonists and phosphodiesterase type-5 inhibitors are possible treatment options.
...
PMID:[Pulmonary complications of liver cirrhosis: hepatopulmonary syndrome, portopulmonary hypertension and hepatic hydrothorax]. 2009 77

<< Previous 1 2 3 Next >>