endothelin-1 and Liver-Cirrhosis

Acute or chronic insults to the liver are usually followed by a tissue repairing process. Unfortunately, this action, in most cases, is not effective enough to restore the normal hepatic structure and function. Instead, fibrogenesis and regenerative nodules formation ensue, which are relatively nonfunctioning. The common final stage of the process is liver cirrhosis with increased intrahepatic resistance to portal venous blood flow. Throughout the entire course, the extrahepatic circulatory dysfunction, including increased splanchnic blood flow, elevated portal venous blood flow and pressure, decreased splanchnic and peripheral vascular resistance, tachycardia, and increased cardiac output, are noted and denoted as portal hypertension with hyperdynamic circulatory dysfunction. When such a condition is established, patients may suffer from fatal complications such as gastroesophageal variceal hemorrhage, hepatic encephalopathy, or hepatorenal syndrome. The cause of such a circulatory dysfunction is not fully elucidated. Nevertheless, clarification of the pathophysiology definitely contributes to the control of portal hypertension-related complications. Herein, the molecular mechanism of this intriguing disaster is reviewed and discussed.

Topics: Animals; Endocannabinoids; Endothelin-1; Humans; Hypertension, Portal; Liver Cirrhosis; Neuropeptide Y; Portal Vein; Splanchnic Circulation; Tumor Necrosis Factor-alpha; Vascular Endothelial Growth Factor A; Vascular Remodeling

Hepatopulmonary syndrome (HPS) is an important cause of dyspnea and hypoxia in the setting of liver disease, occurring in 10-30% of patients with cirrhosis. It is due to vasodilation and angiogenesis in the pulmonary vascular bed, which leads to ventilation-perfusion mismatching, diffusion limitation to oxygen exchange, and arteriovenous shunting. There is evidence, primarily from animal studies, that vasodilation is mediated by a number of endogenous vasoactive molecules, including endothelin-1 and nitric oxide (NO). In experimental HPS, liver injury stimulates release of endothelin-1 and results in increased expression of ET(B) receptors on pulmonary endothelial cells, leading to upregulation of endothelial NO synthase (eNOS) and subsequent increased production of NO, which causes vasodilation. In addition, increased phagocytosis of bacterial endotoxin in the lung not only promotes stimulation of inducible NO synthase, which increases NO production, but also contributes to intrapulmonary accumulation of monocytes, which may stimulate angiogenesis via vascular endothelial growth factor pathway. Despite these insights into the pathogenesis of experimental HPS, there is no established medical therapy, and liver transplantation remains the main treatment for symptomatic HPS, although selected patients may benefit from other surgical or radiological interventions. In this review, we focus on recent advances in our understanding of the pathophysiology of HPS, and discuss current approaches to the investigation and treatment of this condition.

Topics: Animals; Early Diagnosis; Endothelin-1; Hepatopulmonary Syndrome; Humans; Liver Cirrhosis; Lung; Nitric Oxide; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; Predictive Value of Tests; Prognosis; Pulmonary Artery; Pulmonary Circulation; Vasodilation

The contraction of hepatic stellate cells has been proposed to mediate fibrosis by regulating sinusoidal blood flow and extracellular matrix remodeling. Abundant data from diverse, yet complementary, experimental methods support a robust model for the regulation of contractile force generation by stellate cells. In this model, soluble factors associated with liver injury, including endothelin 1 and nitric oxide, are transduced primarily through Rho signaling pathways that promote the myosin II-powered generation of contractile force by stellate cells. The enhanced knowledge of the role and differential regulation of stellate cell contraction may facilitate the discovery of new and targeted strategies for the prevention and treatment of hepatic fibrosis.

Topics: Animals; Contractile Proteins; Endothelin-1; Extracellular Matrix; Hepatic Stellate Cells; Humans; Intracellular Signaling Peptides and Proteins; Liver Cirrhosis; Myosin Type II; Nitric Oxide; Portal System; rho-Associated Kinases; Signal Transduction

Topics: Endothelin-1; Hemodynamics; Humans; Hypertension, Portal; Liver Circulation; Liver Cirrhosis; Receptors, Endothelin; Vascular Resistance

Portopulmonary hypertension (PPHT) is a rare but devastating complication in patients with portal hypertension, characterized by pulmonary arterial obliterative disease with a concomitant rise in pulmonary vascular resistance. A broad body of evidence has accumulated, indicating that endothelin (ET) peptides and their cognate receptors are causally involved in the pathophysiology of pulmonary arterial hypertension (PAH) owing to different aetiologies, including PPHT. In addition, the ET system may be involved in hepatic fibrotic remodelling and portal hypertension. Several experimental models have provided evidence that ET receptor antagonism may have therapeutic potential in PPHT. Initial experience has accumulated during the last 2 years, suggesting that targeting the ET system may have beneficial effects in the clinical setting. In these studies, the orally active, dual ET receptor antagonist bosentan improved pulmonary haemodynamics and functional capacity. These effects were sustained and occurred in the absence of adverse events. If these observations can be corroborated by controlled clinical trials, bosentan would offer several advantages over available therapies, which have major drawbacks owing to their invasive and demanding mode of application.

Topics: Administration, Oral; Antihypertensive Agents; Bosentan; Endothelin Receptor Antagonists; Endothelin-1; Endothelins; Humans; Hypertension, Portal; Hypertension, Pulmonary; Liver Cirrhosis; Liver Transplantation; Pulmonary Circulation; Sulfonamides; Treatment Outcome

Pulmonary vascular abnormalities occurring in the setting of liver disease have been increasingly recognized as important clinical entities that influence survival and liver transplant candidacy in affected patients. The most common such abnormality, the hepatopulmonary syndrome, is found in 15% to 20% of patients with cirrhosis. These disorders have no effective medical therapies. Experimental models of hepatopulmonary syndrome have identified a sequence of hepatic and pulmonary endothelial alterations that lead to nitric oxide and carbon monoxide-mediated intrapulmonary vasodilatation. A key role for shear stress-mediated pulmonary endothelial endothelin B receptor overexpression and cholangiocyte ET-1 production and release has emerged as a mechanism for local nitric oxide production in the lung. How these alterations are influenced by bacterial translocation and the systemic hyperdynamic circulatory state and whether similar changes occur in human disease are areas of ongoing investigation.

Topics: Animals; Common Bile Duct; Endothelin-1; Hepatopulmonary Syndrome; Humans; Ligation; Liver; Liver Cirrhosis; Rats

Topics: Angiotensin II; Animals; Cell Division; Collagen; Endothelin-1; Extracellular Matrix; Fibroblast Growth Factor 2; Fibroblasts; Glomerulosclerosis, Focal Segmental; Humans; Hypertension; Liver Cirrhosis; Myoblasts, Cardiac; Myocardial Infarction; Pulmonary Fibrosis; Receptors, Endothelin; Transforming Growth Factor beta; Ventricular Remodeling

Topics: Adult; Animals; Blood Pressure; Calcium Channels; Endothelin-1; Fibrosis; Hemorheology; Humans; Hypertension, Portal; Ion Channel Gating; Lipids; Liver; Liver Cirrhosis; Liver Cirrhosis, Experimental; Neovascularization, Pathologic; Nitric Oxide; Pericytes; Rats; Vasoconstrictor Agents; Vasodilator Agents

Hepatic stellate cells (HSC) are presently regarded as one of the key cell types involved in the progression of liver fibrosis and in the related pathophysiological and clinical complications. Following acute or chronic liver tissue damage, HSC undergo a process of activation towards a phenotype characterised by increased proliferation, motility, contractility and synthesis of extracellular matrix (ECM) components. Several factors have been shown to play a key role in the promotion of the full-blown picture of activated HSC. These include extensive changes in the composition and organisation of the ECM, the secretion of several growth factors, cytokines, chemokines, products of oxidative stress and other soluble factors. It is evident that each cellular response to extracellular stimuli must be framed in a scenario where different forces modulate one another and result in a prevalent biological effect. Along these lines, the identification and characterisation of intracellular signalling pathways activated by different stimuli in HSC represent a mandatory step. In this review article we have made an attempt to summarise recent acquisitions to our knowledge of the involvement of different intracellular signalling pathways in key aspects of HSC biology.

Topics: Animals; Cell Differentiation; Endothelin-1; Extracellular Matrix; Humans; Integrins; Liver; Liver Cirrhosis; Platelet-Derived Growth Factor; Rats; Signal Transduction

Topics: Amino Acid Sequence; Bile; Endothelin-1; Glycogen; Humans; Liver; Liver Circulation; Liver Cirrhosis; Molecular Sequence Data; Peptide Fragments; Receptors, Endothelin

Social anxiety (SA) and depression are prevalent, often comorbid disorders, associated with poor psychosocial functioning. Experimental psychopathology approaches can clarify the transdiagnostic mechanisms underlying these disorders, but most laboratory tasks are limited. We developed and validated the Audio-Dialogue Inductions of Social Stress (A-DISS) experimental task to model real-time rejection sensitivity in a realistic and developmentally relevant context. Participants are asked to imagine overhearing peers at a party talking badly about them (Rejection) or a teacher at their school (Neutral).. The Rejection condition elicited higher negative affect/lower positive affect while the Neutral condition sustained stable affect. Findings were consistent across gender and race/ethnicity. Moderation analyses were statistically significant; participants with elevated SA or depression reported feeling more rejected, insecure, and anxious after Rejection than those with below average symptoms.. Findings provide preliminary validation of a novel peer rejection task for research on understanding the affective experience of real-time rejection overall, especially for those with elevated SA and depression. SA and depression symptoms each uniquely moderating the effects of Rejection exposure on similar affective states, suggests individuals with SA or depression may benefit from interventions targeting specific reactions to rejection/stress and transdiagnostic risk factors.. Our results suggest that T lymphocyte immune dysfunction does exist in adult ITP patients and plays an important role in the pathogenesis of ITP.. ClinicalTrials.gov, identifier NCT03575988.. Brown/beige adipocyte-specific h

Topics: A549 Cells; Acute Lung Injury; Adipose Tissue, Brown; Adipose Tissue, White; Adolescent; Adult; Aged; Animals; Anthropometry; Anti-Inflammatory Agents; Antiviral Agents; Arachidonic Acid; Archaeoglobus fulgidus; Australia; Blood Glucose; Blotting, Western; Carcinoma, Hepatocellular; Cathartics; Cell Differentiation; Chemokine CCL2; Child; China; Colonoscopy; Crosses, Genetic; Cyclin B1; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Drugs, Chinese Herbal; Endothelin-1; Endothelium, Vascular; Enzyme-Linked Immunosorbent Assay; Female; Finland; Follow-Up Studies; Genes, Dominant; Glycated Hemoglobin; Hepatitis B e Antigens; Hepatitis B virus; Hepatitis B, Chronic; Homeodomain Proteins; Humans; Hypothalamus; Incidence; Inflammatory Bowel Diseases; Interleukin-1beta; Interleukin-6; Italy; Lipopolysaccharides; Liver Cirrhosis; Liver Neoplasms; Lung; Male; Mice; MicroRNAs; Middle Aged; Motivational Interviewing; NAD; Neuroendocrine Tumors; NF-kappa B; Nitric Oxide; Nitriles; Outpatients; Oxidoreductases; Phenotype; Pilot Projects; Polyethylene Glycols; Polymorphism, Genetic; Prospective Studies; Protein Interaction Maps; Quality of Life; Reproducibility of Results; Shewanella; Signal Transduction; Spain; Sulfides; Sulfones; Thermogenesis; Transcription Factors; Treatment Outcome; Tumor Necrosis Factor-alpha; Uncoupling Protein 1; United Kingdom

To assess the effect of tezosentan, a parenteral dual ET receptor antagonist, on splanchnic and systemic hemodynamics in patients with cirrhosis. In addition, the safety, pharmacokinetics, and pharmacodynamics of tezosentan were evaluated.. The population consisted of patients with cirrhosis with clinically significant portal hypertension. This was a randomized, double-blind, multicenter study. The patients were randomized 3:1 to tezosentan (3 mg/h for 2-3 h) or placebo. HVPG, hepatic blood flow (HBF, ICG method), and systemic arterial pressures were measured before and after tezosentan administration. Plasma concentrations of tezosentan and ET-1 were determined peripherally and in the hepatic vein.. Eighteen patients received tezosentan and six placebo. Baseline clinical, biochemical, and hemodynamic characteristics were balanced between the two groups. There was no significant treatment effect on HVPG. The extraction ratio (0.31), the plasma clearance of ICG (280 ml/min), and the HBF (1,430 ml/min) did not show any relevant changes during the infusion of tezosentan, and there were no differences between placebo- and tezosentan-treated patients. A linear relationship was observed between the maximum-fold increase in ET-1 concentration and the steady-state tezosentan plasma concentration (r = 0.82). There was a strong correlation (r = 0.88) between plasma clearance of ICG and that of tezosentan (10.2 l/h). Arterial pressure and heart rate did not significantly change in either group.. In patients with cirrhosis, a 2- to 3-h tezosentan infusion was safe and well tolerated but did not change the HVPG. Tezosentan infusion had no influence on the extraction ratio and plasma clearance of ICG and did not change HBF.

Topics: Antihypertensive Agents; Double-Blind Method; Endothelin Receptor Antagonists; Endothelin-1; Female; Heart Rate; Hemodynamics; Humans; Hypertension, Portal; Infusions, Parenteral; Liver; Liver Cirrhosis; Liver Cirrhosis, Alcoholic; Male; Metabolic Clearance Rate; Middle Aged; Pyridines; Severity of Illness Index; Splanchnic Circulation; Tetrazoles; Vasodilator Agents

This study investigates the pharmacokinetics, pharmacodynamics, and safety of the parenteral endothelin receptor antagonist tezosentan in patients with Child-Pugh classification B/C liver impairment. Cohorts I and II consist of 5 and 11 patients, respectively, with low serum bilirubin (

Topics: Adult; Bilirubin; Blood Pressure; Dose-Response Relationship, Drug; Double-Blind Method; Endothelin-1; Female; Humans; Infusions, Intravenous; Liver Cirrhosis; Male; Middle Aged; Placebos; Pyridines; Tetrazoles; Vasodilator Agents

Renal vasoconstriction is a key factor in the development of hepatorenal syndrome (HRS) and may be secondary to increased activities of endothelin-1, a potent renal vasoconstrictor. To assess the effects of tezosentan, a nonselective endothelin receptor antagonist, on renal function in patients with type 2 HRS, six male patients, 56.3 +/- 2.5 years old, with cirrhosis and type 2 HRS were treated with tezosentan; ascending doses of 0.3, 1.0, and 3.0 mg/hour, each for 24 hours, were used for the initial 2 patients, but a constant dose of 0.3 mg/hour for up to 7 days was used for the remaining 4 patients. The glomerular filtration rate, renal plasma flow, 24-hour urinary volume, mean arterial pressure (MAP), heart rate, tezosentan levels, and vasoactive hormones were measured daily. Albumin was given as required. The study was stopped early because of concerns about the safety of tezosentan in type 2 HRS. Five patients discontinued the study early; one stopped within 4 hours because of systemic hypotension (MAP < 70 mm Hg), and 4 patients stopped at approximately 4 days because of concerns about worsening renal function (serum creatinine increased from 180 +/- 21 to 222 +/- 58 micromol/L, P > 0.05) and decreasing urine volume (P = 0.03) but without a significant change in MAP. The plasma tezosentan concentrations were 79 +/- 34 ng/mL at a steady state during infusion at 0.3 mg/hour. The plasma endothelin-1 concentrations increased from 2.7 +/- 0.3 pg/mL at the baseline to 19.1 +/- 7.3 pg/mL (P < 0.05).. An endothelin receptor blockade potentially can cause a deterioration in renal function in patients with cirrhosis and type 2 HRS. Caution should be taken in future studies using endothelin receptor antagonists in these patients.

Topics: Endothelin-1; Hemodynamics; Hepatorenal Syndrome; Humans; Kidney; Kidney Function Tests; Liver Cirrhosis; Male; Middle Aged; Pilot Projects; Pyridines; Sodium; Tetrazoles; Treatment Failure; Water

In patients with cirrhosis, acute octreotide administration may transiently decrease the hepatic venous pressure gradient (HVPG). Information on long-term effects of octreotide is limited and controversial. We evaluated portal and systemic hemodynamics following a prolonged administration of long-acting octreotide in patients with cirrhosis.. Eighteen cirrhotic patients (alcoholic 12; age 55 yr [44-69]; Pugh's score 7.8; HVPG 17.3 mmHg [12-22]), no steatohepatitis on histology, were randomized to intramuscular octreotide 20 mg (group A) q 4 wk for 3 months or placebo (group B) in a double-blind fashion. At baseline and 3 months, we measured the HVPG, systemic hemodynamics, endothelin-1 (ET-1), and vascular endothelial growth factor (VEGF) in hepatic venous blood.. Patients remained compensated except for one episode of infection in each group. At 3 months, the HVPG decreased in group A but not in group B (16.5 +/- 1.3 to 11.8 +/- 1.5 mmHg, P < 0.01; 18.2 +/- 1 to 17 +/- 1.1 mmHg, P= 0.4). Systemic hemodynamics and liver function remained unchanged. In group A, but not in group B, VEGF decreased (21.2 +/- 4.7 to 13.7 +/- 3.5 pg/mL, P < 0.01; 22.5 +/- 7.8 to 19.2 +/- 5.4 pg/mL, P= 0.4). ET-1 remained stable. Changes in HVPG and VEGF were correlated (r = 0.49, P < 0.05).. Three months of long-acting octreotide in selected cirrhotic patients with portal hypertension decreases the HVPG independent of systemic hemodynamics and liver function. The decrease in VEGF blood levels suggests an improvement in splanchnic hyperemia.

Topics: Adult; Aged; Biomarkers; Biopsy; Delayed-Action Preparations; Double-Blind Method; Endothelin-1; Female; Follow-Up Studies; Gastrointestinal Agents; Humans; Hypertension, Portal; Immunoenzyme Techniques; Injections, Intramuscular; Liver Cirrhosis; Male; Middle Aged; Octreotide; Portal Pressure; Radioimmunoassay; Retrospective Studies; Time Factors; Treatment Outcome; Urotensins; Vascular Endothelial Growth Factor A

Increased endothelin (ET)-1 activity may contribute to the complications of cirrhosis and portal hypertension. The aim of this study was to assess the systemic and portal haemodynamic effects of selective ET-A and ET-B receptor antagonism in patients with cirrhosis.. Sixteen patients with cirrhosis and portal hypertension (aged 52 (1) years, Pugh score 6.2 (0.3)) underwent 24 studies with infusions of: (A) selective ET-A antagonist, BQ-123 (n = 8), at 1000 and 3000 nmol/min; (B) selective ET-B antagonist, BQ-788 (n = 8), at 100 and 300 nmol/min; or (C) matched saline placebo (n = 8) in a double blind randomised manner. Haemodynamic measurements were performed through pulmonary artery, hepatic venous, and femoral artery catheters.. Baseline patient characteristics were well matched. Compared with placebo, BQ-123 decreased mean arterial pressure (MAP -15 (11) mm Hg (-18%); p<0.02) and pulmonary vascular resistance index (PVRI -81 (54) dyn x s x m2/cm5 (-64%); p<0.05), with no effect on hepatic venous pressure gradient (HVPG), cardiac index (CI), or systemic vascular resistance index (SVRI). Compared with placebo, BQ-788 increased MAP (+11 (3) mm Hg (+12%); p<0.03) and SVRI (+1101 (709) dyn x s x m2/cm5 (+50%); p<0.05), reduced CI (-1.0 (0.4) l/min/m2 (-29%); p = 0.05) with no effect on HVPG or PVRI.. ET-1 contributes to maintenance of systemic and pulmonary haemodynamics without acutely affecting HVPG in patients with early cirrhosis. In this group of patients, the use of selective ET-A and ET-B antagonists for the management of variceal haemorrhage is likely to be limited.

Topics: Adult; Aged; Double-Blind Method; Endothelin A Receptor Antagonists; Endothelin B Receptor Antagonists; Endothelin-1; Female; Hemodynamics; Humans; Hypertension, Portal; Liver Circulation; Liver Cirrhosis; Male; Middle Aged; Oligopeptides; Peptides, Cyclic; Piperidines; Pulmonary Circulation

To explore the efficacy and mechanism of a novel therapeutic method of traditional Chinese medicine in patients with refractory cirrhotic ascites complicated with azotemia.. Seventy-five cases of refractory cirrhotic ascites complicated with azotemia were randomly divided into 3 groups: comprehensive treatment (n = 29), simple treatment (n = 24), and control (n = 22). The basic treatment methods were the same in all groups, including liver protecting medicines, diuretics and supportive drugs. The control group underwent only the basic treatment. Shehuang Paste (SHP) was applied to the navels of the two treatment groups once a day for 30 d. Colon dialysis with Chinese herbs was administered to the comprehensive treatment group once every two days. Before and after treatment, we measured abdominal circumference, BUN, Cr, serum Na+, urine Na+/K+, liver function, endotoxin content, NO, and ET-1. Color Doppler ultrasonography was conducted to measure the portal vein blood flow.. The total effective rate for ascites was 72.4% in the comprehensive treatment group, 45.8% in the simple treatment, contrasting with 18.2% in the controls. Between the two treatment groups and the controls, there were significant differences in the effective rates (P < 0.01, and P < 0.05). There was also a significant difference (P < 0.05) between the two treatment groups. Measurements of Cr and BUN showed higher values for the treatment groups, with the comprehensive better than the simple group (P < 0.05). Sera Na, urine Na/K were different, P < 0.01 between pre- and post-treatment in the comprehensive group, and P < 0.05 in the simple group. The treatment groups' endotoxin content was also significantly reduced (P < 0.01, and P < 0.05), with the comprehensive group better than the simple group (P < 0.05). Portal vein blood flow and NO content significantly reduced (P < 0.05), as did ET-1 content (P < 0.01). There were no significant changes in the control group (P > 0.05). The comprehensive treatment group's pre- and post-treatment portal vein and splenic vein blood flows showed a positive correlation to NO, ET-1 and endotoxin contents.. When treating refractory cirrhotic ascites complicated with azotemia, Shehuang Paste combined with Chinese herbal dialysis is better than Shehuang Paste alone for ascites resolution, azotemia, and endotoxin elimination. However, both methods on their own were also effective for reducing portal and splenic vein blood flow, and lowering the contents of NO, ET-1 in the two treatment groups.

Topics: Administration, Topical; Adult; Ascites; Azotemia; Blood Flow Velocity; Blood Urea Nitrogen; Colon; Drugs, Chinese Herbal; Endothelin-1; Endotoxins; Enema; Female; Humans; Liver Cirrhosis; Male; Middle Aged; Ointments; Portal Vein; Sodium; Splenic Vein; Umbilicus

To explore the influence of Shehuang Paste (SHP) to the hemodynamics, endotoxin, nitric oxide (NO), and endothelin-1 (ET-1) in patients with refractory cirrhotic ascites.. Fifty-nine cases of refractory cirrhotic ascites were randomly assigned to two groups, 32 cases in the treatment group and 27 cases in the control group. The basic treatment was the same for both groups, including liver protecting medicines, diuretics and supportive drugs, but SHP navel sticking was applied for the treatment group additionally once a day. A course of one month of treatment was applied and the general efficacy on ascites was observed by the end of the therapeutic course. Before and after the treatment, examinations by limulus lysate chromogenic test was conducted to measure plasma endotoxin content; colorimetry to measure plasma content of NO indirectly, radioimmunoassay to measure plasma ET-1 content; and color Doppler ultrasonography to measure the blood flow of portal vein and splenic vein. The relationship between the blood flow of portal vein and splenic vein and endotoxin, NO and ET-1 in the treatment group was analyzed as well.. The total effective rate on ascites was 84.4% in the treatment group, and 48. 1% in the control group, with significant difference shown between them (P<0.01). In the treatment group the blood flow of portal vein and splenic vein, contents of endotoxin, NO and ET-1 all got significantly reduced after treatment ( P<0.05 or P<0.01); while these indexes in the control group were not significantly changed ( P 0.05). Moreover, it was found that in the treatment group, the blood flow of portal vein and splenic vein had a positive correlation to the levels of NO, ET-1, and endotoxin, either before or after treatment.. Application of SHP navel sticking could clearly reduce the blood flow of portal vein and splenic vein, and lower the content of endotoxin, NO and ET-1. The blood flow of portal vein and splenic vein in the treatment group showed a positive correlation with the contents of endotoxin, NO and ET-1. liver cirrhosis, refractory ascites, vasoactive substance, hemodynamics

Topics: Adult; Endothelin-1; Endotoxins; Female; Follow-Up Studies; Humans; Liver; Liver Cirrhosis; Male; Medicine, Chinese Traditional; Middle Aged; Nitric Oxide; Portal Vein; Potassium; Regional Blood Flow; Sodium

The renal effects of octreotide, used for bleeding esophageal varices in cirrhosis, are controversial.. Fourteen cirrhotic patients (Child-Pugh; A/B/C: 1/12/1) were enrolled. Plasma nitrite and endothelin (ET) levels, urinary nitrite output, free water clearance (FWC) and fractional excretion of filtered sodium (FENa) were measured and renal Doppler ultrasound was carried out. Octreotide was infused at a rate of 0.75 microg/kg/h for 3 h after a bolus of 0.75 microg/kg body weight. All the parameters were reevaluated during octreotide administration while the patients acted as their own controls.. Octreotide induced significant reductions in urinary nitrite, FENa and FWC. Plasma ET levels increased (baseline: 6.7 pg/ml, octreotide: 8.4 pg/ml), whereas the plasma nitrite level did not change significantly after octreotide infusion. Overall, no significant change in renal resistive index (RRI) could be demonstrated on Doppler after octreotide administration. However, patients with elevated baseline RRI values had significantly more deterioration in FWC and FENa compared with patients with normal RRI in response to octreotide.. A marked decrease in FENa, FWC and urinary nitrite output, together with a significant increase in plasma ET level in response to octreotide, may indicate renal dysfunction in cirrhotic patients. This deleterious renal effect of octreotide may be more enhanced in patients with elevated baseline RRI.

Topics: Adult; Aged; Endothelin-1; Female; Gastrointestinal Agents; Gastrointestinal Hemorrhage; Humans; Hypertension, Portal; Kidney; Liver Cirrhosis; Male; Middle Aged; Nitrites; Octreotide; Salvage Therapy; Sodium; Ultrasonography, Doppler; Varicose Veins

Endothelin-1 (ET-1) is a potent vasoconstrictor that may be involved in the pathogenesis of splanchnic and renal hemodynamic changes associated with portal hypertension. The aim of this study was to measure the concentration of ET-1 and of its precursor Big endothelin-1 (Big ET-1) in the systemic circulation as well as in the splanchnic and renal venous beds and to evaluate changes after the relief of portal hypertension following transjugular intrahepatic portosystemic shunt placement.. Plasma concentrations of ET-1 and of Big ET-1 were measured in the vena cava, renal vein, hepatic vein and portal vein in ten patients with cirrhosis and refractory ascites before and 1-2 months after transjugular intrahepatic portosystemic shunt. The porto-caval gradient, creatinine clearance, plasma aldosterone and renin activity, as well as daily urinary sodium excretion were measured at the same time.. The plasma concentration of ET-1 and Big ET-1, respectively, in peripheral blood of normal volunteers were 0.28 +/- 03 and 3.95 +/- 0.34 pg/ml; the concentrations of both peptides were higher in patients with cirrhosis, both in vena cava (0.61 +/- 0.14 and 10.01 +/- 1.47 pg/ml), hepatic vein (0.62 +/- 0.13 and 13.93 +/- 1.77 pg/ml), portal vein (1.21 +/- 0.12 and 17.84 +/- 1.98 pg/ml) and renal vein (0.76 +/- 0.12 and 14.21 +/- 1.55 pg/ml). Moreover ET-1 and Big ET-1 concentrations were more elevated in the portal vein than in the vena cava (+98% and +70%) and slightly higher in the renal vein as compared to the vena cava (+25% and +42%). After transjugular intrahepatic portosystemic shunt, a rise in creatinine clearance and urinary sodium excretion (+49%; and +53%) was observed together with a marked reduction in plasma aldosterone and renin activity (-59% and -49%). ET-1 and Big ET-1 concentrations remained unchanged in the vena cava whereas a significant reduction of ET-1 and Big ET-1 occurred both in the portal vein (-43% and -44%) and in the renal vein (-53% and -29%). Portal vein and renal vein concentrations of both peptides became similar to vena cava levels.. Splanchnic and renal hemodynamic changes occurring in patients with cirrhosis and refractory ascites could be related to the production of ET-1 by splanchnic and renal vascular beds. This was abolished by transjugular intrahepatic portosystemic shunt, which could explain the exacerbation of systemic vasodilation and the improvement in renal perfusion observed after the procedure.

Topics: Aged; Aged, 80 and over; Ascites; Endothelin-1; Endothelins; Female; Humans; Liver Cirrhosis; Male; Middle Aged; Portasystemic Shunt, Transjugular Intrahepatic; Protein Precursors; Renal Circulation; Splanchnic Circulation

We aim to evaluate the effects of auranofin, a known antioxidant, on hepatic steatosis, inflammation, and fibrosis, contributing to non-alcoholic steatohepatitis (NASH) development in vivo and in vitro.. Transcriptome analysis of LX-2 cells was that expression patterns of genes changed by auranofin, and their related pathways were estimated. We used the gene set enrichment analysis (GSEA) program to determine the pathway involved in overall genetic change. In vitro, LX-2 and HepG2 cells were treated with transforming growth factor (TGF)-β1 and palmitic acid (PA), respectively, and the antifibrotic and antiadipogenic effect function of auranofin was evaluated.. Transcriptome analysis revealed that auranofin decreased the expression of 15 genes, including thrombospondin 1, endothelin 1 (ET-1), fibronectin 1, and LOX. The molecular functions of these genes are involved in collagen binding. GSEA of the overall gene expression pattern revealed that many genes increased in the reactive oxygen species pathway and decreased in the inflammatory response. Auranofin decreased nuclear factor kappa B (NF-κB) and IκBα in TGF-β1-induced LX-2 cells, thereby reducing ET-1 and fibrosis. Furthermore, increased pNRF2 in PA-induced HepG2 cells led to increased antioxidant marker expression and decreased lipid accumulation. In the bile duct ligation model mice, auranofin reduced the fibrosis area and increased the survival rate. Auranofin reduced liver fibrosis and lipid accumulation in NASH model mice fed on a Western diet.. Auranofin inhibits lipogenesis and fibrosis formation and is a proposed candidate for NASH treatment.

Topics: Animals; Antioxidants; Auranofin; Collagen; Endothelin-1; Fibronectins; Humans; Liver; Liver Cirrhosis; Mice; Mice, Inbred C57BL; NF-E2-Related Factor 2; NF-kappa B; NF-KappaB Inhibitor alpha; Non-alcoholic Fatty Liver Disease; Palmitic Acid; Reactive Oxygen Species; Signal Transduction; Thrombospondin 1; Transforming Growth Factor beta1; Transforming Growth Factors

Fibrotic processes in the liver of non-alcoholic steatohepatitis (NASH) patients cause microcirculatory dysfunction in the organ which increases blood vessel resistance and causes portal hypertension. Assessing blood vessel function in the liver is challenging, necessitating the development of novel methods in normal and fibrotic tissue that allow for drug screening and translation toward pre-clinical settings. Cultures of precision cut liver slices (PCLS) from normal and fibrotic rat livers were used for blood vessel function analysis. Live recording of vessel diameter was used to assess the response to endothelin-1, serotonin and soluble guanylate cyclase (sGC) activation. A cascade of contraction and relaxation events in response to serotonin, endothelin-1, Ketanserin and sGC activity could be established using vessel diameter analysis of rat PCLS. Both the sGC activator BI 703704 and the sGC stimulator Riociguat prevented serotonin-induced contraction in PCLS from naive rats. By contrast, PCLS cultures from the rat CCl

Topics: Adenosine Triphosphate; Animals; Blood Vessels; Carbon Tetrachloride; Endothelin-1; Ketanserin; Liver; Liver Cirrhosis; Male; Non-alcoholic Fatty Liver Disease; Oxidative Stress; Pyrazoles; Pyrimidines; Rats, Sprague-Dawley; Rats, Wistar; Serotonin; Signal Transduction; Soluble Guanylyl Cyclase; Vasoconstriction; Vasodilation

In non-alcoholic steatohepatitis (NASH), decreased nitric oxide and increased endothelin-1 (ET-1, also known as EDN1) released by sinusoidal endothelial cells (LSEC) induce hepatic stellate cell (HSC) contraction and contribute to portal hypertension (PH). Statins improve LSEC function, and ambrisentan is a selective endothelin-receptor-A antagonist. We aimed to analyse the combined effects of atorvastatin and ambrisentan on liver histopathology and hemodynamics, together with assessing the underlying mechanism in a rat NASH model. Diet-induced NASH rats were treated with atorvastatin (10 mg/kg/day), ambrisentan (30 mg/kg/day or 2 mg/kg/day) or a combination of both for 2 weeks. Hemodynamic parameters were registered and liver histology and serum biochemical determinations analysed. Expression of proteins were studied by immunoblotting. Conditioned media experiments were performed with LSEC. HSCs were characterized by RT-PCR, and a collagen lattice contraction assay was performed. Atorvastatin and ambrisentan act synergistically in combination to completely normalize liver hemodynamics and reverse histological NASH by 75%. Atorvastatin reversed the sinusoidal contractile phenotype, thus improving endothelial function, whereas ambrisentan prevented the contractile response in HSCs by blocking ET-1 response. Additionally, ambrisentan also increased eNOS (also known as Nos3) phosphorylation levels in LSEC, via facilitating the stimulation of endothelin-receptor-B in these cells. Furthermore, the serum alanine aminotransferase of the combined treatment group decreased to normal levels, and this group exhibited a restoration of the HSC quiescent phenotype. The combination of atorvastatin and ambrisentan remarkably improves liver histology and PH in a diet-induced NASH model. By recovering LSEC function, together with inhibiting the activation and contraction of HSC, this combined treatment may be an effective treatment for NASH patients.

Topics: Alanine Transaminase; Animals; Atorvastatin; Biomarkers; Collagen; Disease Models, Animal; Drug Synergism; Endothelial Cells; Endothelin-1; Enzyme Activation; Hemodynamics; Hepatic Stellate Cells; Insulin Resistance; Liver; Liver Cirrhosis; Nitric Oxide Synthase Type III; Non-alcoholic Fatty Liver Disease; Phenylpropionates; Pyridazines; Weight Gain

Aim To determine the role of endothelin (ET)-1 in predicting hepatopulmonary syndrome (HPS) in patients with liver cirrhosis. Methods A cross sectional study involving 80 liver cirrhosis patients aged 18 years or older was conducted in Adam Malik General Hospital Medan, Indonesia between July 2017 and June 2018. HPS diagnosis was confirmed from the presence of liver cirrhosis, abnormal oxygenation, and intrapulmonary vascular dilatations (IPVD). ET-1 level was measured from serum sample using ELISA method. Patients with coexisting primary pulmonary pathology and intrinsic heart disease were active smokers, and those who declined to participate were excluded. Statistical analysis was conducted at 95% confidence interval. p<0.05 was considered significant. Results Majority the patients were male (56.3%) and had higher educational background (62.5%). Mean age of the patients was 51.3 (SD=12.6) years. The prevalence of HPS was 21.2%. The patients with HPS had higher ET-1 level compared to those without HPS (p<0.001). The patients with hepatic encephalopathy had 2.917 times higher risk for suffering from HPS, while the patients with Child Pugh score A had lower risk (0.738 times) for having HPS compared to subjects with Child Pugh score B and C. ET-1 level >187.5 mg/L had sensitivity and specificity for predicting HPS in subjects with liver cirrhosis of 82.35% and 81.25%, respectively. Conclusion ET-1 could be used as a promising marker for HPS in patients with liver cirrhosis. ET-1 level of >187.5 mg/l had a good accuracy in predicting HPS in liver cirrhosis patient.

Topics: Adolescent; Cross-Sectional Studies; Endothelin-1; Hepatopulmonary Syndrome; Humans; Liver Cirrhosis; Male; Middle Aged; Prospective Studies

Liver sinusoidal endothelial cells (LSECs) undergo capillarization, or loss of fenestrae, and produce basement membrane during liver fibrotic progression. DLL4, a ligand of the Notch signaling pathway, is predominantly expressed in endothelial cells and maintains liver sinusoidal homeostasis. The aim of this study was to explore the role of DLL4 in LSEC capillarization. The expression levels of DLL4 and the related genes, capillarization markers and basement membrane proteins were assessed by immunohistochemistry, immunofluorescence, RT-PCR and immunoblotting as appropriate. Fenestrae and basement membrane formation were examined by electron microscopy. We found DLL4 was up-regulated in the LSECs of human and CCl4-induced murine fibrotic liver, consistent with LSEC capillarization and liver fibrosis. Primary murine LSECs also underwent capillarization in vitro, with concomitant DLL4 overexpression. Bioinformatics analysis confirmed that DLL4 induced the production of basement membrane proteins in LSECs, which were also increased in the LSECs from 4 and 6-week CCl4-treated mice. DLL4 overexpression also increased the coverage of liver sinusoids by hepatic stellate cells (HSCs) through endothelin-1 (ET-1) synthesis. The hypoxic conditions that was instrumental in driving DLL4 overexpression in the LSECs. Consistent with the above findings, DLL4 silencing in vivo alleviated LSEC capillarization and CCl4-induced liver fibrosis. In conclusion, DLL4 mediates LSEC capillarization and the vicious circle between fibrosis and pathological sinusoidal remodeling.

Topics: Adaptor Proteins, Signal Transducing; Animals; Calcium-Binding Proteins; Cell Line; Coculture Techniques; Endothelial Cells; Endothelin-1; Gene Expression Regulation; Gene Knockdown Techniques; Hepatocytes; Humans; Intracellular Signaling Peptides and Proteins; Liver; Liver Cirrhosis; Membrane Proteins; Mice; RNA, Messenger; Signal Transduction

Critical roles for liver sinusoidal endothelial cells (LSECs) in liver fibrosis have been demonstrated, while little is known regarding the underlying molecular mechanisms of drugs delivered to the LSECs. Our previous study revealed that plumbagin plays an antifibrotic role in liver fibrosis. In this study, we investigated whether plumbagin alleviates capillarization of hepatic sinusoids by downregulating endothelin-1 (ET-1), vascular endothelial growth factor (VEGF), laminin (LN), and type IV collagen on leptin-stimulated LSECs. We found that normal LSECs had mostly open fenestrae and no organized basement membrane. Leptin-stimulated LSECs showed the formation of a continuous basement membrane with few open fenestrae, which were the features of capillarization. Expression of ET-1, VEGF, LN, and type IV collagen was enhanced in leptin-stimulated LSECs. Plumbagin was used to treat leptin-stimulated LSECs. The sizes and numbers of open fenestrae were markedly decreased, and no basement membrane production was found after plumbagin administration. Plumbagin decreased the levels of ET-1, VEGF, LN, and type IV collagen in leptin-stimulated LSECs. Plumbagin promoted downregulation of ET-1, VEGF, LN, and type IV collagen mRNA. Altogether, our data reveal that plumbagin reverses capillarization of hepatic sinusoids by downregulation of ET-1, VEGF, LN, and type IV collagen.

Topics: Animals; Basement Membrane; Capillaries; Collagen Type IV; Down-Regulation; Endothelial Cells; Endothelin-1; Hepatic Veins; Hepatocytes; Laminin; Liver; Liver Cirrhosis; Male; Naphthoquinones; Rats; Rats, Sprague-Dawley; Vascular Endothelial Growth Factor A

Hepatopulmonary syndrome (HPS) is characterized by oxygen desaturation and increased intrapulmonary shunting formation in cirrhosis. Due to an unclarified mechanism, there is still no effective therapy except liver transplantation. Recent studies revealed that pulmonary angiogenesis may participate in pathogenesis, in which nitric oxide (NO) and vascular endothelial growth factor (VEGF) play roles. Pioglitazone, a peroxisome proliferator-activated receptor gamma agonist, exerts anti-angiogenesis effect. However, whether pioglitazone influences pulmonary angiogenesis, shunting and HPS remains unexplored.. Cirrhosis with HPS was induced in Spraque-Dawley rats with common bile duct ligation (CBDL). Pioglitazone (10 mg/kg/day, oral gavage) or vehicle was administered from 8th to 28th day post CBDL. On the 28th day, the mortality rate, hemodynamic parameters, concentrations of plasma glucose and liver biochemistry parameters, and arterial blood gas data were evaluated. Lungs were dissected for protein expression analyses. In another series, intrapulmonary shunting degree was determined by color microsphere method in paralleled groups.. The survival rates were similar in HPS rats with or without pioglitazone administration. Pioglitazone did not influence the hemodynamic parameters, glucose and liver biochemistry levels, oxygen saturation and alveolar arterial gradient, but significantly down-regulated pulmonary VEGF protein expression, endothelial NO synthase (eNOS) activation, and decreased intrapulmonary shunts. Pioglitazone significantly decreased intrapulmonary shunts as compared with the vehicle (18.1 ± 4.5 vs. 9.8 ± 3.6, p = 0.015).. Pioglitazone down-regulated VEGF, eNOS and decreased intrapulmonary shunts without improving oxygenation. The current finding suggests a multifactorial mechanism of HPS that could not be successfully overcome merely by pioglitazone-induced anti-angiogenesis and shunting reduction.

Topics: Angiogenesis Inhibitors; Animals; Endothelin-1; Hepatopulmonary Syndrome; Liver Cirrhosis; Male; Nitric Oxide; Pioglitazone; Rats; Rats, Sprague-Dawley; Thiazolidinediones; Vascular Endothelial Growth Factor A

In liver cirrhosis, the altered levels of vasoactive substances, especially endothelin-1 (ET-1) and nitric oxide (NO) lead to elevated intrahepatic resistance, increased portal-systemic collaterals and abnormal intra- and extra-hepatic vascular responsiveness. These derangements aggravate portal hypertension-related complications such as gastro-oesophageal variceal bleeding. Homocysteine, a substance implicated in cardiovascular diseases, has been found with influences on vasoresponsiveness and angiogenesis. However, their relevant effects in liver cirrhosis have not been investigated. In the present study, liver cirrhosis was induced by common bile duct ligation (BDL) in Sprague-Dawley rats. In acute study, the results showed that homocysteine enhanced hepatic vasoconstriction to ET-1 but decreased portal-systemic collateral vasocontractility to arginine vasopressin (AVP). Homocysteine down-regulated hepatic phosphorylated endothelial NO synthase (p-eNOS) and p-Akt protein expressions. Inducible NOS (iNOS) and cyclooxygenase (COX)-2 expressions were up-regulated by homocysteine in splenorenal shunt (SRS), the most prominent intra-abdominal collateral vessel. In chronic study, BDL or thioacetamide (TAA) rats received homocysteine or vehicle for 14 days. The results revealed that homocysteine increased hepatic collagen fibre deposition and fibrotic factors expressions in both BDL- and TAA-induced liver fibrotic rats. Portal-systemic shunting and expressions of mesenteric angiogenetic factors [vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), PDGF receptor β (PDGFRβ) and p-eNOS] were also increased in BDL rats. In conclusion, homocysteine is harmful to vascular derangements and liver fibrosis in cirrhosis.

Topics: Animals; Arginine Vasopressin; Collagen; Endothelin-1; Homocysteine; Humans; Liver; Liver Cirrhosis; Male; Nitric Oxide Synthase Type III; Platelet-Derived Growth Factor; Portal Vein; Rats; Rats, Sprague-Dawley; Vascular Endothelial Growth Factor A

To investigate possible abnormalities of vasoactive compounds, nitrative stress, and antioxidant activity of paraoxonase (PONa) in human hepatopulmonary syndrome (HPS), we determined endothelin-1 (ET), nitric oxide (NOx) metabolites, PONa alongside crude plasma nitrotyrosine (NT) as surrogate marker of nitrative stress.. Liver cirrhosis (LC) patients with HPS (n = 12) were matched by age, sex, and Child-Pugh score to LC patients without HPS (n = 15) and to healthy controls (CTR) (n = 15); plasma NO2(-) (nitrite) (vascular metabolite), NO3(-) (nitrate) (inflammatory metabolite), and PONa were determined by a colorimetric assay, ET, and NT by immunoassays.. HPS patients showed higher level of ET (p = 0.0002), NO2(-) (p = 0.002), NO3(-) (p = 0.0001), NT (p < 0.0001), and lower PONa (p = 0.0004) than CTR; post-hoc analysis revealed greater ET (p < 0.05) and NO3(-) (p < 0.005) in LC patients with HPS than in LC patients without HPS. NT correlated to Child-Pugh score within HPS (p = 0.04) and LC (p = 0.02).. Our HPS patients are characterized by elevated plasma levels of ET and NOx metabolites and lower PONa. Reduced PONa alongside elevated NO3(-) and NT suggests that defective antioxidation may favor nitrative stress and both may be implicated in the pathogenesis of HPS.

Topics: Aged; Aryldialkylphosphatase; Biomarkers; Cross-Sectional Studies; Endothelin-1; Female; Hepatopulmonary Syndrome; Humans; Italy; Liver Cirrhosis; Male; Middle Aged; Nitrates; Nitric Oxide; Nitrites

Transjugular intrahepatic portosystemic shunt (TIPSS) cause haemodynamic changes in patients with cirrhosis, yet little is known about long-term cardiopulmonary outcomes.. To evaluate the long-term cardiopulmonary outcome after TIPSS.. We evaluated cardiopulmonary parameters including echocardiography during long-term follow-up after TIPSS. Results at 1-5 years after TIPSS were compared to those of cirrhotic controls. Pulmonary hypertension (PH) diagnoses rates were included. Endothelin 1, thromboxane B2 and serotonin were measured.. We found significant differences 1-5 years after TIPSS compared to pre-implantation values: median left atrial diameter (LAD) increased from 37 mm [interquartile range (IQR): 33-43] to 40 mm (IQR: 37-47, P = 0.001), left ventricular end-diastolic diameter (LV-EDD) increased from 45 mm (range: 41-49) to 48 mm (IQR: 45-52, P < 0.001), pulmonary artery systolic pressure (PASP) increased from 25 mmHg (IQR: 22-33) to 30 mmHg (IQR: 25-36, P = 0.038). Comparing results 1-5 years post-implantation to the comparison cohort revealed significantly higher (P < 0.05) LAD, LV-EDD and PASP values in TIPSS patients. PH prevalence was higher in the shunt group (4.43%) compared to controls (0.91%, P = 0.150). Thromboxane B2 levels correlated with PASP in the TIPSS cohort (P = 0.033). There was no transhepatic gradient observed for the vasoactive substances analysed.. TIPSS placement is accompanied by long-term cardiovascular changes, including cardiac volume overload, and is associated with an increased rate of pulmonary hypertension. The need for regular cardiac follow-up after TIPSS requires further evaluation.

Topics: Adult; Cardiac Volume; Endothelin-1; Female; Follow-Up Studies; Hemodynamics; Humans; Hypertension, Pulmonary; Liver Cirrhosis; Male; Middle Aged; Portasystemic Shunt, Transjugular Intrahepatic; Serotonin; Thromboxane B2

Both endothelin-1 (ET-1) and the renin-angiotensin system (RAS) may play important roles in renal fibrosis in the obstructed kidney. However, there have been few clear demonstrations of a relationship between their activation and additive or synergistic roles in renal fibrosis. We investigated the protective roles and relationship between renal RAS and ET-1 in unilateral ureteral obstruction (UUO) mice.. 8-week-old male C57BL/6 mice were divided into seven groups: sham, bosentan+sham, valsartan+sham, vehicle+UUO, bosentan+UUO, valsartan+UUO, and valsartan+bosentan+UUO. Valsartan and bosentan were administered orally using an NG tube (valsartan 10 mg/kg/day, bosentan 100 mg/kg/day for 8 days, after which the molecular and structural kidney parameters were evaluated. Bosentan treatment elevated plasma renin activity, renal renin, and AT1R expression in UUO mice.. Although valsartan decreased plasma ET-1 in these mice, it did not affect ET(A) or ET(B) in their kidneys. Co-treatment with valsartan and bosentan decreased ET-1 in these mice compared to the single treatments. Bosentan, but not valsartan, elevated eNOS expression in their kidneys. Co-treatment with valsartan and bosentan reduced TGF-β, α-SMA, and collagen IV expression, and the Masson's trichrome stained area in their kidneys.. Bosentan and valsartan acted complementarily, and co-treatment with both drugs had an additive protective effect against renal fibrosis.

Topics: Acute Kidney Injury; Animals; Antihypertensive Agents; Bosentan; Drug Synergism; Endothelin-1; Liver Cirrhosis; Male; Mice; Mice, Inbred C57BL; Receptors, Angiotensin; Sulfonamides; Ureteral Obstruction; Valsartan

The invasive measurement of hepatic venous pressure gradient is the recommended method for the assessment of portal hypertension. We assessed if the mediators that regulate portal hypertension may be used as noninvasive markers of portal hypertension and liver insufficiency.. We explored in prospective, observational study the concentration of endothelin-1, nitric oxide, and transforming growth factor-β1/2 in peripheral and hepatic venous blood; their relationship with the values of portal hypertension and liver insufficiency; and their level changes 4-6 months after non-selective beta-blocker therapy in cirrhotic patients with non-bleeding esophageal varices.. (1) Cirrhotics have significantly increased peripheral endothelin 1 and decreased transforming growth factor-β1 levels; (2) peripheral levels of all factors correlated significantly with their hepatic levels; (3) after therapy, peripheral endothelin-1 levels significantly increased, but transforming growth factor-β2 levels decreased and were lower in patients with pressure gradient value normalization; (4) before and after therapy, peripheral and hepatic endothelin-1, transforming growth factor-β1/2 levels correlated significantly with liver failure indicators (laboratory parameters, Child-Pough and MELD scores) and pressure gradient values.. Peripheral endothelin-1 and transforming growth factor-β1 levels, which strongly correlate with their hepatic levels, reflect the stage of portal hypertension and liver insufficiency in cirrhosis.

Topics: Adrenergic beta-Antagonists; Adult; Aged; Biomarkers; Endothelin-1; Female; Humans; Hypertension, Portal; Liver; Liver Cirrhosis; Liver Function Tests; Male; Middle Aged; Nitric Oxide; Portal Pressure; Prospective Studies; Transforming Growth Factor beta; Transforming Growth Factor beta1

Hepatocarcinogenesis commonly involves the gradual progression from hepatitis to fibrosis and cirrhosis, and ultimately to hepatocellular carcinoma (HCC). Endothelin 1 (Edn1) has been identified as a gene that is significantly up-regulated in HBx-induced HCC in mice. In this study, we further investigated the role of edn1 in hepatocarcinogenesis using a transgenic zebrafish model and a cell culture system. Liver-specific edn1 expression caused steatosis, fibrosis, glycogen accumulation, bile duct dilation, hyperplasia, and HCC in zebrafish. Overexpression of EDN1 in 293T cells enhanced cell proliferation and cell migration in in vitro and xenotransplantation assays and was accompanied with up-regulation of several cell cycle/proliferation- and migration-specific genes. Furthermore, expression of the unfolded protein response (UPR) pathway-related mediators, such as spliced XBP1, ATF6, IRE1, and PERK, was also up-regulated at both the RNA and protein levels. In the presence of an EDN1 inhibitor or an AKT inhibitor, these increases were diminished and the EDN1-induced migration ability also was disappeared, suggesting that the EDN1 effects act through activation of the AKT pathway to enhance the UPR and subsequently activate the expression of downstream genes. Additionally, p-AKT is enhanced in the edn1 transgenic fish compared to the GFP-mCherry control. The micro RNA miR-1 was found to inhibit the expression of EDN1. We also observed an inverse correlation between EDN1 and miR-1 expression in HCC patients. In conclusion, our data suggest that EDN1 plays an important role in HCC progression by activating the PI3K/AKT pathway and is regulated by miR-1.

Topics: Animals; Carcinoma, Hepatocellular; Cell Cycle; Cell Movement; Cell Proliferation; Endothelin-1; Fatty Liver; Gene Expression; HEK293 Cells; Humans; Liver Cirrhosis; Liver Neoplasms; MicroRNAs; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Unfolded Protein Response; Zebrafish; Zebrafish Proteins

To investigate hemodynamic change of patients with cirrhosis by using Color Doppler ultrasound technique and to explore the significance of change in the content of vasoactive substances-plasma endothelin-1 (ET-1) and calcitonin gene-related peptide (CGRP).. A total of 178 cases with cirrhosis were regarded as study groups, and were divided into three degrees: A, B and C according to child-pugh and meanwhile 60 cases were regarded as normal control group. Portal vein and splenic vein of patients were explored by adopting Color Doppler ultrasound technique, related indexes were recorded and the blood flow as well as their ration in the two groups was calculated. Radio immunoassay was adopted to detect the content of plasma ET-1 and CGRP in both study group and contrast group.. Compared with the healthy cases in the contrast group, there was abnormal hemodynamics in the system of portal vein of patients with cirrhosis and the content of plasma ET-1 and CGRP was increased obviously. In the Child-Pugh liver function grades, the content of ET-1 and CGRP was increased as the degree of cirrhosis became more and more serious. There was no significant difference in the comparison between those without ascites and those in contrast group (P>0.05), the content of plasma ET-1 and CGRP in patients without ascites was increased remarkably. Besides, there was positive correlation between the content of plasma ET-1 and CGRP and Dpv, Dsv and Qsv.. Detection of abnormal hemodynamics of portal vein and splenic vein by Color Doppler ultrasound technique can be one of the means for diagnosis of hypertension. Plasma ET-1 and CGRP of patients with cirrhosis reflect the serious degree of the damage in live function and play an important role in the formation and development of portal hypertension.

Topics: Adult; Calcitonin Gene-Related Peptide; Case-Control Studies; Endothelin-1; Female; Hemodynamics; Humans; Liver Cirrhosis; Male; Middle Aged; Ultrasonography, Doppler, Color; Young Adult

The human immunodeficiency virus type 1 (HIV-1) p17 is a matrix protein involved in virus life's cycle. CXCR2 and Syndecan-2, the two major coreceptors for the p17 protein, are expressed in hepatic stellate cells (HSCs), a key cell type involved in matrix deposition in liver fibrotic disorders.. In this report we have investigated the in vitro impact of p17 on HSCs transdifferentiation and function and underlying signaling pathways involved in these processes.. LX-2 cells, a human HSC line, and primary HSC were challenged with p17 and expressions of fibrogenic markers and of p17 receptors were assessed by qRT-PCR and Western blot. Downstream intracellular signaling pathways were evaluated with qRT-PCR and Western blot as well as after pre-treatment with specific pathway inhibitors.. Exposure of LX2 cells to p17 increases their contractile force, reshapes the cytoskeleton fibers and upregulates the expression of transdifferentiation markers including αSMA, COL1α1 and endothelin-1 through the activation of Jak/STAT and Rho signaling pathways. These effects are lost in HSCs pre-incubated with a serum from HIV positive person who underwent a vaccination with a p17 peptide. Confocal laser microscopy studies demonstrates that CXCR2 and syndecan-2 co-associate at the plasma membrane after exposure to p17. Immunostaining of HIV/HCV liver biopsies from co-infected patients reveals that the progression of liver fibrosis correlates with a reduced expression of CXCR2.. The HIV matrix protein p17 is pro-fibrogenic through its interactions both with CXCR2 and syndecan-2 on activated HSCs.

Topics: Actins; Adult; Aged; Antibodies, Viral; Cell Line; Collagen Type I; Cytoskeleton; Disease Progression; Endothelin-1; Female; gag Gene Products, Human Immunodeficiency Virus; Gene Expression Regulation; Hepatic Stellate Cells; HIV Antigens; HIV-1; Humans; Liver Cirrhosis; Male; Middle Aged; Protein Binding; Protein Transport; Receptors, Interleukin-8; Receptors, Interleukin-8B; rho GTP-Binding Proteins; rho-Associated Kinases; Signal Transduction; Syndecan-2; Vaccination

The effect of splenomegaly in patients with liver cirrhosis and portal hypertension is not fully understood. This study was designed to determine the effect of laparoscopic splenectomy on portal haemodynamics in these patients.. Patients with liver cirrhosis and portal hypertension who underwent laparoscopic splenectomy in Kyushu University Hospital from January 2006 to March 2009 were evaluated retrospectively. Correlations between splenic size and portal haemodynamics, and changes in portal haemodynamics and in levels of the vasoactive agents endothelin (ET) 1 and nitric oxide metabolites (NOx) before and 7-10 days after laparoscopic splenectomy were analysed.. Portal venous (PV) blood flow, PV cross-sectional area and PV congestion index correlated significantly with splenic size (P < 0·050). All three were significantly reduced following splenectomy in 59 patients. The hepatic venous pressure gradient, measured in 18 patients, decreased by 25 per cent after splenectomy (P < 0·001). Portal vascular resistance was also reduced, by 21 per cent (P = 0·009). The peripheral blood concentration of ET-1 decreased from 2·95 to 2·11 pg/ml (P < 0·001), and that of NOx tended to decrease (from 29·2 to 25·0 pg/ml; P = 0·068). In hepatic venous blood, the level of ET-1 decreased from 2·37 to 1·83 pg/ml (P = 0·006), whereas NOx concentration tended to increase (from 24·5 to 30·9 pg/ml; P = 0·067).. In patients with liver cirrhosis and portal hypertension, splenectomy reduced portal venous pressure. A decrease in splanchnic blood flow, by eliminating splenic blood flow, and reduction in intrahepatic vascular resistance, by normalizing hepatic concentrations of ET-1 and NOx, may both have contributed.

Topics: Ascites; Blood Cell Count; Blood Flow Velocity; Endothelin-1; Esophageal and Gastric Varices; Hemodynamics; Humans; Hypertension, Portal; Laparoscopy; Liver Cirrhosis; Male; Middle Aged; Nitric Oxide; Organ Size; Prothrombin Time; Retrospective Studies; Splanchnic Circulation; Spleen; Splenectomy; Treatment Outcome

Liver fibrosis is mediated by hepatic stellate cells (HSCs), which respond to a variety of cytokine and growth factors to moderate the response to injury and create extracellular matrix at the site of injury. G-protein coupled receptor (GPCR)-mediated signaling, via endothelin-1 (ET-1) and angiotensin II (AngII), increases HSC contraction, migration and fibrogenesis. Regulator of G-protein signaling-5 (RGS5), an inhibitor of vasoactive GPCR agonists, functions to control GPCR-mediated contraction and hypertrophy in pericytes and smooth muscle cells (SMCs). Therefore we hypothesized that RGS5 controls GPCR signaling in activated HSCs in the context of liver injury. In this study, we localize RGS5 to the HSCs and demonstrate that Rgs5 expression is regulated during carbon tetrachloride (CCl4)-induced acute and chronic liver injury in Rgs5LacZ/LacZ reporter mice. Furthermore, CCl4 treated RGS5-null mice develop increased hepatocyte damage and fibrosis in response to CCl4 and have increased expression of markers of HSC activation. Knockdown of Rgs5 enhances ET-1-mediated signaling in HSCs in vitro. Taken together, we demonstrate that RGS5 is a critical regulator of GPCR signaling in HSCs and regulates HSC activation and fibrogenesis in liver injury.

Topics: Animals; Cell Line; Chemical and Drug Induced Liver Injury; Disease Models, Animal; Endothelin-1; Gene Expression; Gene Expression Regulation; Hematopoietic Stem Cells; Hepatic Stellate Cells; Liver Cirrhosis; Liver Diseases; Liver Neoplasms; Male; Mice; Mice, Knockout; Mice, Transgenic; RGS Proteins; RNA, Small Interfering; Signal Transduction

Our previous nutrigenomic findings indicate that eggshell membrane (ESM) may prevent liver fibrosis. Here we investigated the effects and mechanisms underlying ESM intervention against liver injury by using DNA microarray analysis and comparative proteomics. In vitro hydrolyzed ESM attenuated the TGFβ1-induced procollagen production of human hepatocyte C3A cells and inhibited the expression of Endothelin 1 (EDN1) and its two receptors, and extracellular matrix components. In vivo male Wistar rats were allocated into a normal control group, a CCl4 group (hypodermic injection of 50% CCl4 2×/wk) and an ESM group (20 g ESM/kg diet with CCl4 injection) for 7 wks. Dietary ESM ameliorated the elevated activity of ALT/AST, oxidative stress and collagen accumulation in liver, accompanied by the down-regulated expression of Edn1 signaling and notable profibrogenic genes and growth factors as well as peroxisome proliferator-activated receptor gamma (PPARγ). Concomitantly, the decreased expressions of Galectin-1 and Desmin protein in the ESM group indicated the deactivation of hepatic stellate cells (HSCs). Through a multifaceted integrated omics approach, we have demonstrated that ESM can exert an antifibrotic effect by suppressing oxidative stress and promoting collagen degradation by inhibiting HSCs' transformation, potentially via a novel modulation of the PPARγ-Endothelin 1 interaction signaling pathway.

Topics: Animals; Apoptosis; Biomarkers; Blotting, Western; Cell Proliferation; Cells, Cultured; Egg Shell; Endothelin-1; Gene Expression Profiling; Hepatocytes; Humans; Liver; Liver Cirrhosis; Male; Oligonucleotide Array Sequence Analysis; Oxidative Stress; PPAR gamma; Proteomics; Rats; Rats, Wistar; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction

Both angiotensin (Ang)-II and endothelin-1 (ET-1) are involved in the pathogenesis of liver fibrosis. Activated hepatic stellate cells (HSCs) are considered a key effector of liver fibrosis.. To explore the effect of Ang-II on ET-1 expression in cultured human HSCs and the underlying mechanisms.. Human HSCs were treated with Ang-II in different concentrations (0.1, 0.5, 1, 5, or 10 nM) for different lengths of time (0.5, 1, 2, 4, or 6 h) with or without transcription inhibitor actinomycin D, Ang-II type 1 (AT1) receptor blocker losartan, AT2 receptor blocker PD123177, or different kinase inhibitors.. Ang-II increased the ET-1 mRNA level in a statistically significant dose- and time-dependent manner within 4 h, which led to dose-dependent up-regulation of the ET-1 protein level. Actinomycin D (1 mg/ml), losartan (50 μM), and phosphatidylinositol-3 kinase inhibitor LY294002 (50 μM) abolished the promoting effect of Ang-II on ET-1 expression. Ang-II (10 nM) significantly increased the expression of α-smooth muscle actin and type I collagen in HSCs, which was abolished by losartan, LY294002, ET A receptor blocker BQ123, and ET-1 siRNA, but not PD123177 and ET B receptor blocker BQ788.. Ang-II induces ET-1 expression in human HSCs via the AT1 receptor by the PI3 K/Akt signaling pathway. The ET-1/ET A receptor axis could mediate the promoting effects of Ang-II on HSCs' transdifferentiation into myofibroblast-like cells. This is the first evidence of crosstalk between the Ang-II/AT1 axis and the ET-1 system in regard to the pathogenesis of liver fibrosis.

Topics: Angiotensin I; Angiotensin II; Angiotensin Receptor Antagonists; Cells, Cultured; Endothelin-1; Hepatic Stellate Cells; Humans; Liver Cirrhosis; Renin-Angiotensin System

Hepatopulmonary syndrome is a pulmonary vascular complication of cirrhosis in which intrapulmonary vasodilatation (IPV) results in hypoxemia. Endothelin-1 (ET-1), produced by proliferating cholangiocytes, has been identified as a mediator of IPV in an animal model of HPS, but the pathophysiology of IPV in humans has not been defined.. The purpose of this study was to assess whether cirrhosis with IPV, which often leads to HPS, is associated with increased hepatic venous ET-1 blood levels.. We performed a prospective cohort pilot study of 40 patients with liver disease undergoing transjugular liver biopsy from November 1, 2008 to September 1, 2009. Patients were categorized according to absence (-) or presence (+) of IPV as determined by bubble-contrasted echocardiography. Hepatic venous blood was assayed for ET-1 by ELISA. The percent volume of cholangiocytes in the liver biopsy specimen was determined by morphometric analysis, as a measure of bile duct proliferation.. Nine subjects were excluded, due to absence of cirrhosis (6) and patent foramen ovale (3). Of the remaining 31 subjects, IPV was present in 18 (58%). Median hepatic venous ET-1 was higher with IPV+ than IPV- at levels of 9.1 pg/mL (range 7.5-11.7) versus 2.1 pg/mL (1.3-5.6), respectively (P = 0.004). ET-1 levels correlated positively with cholangiocyte percent volume (r = 0.72, P < 0.001) but not with measures of liver dysfunction (bilirubin, INR, MELD score, or hepatic venous pressure gradient).. In human cirrhosis, increased hepatic venous ET-1 is associated with IPV and increased hepatic cholangiocyte volume.

Topics: Bile Ducts; Cell Proliferation; Cross-Sectional Studies; Dilatation, Pathologic; Endothelin-1; Female; Hepatic Veins; Hepatopulmonary Syndrome; Humans; Immunohistochemistry; Liver Cirrhosis; Male; Middle Aged; Pilot Projects; Prospective Studies; Pulmonary Veins; Vasodilation

Hepatic stellate cells (HSC) play a major role in the progression of liver fibrosis.. The aim of our study was to investigate whether rat HSC cultured on a nanofiber membrane (NM) retain their quiescent phenotype during both short- and long-term culture and whether activated HSC revert to a quiescent form when re-cultured on NM.. Rat HSC cultured for 1 day on plastic plates (PP) were used as quiescent HSC, while cells cultured for 1 week on PP were considered to be activated HSC. Quiescent or activated HSC were subsequently plated on PP or NM and cultured for an additional 4 days at which time their gene expression, stress fiber development, and growth factor production were determined. For long-term culture, HSC were grown on NM for 20 days and the cells then replated on PP and cultured for another 10 days.. Expression of marker genes for HSC activation, stress fiber development, and growth factor production were significantly lower in both quiescent and activated HSC cultured on NM than in those cultured on PP. After long-term culture on NM, activation marker gene expression and stress fiber development were still significantly lower in HSC than in PP, and HSC still retained the ability to activate when replated onto PP.. HSC cultured on NM retained quiescent characteristics after both short- and long-term culture while activated HSC reverted toward a quiescent state when cultured on NM. Cultures of HSC grown on NM are a useful in vitro model to investigate the mechanisms of activation and deactivation.

Topics: Animals; Biological Factors; Cell Adhesion; Cell Movement; Endothelin-1; Gene Expression Profiling; Hepatic Stellate Cells; Liver Cirrhosis; Male; Nanofibers; Plastics; Primary Cell Culture; Rats; Rats, Wistar; Stress Fibers; Time Factors; Transforming Growth Factor beta2

Increased serum angiotensin-converting enzyme (SACE) activity and serum concentration of endothelin-1 (ET-1) were found in liver cirrhosis. We investigated a correlation between the different stages of liver fibrosis and SACE activity and serum ET-1 concentration. Seventy patients with pathohistologically established chronic liver disease were divided in three groups according to Ishak criteria for liver fibrosis: minimal fibrosis (Ishak score 0-1, n =20), medium fibrosis (Ishak score 2-5, n=20) and cirrhosis (Ishak score 6, n=30). SACE activity and ET-1 concentration were determined using commercial ELISA kits. SACE activity and ET-1 concentrations were proportional to the severity of disease, the highest being in patients with liver cirrhosis. Maximal increase in SACE activity was found between minimal and medium fibrosis while maximal increase in ET-1 concentration was revealed between medium fibrosis and cirrhosis. The analysis of the Receiver Operating Characteristic (ROC) curve for SACE activity suggested a cut-off value to separate minimal from medium fibrosis at 59.00 U/L (sensitivity 100%, specificity 64.7%). The cut-off value for serum ET-1 concentration to separate medium fibrosis from cirrhosis was 12.4 pg/mL (sensitivity 96.8%, specificity 94.4%). A positive correlation between SACE activity and ET-1 concentration was registered (Spearman's ñ = 0.438, p = 0.004). Both SACE activity and ET-1 concentration were increased in all stages of liver fibrosis. Cut-off points for SACE activity and ET-1 concentration could be a biochemical marker for the progression of fibrosis. Positive correlation between SACE activity and ET-1 concentration might indicate their interaction in the development of liver cirrhosis.

Topics: Adult; Aged; Endothelin-1; Enzyme Activation; Female; Humans; Liver Cirrhosis; Male; Middle Aged; Peptidyl-Dipeptidase A; Prospective Studies; Severity of Illness Index; Young Adult

Non-alcoholic fatty liver disease can progress to steatohepatitis and fibrosis, and is also associated with impaired liver regeneration. The pathophysiology remains elusive. We recently showed that severe steatosis is associated with an increase in portal pressure, suggesting liver flow impairment. The objective of this study is to directly assess total intrahepatic resistance and its potential functional and structural determinants in an in situ perfusion model. Male Wistar rats fed a control (n = 30) or a methionine-choline-deficient (MCD) diet (n = 30) for 4 weeks were compared. Liver tissue and serum analysis, in vivo haemodynamic measurements, in situ perfusion experiments and vascular corrosion casts were performed. The MCD group showed severe steatosis without inflammation or fibrosis on histology. Serum levels and liver tissue gene expression of interleukin (IL)-6, tumour necrosis factor-α, IL-1β and interferon-γ, liver tissue myeloperoxidase activity and liver immunohistochemistry with anti-CD68 and anti-α smooth muscle actin were comparable between groups, excluding significant inflammation. Flow-pressure curves were significantly different between groups for all flows (slope values: 0.1636 ± 0.0605 mm Hg/ml/min in controls vs 0.7270 ± 0.0408 mm Hg/ml/min in MCD-fed rats, P < 0.001), indicating an increased intrahepatic resistance, which was haemodynamically significant (portocaval pressure gradient 2.2 ± 1.1 vs 8.2 ± 1.3 mm Hg in controls vs MCD, P<0.001). Dose-response curves to acetylcholine were significantly reduced in MCD-fed rats (P < 0.001) as was the responsiveness to methoxamine (P<0.001). Vascular corrosion casts showed a replacement of the regular sinusoidal anatomy by a disorganized pattern with multiple interconnections and vascular extensions. Liver phosphorylated endothelial NO synthase (eNOS)/eNOS and serum nitrite/nitrate were not increased in severe steatosis, whereas liver thromboxane synthase expression, liver endothelin-1 (ET-1) expression and serum andothelin-1 concentration were significantly increased. Severe steatosis induces a haemodynamically significant increase in intrahepatic resistance, which precedes inflammation and fibrogenesis. Both functional (endothelial dysfunction and increased thromboxane and ET-1 synthesis) and structural factors are involved. This phenomenon might significantly contribute to steatosis-related disease.

Topics: Analysis of Variance; Animals; Cytokines; Endothelin-1; Endothelium, Vascular; Fatty Liver; Hypertension, Portal; Liver; Liver Circulation; Liver Cirrhosis; Male; Methoxamine; Microscopy, Electron, Scanning; Microvessels; Nitric Oxide; Nitric Oxide Synthase Type III; Rats; Rats, Wistar; Thromboxane-A Synthase; Vasoconstriction; Vasoconstrictor Agents

Primary sclerosing cholangitis (PSC) is a cholestatic liver disease with high propensity to develop into cholangiocarcinoma. The hepatobiliary disorder of PSC is due to progressive fibrosis surrounding the intra- and extrahepatic bile ducts. Until now, no effective medical therapy exists. To study the progression of sclerosing cholangitis after inhibition of the sympathetic nervous system by blockade of the β-adrenoceptors, we used the Mdr2(-/-) mouse model, which develops periportal fibrosis similar to human PSC. Liver tissues of Mdr2(-/-) mice untreated or treated with the β-adrenoceptor antagonist propranolol were analyzed for inflammation and fibrosis progression at different time points by histological scoring and immunostaining for α-smooth muscle actin (α-SMA), CD45 and S100A4. Transaminases and hydroxyproline contents were determined. Expression of angiotensinogen, endothelin-1, TGF-β, TNF-α, CTGF and procollagen 1A1 was studied by real-time PCR on laser-microdissected areas of acinar zones I and II-III. After 3 months, periportal fibrosis had developed in Mdr2(-/-) mice, but immunostaining revealed no sinusoidal and only minor periportal contribution of myofibroblasts with prominent fibroblasts. Propranolol treatment of Mdr2(-/-) mice improved liver architecture. Additionally, inflammation and fibrosis were significantly reduced. After 3 months of treatment, the antifibrotic effect of the β-blockade was most obvious. The transcript levels of procollagen 1A1, TNF-α, TGF-β, CTGF and endothelin-1 were markedly repressed in the portal areas of treated mice. Taken together, these data show that propranolol efficiently delays progression of sclerosing cholangitis. Therefore, the blockade of β-adrenoceptors is a promising option to support future therapeutic strategies in the treatment of human PSC.

Topics: Actins; Adrenergic beta-Antagonists; Animals; ATP Binding Cassette Transporter, Subfamily B; ATP-Binding Cassette Sub-Family B Member 4; Bile Ducts; Blood Pressure; Cholangitis, Sclerosing; Collagen Type I; Collagen Type I, alpha 1 Chain; Connective Tissue Growth Factor; Endothelin-1; Histological Techniques; Immunohistochemistry; Lasers; Leukocyte Common Antigens; Liver Cirrhosis; Mice; Mice, Knockout; Microdissection; Propranolol; Reverse Transcriptase Polymerase Chain Reaction; S100 Calcium-Binding Protein A4; S100 Proteins; Sympathetic Nervous System; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

TGF-β1 a key pro-fibrotic factor activates signaling via the canonical ALK/SMAD as well as the Rho GTPase pathways. Rho kinase is a major downstream effector of Rho GTPase signaling. To understand the contribution of Rho kinase activation towards the synthesis of fibrotic mediators by hepatic stellate cells (HSC), we first profiled activated HSC and fibrotic liver tissues to identify common transcripts that were most significantly up-regulated across all samples. We then applied a pharmacologic as well as a genomics approach in a TGF-β1 activated human HSC line (LX-2) to study the involvement of Rho kinase signaling in the expression of a subset of these up-regulated fibrotic genes.. Total RNA was profiled using microarray chips. Data analysis was performed using Ingenuity Pathway Analysis software. LX-2 cells were activated with 10 ng/ml of TGF-β1 for 24 h. Activation of downstream pathways was assessed by Western blotting with phospho-specific target biomarker antibodies. Targeted knockdown of Rho kinase isoforms 1 and 2 was achieved with RNAi. Secreted levels of endothelin-1, TGF-β2, and thrombospondin-1 were measured by ELISA.. TGF-β1 activated Rho kinase and Smad pathways in LX-2 cells. The syntheses of endothelin-1 and TGF-β2 were significantly inhibited in TGF-β1 treated LX-2 cells, by isoform non-selective Rho kinase inhibitors. siRNA knockdown of each isoform suggested that endothelin-1 synthesis was largely mediated by the Rho kinase-1 isoform, while both isoforms contributed to the synthesis of TGF-β2.. The TGF-β1 mediated secretion of endothelin-1 and TGF-β2 is mediated by Rho kinase activation in human HSC.

Topics: Animals; Cell Line; Endothelin-1; Enzyme Activation; Enzyme Inhibitors; Gene Expression Profiling; Gene Knockdown Techniques; Hepatic Stellate Cells; Humans; Liver Cirrhosis; Male; Oligonucleotide Array Sequence Analysis; Rats; Rats, Sprague-Dawley; rho-Associated Kinases; RNA, Messenger; RNA, Small Interfering; Signal Transduction; Thrombospondin 1; Transforming Growth Factor beta1; Transforming Growth Factor beta2

Cirrhosis is associated with several extrahepatic manifestations including portopulmonary hypertension (PPHT). Recent data suggest that endothelins (ETs) are related to the pathophysiology of PPHT. The study aimed to measure serum ET levels in hospitalized cirrhotic patients and to determine their association with PPHT and patient outcome.. Fifty-seven cirrhotic patients [43 males; median age 58 (28-87) years] underwent Doppler echocardiography. Patients with systolic pulmonary arterial pressure ≥40 mmHg and pulmonary acceleration time <100 ms were deemed to have PPHT. ET-1, 2, and 3 serum levels were measured with an ELISA assay. All-cause mortality was recorded over a median period of 24 months.. Nine out of 57 patients (15.8%) had PPHT. Among various clinical variables, only autoimmune hepatitis was associated with PPHT (OR=11.5; 95% CI, 1.58-83.4; P=0.01). ET-1 levels [9.1 (1.6-20.7) vs 2.5 (1.4-9.2) pg/mL, P=0.02] and the ET-1/ET-3 ratio [4.73 (0.9-22.4) vs 1.6 (0.3-10.7), P=0.02] were significantly higher in patients with PPHT than in those without. ET-2 and ET-3 levels did not differ between the two groups. There was no difference in survival between the two groups, although ET-1 levels were associated with an adverse outcome in Cox regression analysis (HR=1.11; 95% CI, 1.02-1.22; P=0.02 per unit increase in ET-1).. Our data suggest that ET-1 and the ET-1/ET-3 ratio are elevated in patients with PPHT and that ET-1 is associated with a poor outcome irrespective of PPHT.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Chi-Square Distribution; Echocardiography, Doppler, Color; Echocardiography, Doppler, Pulsed; Endothelin-1; Endothelin-2; Endothelin-3; Endothelins; Enzyme-Linked Immunosorbent Assay; Female; Greece; Hospitalization; Humans; Hypertension, Portal; Hypertension, Pulmonary; Kaplan-Meier Estimate; Liver Cirrhosis; Logistic Models; Male; Middle Aged; Prognosis; Proportional Hazards Models; Risk Assessment; Risk Factors; Time Factors

Hereditary hemochromatosis is commonly associated with liver fibrosis. Likewise, hepatic iron overload secondary to chronic liver diseases aggravates liver injury. To uncover underlying molecular mechanisms, hemochromatotic hemojuvelin knockout (Hjv-/-) mice and wild type (wt) controls were intoxicated with CCl(4). Hjv-/- mice developed earlier (by 2-4 weeks) and more acute liver damage, reflected in dramatic levels of serum transaminases and ferritin and the development of severe coagulative necrosis and fibrosis. These responses were associated with an oxidative burst and early upregulation of mRNAs encoding α1-(I)-collagen, the profibrogenic cytokines TGF-β1, endothelin-1 and PDGF and, notably, the iron-regulatory hormone hepcidin. Hence, CCl4-induced liver fibrogenesis was exacerbated and progressed precociously in Hjv-/- animals. Even though livers of naïve Hjv-/- mice were devoid of apparent pathology, they exhibited oxidative stress and immunoreactivity towards α-SMA antibodies, a marker of hepatic stellate cells activation. Furthermore, they expressed significantly higher (2-3 fold vs. wt, p<0.05) levels of α1-(I)-collagen, TGF-β1, endothelin-1 and PDGF mRNAs, indicative of early fibrogenesis. Our data suggest that hepatic iron overload in parenchymal cells promotes oxidative stress and triggers premature profibrogenic gene expression, contributing to accelerated onset and precipitous progression of liver fibrogenesis.

Topics: Animals; Blotting, Western; Carbon Tetrachloride; Endothelin-1; GPI-Linked Proteins; Hemochromatosis Protein; Immunohistochemistry; Liver; Liver Cirrhosis; Membrane Proteins; Mice; Mice, Knockout; Platelet-Derived Growth Factor; Polymerase Chain Reaction; Transforming Growth Factor beta1

Portopulmonary hypertension (PPHTN) is a rare complication in patients with portal hypertension. A role of endothelin 1 (ET-1) and other cytokines was demonstrated in primary pulmonary hypertension but not in PPHTN. We evaluated the possible role of ET-1, interleukin 6 (IL-6), interleukin 1β (IL-1β), and tumor necrosis factor alpha (TNF-α) in the pathogenesis of PPHTN. Plasmatic concentrations of ET-1, IL-6, IL-1β, and TNF-α were measured in patients with pulmonary systolic arterial pressure (PAPs) >30 mm Hg and in patients with cirrhosis. In all, Six out of 11 patients with PAPs >30 mm Hg had PPHTN on right heart catheterization. The remaining 10 patients had an hyperdynamic circulation (HC). In PPHTN patients, ET-1 and IL-6 were significantly higher compared with HC and patients with cirrhosis. Endothelin 1 and IL-6 could be implicated in the pathogenesis of PPHTN. On the basis of these results, ET-1 receptor antagonists or anti-IL-6 could have a rationale in the treatment of PPHTN.

Topics: Cardiac Catheterization; Cytokines; Echocardiography, Doppler, Color; Endothelin-1; Humans; Hypertension, Portal; Hypertension, Pulmonary; Interleukin-1beta; Interleukin-6; Liver Cirrhosis; Liver Transplantation; Middle Aged; Tumor Necrosis Factor-alpha

Hepatic and circulating endothelin-1 (ET-1) are increased in patients with cirrhosis and in cirrhotic animals. However, the distinct roles of ET receptor subtypes ETA and ETB in cirrhosis and portal hypertension (PHT) have not been clearly elucidated. Thus, we studied the effects of selective ET-1 antagonists (ETA-ant or ETB-ant) and nonselective ET-1 antagonist (ETA/B-ant) on hepatic hemodynamics in cirrhotic rats. Liver fibrosis and PHT were induced by complete bile duct ligation (BDL) in rats. Two weeks after BDL or sham surgery, hemodynamic responses were measured during intraportal infusion of incremental doses of the following ET-ants: (i) BQ-123, (ii) BQ-788, and (iii) bosentan. After equilibration with vehicle, doses of ET-ants were infused for 30 min periods, and steady-state systemic and hepatic hemodynamics, portal venous pressure (PVP), and hepatic blood flow (HBF) were measured. BDL induced significant PHT and elevated concentrations of plasma ET-1 compared with sham. ETA-ant decreased PVP of cirrhotic rats but had no effect on sham, whereas ETB-ant increased PVP in sham but had no effect in BDL. Nonselective ETA/B-ant decreased PVP of BDL similarly to ETA-ant. Both ETA-ant and ETB-ant decreased local HBF, whereas a nonselective antagonist did not change HBF in sham; however no significant changes were observed in HBF of BDL rats with any of the antagonists. These findings suggest ETA activation contributes to PHT in cirrhotic rats, whereas ETB-mediated portal depressor effects are attenuated in cirrhotic rats compared with noncirrhotic rats.

Topics: Animals; Antihypertensive Agents; Blood Pressure; Bosentan; Disease Models, Animal; Endothelin Receptor Antagonists; Endothelin-1; Gene Expression; Hemodynamics; Hepatic Stellate Cells; Hypertension, Portal; Liver; Liver Cirrhosis; Male; Oligopeptides; Peptides, Cyclic; Piperidines; Portal Pressure; Rats; Rats, Sprague-Dawley; Receptor, Endothelin A; Receptor, Endothelin B; Regional Blood Flow; Sulfonamides

Apelin is a peptide with relevant functions in angiogenesis and inflammation. Recent studies have demonstrated that apelin is overexpressed in hepatic stellate cells (HSCs) of cirrhotic rats. Moreover, patients with cirrhosis show high circulating levels of this peptide. We evaluated the role of endogenous apelin system in fibrogenesis-related gene induction in human HSCs. Messenger expression and immunolocalization of apelin were analyzed in human cirrhotic liver and in control samples. Apelin expression was analyzed in a human HSC line (LX-2) under hypoxic conditions or in the presence of proinflammatory or profibrogenic stimuli. LX-2 cells were stimulated with apelin, and a selected profile of fibrogenesis-related genes was quantified. In vivo inactivation of apelin was analyzed in the liver of fibrotic rats after administrating specific blockers of the molecules triggering apelin induction. Apelin was overexpressed in HSCs from human cirrhotic liver. Neither hypoxia nor proinflammatory substances induced the expression of apelin in LX-2. By contrast, both profibrogenic molecules angiotensin II (AII) and endothelin-1 (ET-1) enhanced apelin expression in these cells. Apelin increased the synthesis of collagen-I and platelet-derived growth factor receptor β (PDGFRβ) in LX-2. AII and ET-1 stimulated collagen-I and PDGFRβ expression, and this induction was drastically reduced when apelin receptor was blocked in these cells. In accordance, AII or ET-1 receptor antagonists reduced the hepatic synthesis of apelin, collagen-I, and PDGFRβ in fibrotic rats.. apelin mediates some of the fibrogenic effects triggered by AII and ET-1, thus suggesting that apelin could be an important mediator of fibrogenesis in human liver disease.

Topics: Analysis of Variance; Angiotensin II; Animals; Apelin; Blotting, Western; Cell Line; Cells, Cultured; Collagen Type I; Endothelin-1; Fluorescent Antibody Technique; Gene Expression; Hepatic Stellate Cells; Humans; Intercellular Signaling Peptides and Proteins; Liver; Liver Cirrhosis; Male; Middle Aged; Rats; Rats, Wistar; Receptor, Platelet-Derived Growth Factor beta; Receptors, Transforming Growth Factor beta; Reverse Transcriptase Polymerase Chain Reaction; Statistics, Nonparametric

In this article, the authors discuss three pathophysiologic mechanisms that influence the coagulation system in patients who have liver disease. First, bacterial infections may play an important role in the cause of variceal bleeding in patients who have liver cirrhosis, affecting coagulation through multiple pathways. One of the pathways through which this occurs is dependent on endogenous heparinoids, on which the authors focus in this article. Secondly, the authors discuss renal failure, a condition that is frequently encountered in patients who have liver cirrhosis. Finally, they review dysfunction of the endothelial system. The role of markers of endothelial function in cirrhotic patients, such as von Willebrand factor and endothelin-1, is discussed.

Topics: Bacterial Infections; Biomarkers; Blood Coagulation; Blood Coagulation Disorders; Endothelin-1; Endothelium, Vascular; Heparinoids; Humans; Liver Cirrhosis; Renal Insufficiency; Varicose Veins; von Willebrand Factor

The patients with chronic diffuse liver diseases were found to have signs of endothelial damage, which manifests itself as increases in the count of desquamated endotheliocytes, the level of vascular endothelial growth factor, and the concentration of von Willebrand factor in plasma and to have signs of endothelial dysfunction as reduced nitric oxide levels and elevated endothelin-1 concentrations in plasma. The magnitude of changes in the indicators of endothelial dysfunction and in the markers of endothelial damage depends on the severity of hepatic damage.

Topics: Cell Count; Endothelial Cells; Endothelin-1; Endothelium, Vascular; Hepatitis C, Chronic; Humans; Liver; Liver Cirrhosis; Liver Function Tests; Nitric Oxide; Sensitivity and Specificity; Vascular Endothelial Growth Factor A; von Willebrand Factor

We have found out the clinical presentations and peculiarities of endoscopic and morphologic view of pathologies of mucous membrane of gastroduodenal zone caused by liver cirrhosis. We have examined 74 patients with liver cirrhosis of viral and nonviral etiology using the clinical, endoscopic, morphologic and immunohistochemical methods.We have found that during liver cirrhosis morphometric rates of epithelial cells of mucous coat of stomach that produce somatostatin and endothelin-1 decrease and morphometric rates of epithelial cells that produce nitrogen oxide synthase increase. We have also found out that during liver cirrhosis proliferate activity decrease and apoptosis of epithelial cell of mucous coat of stomach increase.

Topics: Adult; Apoptosis; Cell Proliferation; Duodenal Diseases; Endothelin-1; Enteroendocrine Cells; Female; Gastric Mucosa; Humans; Hypertension, Portal; Intestinal Mucosa; Liver Cirrhosis; Male; Middle Aged; Nitric Oxide Synthase; Severity of Illness Index; Somatostatin; Stomach Diseases

Expression of endothelin receptors in terminal liver cirrhosis is not well investigated. The aim of this study was to investigate the expression of the endothelin type A receptor (ETAR) and endothelin type B receptor (ETBR) immunohistochemically using paraffin-embedded tissue sections from patents with terminal liver cirrhosis (TLC), non-terminal liver cirrhosis (NTLC) and non-cirrhotic liver fibrosis (NCLF) caused by hepatitis C viral infection.. Liver tissue sections from 38 autopsy cases, including 12 cases of NCLF (mild, moderate or severe liver fibrosis), 11 cases of NTLC and 15 cases of TLC, were stained using anti-ETAR and anti-ETBR antibodies after antigen retrieval. Double staining using antibodies to alpha-smooth muscle actin (ASMA) was also performed.. There were significantly fewer ETBR-positive cells in TLC compared with NTLC and NCLF. Numbers of ASMA-positive stellate cells expressing ETBR were also significantly lower in TLC. Therefore, the ETAR/ETBR ratio of sinusoidal cells is significantly higher in TLC than in NTLC and NCLF. ASMA-positive stellate cells showed similar evidence of ETAR and ETBR expression.. There is a difference in ETAR and ETBR expression among TLC, NTLC and NCLF: the ETAR/ETBR ratio is increased in TLC due to a relative decrease in ETBR expression. This finding may be useful for the diagnosis of TLC with regard to circulatory disturbances in the liver.

Topics: Aged; Aged, 80 and over; Autopsy; Endothelin-1; Female; Hepatitis C; Humans; Immunohistochemistry; Liver Cirrhosis; Male; Middle Aged; Receptor, Endothelin A; Receptor, Endothelin B; Terminally Ill

To determine the platelet-activating factor (PAF) synthesis and its receptor expression in Kupffer cells in rat carbon tetrachloride-induced cirrhosis.. Kupffer cells, isolated from the livers of control and CCl4-induced cirrhotic rats, were placed in serum-free medium overnight. PAF saturation binding, ET-1 saturation and competition binding were assayed. ET-1 induced PAF synthesis, mRNA expression of PAF, preproendothelin-1, endothelin A (ETA) and endothelin B (ETB) receptors were also determined.. A two-fold increase of PAF synthesis (1.42 +/- 0.14 vs 0.66 +/- 0.04 pg/microg DNA) and a 1.48-fold increase of membrane-bound PAF (1.02 +/- 0.06 vs 0.69 +/- 0.07 pg/microg DNA) were observed in activated Kupffer cells of cirrhotic rats. The application of ET-1 to Kupffer cells induced PAF synthesis in a concentration-dependent manner in both cirrhotic and normal rats via ETB receptor, but PAF synthesis in the activated Kupffer cells was more effective than that in the normal Kupffer cells. In activated Kupffer cells, PAF receptor expression and PAF binding capacity were markedly enhanced. Activated Kupffer cells raised the [125 I]-ET-1 binding capacity, but changed neither the affinity of the receptors, nor the expression of ETA receptor.. Kupffer cells in the course of CCl4-induced cirrhosis are the main source of increased PAF. ET-1 is involved endogenously in stimulating the PAF synthesis in activated Kupffer cells via ETB receptor by paracrine. ETA receptor did not appear in activated Kupffer cells, which may exacerbate the hepatic and extrahepatic complications of cirrhosis.

Topics: Animals; Carbon Tetrachloride; Disease Models, Animal; Endothelin-1; Kupffer Cells; Liver Cirrhosis; Male; Platelet Activating Factor; Platelet Membrane Glycoproteins; Rats; Rats, Sprague-Dawley; Receptor, Endothelin A; Receptor, Endothelin B; Receptors, G-Protein-Coupled; RNA, Messenger

Idiopathic portal hypertension (IPH) is characterized by noncirrhotic portal hypertension due mainly to increased intrahepatic, presinusoidal resistance to portal blood flow. Marked splenomegaly is always seen in IPH. To clarify the pathogenetic significance of splenomegaly, immunohistochemical expression of inducible nitric oxide synthese (iNOS), endothelial NOS (eNOS), and endothelin-1 (ET-1) in spleens from patients with IPH was examined. Sinus lining cells of IPH spleens showed diffuse and strong expression of iNOS and eNOS. Sinus lining cells of spleens from patients with liver cirrhosis (LC) also showed positive signals for iNOS and eNOS, but the staining intensity was significantly weak. ET-1 was detectable in only a few mononuclear leukocytes in the red pulp of both IPH and LC spleens. These results suggest that NO liberated in spleen, rather than ET-1, is responsible for the dilatation of splenic sinuses, leading to splenomegaly, and thereby contributes to portal hypertension in IPH.

Topics: Aged; Endothelin-1; Female; Humans; Hypertension, Portal; Immunohistochemistry; Liver Cirrhosis; Male; Middle Aged; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; Portal System; Spleen; Splenomegaly

Endothelin-1 (ET-1) is known to play an important role in hepatic fibrosis. ET-1 is also a mediator that is elevated in conditions such as insulin resistance, hyperglycemia, oxidative stress, and endothelial cell dysfunction. In this study, we investigated whether ET-1 has a role in determining the severity of liver fibrosis in NASH. Also, the relation between ALT levels, obesity, diabetes, and AST/ALT ratio and fibrosis and ET-1 level was sought. A total of 92 patients were enrolled in the study. The patients were categorized into three groups: group 1, patients with elevated transaminase levels who were diagnosed as NASH by liver biopsy (n=40); group II, patients with only hepatosteatosis determined by biopsy but having elevated transaminase levels (n=12); and group III, patients with hepatosteatosis observed by ultrasonography, having normal transaminase levels (n=40). The serum ET-1 level was measured by an appropriate ELISA kit for all patients. Mean serum ET-1 level was statistically significantly higher in the NASH group compared to the other two groups (15.56+/-4.63 vs 6.75+/-2.46 and 5.74+/-2.34 micromol/L; P < 0.01). Mean serum ET-1 levels in NASH patients with grade I, grade II, and grade IV fibrosis were 14.06+/-0.92, 17.70+/-2.32, and 20.40+/-1.40 micromol/L, respectively. None of the patients were identified as grade III fibrosis. It was found that the serum ET-1 level showed a statistically significant increase as fibrosis severity increased in NASH patients (P < 0.05). In conclusion, the serum ET-1 level is higher in NASH patients compared to patients having only steatosis. There appears to be a correlation between severity of fibrosis and serum ET-1 level in NASH patients. It has been found that NASH patients having a twofold increase in their ALT levels had higher ET-1 levels and a more severe grade of fibrosis.

Topics: Adult; Aged; Biomarkers; Endothelin-1; Enzyme-Linked Immunosorbent Assay; Fatty Liver; Female; Follow-Up Studies; Humans; Insulin Resistance; Liver Cirrhosis; Male; Middle Aged; Prognosis; Retrospective Studies; Severity of Illness Index; Transaminases; Ultrasonography

Hepatic stellate cells play an important role in liver fibrosis but little is known about liver myofibroblasts located around the central vein and in the portal area. In this study, intracellular Ca(2+) concentration ([Ca(2+)](i)) was measured to assess the response to endothelin-1 (ET-1), platelet derived growth factor (PDGF) and ATP in rat liver myofibroblasts.. Rat liver myofibroblasts were compared in 'quiescent' (cultured on Matrigel-coated dishes) and 'activated' (cultured on non-coated plastic dishes) conditions. [Ca(2+)](i) was measured with the fluorescent dye fura-2 and mRNA for ET-1, PDGF and their receptors by RT-PCR.. ET-1 increased [Ca(2+)](i) in quiescent cells but not in activated cells, whereas PDGF-BB increased [Ca(2+)](i) in activated cells but not in quiescent cells. However, there was no difference between responses to ATP in quiescent or activated cells. ET-1 (in quiescent cells), PDGF-BB (in activated cells) and ATP (in both cells) all induced transient increases in [Ca(2+)](i) in the absence of extracellular Ca(2+) (with EGTA), indicating the involvement of Ca(2+) release from intracellular Ca(2+) stores. The sustained increase in [Ca(2+)](i) in the presence of external Ca(2+) in activated cells (ATP and PDGF) was significantly reduced by nicardipine, a L-type Ca(2+) channel blocker, but not in quiescent cells (ATP and ET-1).. The different pharmacological profiles of [Ca(2+)](i)-response in quiescent and activated myofibroblasts suggest that ET-1 and PDGF contribute differently to myofibroblast activation during the process of liver fibrosis.

Topics: Adenosine Triphosphate; Animals; Becaplermin; Calcium; Calcium Signaling; Cell Differentiation; Cells, Cultured; Endothelin-1; Fibroblasts; Liver; Liver Cirrhosis; Male; Platelet-Derived Growth Factor; Proto-Oncogene Proteins c-sis; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger

Connective tissue growth factor (CTGF/CCN2) has been implicated in the pathogenesis of hepatic fibrosis and suggested as a downstream mediator of the fibrogenic master cytokine TGF-beta.. We investigated the effect of TGF-beta1 on CTGF/CCN2 expression in cultured rat hepatic stellate cells and hepatocytes by means of Western and Northern blotting, immunocytochemistry, reporter gene analysis, and metabolic labelling.. We found that the expression of CTGF/CCN2 in hepatic stellate cells is (i) only marginally (if at all) stimulated by TGF-beta and by a constitutively active type I TGF-beta receptor, (ii) independent from Smad2/3 phosphorylation, (iii) not reduced by TGF-beta1 antagonists or ALK5-receptor inhibitors and (iv) not upregulated during transdifferentiation to myofibroblasts in culture. However, expression and secretion of CTGF/CCN2 in cultured hepatocytes increased spontaneously during culture and was strongly stimulated by TGF-beta1. In bile-duct ligated and CCl(4)-treated rat livers, a strong CTGF/CCN2 expression in hepatocytes was noticed. Endothelin-1 stimulated CTGF/CCN2 expression in stellate cells but not in hepatocytes. Pathway specific signalling inhibitors point to the involvement of non-Smad signalling cascades but their contribution to CTGF/CCN2 regulation is different in both cell types.. The results do not reveal a relevant interrelation between TGF-beta function and CTGF/CCN2 expression in hepatic stellate cells, which is in contrast to hepatocytes.

Topics: Animals; Cells, Cultured; Connective Tissue; Connective Tissue Growth Factor; Endothelin-1; Hepatocytes; Immediate-Early Proteins; Intercellular Signaling Peptides and Proteins; Liver; Liver Cirrhosis; Protein Serine-Threonine Kinases; Rats; Receptor, Transforming Growth Factor-beta Type I; Receptors, Transforming Growth Factor beta; RNA, Messenger; Signal Transduction; Smad Proteins; Transforming Growth Factor beta1

Prolonged Q-T interval (QT) has been reported in patients with cirrhosis who also exhibit profound abnormalities in vasoactive peptides and often present with elevated heart rate (HR). The aim of this study was to relate QT to the circulating level of endothelins (ET-1 and ET-3) and calcitonin gene-related peptide (CGRP) in patients with cirrhosis. In addition, we studied problems with HR correction of QT.. Forty-eight patients with cirrhosis and portal hypertension were studied during a haemodynamic investigation. Circulating levels of ETs and CGRP were determined by radioimmunoassays. Correction of QT for HR above 60 beats per min was performed using the methods described by Bazett (QT(C)) and Fridericia (QT(F)).. Prolonged QT(C) (above 440 ms), found in 56% of the patients, was related to the presence of significant portal hypertension and liver dysfunction (p < 0.05 to 0.001), but not to elevated ET-1, ET-3 or CGRP. When corrected according to Bazett, QT(C) showed no significant relation to differences in HR between patients (r = 0.07, ns). QTF showed some undercorrection of HR (r = -0.36; p < 0.02). During HR variation in the individual patient, QT(C) revealed a small but significant overcorrection (2.6 ms per heartbeat per min; p < 0.001). This value was significantly (p < 0.02) smaller with QTF (1.2 ms per heartbeat per min).. The prolonged QT(C) in cirrhosis is related to liver dysfunction and the presence of portal hypertension, but not to the elevated powerful vasoconstrictor (ET-1) or vasodilator (CGRP, ET-3) peptides. The problems with correction of the QT for elevated HR in cirrhosis are complex, and the lowest HR should be applied for determination of the QT.

Topics: Adult; Aged; Blood Pressure; Calcitonin Gene-Related Peptide; Cardiac Pacing, Artificial; Catecholamines; Electrocardiography; Endothelin-1; Endothelin-3; Endothelins; Female; Heart Rate; Hemodynamics; Humans; Hypertension, Portal; Liver Cirrhosis; Long QT Syndrome; Male; Middle Aged; Reference Values

Pancreatic stellate cells (PSCs) are essentially involved in pancreatic fibrogenesis and considered as a target for antifibrotic therapies. Here, we have analyzed the effects of three histone deacetylase inhibitors (HDACIs), sodium butyrate, sodium valproate (VPA) and trichostatin A (TSA), on profibrogenic activities of PSC and elucidated molecular targets of HDACI action. Therefore, cultured PSCs were exposed to HDACI. Cell proliferation and viability were assessed by 5-bromo-2'-deoxyuridine (BrdU) incorporation and trypan blue staining assays. Exhibition of the myofibroblastic PSC phenotype was monitored by immunofluorescence analysis of alpha-smooth muscle actin (alpha-SMA) expression. [(3)H]-proline incorporation into acetic acid-soluble proteins was measured to quantify collagen synthesis. Levels of mRNA were determined by quantitative reverse transcriptase real-time PCR. Protein expression, phosphorylation and acetylation were analyzed by immunoblotting, and gel shift assays were performed to study DNA binding of nuclear proteins. HDACI enhanced histone H3 acetylation in a dose-dependent manner. In the same dose range, they strongly inhibited cell proliferation, alpha-SMA expression and collagen synthesis. A significantly increased rate of cell death was observed in response to TSA at 1 microM. While all three HDACI inhibited mRNA expression of endothelin-1, only VPA significantly reduced expression of transforming growth factor-beta1. Both mediators exert autocrine profibrogenic effects on PSC. Furthermore, HDACI-treated PSC displayed a diminished DNA binding of AP-1, a key transcription factor in profibrogenic signaling. Together, the results suggest that HDACI exert antifibrogenic effects on PSC. Interruption of AP-1 signaling and autocrine loops enhancing PSC activation might be key mechanisms of HDACI action.

Topics: Actins; Animals; Base Sequence; Cells, Cultured; Collagen; DNA Primers; Endothelin-1; Enzyme Inhibitors; Fluorescent Antibody Technique; Histone Deacetylase Inhibitors; Liver Cirrhosis; Male; Pancreas; Rats; Rats, Inbred Lew; Reverse Transcriptase Polymerase Chain Reaction; Transcription Factor AP-1; Transforming Growth Factor beta

To evaluate the role of intestinal endotoxemia in the genesis of hepatopulmonary syndrome.. A rat model of cirrhosis was prepared with the method of compound factors. At the end of the eighth week, rats with cirrhosis were treated with 300 microg LPS/100 g body weight, and 1 g/rat of glycine about four h prior to LPS. After three h of LPS treatment, blood and tissues were collected for various measurements. Kupffer cells were isolated from male Wistar rats and cultured, and divided into five groups. Supernatant was harvested at 3 h after treatment with LPS for measurement of tumor necrosis factor-alpha (TNF-alpha).. Our results showed that in rats with cirrhosis, slowed and deepened breath with occasional pause was. PaO2, PaCO2 and standard bicarbonate (SB) in arterial blood were decreased. Arterial O2 and actual bicarbonate (AB) were markedly decreased. There was a close correlation between decreased O2 and endotoxin. Metabolic acidosis accompanying respiratory alkalosis was the primary type of acid-base imbalance. The alveolar-arterial oxygen gradient was sharply widened. Massive accumulation of giant macrophages in the alveolar spaces and its wall and widened alveolar wall architecture were observed. The number of bacterial translocations in mesenteric lymph nodes increased. The ratio of TC99M-MAA brain-over-lung radioactivity rose. Endotoxin, and TNF-alpha, endothelin-1 (ET-1), nitric oxide (NO) in plasma and ET-1, carbon monoxide (CO) in lung homogenates increased. After administration of a given dosage of LPS in rats with cirrhosis, various pathological parameters worsened. Plasma level of endotoxin was related to TNF-alpha, ET-1, NO in plasma and ET-1, NO, CO in lung homogenates. TNF-alpha level was related to ET-1 and NO in plasma and lung homogenates and CO in lung homogenate as well. The level of TNF-alpha increased after infusion of LPS into culture supernatant of Kupffer cells in vitro. However, TNF-alpha significantly decreased after pretreatment with glycine, PD98059 and SB212850. Glycine could antagonize the effect of LPS in vivo and in vitro.. Intestinal endotoxemia accompanying by cirrhosis may be an important mechanism in the development of hepatopulmonary syndrome in rats. Overproduction of TNF-alpha due to endotoxin stimulation of Kupffer cells via mitogen-activated protein kinase (MAPK) signal transduction pathway may be a major mechanism mediating the pathologic alterations of hepatopulmonary syndrome.

Topics: Acid-Base Imbalance; Acidosis; Animals; Bacterial Translocation; Brain; Carbon Monoxide; Endothelin-1; Endotoxemia; Hepatopulmonary Syndrome; Kupffer Cells; Lipopolysaccharides; Liver Cirrhosis; Lung; Male; MAP Kinase Signaling System; Nitric Oxide; Rats; Rats, Wistar; Respiratory Mechanics; Sulfhydryl Compounds; Technetium Tc 99m Aggregated Albumin; Tumor Necrosis Factor-alpha

Topics: Endothelin-1; Humans; Hypertension, Portal; Hypertension, Pulmonary; Liver Cirrhosis

It is postulated that nitric oxide (NO) is responsible for the hyperdynamic circulation of portal hypertension. Therefore, we investigated induction of fibrosis and hyperdynamic circulation in endothelial NO synthase knock-out (KO) mice.. Fibrosis was induced by bile duct ligation. Hemodynamic studies were performed after portal vein ligation. All studies were performed in wild-type (WT) and KO mice.. Three to 4 weeks after bile duct ligation (BDL), both WT and KO groups had similar degrees of portal hypertension, 12 (9-14) and 11(8-15) mmHg, median (range), and liver function. Fibrosis increased from 0.0% in sham operated to 1.0 and 1.1% in WT and KO mice, respectively. Cardiac output was similar after portal vein ligation (20 and 17 ml/min in WT and KO mice, respectively). There was no difference in liver of mRNA for endothelin 1, inducible NO synthase (iNOS) and hem-oxygenase 1 (HO1); proteins of iNOS, HO1 and HO2; nor in endothelin A and B (EtA and EtB) receptor density between WT and KO mice after BDL.. These results suggest that endothelial NO synthase is neither essential for the development of fibrosis and portal hypertension in bile duct ligated mice, nor for the hyperdynamic circulation associated with portal hypertension in the portal vein ligated mice.

Topics: Animals; Bile Ducts; Disease Models, Animal; Endothelin-1; Heme Oxygenase (Decyclizing); Heme Oxygenase-1; Hypertension, Portal; Ligation; Liver; Liver Cirrhosis; Mice; Mice, Inbred C57BL; Mice, Knockout; Nitric Oxide Synthase Type III; RNA, Messenger

The aims of this study were to examine the plasma nitrate/nitrite (NOx; two end products of nitric oxide metabolism) and endothelin-1 (ET-1) concentrations in patients with liver cirrhosis, and to investigate whether there is a relationship between these two vasoactive parameters and the course of disease. Twenty-eight patients with liver cirrhosis (11 HBV-related, four HCV-related, four alcohol-related, and nine with idiopathic etiology) and 25 healthy subjects (controls) were included in the study. The venous plasma concentrations of NOx and ET-1 were significantly higher (P<0.01 and P<0.001) in the patients with cirrhosis than in the controls. A significant increase in ET-1 was observed in the Child B subgroup vs. Child A (P<0.05), and in the Child C subgroup vs. either subgroup A or B (P<0.05). There were no statistical differences between study subgroups (Child A-C) in the mean of NOx values. Plasma NOx and ET-1 were significantly increased in patients with ascites compared to those without ascites (P<0.05 and P<0.01). Increased nitric oxide synthesis may be a compensation mechanism against endothelial injury. The highest ET-1 levels in Child C and moderately increased ET-1 levels in Child B, and the lower increase of ET-1 levels in Child A patients suggest that plasma ET-1 increases with the progression of the disease. The fact that NOx and ET-1 levels were higher in patients with decompensated cirrhosis (patients with ascites) than in those with compensated cirrhosis (patients without ascites), and the presence of a strong correlation between ET-1, NOx, and the degree of varices, supports the suggestion that there is a relationship between NOx, ET-1, and portal hypertension. Our study demonstrates that increased ET and nitric oxide metabolism is associated with the hemodynamic alterations induced by portal hypertension.

Topics: Adult; Disease Progression; Endothelin-1; Female; Humans; Liver Cirrhosis; Male; Middle Aged; Nitrates; Nitric Oxide; Nitrites

To study the systemic and pulmonary hemodynamic changes of patients with cirrhosis during liver transplantation and evaluate the role of nitric oxide (NO) and endothelin-1(ET-1).. Twenty-four patients with cirrhosis at terminal stage underwent modifying piggy-back liver transplantation. Hemodynamic parameters including cardiac index (CI), arterial blood pressure (ABP) and pulmonary arterial pressure (PAP) were monitored continuously. NO and ET-1 levels were measured by radioimmunoassay. Blood samples were obtained from superior vena cava at induction of anesthesia (T1), 10 minutes before vascular cross clamping (T2), 30 minutes after vascular cross clamping (T3), 30 minutes after reperfusion of the new liver (T4), and at the end of surgery (T5).. (1) Mean arterial blood pressure (MABP) lowered significantly in the early stage of anhepatic period and neohepatic period (P<0.05 or P<0.01). (2) Central venous pressure (CVP), mean pulmonary arterial pressure (MPAP) and pulmonary arterial wedge pressure (PAWP) lowered significantly during anhepatic period. They rose significantly after graft reperfusion, and remained at a high level with respect to the baseline level (P<0.05). (3) CI declined significantly during anhepatic period and increased 10 minutes after reperfusion of new liver. (4) Systemic vascular resistance index and pulmonary vascular resistance index increased during anhepatic period and were higher than the baseline level 15 minutes after reperfusion. SVRI was lower than baseline level 30 minutes after reperfusion. (5) Compared with the baseline level, NO decreased significantly after vascular cross-clamping and elevated 30 minutes after reperfusion. ET levels were significant elevated 30 minutes after clamping and after reperfusion (P<0.05).. Significant hemodynamic changes occur in patients with cirrhosis during liver transplantation, and pulmonary hypertension develops during neohepatic period. The role of elevated contents of NO and ET-1 after reperfusion needs further study.

Topics: Adult; Aged; Endothelin-1; Female; Hemodynamics; Humans; Liver Cirrhosis; Liver Transplantation; Male; Middle Aged; Nitric Oxide

Common bile duct ligation (CBDL) triggers a molecular cascade resulting in the hepatopulmonary syndrome (HPS). Both increased hepatic endothelin-1 (ET-1) production and pulmonary vascular ET(B) receptor expression with stimulation of endothelial nitric oxide synthase and TNF-alpha mediated inducible nitric oxide synthase and heme oxygenase-1 expression in pulmonary intravascular macrophages occur. Whether biliary cirrhosis is unique in triggering ET-1 and TNF-alpha alterations and HPS is unknown. We evaluated for HPS in rat prehepatic portal hypertension [partial portal vein ligation (PVL)], biliary (CBDL) and nonbiliary [thioacetamide treatment (TAA)] cirrhosis, and assessed ET-1 infusion in normal and PVL animals. Control, PVL, CBDL, TAA-treated, and ET-1-infused PVL animals had ET-1 and TNF-alpha levels measured and underwent molecular and physiological evaluation for HPS. HPS developed only in biliary cirrhosis in association with increased plasma ET-1 and TNF-alpha levels and the development of established molecular changes in the pulmonary microvasculature. In contrast, PVL did not increase ET-1 or TNF-alpha levels and TAA treatment increased TNF-alpha levels alone, and neither resulted in the full development of molecular or physiological changes of HPS despite portal pressure increases similar to those after CBDL. Exogenous ET-1 increased TNF-alpha levels and triggered HPS after PVL. Combination of ET-1 and TNF-alpha overproduction is unique to biliary cirrhosis and associated with experimental HPS. ET-1 infusion increases TNF-alpha levels and triggers HPS in prehepatic portal hypertension. ET-1 and TNF-alpha interact to trigger pulmonary microvascular changes in experimental HPS.

Topics: Animals; Endothelin-1; Heme Oxygenase (Decyclizing); Heme Oxygenase-1; Hepatopulmonary Syndrome; Hypertension, Portal; Ligation; Liver Cirrhosis; Liver Cirrhosis, Biliary; Lung; Male; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; Portal Vein; Rats; Rats, Sprague-Dawley; Thioacetamide; Tumor Necrosis Factor-alpha

Topics: Endothelin-1; Forearm; Humans; Liver Cirrhosis; Liver Transplantation; Vasodilation

Topics: Endothelin-1; Forearm; Humans; Liver Cirrhosis; Liver Transplantation; Vasodilation

It is considered that endothelin-1 participates in the development of liver cirrhosis and it has been recognized that every component of the endothelin system is upregulated in cirrhotic livers. However, the expression pattern of this system, including interaction between its components, is not fully understood in human livers. In this study, the expression pattern of the endothelin system was examined. Immunohistochemical analysis for endothelin-1, endothelin receptors and endothelin-converting enzyme was performed in 16 cirrhotic and 17 normal human liver tissues. Peptides, proteins, and RNAs extracted from the livers were also investigated using quantitative assays for the components of the hepatic endothelin system. Hepatic endothelin-1 levels were significantly higher in cirrhotic livers (0.084 +/- 0.052 pg/mg wet liver) than in normal livers (0.041 +/- 0.032 pg/mg; p < 0.01), and were closely related to the severity of liver fibrosis and portal hypertension. Immunoreactivity for endothelin-1, endothelin receptors, and endothelin-converting enzyme was detected mainly in fibrous areas and in the hepatic vasculature, and was enhanced in cirrhosis. Although there was a negative correlation between the expression of receptor mRNA and the hepatic endothelin-1 level, the amounts of the mRNAs were greater in cirrhotic livers than in normal livers. However, expression of endothelin-converting enzyme in cirrhotic livers was increased at the protein level but was relatively reduced at the mRNA level. These findings suggest that the hepatic endothelin system is activated in human cirrhotic livers in association with worsening of the disease, but that the regulation of the components of this system in this disorder is complex.

Topics: Aged; Aspartic Acid Endopeptidases; Blotting, Western; Endothelin-1; Endothelin-Converting Enzymes; Enzyme-Linked Immunosorbent Assay; Female; Humans; Immunohistochemistry; Liver; Liver Cirrhosis; Male; Metalloendopeptidases; Polymerase Chain Reaction; Receptor, Endothelin A; Receptor, Endothelin B; Receptors, Endothelin; RNA, Messenger; Severity of Illness Index

To study whether liver cirrhosis and portal hypertension are associated with ET-1 TaqI polymorphism and TNFa promoter-308G to A polymorphism.. A case control study of 106 patients with liver cirrhosis following HBV C infection was performed in comparison with 108 controls by PCR-RFLP.. The frequency of C allele and CC+TC genotype in TaqI polymorphism of ET-1 gene in the portal hypertension group (LC+) was significantly higher than that in the healthy controls, and the frequency of TNF2/1 genotype in TNFa promoter -308 G to A polymorphism in LC+ group was significantly higher than that in the control group. The results by stratification analysis showed that TCF2 genotype frequency was higher in the LC+ group than in the control group. ET-1 TaqI polymorphism and TNFa polymorphism were risk factors for the occurrence of portal hypertension by Logistic regression analysis.. ET-1 TaqI polymorphism and TNFa polymorphism are associated with portal hypertension, and are new risk factors for the occurrence of portal hypertension. TCF2 genotype may be a susceptible gene of portal hypertension.

Topics: Adult; Case-Control Studies; Endothelin-1; Female; Gene Frequency; Hepatitis B, Chronic; Humans; Hypertension, Portal; Liver Cirrhosis; Male; Middle Aged; Polymerase Chain Reaction; Polymorphism, Genetic; Polymorphism, Restriction Fragment Length; Promoter Regions, Genetic; Taq Polymerase; Tumor Necrosis Factor-alpha

Patients with advanced cirrhosis have systemic vasodilatation and increased nitric oxide (NO) production despite activated vasopressor systems, including the endothelin system. The aims of this study were to assess the contribution of endogenous endothelin 1 (ET-1) and NO to the maintenance of basal forearm vascular tone in patients with preascitic cirrhosis (n=7) and in age and sex matched healthy controls (n=7).. Using venous occlusion plethysmography, forearm blood flow (FBF) responses to subsystemic locally active intra-arterial infusion of BQ-123 (a selective endothelin type A receptor (ET(A)) receptor antagonist; 10 nmol/min) were measured before and during application of an "NO clamp": a balanced co-infusion of L-N(G)-monomethyl-arginine (a selective NO synthase inhibitor) and sodium nitroprusside (an exogenous NO donor) to block endogenous NO production and restore NO mediated basal FBF, respectively.. L-NMMA infusion produced a reduction in FBF (p<0.001) which was similar in both groups. Before applying the "NO clamp", BQ-123 caused an increase in FBF in both groups (p<0.001) that was greater in patients with cirrhosis (p<0.01). During the "NO clamp", BQ-123 induced vasodilatation was abolished in controls and attenuated in patients (p<0.001) but remained significantly greater in patients with cirrhosis (p<0.01).. These findings indicate a greater ET(A) mediated contribution of endogenous ET-1 to the maintenance of basal forearm vascular tone in patients with preascitic cirrhosis. In addition, enhanced vasodilatation to ET(A) receptor antagonism in cirrhosis cannot be entirely attributed to NO release but is likely to be related to reversal of direct ET-1 mediated tone.

Topics: Adult; Case-Control Studies; Endothelin Receptor Antagonists; Endothelin-1; Enzyme Inhibitors; Female; Forearm; Hemodynamics; Humans; Liver Cirrhosis; Male; Middle Aged; Nitric Oxide; Nitric Oxide Synthase; omega-N-Methylarginine; Peptides, Cyclic; Plethysmography; Regional Blood Flow; Vasodilation

In experimental hepatopulmonary syndrome (HPS), hepatic endothelin-1 (ET-1) release during common bile duct ligation (CBDL) and ET-1 infusion in pre-hepatic portal hypertension after portal vein ligation (PVL) initiate vasodilatation through an endothelin B receptor mediated increase in pulmonary endothelial nitric oxide synthase (eNOS). We evaluated if pulmonary ET receptor expression changes in experimental cirrhosis and portal hypertension and confers susceptibility to HPS.. In normal, PVL and CBDL animals, lung ET receptor expression and localization were assessed and ET receptor levels and functional analysis of ET-1 effects on eNOS levels were evaluated in intralobar pulmonary artery (PA) and aortic (AO) segments. Normal rats underwent evaluation for HPS after ET-1 infusion.. There was a selective increase in ET(B) receptor expression in the pulmonary vasculature from PVL and CBDL animals. ET-1 stimulated NO production and an ET(B) receptor mediated increase in eNOS levels in PA segments from PVL and CBDL animals, but not normal animals. ET-1 did not alter lung eNOS levels or cause HPS in normal rats.. ET(B) receptor expression and ET-1 mediated eNOS and NO production are enhanced in the lung vasculature in cirrhotic and portal hypertensive animals and correlate with in vivo susceptibility to ET-1 mediated HPS.

Topics: Animals; Common Bile Duct; Endothelin-1; Endothelium, Vascular; Hepatopulmonary Syndrome; Hypertension, Portal; Ligation; Liver Cirrhosis; Male; Nitric Oxide; Nitric Oxide Synthase; Nitric Oxide Synthase Type III; Portal Vein; Pulmonary Artery; Pulmonary Circulation; Rats; Rats, Sprague-Dawley; Receptor, Endothelin B

Topics: Animals; Cells, Cultured; Drugs, Chinese Herbal; Endothelin-1; Hepatocytes; Liver; Liver Cirrhosis; Rats; Rats, Sprague-Dawley; RNA, Messenger; Simian virus 40; Transfection

Endothelin (ET)-1 contributes to hepatic ischemia and reperfusion (HIR) injury in normal liver. This study was conducted to clarify the role of ET-1 in HIR injury in cirrhotic state.. Using thioacetamide-induced cirrhotic rats with spontaneous portosystemic shunt, we determined the changes in plasma aspartate aminotransferase (AST) levels, plasma and hepatic ET-1 values, 7-day survival rates, and hepatic oxygen saturation (SO(2)) by time-resolved spectroscopy as an indicator of hepatic microcirculation under intermittent or continuous total hepatic ischemia with subsequent partial hepatectomy.. Hepatic ET-1 levels in cirrhotic rats were significantly higher than those in noncirrhotic rats. Plasma and hepatic ET-1 levels at 1, 3 and 6 h of reperfusion after intermittent hepatic ischemia were significantly lower than those after continuous hepatic ischemia. In cirrhotic animals subjected to intermittent hepatic ischemia, the elevation of plasma AST levels at 1, 3 and 6 h of reperfusion and the decline in hepatic SO(2) at the end of 60-min hepatic ischemia and after reperfusion were significantly suppressed when compared with those subjected to continuous hepatic ischemia. Pretreatment with a nonselective endothelin receptor antagonist in continuous hepatic ischemia significantly ameliorated plasma AST levels and hepatic SO(2) values with less hepatic sinusoidal congestion, resulting in an improvement in the 7-day survival rate.. Continuous hepatic ischemia in the cirrhotic liver has disadvantages relating to microcirculatory derangement with more ET-1 production in partial hepatectomy. In liver surgery, pharmacological regulation of ET-1 production may lead to attenuation of reperfusion injuries for ischemically damaged cirrhotic liver.

Topics: Animals; Aspartate Aminotransferases; Endothelin-1; Hepatectomy; Liver; Liver Cirrhosis; Male; Microcirculation; Oxygen; Portasystemic Shunt, Surgical; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Survival Rate; Thioacetamide

Endothelin-1 (ET-1) stimulates the synthesis of platelet-activating factor (PAF) by Kupffer cells in vitro. Hepatic concentrations of both ET-1 (a potent vasoconstrictor) and PAF (a mediator of hepatic vasoconstriction and the cirrhotic hyperdynamic state) increase in cirrhosis. The aim of this study was to determine if the responsiveness of Kupffer cells to produce PAF upon ET-1 challenge is modified by cirrhosis.. Kupffer cells, isolated from the livers of control and CCl(4)-induced cirrhotic rats, were placed in serum-free medium after overnight culture. PAF and ET-1 receptors, ET-1-induced PAF synthesis, and PAF- and ET-1-induced prostaglandin E(2) (PGE(2)) synthesis were determined 24 h later.. Both basal and ET-1-stimulated PAF synthesis was increased in cirrhotic Kupffer cells as indicated by increased cell-associated and released PAF. Cirrhotic Kupffer cells also had elevated densities of functional receptors for both PAF and ET-1 (exclusively ET(B)), as measured by ligand binding, mRNA expression of the respective receptors, and ligand-stimulated PGE(2) synthesis.. Cirrhosis sensitizes Kupffer cells to both ET-1 and PAF by elevating their respective receptor levels. Since both mediators individually cause portal hypertension, an increase in ET-1-stimulated PAF synthesis in Kupffer cells will exacerbate the hepatic and extrahepatic complications of cirrhosis.

Topics: Animals; Carbon Tetrachloride; Cells, Cultured; Dinoprostone; Endothelin-1; Gene Expression; Kupffer Cells; Liver Cirrhosis; Male; Platelet Activating Factor; Platelet Membrane Glycoproteins; Rats; Rats, Sprague-Dawley; Receptor, Endothelin B; Receptors, G-Protein-Coupled

To investigate the correlation between polymorphism of TaqI of endothelin (ET)-1 gene intron 4 and cirrhotic portal hypertension and to search new risk factor of portal hypertension.. Peripheral venous blood was extracted from 106 patients with cirrhosis after hepatitis B (PH+ group) and 108 healthy blood donors (PH- group). PCR-RFLP was used to analyze the polymorphism of TaqI of ET-1 gene. The plasma ET-1 concentration was detected with immunoassay. Multivariate logistic regression analysis was made to analyze the risk factors.. The C allele frequency in the PH+ group was 25.4%, significantly higher than that of the controls (16.7%, P < 0.05). The frequency of CC + TC genotype in PH+ group was 46.2%, significantly lower than that in the controls (29.6%, P < 0.05). In the PH+ group, the thickness of spleen was greater, hemorrhage rate was higher, and III degrees ascites was more in C allele carrier than in T allele carriers (P < 0.05). The plasma ET-1 concentration was higher in PH+ group than in PH- group. In the PH+ group, the plasma ET-1 concentrations in those with CC genotype and those with TC genotype were significantly higher than in those with TT genotype (P < 0.05). Correlation analysis showed that ET-1 gene polymorphism was positively correlated with plasma ET-1 concentration (R = 0.808 2). Multivariate logistic regression analysis showed that gradation of liver function, diameter of portal vein, and ET-1 gene polymorphism were independent risk factors of portal hypertension.. Polymorphism of TaqI of ET-1 gene is correlated with the pathogenesis of cirrhotic portal hypertension. It may be one of the risk factors of portal hypertension.

Topics: Adult; Deoxyribonucleases, Type II Site-Specific; Endothelin-1; Female; Humans; Hypertension, Portal; Liver Cirrhosis; Logistic Models; Male; Middle Aged; Polymorphism, Genetic

Topics: Echocardiography, Doppler; Endothelin-1; Hemodynamics; Humans; Hypertension, Pulmonary; Liver Cirrhosis; Nitric Oxide; Prospective Studies; Pulmonary Artery

The prevalence of portopulmonary hypertension (PPHTN) in patients with cirrhosis and refractory ascites is unknown. Its presence may preclude patients from receiving a transjugular intrahepatic portosystemic shunt or liver transplantation as a definitive treatment for their end stage cirrhosis.. To determine the prevalence, possible aetiological factors, and predictive factors for the development of PPHTN in these patients.. Sixty two patients (53 males, nine females; mean age 54.5 (1.4) years) with biopsy proven cirrhosis and refractory ascites underwent angiographic measurements of pulmonary and splanchnic haemodynamics. Endothelin 1 levels were measured from the pulmonary artery. Forty nine patients underwent radionuclide angiography for measurements of central blood volume, pulmonary vascular, and cardiac chamber volumes. Forty seven patients also underwent two dimensional echocardiography for measurements of cardiac structural and functional parameters. Cardiac output, and systemic and pulmonary vascular resistance were calculated.. Ten patients (16.1%) fulfilled the criteria for PPHTN (mean pulmonary artery pressure >/= 25 mm Hg and pulmonary vascular resistance >/= 120 dynxs/cm(5)), with significantly higher mean right atrial (15.4 (1.2) v 7.9 (0.5) mm Hg; p<0.001), and right ventricular pressures (24.7 (1.5) v 14.7 (0.6) mm Hg; p<0.001), and endothelin 1 levels (3.04 (0.40) v 1.98 (0.12) pg/ml; p=0.02). No significant differences in any of the other parameters measured were detected between the two groups. A right atrial pressure of >/= 14 mm Hg had a 83% positive predictive value for the presence of PPHTN.. Portopulmonary hypertension is common in cirrhosis with refractory ascites, possibly due to excess endothelin 1 in the pulmonary circulation. An elevated right atrial pressure >/= 14 mm Hg predicts the presence of PPHTN, which may be helpful in deciding management options in these patients.

Topics: Ascites; Echocardiography; Endothelin-1; Female; Heart Atria; Humans; Hypertension, Portal; Hypertension, Pulmonary; Liver Cirrhosis; Male; Middle Aged; Radionuclide Angiography

There is evidence that dampened responses to endogenous vasoconstrictors contribute to the hyperdynamic circulation that is characteristic of advanced cirrhosis. The aim of this study was to determine whether there is an altered vascular responsiveness to the endothelium derived constricting factor endothelin-1 (ET-1) in patients with decompensated chronic liver disease which might contribute to this abnormal circulatory state, and whether normal endothelin responses are restored following liver transplantation.. Using forearm plethysmography, we studied the vascular response to an intra-arterial ET-1 infusion in six patients with end stage cirrhosis, before and after liver transplantation, compared with six normal control subjects. Responses to the selective endothelin A (ET(A)) receptor subtype antagonist, BQ123, were also examined.. The forearm vessels of patients with cirrhosis vasodilated in response to ET-1 infusion while in healthy controls a marked vasoconstriction response was observed (p<0.0001, area under the curve time-blood flow was normal compared with the cirrhosis groups, ANOVA). Prior to commencement of liver transplant surgery, cirrhotic patients were confirmed to have a hyperdynamic circulation with a high cardiac index (4.07 (0.23) l/min/m(2) (normal range 2.8-3.6 l/min/m(2))) and low systemic vascular resistance index (1284 (115) dynxs/cm(5)/m(2) (normal range 1760-2600 dynxs/cm(5)/m(2))). Following transplantation, normal vasoconstrictor responses to ET-1 were restored. Responses to BQ123 were not different in patients with advanced cirrhosis compared with controls.. In patients with end stage cirrhosis, ET-1 produces vasodilatation at a dose that causes marked vasoconstriction in normal control subjects. This effect is not attributable to impairment of ET(A) receptor responses. Our findings suggest that altered endothelin responses may contribute to the generalised dilatation of the circulation that occurs in patients with advanced liver disease.

Topics: Analysis of Variance; Case-Control Studies; Chronic Disease; Endothelin A Receptor Antagonists; Endothelin-1; Endothelium, Vascular; Female; Forearm; Humans; Infusions, Intravenous; Liver Cirrhosis; Liver Transplantation; Male; Middle Aged; Peptides, Cyclic; Plethysmography; Postoperative Period; Vasodilation; Vasodilator Agents

Topics: Child; Endothelin-1; Hemodynamics; Humans; Hypertension, Portal; Kidney; Liver Cirrhosis; Renal Circulation

Plasma endothelin-1 (ET-1) is a potent vasoconstrictor peptide involved in the pathogenesis of several disorders. Endothelin-1 concentrations are increased in adult patients with cirrhosis. However, little is known about ET-1 concentrations in children with cirrhosis.. Radioimmune assay was used to measure plasma ET-1 concentrations in 19 children with cirrhosis (8 patients with ascites, and 11 without ascites), and 11 age- and sex-matched healthy children. The plasma ET-1 concentrations were correlated with the mean blood pressure, creatinine clearance, and severity of portal hypertension, as measured by portal flow volume and portal flow velocity.. Patients with cirrhosis and ascites had increased plasma ET-1 concentrations compared with patients who did not have ascites (6.8 pg/mL +/- 0.62 pg/mL vs. 4.6 pg/mL +/- 0.35 pg/mL; mean +/- SEM; < 0.01) and controls (3.6 pg/mL +/- 0.27 pg/mL; mean +/- SEM; < 0.0005). Plasma ET-1 concentrations were higher in patients with cirrhosis who did not have ascites compared with controls ( < 0.005). No significant differences were observed between concentrations of the patients with cholestasis and those without cholestasis (5.4 pg/mL +/- 0.52 pg/mL vs. 5.2 +/- 0.32 pg/mL; mean +/- SEM; = 0.1). Plasma ET-1 concentrations correlated positively with the mean blood pressure ( = 0.58; < 0.05) and negatively with renal function, as measured by creatinine clearance ( = -0.7; <0.005). However, no correlation was detected between ET-1 concentrations and portal flow volume ( = -0.02; = 0.4) or portal flow velocity ( = -0.16; = 0.4).. Plasma ET-1 concentrations are increased in children with cirrhosis, with or without ascites, compared with controls. Patients with cirrhosis and ascites have increased ET-1 concentrations compared with those without ascites. The degree of increase does not relate to the severity of portal hypertension. This increase tends to maintain systemic blood pressure but is associated with a decrease in renal function.

Topics: Ascites; Blood Pressure; Case-Control Studies; Child; Cholestasis; Creatinine; Endothelin-1; Female; Humans; Hypertension, Portal; Kidney; Liver Cirrhosis; Male; Radioimmunoassay; Renal Circulation

Patients with cirrhosis and portal hypertension have a hyperkinetic systemic circulation. A number of circulating vasoactive peptides, including endothelin-1 (ET-1), are elevated and, recently, increased arterial compliance has been described in these patients. The aim of the present study was to investigate a potential relation between altered arterial compliance and arterial ET-1 in patients with cirrhosis. As ET-1 may be manipulated by somastostatin, the study includes infusion of octreotide in a subset of patients.. A total of 67 patients with cirrhosis and 27 controls were studied during a haemodynamic investigation. Arterial ET-1 was determined by two different radioimmunoassays and arterial compliance was determined as the stroke volume/pulse pressure index.. Arterial compliance was elevated by 32%-40% in the cirrhotic patients as compared to the controls (P < 0.005). Arterial ET-1 was elevated by 26%-170% in the cirrhotic patients (P<0.001). No significant relationships could be established between arterial compliance and arterial ET-1 (r = -0.15 to 0.23, ns). Intravenous bolus injection and infusion of octreotide (100 pg + 100 microg/h, n = 9) did not significantly change either arterial compliance or arterial ET-1.. Both arterial compliance and arterial ET- I are substantially elevated in patients with cirrhosis, but there is no significant relation between arterial compliance and arterial ET- I in these patients.

Topics: Adult; Aged; Arteries; Endothelin-1; Female; Hemodynamics; Humans; Hypertension, Portal; Liver Cirrhosis; Male; Middle Aged; Octreotide; Vasoconstrictor Agents

To investigate the effects of ET-1 on isolated perfused rat liver and vascular rings at early and late stages of cirrhosis.. Liver cirrhosis was induced by an intraperitoneal injection of 50% CCl(4) (0.3 ml/100 g, twice a week). In the 9th and 14th weekend after injecting CCl(4), the isolated perfused liver and vascular rings were performed to evaluate effects of four concentrations of ET-1 on early and late stages of cirrhosis.. The Ppv of L-HC group at baseline was higher than that of E-HC group, both were higher than that of the controls. However, there showed no differences on Phv in these groups. With the concentration of ET-1 increasing, PVP was elevated accordingly in E-HC and L-HC group. L-HC group showed higher PVP compared with E-HC group, both were higher than the controls. While in isolated vascular rings, with the deteriorating of cirrhosis, the cumulative response curves showed right-shift. 0.1 nmol/L ET-1 showed mild relaxation on vascular rings in L-HC group.. ET-1 can increase the PVP, especially with the deterioration of cirrhosis, there showed higher reaction compared with normal controls. The vascular rings showed low response on the contrary. So ET-1 plays an important role in the pathogenesis of portal hypertension. In view of its different roles on liver and vascular rings at early and late stages, administration of different selective antagonist of ET receptor at different stages of cirrhosis should be well considered.

Topics: Animals; Carbon Tetrachloride; Dose-Response Relationship, Drug; Endothelin-1; Hypertension, Portal; In Vitro Techniques; Liver; Liver Cirrhosis; Male; Perfusion; Portal Vein; Rats; Rats, Sprague-Dawley; Vasoconstriction

Aims of this study are to analyze the influence of endothelin-1 (ET-1) on hemodynamic evolution during liver transplantation (LT) and study the role of a temporary portacaval shunt in ET-1 synthesis. Forty LTs in patients with cirrhosis were studied. Two groups were analyzed: the first group had a temporary portacaval shunt during the anhepatic phase, and the second group did not. Portal and systemic ET-1 levels were measured at several times. At the end of the anhepatic phase, systemic (16.1 +/- 6.5 pg/mL) and portal (19.2 +/- 7 pg/mL) ET-1 levels increased, whereas they decreased after reperfusion (systemic, 11.8 +/- 7.1 pg/mL; portal, 13.2 +/- 6.8 pg/mL). Portal flow at the beginning of LT correlated with systemic ET-1 levels (R2 = 0.3; P =.004). A temporary portacaval shunt reduced portal pressure during the anhepatic phase, but did not modify ET-1 levels. Patients with reperfusion syndrome had greater systemic ET-1 levels in the anhepatic phase (19.1 +/- 6.9 v 15.1 +/- 6.1 pg/mL; P =.07). Although there is a relationship between ET-1 levels and portal flow and reperfusion syndrome, no clear clinical effect on hemodynamics could be shown. Creation of a portacaval shunt made no change in ET-1 levels.

Topics: Adult; Aged; Endothelin-1; Female; Hemodynamics; Humans; Kidney Function Tests; Liver Cirrhosis; Liver Function Tests; Liver Transplantation; Male; Middle Aged; Portacaval Shunt, Surgical; Reperfusion Injury

Nitric oxide synthase (NOS) inhibition has been demonstrated to correct systemic vasodilation and renal hypoperfusion in studies of patients with cirrhosis. In patients with decompensated cirrhosis, NOS blockade increases arterial pressure, but the acute effects on hepatic and renal hemodynamics are not known.. We examined the acute systemic, hepatic, and renal hemodynamic effects of N(G)-monomethyl-L-arginine (L-NMMA) in 10 patients with decompensated cirrhosis. After baseline measurements, 3 mg/kg L-NMMA was administered as an IV bolus. At 20 minutes, if mean arterial pressure did not increase by at least 10 mm Hg above the baseline value, a second injection of 6 mg/kg was administered.. In 5 of 10 patients, the second injection of L-NMMA 6mg/kg was necessary to achieve at least a 10 mm Hg increase in mean arterial pressure. Acute NOS inhibition increased systemic vascular resistance and decreased cardiac output, without causing changes in the hepatic venous pressure gradient. Hepatic blood flow decreased, but the indocyanine green intrinsic clearance and extraction remained unchanged. Plasma renin activity (from 9.5 +/- 2.9 to 6.7 +/- 1.6 ng/ml/h) and urinary prostaglandin E2 (from 299 +/- 40 to 112 +/- 36 pg/ml) significantly decreased. No significant changes in glomerular filtration rate, renal plasma flow, and natriuresis occurred, however.. Acute L-NMMA infusion in patients with decompensated cirrhosis reduced hepatic blood flow and decreased plasma renin activity and urinary prostaglandin E2, without causing significant changes in renal hemodynamics.

Topics: Adult; Aged; Aspartate Aminotransferases; Atrial Natriuretic Factor; Dinoprostone; Dose-Response Relationship, Drug; Endothelin-1; Enzyme Inhibitors; Female; Hemodynamics; Humans; Injections, Intravenous; Liver Circulation; Liver Cirrhosis; Male; Middle Aged; Nitric Oxide Synthase; omega-N-Methylarginine; Renal Circulation

Cirrhosis predisposes the liver to secondary stresses such as endotoxemia possibly via dysregulation of the hepatic portal circulation secondary to imbalanced upregulation of vascular stress genes. In this study we determined the effect of cirrhosis on hepatic vasoregulatory gene expression in response to endotoxin (LPS, i.p., 1 mg/kg). Cirrhosis was induced by bile duct ligation (BDL) for 21 days in male Sprague-Dawley rats. Plasma and liver samples were taken 6 h following an injection of LPS for alanine aminotransferase (ALT) assays and RT-PCR analysis of mRNA levels for genes of interest: endothelin (ET-1), its receptors ET(A) and ET(B), endothelial nitric oxide synthase (eNOS), inducible NOS (iNOS), and heme oxygenase-1 (HO-1). ALT release increased by 5.5-fold in the BDL animals and 9.9-fold in BDL + LPS compared to sham. ET-1 mRNA was increased by either LPS or BDL treatment alone and increased significantly more in BDL + LPS compared to sham + LPS. mRNA levels for ET(B) receptors showed no change, whereas ETA transcripts decreased in BDL animals compared to sham, with no significant difference between the saline and LPS treatment groups. The resultant increased ratio of ET(B) over ET(A) in BDL animals was reflected functionally in the portal pressure responses to ET(A) and ET(B) agonists ET-1 and IRL-1620 (a specific ETB receptor agonist). The pressor response to ET-1 was attenuated, while the response to IRL-1620 was similar in BDL and sham. eNOS mRNA levels did not increase in response to either BDL or LPS or a combination of both compared to sham. The increase in iNOS mRNA was attenuated in BDL + LPS compared to sham + LPS. HO-1 expression increased significantly in sham + LPS, but failed to increase in BDL + LPS. Taken collectively, significantly greater induction of the constrictor ET-1 over the dilation forces (i.e., eNOS, iNOS, and HO-1) was observed in BDL + LPS. This suggests a compromised ability of the cirrhotic liver to upregulate sufficient dilatory forces to counterbalance the constrictive effect of ET-1 upon a secondary insult of endotoxemia. These results may partly explain the increased susceptibility of cirrhotic livers to injury as a result of endotoxemia.

Topics: Alanine Transaminase; Animals; Blood Pressure; Endothelin-1; Endotoxemia; Gene Expression; Heme Oxygenase (Decyclizing); Heme Oxygenase-1; Lipopolysaccharides; Liver Cirrhosis; Male; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; Rats; Rats, Sprague-Dawley; Receptor, Endothelin A; Receptor, Endothelin B; Receptors, Endothelin; RNA, Messenger; Vasoconstriction; Vasodilation

A multifunctional mediator, endothelin (ET)-1 is implicated in the pathophysiology of liver cirrhosis. Carbon tetrachloride (CCl4)-induced cirrhosis in rats resolves upon termination of CCl4 treatment. We determined the hepatic ET-1 system during such reversal and assessed whether ET-1 receptor antagonism enhances this process.. Cirrhosis was induced in rats by CCl4 treatment for 8 weeks. Treatment with an ETA/ETB antagonist TAK-044 (10 mg/kg per day) was then started and determinations were made at 1, 2 and 4 weeks.. After termination of CCl4 treatment, accelerated normalization of liver architecture and portal hypertension occurred in TAK-044-treated rats compared with saline-treated rats. The increased hepatic hydroxyproline concentration and collagen I mRNA expression also declined to greater extents in the TAK-044-treated group. Higher collagenase activity in cirrhosis decreased in saline-treated rats, but did not reach basal values. In TAK-044-treated rats, collagenase activity tended to increase at weeks 2 and 4. Increased ET-1 concentration and ETA receptor density declined to normal values in both groups. In contrast, increased ETB receptor density did not change in saline-treated rats, but decreased to control values in TAK-044-treated rats.. Our results emphasize the role of ET-1 in chronic liver disease and strongly indicate the potential for ET-1 receptor antagonists in its treatment.

Topics: Animals; Arteries; Blood Pressure; Carbon Tetrachloride; Collagen; Collagenases; Endothelin Receptor Antagonists; Endothelin-1; Hydroxyproline; Liver; Liver Cirrhosis; Male; Peptides, Cyclic; Portal Vein; Rats; Rats, Sprague-Dawley; Receptor, Endothelin A; Receptors, Endothelin; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1

The aims of this study were to determine 1. the variation of blood TGF beta 1 and ET-1 in patients with liver cirrhosis; 2. the relationship of the blood TGF beta 1 and ET-1 with Child degree of liver function and the severity of esophageal varices.. Peripheral blood samples were obtained from 72 patients and 24 normal controls. The blood levels of TGF beta 1 and ET-1 were measured by using a standard bioassay and the radioimmunoassay.. TGF beta 1 level (11.77 +/- 1.32 ng/ml) and ET-1 level (78.37 +/- 17.54 pg/ml) were significantly higher in the patients than those in controls(P < 0.05). The increase of the ET-1 in the patients is closely associated with Child degree of liver function (r = 0.94) and the severity of esophageal varices(r = 0.87). TGF beta 1 concentration is not associated with Child degree of liver function (r = 0.11) and the severity of esophageal varices (r = 0.03).. TGF beta 1 and ET-1 may play an important role in the pathophysiologic process of cirrhosis. ET-1 concentration may reflect portal hypertension development.

Topics: Adult; Aged; Biomarkers; Endothelin-1; Esophageal and Gastric Varices; Female; Humans; Liver Cirrhosis; Male; Middle Aged; Prognosis; Transforming Growth Factor beta; Transforming Growth Factor beta1

A balance between endothelins (ET) and nitric oxide (NO) might interfere with liver haemodynamics and disease progression in various liver diseases. Increased levels of endothelin 1 (ET-1) and nitrites and nitrates (NOx, the end products of NO metabolism) have been reported in hepatocellular carcinoma (HCC), but the balance has not been studied. The purpose of this study was to assess the ratio of NOx to ET-1 in patients with virus-related hepatocellular carcinoma and to investigate its correlation with the extent of the disease. Eighteen patients with virus-related HCC (six Okuda stage I, six Okuda stage II and six Okuda stage III) were included in the study and were compared with 22 patients with viral cirrhosis (14 decompensated, eight compensated) and seven normal controls. ET-1 was measured with an ELISA assay and NOx with a modification of the Griess reaction. Patients with virus-related HCC had the highest levels of circulating ET-1 and NOx (13.24 +/- 0.82 pg/ml and 112.28 +/- 18.56 micromol/l) compared to compensated cirrhosis (9.47 +/- 0.50 pg/ml, P < 0.004 and 54.47 +/- 2.36 micromol/l, P < 0.01), decompensated cirrhosis (9.57 +/- 0.32 pg/ml, P < 0.001 and 90.20 +/- 11.23 micromol/l, NS) and normal controls (8.84 +/- 0.61 pg/ml, P < 0.001 and 51.17 +/- 6.18 micromol/l, P < 0.01). There was a significant increase of ET-1 and NOx at HCC stage III compared to HCC stages I and II, cirhotics and controls. HCC stage III patients also had a NOx/ET-1 ratio that was higher than HCC stages I and II patients, normal controls and patients with compensated cirrhosis. Virus-related HCC patients have high levels of circulating ET-1, compared to compensated or decompensated cirrhosis. Highest levels of ET-1 are produced in Okuda III tumours. NOx are also increased but only in Okuda stage III tumours. The NOx/ET-1 ratio is increased in virus-related HCC and DC. This increase may account for the known increase in tumour blood flow.

Topics: Carcinoma, Hepatocellular; Endothelin-1; Female; Hepacivirus; Hepatitis B; Hepatitis B virus; Hepatitis C; Humans; Liver Cirrhosis; Liver Neoplasms; Male; Middle Aged; Nitrates; Nitrites

Plasma endothelin concentrations are elevated in cirrhosis and correlate with disease severity. This study assessed forearm vascular responses to exogenous endothelin-1 (ET-1), and evaluated the contribution of endogenous ET-1 to the maintenance of basal peripheral vascular tone in patients with well-compensated cirrhosis (n = 11) and matched healthy controls (n = 8). Bilateral forearm blood flow (FBF) was measured at baseline and following unilateral, subsystemic, intrabrachial artery infusions of ET-1 (2 and 6 pmol/min); BQ-123, a selective ET(A) receptor antagonist (3 and 10 nmol/min); and BQ-788, a selective ET(B) receptor antagonist (0.3 and 1 nmol/min) using venous occlusion plethysmography. Baseline systemic hemodynamics and plasma ET-1 and big ET-1 concentrations were measured using electrical bioimpedance and radioimmunoassay, respectively. Patients and controls had similar baseline FBF, systemic hemodynamics, and plasma ET-1 and big ET-1 concentrations. In both groups, ET-1 and BQ-788 caused significant vasoconstriction (P < .001) and BQ-123 caused significant vasodilatation (P < .001). Compared with controls, cirrhotic patients had attenuated ET-1 responses (P < .001), augmented BQ-123 responses (P < .001), and similar BQ-788 responses (P = .62). Despite normal systemic hemodynamics and plasma ET-1 concentrations, forearm vascular responses to exogenous ET-1 are reduced in cirrhotic patients. The augmented vasodilatation to BQ-123 in cirrhotic patients is consistent with a compensated vasodilated state, and a greater contribution of ET-1 to the maintenance of basal vascular tone acting through the ET(A) receptor.

Topics: Antihypertensive Agents; Endothelin Receptor Antagonists; Endothelin-1; Endothelins; Female; Forearm; Hemodynamics; Humans; Liver Cirrhosis; Male; Middle Aged; Oligopeptides; Peptides, Cyclic; Piperidines; Protein Precursors; Receptor, Endothelin A; Receptor, Endothelin B; Reference Values; Vascular Resistance

The aim of this study was to examine if the plasma endothelin-1 (ET-1), a potent vasoconstrictor, level may reflect the severity of portal hypertension associated with liver cirrhosis in biliary atresia (BA).. Forty-eight postoperative BA patients aged 6 months to 20 years were studied. Plasma ET-1 was measured by a sandwich method of enzyme immunoassay. ET-1 was compared with Child's score and laboratory data. ET-1 levels were compared among groups of patients with various degrees of histologic fibrosis and portal hypertension.. Plasma ET-1 was 5.3 +/- 3.5 pg/mL in BA, higher than in controls (3.1 +/- 0.8, n = 27; P <.05). ET-1 correlated with Child's score, serum total bilirubin, direct bilirubin, aspartate aminotransferase, albumin, prothrombin time, hepaplastin test, fibrinogen, cholinesterase, total cholesterol, Fischer's molar ratio, prealubumin, and hyaluronic acid, respectively (P <.05). ET-1 also correlated with the severity of histologic fibrosis, gastroesophageal varices, the presence of splenomegaly, ascites, venous dilatation on the abdominal wall, or pulmonary vascular abnormalities. In 4 patients undergoing liver transplantation (LTx), ET-1 after LTx was lower than that before LTx (P <.05).. Plasma ET-1 level may be a useful index reflecting the severity of cirrhosis and portal hypertension in BA.

Topics: Adolescent; Adult; Biliary Atresia; Biomarkers; Child; Child, Preschool; Endothelin-1; Humans; Hypertension, Portal; Infant; Liver Cirrhosis; Portoenterostomy, Hepatic; Severity of Illness Index

Plasma endothelin-1 (ET-1) levels are increased in patients with cirrhosis and ET-1 production is increased in the liver itself during experimental injury. These data suggest a possible role for this vasoactive peptide in intrahepatic microcirculatory changes that contribute to the pathogenesis of portal hypertension in cirrhosis. Therefore the aims of this study were to determine whether ET-1 levels were abnormal in the livers of patients with cirrhosis and to investigate possible clinical correlates of altered hepatic ET-1 in cirrhosis.. Liver specimens were obtained from explants at the time of liver transplantation in 62 cirrhotic patients; 49 without pretransplantation transjugular intrahepatic portosystemic shunt (TIPS) and 13 with pretransplantation TIPS. The presence of ascites was evaluated by physical examination and ultrasonography. Control specimens consisted of livers with normal morphology obtained from patients who died from nonliver-related causes. Hepatic ET-1 was measured by enzyme immunoassay.. Hepatic ET-1 levels in cirrhotics without (0.17 pg/mg liver tissue) or with TIPS (0.12 pg/mg) were higher than in control patients [0.04 pg/mg (p = 0.02 for ET-1 levels in cirrhotics with or without TIPS vs. control)]. In cirrhotics without ascites who had not had TIPS, ET-1 levels (0.07 pg/mg [0.04-1.00]) were similar to those of the controls. In contrast, ET-1 content was increased in cirrhotics with small (0.11 pg/mg; p = 0.0002) and moderate-to-large (0.69 pg/mg; p = 0.0002) amounts of ascites compared to patients without ascites. There was a modest correlation between ET-1 levels and Child-Pugh score (correlation coefficient 0.32; p = 0.03) and ET-1 levels were significantly higher in patients with Child-Pugh score of 13 or greater (0.88 pg/mg; p = 0.02) than in those with Child-Pugh score of 12 or less (0.16 pg/mg).. Hepatic tissue ET-1 levels are increased in the liver of patients with cirrhosis. This increase appears to be proportional to the severity of both liver disease and ascites. These data raise a possible role for ET-1 in modulation of intrahepatic resistance in cirrhotic portal hypertension.

Topics: Adult; Aged; Ascites; Biomarkers; Chronic Disease; Endothelin-1; Female; Humans; Hypertension, Portal; Liver; Liver Cirrhosis; Liver Transplantation; Male; Middle Aged; Portasystemic Shunt, Transjugular Intrahepatic

Endothelin-1 (ET-1) may be a mediator for portal hypertension in liver cirrhosis. The aim of the present study was to determine the concentrations of ET-1 in the systemic and splanchnic circulation before and after reduction of portal hypertension by transjugular intrahepatic portosystemic shunt implantation (TIPS).. Plasma concentrations of immunoreactive ET-1 were measured in peripheral venous blood samples from 25 patients with liver cirrhosis before and at 1, 3, 9 and 15 months after TIPS. Furthermore, acute effects of TIPS on ET-1 were studied in plasma samples from the hepatic vein, the portal vein 30 minutes before and after TIPS and in the femoral artery (only after TIPS) in a subgroup of 15 patients. In addition, the portocaval pressure gradient was determined before and after TIPS.. Before TIPS peripheral venous plasma ET-1 concentrations (n=25; median 4.2 pg/ml; range 1.9-14.7) were significantly increased in patients with refractory ascites (n=7; median 7.8, range 3.5 14.7) compared to patients with repetitive bleeding (n=18; median 3.4; range 1.9-7.1) (p=0.003). Furthermore, peripheral ET-1 concentrations correlated with the degree of liver dysfunction according to the Child-Pugh classification (Spearman's r=0.46; p=0.02). Following TIPS, peripheral ET-1 concentrations remained unchanged during a follow-up of 15 months. Before TIPS, a positive gradient of ET-1 concentrations from portalvenous to hepatovenous and peripheral venous levels was found (p<0.03). Immediately after TIPS, arterial ET-1 concentrations reached markedly increased levels in individual patients (88, 92 and 103 pg/ml). Severe systemic reactions to these high levels were not observed. Peripheral venous, hepatovenous and portalvenous ET-1 concentrations did not correlate with portocaval pressure gradients.. Cirrhotic patients demonstrated unchanged peripheral venous ET-1 concentrations up to 15 months after TIPS. Portal congestion was associated with increased ET-1 levels in the prehepatic splanchnic area. The effect of portal decompression on splanchnic and systemic ET-1 levels deserves further investigation.

Topics: Adult; Aged; Endothelin-1; Female; Humans; Hypertension, Portal; Liver Cirrhosis; Male; Middle Aged; Portasystemic Shunt, Transjugular Intrahepatic; Prospective Studies; Radioimmunoassay; Splanchnic Circulation

This study was aimed to evaluate the source of endothelin-1 (ET-1) in cirrhotic patients. ET-1 is implicated in the pathogenesis of portal hypertension. However, the mechanism and source for increased plasma ET-1 in cirrhotic patients are still obscure. Plasma ET-1 levels in systemic (SV), superior mesenteric (SMV), and splenic venous (SPV) blood were measured in 23 patients with cirrhosis and 8 controls with normal liver. Fourteen removed spleens were immunohistochemically studied for ET-1, CD34, CD68, and CD20. In situ hybridization was done to localize ET-1 messenger RNA (mRNA). In cirrhosis, ET-1 levels in both SMV and SPV were higher than in SV. ET-1 in SV and SPV were significantly higher in cirrhotic patients than in control patients. Three groups of cells in the spleen expressed both protein and mRNA of ET-1: endothelial cells in the sinus, which were also stained for CD34; cells in the germinal center; and cells in the marginal zone of lymphoid sheaths and follicles, which were also stained for CD20 but not for CD34 and CD68. The ET-1 concentration released from the spleen was in parallel with the grade of ET-1 expression in the spleen. The spleen is one of the major sites of ET-1 release in cirrhotic patients. Endothelial cells of the splenic sinus and possibly B lymphocytes in the germinal center and marginal zone of lymphoid sheaths and follicles seem to be the sites of ET-1 production in the spleen.

Topics: Adult; Aged; Aged, 80 and over; Antigens, CD; Antigens, CD34; Antigens, Differentiation, Myelomonocytic; Endothelin-1; Female; Humans; Hypertension, Portal; In Situ Hybridization; Intestinal Mucosa; Liver Cirrhosis; Male; Middle Aged; Portal Vein; Spleen; Venous Pressure

Our pilot study disclosed that tryptase-positive mast cells (MC) were densely distributed around the intrahepatic bile ducts (peribiliary MC). In this study, the pathophysiologic roles of these MC were examined with respect to the microcirculation around the bile duct in 71 cases of histologically normal liver, 24 cases of chronic hepatitis, and 45 cases of liver cirrhosis. The tryptase-positive MC were very close to the microvessels of the peribiliary vascular plexus (PVP), which supply the intrahepatic biliary tree. The tryptase-positive MC were frequently found adjacent to vascular smooth muscle cells, including pericytes. The location of the tryptase-positive MC was confirmed by ultrastructural analysis. In cirrhosis, the numbers of both microvessels of PVP and peribiliary MC increased in parallel. Peribiliary MC were immunoreactive for endothelin 1 (ET-1), and were variably immunoreactive for histamine, chymase, inducible nitric oxide synthase (iNOS), and endothelin A and B (ET(A) and ET(B)) receptors, particularly in cirrhotic livers. On vascular endothelial cells of PVP, endothelial nitric oxide synthase (eNOS) and ET-1 were consistently detectable, and ET(A) receptors, ET(B) receptors, and iNOS were variably detectable. Pericytes of PVP expressed ET(A) and ET(B) receptors in addition to ET-1 and iNOS. Biliary epithelial cells also focally expressed iNOS, ET-1, and ET(A) and ET(B) receptors. These vasoactive substances were strongly expressed on the cellular components in cirrhotic liver. By in situ hybridization, iNOS mRNA signals were observed on iNOS-immunoreactive cell components, including peribiliary MC. These morphologic and immunohistochemical findings suggest that the cellular components displaying vasoactive substances in the milieu of the intrahepatic biliary tree are very dynamic in the vasoregulation of PVP in normal livers, even more so in cirrhosis, and that peribiliary MC exert local effects on the microcirculation of PVP, directly and indirectly.

Topics: Bile Ducts, Intrahepatic; Biliary Tract; Blood Vessels; Chymases; Endothelin-1; Histamine; Humans; Immunohistochemistry; Liver Cirrhosis; Mast Cells; Microcirculation; Nitric Oxide Synthase; Receptors, Endothelin; Reference Values; Serine Endopeptidases

Endothelin-1 (ET-1) may mediate increased resistance to hepatic sinusoidal blood flow. We evaluated the hepatic distribution of ET-1 in patients with idiopathic portal hypertension (IPH), in which liver architecture may be normal, and in patients with cirrhosis, in which distortion of hepatic sinusoidal architecture is prominent. Immunohistochemistry and in situ hybridization were used to localize ET-1 in hepatic tissue of patients with IPH and cirrhosis. ET-1 was measured in plasma from a peripheral vein, the hepatic vein, and the portal vein of patients with cirrhosis of the liver and controls. On immunohistochemistry and in situ hybridization, ET-1 was localized to periportal hepatocytes and sinusoidal cells in patients with IPH and cirrhosis. Minimal positive staining for ET-1 was observed in control livers. Plasma ET-1 levels were significantly greater in patients with cirrhosis than in controls. In patients with cirrhosis, ET-1 was greater in the hepatic vein compared with the portal vein. However, the level of plasma ET-1 in patients with cirrhosis did not correlate with either the presence of ascites or portacaval pressure gradient. We conclude that in IPH, ET-1 is localized to sites in which it can modulate intrahepatic resistance. In late stages of cirrhosis, ET-1 may not modulate resistance. We speculate that vascular resistance in late stages of cirrhosis probably results from distortion of hepatic architecture.

Topics: Blood Pressure; Endothelin-1; Humans; Hypertension, Portal; Immunohistochemistry; In Situ Hybridization; Liver; Liver Circulation; Liver Cirrhosis; Portal Vein; Tissue Distribution; Veins; Venae Cavae

Hepatic concentration of endothelin-1 (ET-1) is increased in human and experimental liver cirrhosis. Because of its potent actions in the liver, ET-1 has been suggested to play an important role in the pathophysiology of cirrhosis. Since hepatocytes are the major cell type to metabolize ET-1, we investigated whether their reduced capacity to degrade ET-1 is a mechanism of its elevated levels in cirrhosis.. The expression of ET-1 receptors, ET-1 and endothelin converting enzyme (ECE), and metabolism of ET-1 and ECE activity were compared in hepatocytes isolated from control and carbon tetrachloride-induced cirrhotic rats.. ET-1 receptor density and receptor-mediated internalization of ET-1 were significantly increased in cirrhotic hepatocytes relative to the control cells. However, compared to control hepatocytes, metabolism of ET-1 by the cirrhotic cells was reduced significantly. Interestingly, hepatocytes were found to contain preproET-1 mRNA, ECE-1 mRNA and ET-1. PreproET-1 mRNA and ET-1 levels were increased in cirrhotic hepatocytes but their ECE mRNA and ECE activity were not altered.. These results provide the first evidence that hepatocytes have the ability to synthesize ET-1 and demonstrate that decreased metabolism and enhanced synthesis, of ET-1 in hepatocytes are an important mechanism of its elevated levels in cirrhosis.

Topics: Animals; Aspartic Acid Endopeptidases; Cells, Cultured; Endothelin-1; Endothelin-Converting Enzymes; Hepatocytes; Liver Cirrhosis; Male; Metalloendopeptidases; Rats; Rats, Sprague-Dawley; Receptor, Endothelin A; Receptors, Endothelin

The levels of plasma nitric oxide (NO), endothelin-1 (ET-1) and ALT in the patients with chronic hepatitis B and active cirrhosis and the correlation among them were observed and analyzed. NO3- was restored by using cadmium column assay and NO2- measured by heavy nitrogen assay. The primitive NO3- and total restored NO2- (NO3-/NO2-) in plasma of the patients with chronic hepatitis and cirrhosis. Plasma ET-1 and ALT levels were determined by using radioimmunological assay and Lai's assay, respectively. Compared with normal control group, the plasma levels of NO2-/NO2- and ET-1 in the patients with chronic active hepatitis and active cirrhosis were significantly increased (P < 0.05-0.01). There was a positive correlation between NO and ALT, and ET-1 and ALT in the patients with chronic active hepatitis and active cirrhosis respectively. It was suggested that elevation of both NO and ET-1 levels were closely related with injury severity of liver function.

Topics: Adolescent; Adult; Alanine Transaminase; Endothelin-1; Female; Hepatitis B, Chronic; Humans; Liver Cirrhosis; Male; Middle Aged; Nitric Oxide

The role of circulating endothelin- , a potent vasoconstricting peptide, in liver cirrhosis is still controversial. It has been postulated that endothelin-1 may play a role in the circulatory derangement occurring in cirrhotic subjects, and increased plasma endothelin-1 levels have been reported in these patients. In this study we looked for a relationship between the severity of the liver disease according to Child's classification and plasma endothelin-1 concentrations in a group of cirrhotic patients compared with a healthy control group. Twenty-two cirrhotic patients and 10 healthy controls, matched for sex and age, were selected for study after informed consent. The etiology of cirrhosis was posthepatitis B in 8 of 22 cases, posthepatitis C in 13 of 22 cases, and alcoholism in 1 patient. According to Child's classification, 6 patients were in class A, 6 in class B, and 10 in class C. Plasma endothelin-1 was measured by a commercial RIA kit (Amersham UK). Mean +/- SD plasma endothelin-1 levels were 8.8 +/- 0.9 pg/ml in controls and 9.2 +/- 1.1 pg/ml in all cirrhotic patients (P > 0.05). In each sub-group of cirrhotics, plasma endothelin- was 8.6 +/- 1.2 pg/ml in Child A, 8.9 +/- 1.9 pg/ml in Child B, and 10.6 +/- 1.5 pg/ml in Child C groups, respectively. There were no statistical differences between control subjects and Child A and B cirrhotic patients (P > 0.05). A significant increase in endothelinl was observed only in the Child C group versus either group A or B (P = 0.004). Our results show that alterations of circulating endothelin-1 do not occur in all cirrhotic patients; higher plasma levels than controls are only detectable in patients with more-severe hepatic failure. We do not know whether increased endothelin-1 levels are a consequence of hemodynamic disorders occurring in the advanced phase of liver cirrhosis or play a pathogenic role.

Topics: Biomarkers; Blood Pressure; Endothelin-1; Female; Glomerular Filtration Rate; Heart Rate; Humans; Liver Cirrhosis; Male; Middle Aged; Severity of Illness Index

Impaired renal function in patients with liver cirrhosis is a serious complication and is characterized by sodium and water retention in the absence of identifiable specific causes of renal dysfunction. The endothelin system has been shown to be activated in liver cirrhosis and might contribute to impaired renal function. However, the mechanisms leading to an activation of the endothelin system in these patients and the effects of an activated endothelin system on renal function in these patients are as yet unknown.. To determine the correlation between the activity of the endothelin system and the ability to excrete water and sodium in patients with liver cirrhosis, we measured plasma endothelin-1 concentrations by reversed phase-HPLC followed by an endothelin RIA and performed an oral water load tests in 10 healthy control subjects and 43 patients with liver cirrhosis. In addition, we analysed possible mechanisms/factors like plasma endotoxin that might contribute to the activation of the endothelin system in liver cirrhosis.. This study showed that the endothelin system is activated in patients with liver cirrhosis in a disease-stage-dependent manner. Patients with Child C liver cirrhosis have a 5.45-fold increased plasma ET-1 concentration compared to healthy controls, whereas plasma ET-1 is only increased 2.74-fold in Child A patients. An oral water load test revealed a highly significant (P < 0.0001) inverse correlation between the plasma endothelin-1 concentrations and the ability to excrete a given water load. Plasma endotoxin, a well-known stimulus of ET-1, is significantly (P < 0.03) correlated with plasma ET-1 in cirrhotic patients. The ET-1 concentrations in the ascites of patients with liver cirrhosis were lower and not related to plasma ET-1.. The activity of the endothelin system in patients with liver cirrhosis depends on the severity of liver impairment. Plasma endotoxin might be an important stimulus of the endothelin system in liver cirrhosis. We observed a highly significant inverse correlation between the plasma endothelin-1 concentrations and the ability to excrete a given water and sodium load, suggesting that the endothelin system plays a role in the regulation of water excretion in patients with liver cirrhosis.

Topics: Case-Control Studies; Diuresis; Endothelin-1; Endotoxins; Female; Humans; Liver Cirrhosis; Male; Middle Aged; Natriuresis

To investigate the level of plasma calcitonin gene related peptide (CGRP) and endothelin-1 (ET-1) to assess their role on portal hypertension formation and progression and liver function injury in liver cirrhosis and the possible relation between them.. CGRP and ET-1 were measured in plasma samples collected from 24 healthy controls and 61 liver cirrhosis patients.. Plasma CGRP and ET-1 level were significantly higher in cirrhotic patients than those in healthy controls. Comparisons of the levels of plasma CGRP and ET-1 in group of patients with different liver function were shown as follows: Child C > Child B > Child A. An analysis among the groups showed that plasma CGRP and ET-1 were markedly higher in the groups with esophageal varices accompanied by severe or moderate ascites (LC(4)) and with simple severe or moderate ascites (LC(3)) than in the groups with esophageal varices accompanied by mild or no ascites (LC(2)). The levels were also significantly higher in group LC(2) than those in group without varices and ascites (LC(1)). No statistical difference of plasma CGRP and ET-1 levels was found between group LC(1) or Child A and normal controls. There was positive correlation between plasma CGRP and ET-1. The increased concentration of both of them correlated negatively with the declined level of plasma albumin.. The increase of plasma CGRP and ET-1 is closely associated with the severity of liver cirrhosis and the formation and progression of portal hypertension. The disturbance of the balance between plasma CGRP and ET-1 may contribute to the pathologic process of liver injury.

Topics: Adult; Ascites; Calcitonin Gene-Related Peptide; Endothelin-1; Esophageal and Gastric Varices; Female; Humans; Hypertension, Portal; Liver Cirrhosis; Male; Middle Aged; Radioimmunoassay

We investigated plasma and urinary endothelin-1 levels in eleven cirrhotic patients and ten healthy control subjects, to evaluate whether endothelin is involved in renal functional alterations of liver cirrhosis.. No significant difference in plasma ET-1 levels was observed between the two groups (p > 0.05) but urinary ET-1 excretion was significantly higher in cirrhotics than in controls (p < 0.001). Creatinine clearance (mean 56 +/- 7.6 ml/min) showed an inverse correlation with plasma ET-1 levels (p < 0.05) in cirrhotics.. We believe this may be caused by enhanced local ET-1 activity linked to an up-regulation of its specific receptors and/or increased renal synthesis, resulting in augmented urinary excretion.

Topics: Aged; Creatinine; Endothelin-1; Female; Humans; Kidney; Liver Cirrhosis; Male; Middle Aged

The pathogenesis of cirrhotic ascites and hepatorenal syndrome remains unresolved. The involvement of both endothelin-1 and atrial natriuretic peptide have recently been suggested. This study investigated the concentrations of serum endothelin and atrial natriuretic peptide in cirrhotic patients.. Seven healthy subjects and 31 cirrhotic patients were studied. Cirrhotic patients were divided into three groups: Group I, 16 cirrhotic patients without ascites; Group II, 10 cirrhotic patients with ascites, but without hepatorenal syndrome; and Group III, five cirrhotic patients with hepatorenal syndrome and ascites. Their sera were analyzed for endothelin-1 and atrial natriuretic peptide concentrations.. Cirrhotic patients with ascites, Group II and Group III, had higher plasma endothelin-1 concentrations (15.9 +/- 2.3 pg/ml and 24 +/- 2.1 pg/ml, respectively) than normal subjects and compensated cirrhotics (3.8 +/- 0.7 pg/ml and 6.4 +/- 1.1 pg/ml, respectively); p < 0.001). Atrial natriuretic peptide concentrations were also significantly higher in cirrhotic patients than in normal subjects (p < 0.025). Plasma endothelin-1 concentration had a negative correlation with creatinine clearance (r = -0.65, p < 0.001), as did atrial natriuretic peptide concentrations (r = -0.44, p = 0.012). Plasma endothelin-1 correlated significantly with atrial natriuretic peptide concentrations (r = 0.38, p = 0.035).. Both endothelin-1 and atrial natriuretic peptide concentrations were elevated in cirrhotic patients with ascites and hepatorenal syndrome. Endothelin-1 may have a negative impact on renal function. Our data also suggested that impaired responsiveness rather than impaired secretion of atrial natriuretic peptide is responsible for sodium retention in cirrhotic patients with ascites.

Topics: Adult; Aged; Ascites; Atrial Natriuretic Factor; Endothelin-1; Female; Hepatorenal Syndrome; Humans; Liver Cirrhosis; Male; Middle Aged

In order to clarify the characteristics of cellular localization of ET-1/big ET-1 in liver tissues, we carried out immunohistochemical study on 30 normal, 87 cirrhosis (LC) and 55 hepatocellular carcinoma (HCC) liver specimens using anti-ET-1 antibody and anti-big ET-1 antibody and further performed in situ hybridization on 5 LC liver specimens. Positive immunostaining of hepatocytes of normal and LC livers, and tumor cells of HCC was obtained. The frequency of positive cells for ET-1 and big ET-1 of normal liver was very low. In contrast, LC hepatocytes were stained much more frequently for both ET-1 and big ET-1 than those of normal liver (P < 0.01). In the HCC livers hepatoma cells showed intermediate frequency of positive cells between normal and LC livers. Big ET-1, not ET-1, expression in HCC was significantly high compared with that of normal liver (P < 0.01). Specific signals for ET-mRNA were not detected in hepatocytes of LCs by in situ hybridization. ETs detected in hepatocytes by immunohistochemistry, therefore, seem not to have been synthesized locally. The origin of ETs is not clear but they might have been taken up from the circulation through ET receptors on hepatocytes. Although the clearance mechanism of ETs by ET-converting enzyme or other peptidases in liver has not been elucidated, the mechanisms seem to be absent or impaired in LC and/or HCC liver since the frequency and intensity of ET-positivity in the diseased hepatocytes are significantly high than those of normal liver. In addition, a disturbance of ET excretion into the bile may be also responsible for the ET storage. Elevation of serum ET levels in LC may be caused by disturbance of ET degradation and/or leakage of bile into the blood, as the ET is excreted through the biliary system.

Topics: Carcinoma, Hepatocellular; Endothelin-1; Endothelins; Humans; Immunohistochemistry; In Situ Hybridization; Liver; Liver Cirrhosis; Liver Neoplasms; Protein Precursors; RNA, Messenger; RNA, Neoplasm

Endothelin, a potent vasoconstrictor, is thought to play a role in liver cirrhosis-related functional kidney failure. Our aim was to investigate the correlation between renal vasoconstriction, as detected by a Doppler ultrasound technique, and plasma concentrations of endothelin in cirrhotic patients. Fifty cirrhotic patients underwent Doppler examinations to detect renal vasoconstriction. The plasma concentration of endothelin was measured in 10 patients who exhibited vasoconstriction of the renal microvessels diagnosed by Doppler waveform analysis and was compared to that of patients in whom there was no sign of such vasoconstriction. No difference was observed in the plasma concentration of endothelin between patients in whom renal vasoconstriction was diagnosed and those in whom it was not. Our results suggested that the circulating endothelin does not reflect renal vasoconstriction, at least in the early phase of the functional renal failure associated with cirrhosis of the liver.

Topics: Endothelin-1; Hepatorenal Syndrome; Humans; Immunoenzyme Techniques; Kidney; Liver Cirrhosis; Microcirculation; Regression Analysis; Ultrasonography, Doppler, Duplex; Vascular Resistance; Vasoconstriction

Measurements of plasma endothelin-1 and -3 in pre-ascitic cirrhosis have provided controversial results. Similarly, the role of the endothelin system in the pathogenesis of volume and hemodynamic disturbances of cirrhosis is still debated. To provide a further insight into this issue, we assessed the daily fluctuations of plasma endothelins and their relationship with arterial pressure and renal function in pre-ascitic cirrhosis.. Endothelin-1 and -3, plasma renin activity, atrial natriuretic peptide, noradrenaline and mean arterial pressure were measured at 11 pm, 7 am, 9 am and 6 pm in 10 patients with pre-ascitic cirrhosis and in 10 healthy subjects on normal sodium diet and carrying on their usual activities (supine from 10 pm to 7 am, standing and mobile after 7 am). Glomerular filtration rate and daily renal sodium excretion were assessed during the supine period, and from 7 am to 12 am and from 12 am to 10 pm during the standing period.. Endothelin-1 was higher in patients than in control subjects (p=0.000) and did not change during the study. Endothelin-3 was also higher in patients (p=0.002) and showed slight fluctuation in control subjects. The mean daily level of plasma renin activity was lower (p=0.016) and that of atrial natriuretic peptide higher (p=0.000) in patients with cirrhosis. Norepinephrine and mean arterial pressure did not differ significantly between the two groups. No correlations were found between endothelins and either hemodynamic or neuro-hormonal and renal function parameters in the two groups.. Despite the presence of increased effective volemia (as suggested by the reduced plasma renin activity and elevated atrial natriuretic peptide) and normal adrenergic tone, patients with pre-ascitic cirrhosis show elevated levels of endothelin-1 and endothelin-3 throughout the day. In early cirrhosis circulating endothelins, although elevated, do not appear to play a more prominent role in setting arterial pressure than in normal subjects, and endothelin elevation is not detrimental to renal function.

Topics: Adult; Aged; Ascites; Atrial Natriuretic Factor; Blood Pressure; Circadian Rhythm; Endothelin-1; Endothelin-3; Female; Glomerular Filtration Rate; Humans; Kidney; Liver Cirrhosis; Male; Middle Aged; Natriuresis; Norepinephrine; Renin

Topics: Endothelin-1; Endothelin-3; Humans; Liver Cirrhosis

To clarify whether hepatocellular carcinoma (HCC) may produce and secrete endothelin (ET), we measured plasma levels of ET-1 and big ET-1, a precursor form of ET-1, in 30 patients with HCC. When compared to normal subjects, a substantial number of patients had elevated plasma ET-1 and big ET-1 levels, determined by specific enzyme immunoassays. The mean (+/- SD) plasma concentrations of ET-1 (1.7 +/- 0.9 pmol/L) and big ET-1 (6.1 +/- 4.8 pmol/L) in patients' group were significantly (P < 0.01) higher than those (1.0 +/- 0.3 and 2.0 +/- 0.8 pmol/L, respectively) in control group. There was a significant positive correlation between plasma big ET-1 and alpha-fetoprotein (r = 0.77, P < 0.01). Some of the 29 patients with liver cirrhosis also had modestly elevated plasma big ET-1 levels. The mean (+/- SD) plasma big ET-1 concentration (3.1 +/- 0.9 pmol/L) in patients with liver cirrhosis was significantly (P < 0.01) higher than that in control group, although there was no significant difference between the mean plasma ET-1 levels of both groups. Raised plasma big ET-1 and, less markedly, ET-1 levels in patients with HCC decreased after successful transcatheter arterial embolization concomitantly with a reduction in tumor sizes and a decrease in plasma alpha-fetoprotein levels. In six patients, an arteriovenous difference in ET-1 and big ET-1 levels across the tumor bed with a higher concentration in the venous circulation was found. Reverse-phase high performance liquid chromatography revealed that major portions of immunoreactive ET-1 and big ET-1 in hepatic venous plasma coeluted with synthetic ET-1 and big ET-1, respectively. Immunohistochemistry of HCC tissues from two patients demonstrated HCC cells positive for ET-1 and big ET-1, whereas no ET immunoreactivity was found in adjacent nontumorous hepatocytes. We conclude from these results that ET is produced by and released from a substantial number of HCC, which may stimulate proliferation of carcinoma cells as an autocrine or paracrine growth factor.

Topics: Adult; Aged; alpha-Fetoproteins; Arteries; Carcinoma, Hepatocellular; Chromatography, High Pressure Liquid; Embolization, Therapeutic; Endothelin-1; Endothelins; Female; Humans; Immunoenzyme Techniques; Liver Cirrhosis; Liver Neoplasms; Male; Middle Aged; Protein Precursors; Veins