Alcohol-induced liver cirrhosis as a cause of portal hypertension

Basic data on pathomorphology and symptomatology of the alcohol-induced liver cirrhosis accompanied by portal hypertension are discussed. Respective data were compared with the group of cirrhotic patients not abusing alcohol. A high percentage of encephalopathic disorders and nearly 50% of the patients suffering from the hemorrhage from esophageal varices were the first sign of the cirrhosis in both groups. Despite hemorrhage from esophageal varices a few patients obtained surgical help preventing recurrence of the hemorrhage. Liver functional reserve, incidence of encephalopathies and the degree of liver involvement are in favour for non-alcohol cirrhosis. Inflammatory process in the liver, splenomegaly and hypersplenism were more frequent in the liver cirrhosis of non-alcohol origin.     

Eicosanoids in cirrhosis and portal hypertension

In the last decade, the knowledge of the pathogenesis of portal hypertension and cirrhosis has increased dramatically. In portal hypertension, almost all the known vasoactive systems/substances are activated or increased and the most recent studies have stressed the importance of the endothelial factors, in particular, prostaglandins. Prostaglandins are formed following the oxygenation of arachidonic acid by the cyclooxygenase (Cox) pathway. An important consideration in portal hypertension and cirrhosis in the periphery is the altered hemodynamic profile and its contributory role in controlling endothelial release of these vasoactive substances. Prostaglandins are released from the endothelium in response to both humoral and mechanical stimuli and can profoundly affect both intrahepatic and peripheral vascular resistance. Within the liver, intrahepatic resistance is altered due to a diminution in sinusoidal responsiveness to vasodilators and an increase in prostanoid vasoconstrictor responsiveness. This review will examine the contributory role of both hormonal and/or hemodynamic force-induced changes in prostaglandin production and signaling in cirrhosis and portal hypertension and the consequence of these changes on the structural and functional response of both the vasculature and the liver.     

Hydrogen sulfide attenuates carbon tetrachloride-induced hepatotoxicity, liver cirrhosis and portal hypertension in rats

Background

Hydrogen sulfide (H₂S) displays vasodilative, anti-oxidative, anti-inflammatory and cytoprotective activities. Impaired production of H₂S contributes to the increased intrahepatic resistance in cirrhotic livers. The study aimed to investigate the roles of H₂S in carbon tetrachloride (CCl₄)-induced hepatotoxicity, cirrhosis and portal hypertension.

Methods and Findings

Sodium hydrosulfide (NaHS), a donor of H₂S, and DL-propargylglycine (PAG), an irreversible inhibitor of cystathionine γ-lyase (CSE), were applied to the rats to investigate the effects of H₂S on CCl₄-induced acute hepatotoxicity, cirrhosis and portal hypertension by measuring serum levels of H₂S, hepatic H₂S producing activity and CSE expression, liver function, activity of cytochrome P450 (CYP) 2E1, oxidative and inflammatory parameters, liver fibrosis and portal pressure. CCl₄ significantly reduced serum levels of H₂S, hepatic H₂S production and CSE expression. NaHS attenuated CCl₄-induced acute hepatotoxicity by supplementing exogenous H₂S, which displayed anti-oxidative activities and inhibited the CYP2E1 activity. NaHS protected liver function, attenuated liver fibrosis, inhibited inflammation, and reduced the portal pressure, evidenced by the alterations of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), hyaluronic acid (HA), albumin, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and soluble intercellular adhesion molecule (ICAM)-1, liver histology, hepatic hydroxyproline content and α-smooth muscle actin (SMA) expression. PAG showed opposing effects to NaHS on most of the above parameters.

Conclusions

Exogenous H₂S attenuates CCl₄-induced hepatotoxicity, liver cirrhosis and portal hypertension by its multiple functions including anti-oxidation, anti-inflammation, cytoprotection and anti-fibrosis, indicating that targeting H₂S may present a promising approach, particularly for its prophylactic effects, against liver cirrhosis and portal hypertension.     

肝硬化门脉高压症大鼠模型制作方法的探讨

目的：建立稳定可靠的肝硬化门脉高压大鼠动物模型。材料与方法：50只雄性sD大鼠,随机分为3组。正常对照组10只,行假手术,给予正常饮食。肝硬化A组20只,先行左肾上腺静脉结扎,然后给予初始浓度为0．03％的硫代乙酰胺（thioacetamide,TAA）溶液作为饮用水并根据大鼠体重变化调节给药浓度。肝硬化B组20只,行假手术,给予固定浓度为0．03％TAA溶液。给药时间为14周。结果：肝硬化A组大鼠死亡率为0,肝硬化形成率达到100％。肝硬化B组大鼠死亡率15％,肝硬化形成率75％。肝硬化A组大鼠的门静脉压力明显高于肝硬化B组和对照组。结论：采用左肾上腺静脉结扎并根据体重变化调节TAA给药浓度可建立稳定可靠的肝硬化门脉高压大鼠动物模型。     

Insulin resistance in patients with cirrhosis and portal hypertension

Insulin resistance (IR) is involved in the pathogenesis of endothelial dysfunction and is also present in patients with cirrhosis. Intrahepatic endothelial dysfunction plays a major role, increasing hepatic vascular resistance and promoting portal hypertension (PH). In addition, β-adrenergic agonists and insulin share several intracellular signaling pathways. Thus IR may influence the response to β-blockers. This study aimed at evaluating the relationship between IR and hepatic hemodynamics in patients with cirrhosis and with the portal pressure response to acute β-blockade. Forty-nine patients with cirrhosis and PH were included. Hepatic and systemic hemodynamics were measured, and IR was estimated by using the updated homeostasis model assessment (HOMA)-2 index. Patients with HOMA-2 > 2.4 were considered IR. In patients with hepatic venous pressure gradient (HVPG) ≥ 10 mmHg) [clinically significant PH (CSPH)], hemodynamic measurements were performed again 20 min after intravenous propranolol. Mean HOMA-2 index was 3 ± 1.4. Fifty-seven percent of patients had IR. A weak correlation between HOMA-2 index and HVPG was observed. Eighty-six percent of patients had CSPH. HOMA-2 index was an independent predictor of CSPH. However, in patients with CSPH, the correlation between HOMA-2 index and HVPG was lost. HVPG, but not IR, predicted the presence of esophageal varices. Response to propranolol was not different between patients with or without IR. In nondiabetic patients with cirrhosis, HOMA-2 index is directly associated with the presence of CSPH and indirectly with varices, but does not allow either grading HVPG or predicting its response to propranolol.     

Long-term effectiveness of high-dosed ornithine-aspartate on urea synthesis rate and portal hypertension in human liver cirrhosis

Summary The effectiveness of ammonia reducing amino acids on hyperammonemia and hepatic encephalopathy is well known in patients suffering from liver cirrhosis. Data concerning long-term therapy on hepatic function and urea synthesis rate (UNSR) are still lacking. According to Vilstrup/Poulsen it is a good standard for functioning liver mass. Therefore, 25 patients with histologically proven liver cirrhosis and distinct portal hypertension were treated daily with 9 gr. ornithinasparte over 13 years (8–20 years). Shunt operations, esophageal varicosis sclerosis, or portal pressure reducing medication were not applied. Rigorous alcohol abstinence and 60 gr protein/day were prescribed. During the investigation, 3 laparoscopies and 4 liver biopsies were performed, on the average, on each individual. Significant improvements of clinical and biochemical results (Child-Pugh-Index; Composite Clinical and Laboratory Index) were obtained during the long-term therapy with ornithine-aspartate. Esophageal varicosis II–III was either reduced to 0-I or totally eliminated. Also significant was an increased urea synthesis rate and a decreased hyperammonemia.A plausible explanation for the long-term therapy effectiveness with ornithine-aspartate is the possible recovery of the functioning mass without hepatic size increase. Also important is the rigorous alcohol abstinence. It leads to a significant reduction of portal hypertension in patients suffering from alcohol induced liver cirrhosis (Reynolds, own observations).Additional favorable factors are intensive muscle training and absence of gastrointestinal bleeds.     

肝硬化门脉高压症食道胃底静脉破裂出血的治疗

目的：探讨Child C级肝硬化门脉高压症食道胃底静脉破裂出血病人的安全有效的治疗方案。方法：对89例急性大出血入院的Child C级肝硬化门脉高压症病人的治疗结果进行回顾性分析,对外科手术（19例）、内科治疗（51例）和TIPSS（颈内静脉肝内门体分流术）（19例）三种治疗方法的疗效、并发症和死亡率进行对比。结果：急诊手术、内科治疗、TIPSS的住院死亡率分别为65．5％。36．1％和26．3％;住院期间再出血率分别为24．1％,36．1％％15．8％。随访期的再出血率分别为33．0％,36．1％和21．4％。住院死亡率手术组显著高于另外两组（P〈0.01）。TIPSS组的住院再出血率及随访期再出血率显著低于内科组（P〈0．05和P〈0.01）。三组病人的生存率无显著性差异（Kaplan—Meier分析,P=0．07〉0．05）。结论：TIPSS作为一种微创介入技术是一种挽救Child C级门脉高压症食管静脉破裂出血病人生命的有效方法。其止血效果不亚于手术治疗,死亡率低于手术治疗,而再出血率低于内科治疗。更长期的疗效尚待进一步研究。     

Increased plasma volume in two models of portal hypertension in the rat: cirrhosis of the liver and partial portal vein ligation

Portal hypertension has been studied in the rat to see if it is associated to altered blood volume composition, as it has been shown in other species. Plasma volume was measured by isotope dilution using 99mTc labelled albumin in three groups of male Sprague-Dawley rats: normal rats (controls), partially ligated portal vein rats and rats with Cl4C induced cirrhosis. Plasma volume was significantly higher in rats with portal hypertension due to partially ligated portal vein and cirrhosis than in control animals. Similarly, the calculated blood volume was also significantly higher in the portal hypertensive animals than in control group. Portal hypertension in the rat, therefore, has been demonstrated to be associated to a marked hypervolemia and this finding should be taken into consideration in haemodynamic and pharmacokinetic studies in portal hypertensive rat models.     

Serum neopterin levels in liver cirrhosis

Neopterin is a pyrazino-pyrimidine compound which is biosynthesized by macrophages. Increased concentrations of neopterin have been reported in conditions causing a stimulation of cellular immunity, such as viral and other infections, graft versus host disease, autoimmune disease and different malignancies. Recently, urinary neopterin levels have been found increased in patients with acute viral hepatitis and NANB chronic hepatitis. In the present study, neopterin serum levels have been measured in 23 cirrhotic patients (6 HBV related, and 17 cryptogenetic cirrhosis, 7 of them occurring in alcoholic subjects) and in 24 normal subjects. Mean values of serum neopterin were significantly increased in cirrhotics (3.92 +/- 3.28 ng/ml versus 1.24 +/- 0.51 ng/ml in controls, p less than 0.01). Serum neopterin values were not found to be significantly different in cirrhotics assessed in three different clinical classes according to Child's classification and in cirrhotics with and without serological findings of active disease. In fact, in cirrhotic patients, serum neopterin levels did not correlate with the values of serum AST, ALT, ALP, GGT and gamma-globulin. These data show that increased levels of serum neopterin occur in cirrhotic patients, but there is no relation between serum neopterin values and the activity or the clinical severity of the disease. The results are consistent with the hypothesis that activated macrophages are involved in all stages of liver cirrhosis irrespective of its aetiology.     

Vasoactive factors and hemodynamic mechanisms in the pathophysiology of portal hypertension in cirrhosis

Portal hypertension is primarily caused by the increase in resistance to portal outflow and secondly by an increase in splanchnic blood flow, which worsens and maintains the increased portal pressure. Increased portal inflow plays a role in the hyperdynamic circulatory syndrome, a characteristic feature of portal hypertensive patients. Almost all the known vasoactive systems/substances are activated in portal hypertension, but most authors stress the pathogenetic role of endothelial factors, such as COX-derivatives, nitric oxide, carbon monoxide. Endothelial dysfunction is differentially involved in different vascular beds and consists in alteration in response both to vasodilators and to vasoconstrictors. Understanding the pathogenesis of portal hypertension could be of great utility in preventing and curing the complications of portal hypertension, such as esophageal varices, hepatic encephalopathy, ascites.