Glomerulopressin activity in carbon tetrachloride-induced cirrhosis in male rats.

The activity of glomerulopressin, a putative renal vasoregulatory hormone that is synthesized in the liver, was assayed in male rats with carbon tetrachloride-induced cirrhosis and the results were compared to glomerulopressin activity in normal-control and pair-fed animals. Glomerulopressin activity in blood samples collected from the hepatic vein of the cirrhotic group was significantly lower than the activity in the normal-control and pair-fed groups. Glomerulopressin activity in the normal-control and the pair-fed groups were not significantly different. The data support the concept that glomerulopressin deficiency in liver disease, such as cirrhosis, may play a role in the genesis of the functional renal failure associated with liver disease.     

The pharmacodynamics of mivacurium in the rabbit with carbon tetrachloride-induced liver disease

BACKGROUND AND OBJECTIVE: Neuromuscular blocking effects according to the severity of liver dysfunction have not been evaluated. We assessed the neuromuscular effects of mivacurium in carbon tetrachloride (CCl4)-treated rabbits with toxic hepatitis in vivo. METHODS: We compared the dose-response relationships and the neuromuscular blocking effects of mivacurium in 66 rabbits randomly treated with 0.3 mL kg(-1) of corn oil, 0.3 mL kg(-1) of CCl4 or 0.6 mL kg(-1) of CCl4 for 11 weeks, respectively. Train-of-four stimuli were applied every 10 s to the common peroneal nerve and the force of contraction of the tibialis anterior muscle was measured. RESULTS: Severe hepatitis was associated with a rightward shift of the mivacurium dose-response curves, but mild hepatitis had no effect. The calculated ED50 values for the control, mild and severe hepatitis were 17.1+/-2.6, 18.2+/-2.7 and 31.8+/-3.2 microg kg(-1), respectively. Rabbits with severe hepatitis had a significantly prolonged recovery time from neuromuscular blockade compared with other rabbits. Cholinesterase activity had a negative correlation with recovery indices of mivacurium even in severe hepatic injury. Severe hepatitis induced a prolongation of action duration of repeated doses, but maintained the constant intervals. CONCLUSIONS: The dose-response and the time course of neuromuscular blockade of mivacurium differ in mild hepatitis compared with severe hepatitis, but required no adjustments of different doses for repeated injection after the desired depth of neuromuscular block, and had a negative correlation with the activity of plasma cholinesterase in both hepatic injuries.     

DDR2RNA干扰对CCl4诱导肝纤维化动物模型的实验研究

目的 探讨沉默大鼠盘状结构域受体2(discoidin domain receptor 2,DDR2)基因表达对CCl4诱导大鼠肝纤维化的影响及其机制.方法 SD大鼠随机分为正常组(8)、纤维化组(18)、阴性对照组(18)和治疗组(18),每组又据干预时间不同平均分为4周、6周两组.化学合成经胆固醇修饰的siRNA-DDR2尾静脉体内注射,干扰CCl4诱导大鼠纤维化模型DDR2基因表达.用荧光实时定量PCR及Western blot分别检测干扰DDR2基因后DDR2、MMP-2和Ⅰ型胶原纤维(COLⅠ)的表达;同时行肝脏组织学观察及肝功能检测.结果 经siRNA-DDR2干扰后,纤维化组大鼠DDR2、MMP-2和COL Ⅰ的mRNA水平(t4=6.78,t6=9.02;t4=4.71,t6=6.37;t4=8.81,t6=6.50,均P＜0.01)及蛋白表达水平(t=6.11,t=4.39,t=5.23,均P＜0.01,4周;t=7.82,t=4.80,t=7.64,均P＜0.01,6周)均显著降低;同时,肝脏的组织学病变及肝功能指标也显著改变.结论 尾静脉注射化学合成经胆固醇修饰的抗DDR2siRNA能显著降低DDR2基因表达,促进细胞外基质降解,具有潜在的抗肝纤维化作用.

Abstract：

Objective To explore the effects of silencing DDR2 expression by siRNA on CCl4-induced liver fibrosis and its mechanism in rats. Methods Liver fibrosis model was induced by intraperitoneal injection of CCl4 twice a week for 6 consecutive weeks. Some rats were administered siRNA targeting DDR2 (0. 3 mg/kg), saline or control siRNA every three days from the beginning of CCl4 injection via tail vein injection, while other rats were treated in the same pattern after 2-week CCl4 injection. Quantitative real-time polymerase chain reaction (QRT-PCR) and Western blot were used to detect the mRNA and protein expressions of DDR2, MMP-2 and COL Ⅰ . Meanwhile, the pathological changes of liver tissues and the levels of liver function were also observed. Results QRT-PCR showed that the DDR2, MMP-2 and COL Ⅰ mRNA in the chemically synthetic cholesterol-modified siRNADDR2 group were significantly decreased as compared with those in the control group (P＜0.01) ,and the protein expressions of DDR2, MMP-2 and COL Ⅰ were also significantly decreased (P＜0. 01,4 wand 6w). In addition, in comparison with those in the control group, the pathological changes of liver tissues in the siRNA-DDR2 treated group were markedly attenuated, and the levels of ALT(1356.17 ±83.80 nkat/L vs 2532. 70±145.11 nkat/L,4w,1367. 60±321.76 nkat/L vs 2604.37±255.02 nkat/L,6w,P＜0. 01 ) and AST (2460. 80 ± 207. 58 nkat/L vs 3983. 70 ± 253. 08 nkat/L, 4w, P＜ 0. 01,2383.27±290.16 nkat/L vs 3227.70±353. 34 nkat/L,6w,P＜0. 05)were also significantly lowered,while the level of TBIL (7. 97 ± 1.60 μmol/L vs 3.80± 0.60 μmol/L, 4w, 10.40±1.61 μmol/L vs 6.10±0.79 μmol/L,6w,P＜0. 01)was markedly increased. Conclusion Systemic administration of cholesterol-modified siRNA targeting DDR2 could significantly suppress the expression of DDR2, decrease the contents of the extracellular matrix,and thus has a potential antifibrotic effect.     

Systemic infusion of FLK1(+) mesenchymal stem cells ameliorate carbon tetrachloride-induced liver fibrosis in mice

BACKGROUND: Fibrosis is the common end stage of most liver diseases, for which, unfortunately, there is no effective treatment available currently. It has been shown that mesenchymal stem cells (MSCs) from bone marrow (BM) could engraft in the lung after bleomycin exposure and ameliorate its fibrotic effects. This study was designed to evaluate the effect of Flk1 MSCs from murine BM (termed here Flk1 mMSCs) on fibrosis formation induced by carbon tetrachloride (CCl4). METHODS: A CCl(4)-induced hepatic fibrosis model was used. Flk1 mMSCs were systemically infused immediately or 1 week after mice were challenged with CCl(4). Control mice received only saline infusion. Fibrosis index and donor-cell engraftment were assessed 2 or 5 weeks after CCl(4) challenge. RESULTS: We found that Flk1 mMSCs transplantation immediately, but not 1 week after exposure to CCl(4), significantly reduced CCl(4)-induced liver damage and collagen deposition. In addition, levels of hepatic hydroxyproline and serum fibrosis markers in mice receiving immediate Flk1 mMSCs transplantation after CCl(4) challenge were significantly lower compared with those of control mice. More importantly, histologic examination suggested that hepatic damage recovery was much better in these immediately Flk1 mMSCs-treated mice. Immunofluorescence, polymerase chain reaction, and fluorescence in situ hybridization analysis revealed that donor cells engrafted into host liver, had epithelium-like morphology, and expressed albumin, although at low frequency. CONCLUSION: These results suggest that Flk1 mMSCs might initiate endogenous hepatic tissue regeneration, engraft into host liver in response to CCl(4) injury, and ameliorate its fibrogenic effects.     

Protective effect of interferon-alpha on carbon tetrachloride-induced nephrotoxicity

BACKGROUND: The aim of this study was to investigate the effect of chronic administration of interferon-alpha 2b for the prevention of carbon tetrachloride (CCl4)-induced oxidative stress and nephrotoxicity. METHODS: Thirty rats were divided into three groups: control, CCl4+placebo (CCl4+P) and CCl4+interferon-alpha 2b (CCl4+INF). Control rats were treated with pure olive oil. The other rats were treated for seven weeks with subcutaneous injections of CCl4 (0.15 mL /kg) in pure olive oil three times a week. Rats were killed at the end of the seventh week and renal histopathological examinations were done: specimens of renal tissue were obtained for investigating oxidative stress parameters, including malondialdehyde (MDA) and glutathione peroxidase (GSH-Px). RESULTS: Tubular changes, glomerular hypercellularity, and capillary obliteration were significantly less in the CCl4+INF group than with CCl4+P (p<0.05) and the interstitial fibrosis score for the CCl4+INF group was similar to the control group. However, the interstitial inflammation score was higher in the CCl4+INF group than the control group (p<0.05). No change was observed in the CCl4+P group. Renal MDA levels in the control and CCl4+INF groups were significantly lower than the CCl4+P group, while GSH-Px was significantly higher (p<0.001). There was no difference between the control and CCl4+INF groups in oxidative stress markers (p>0.05). CONCLUSIONS: Administration of interferon-alpha 2b to CCl4-treated rats prevented interstitial fibrosis, probably as a result of its antifibrogenic effect. It also reduced intrarenal oxidative stress in rats with CCl4-induced nephrotoxicity.     

Decompensated liver cirrhosis

The incidence of liver disease continues to increase and is now one of the leading causes of death in the United Kingdom. The increasing prevalence of viral hepatitis combined with a surge in the incidence of both alcohol and obesity related liver disease mean that critical care units are increasingly being called upon to assist in managing those with life-threatening complications or end-stage liver disease. Decompensated cirrhosis is not a single organ illness but a complex multi-system disorder typified by impaired immunity, malnutrition and multi-organ failure and presents a significant challenge to the critical care physician. In this article we describe the epidemiology, aetiology and pathophysiology of decompensated liver disease and describe the management strategies of a range of resulting clinical complications.     

Decompensated liver cirrhosis

The incidence of liver disease continues to increase and is now one of the leading causes of death in the United Kingdom. The increasing prevalence of viral hepatitis combined with a surge in the incidence of both alcohol- and obesity-related liver disease mean that critical care units are increasingly being called upon to assist in managing those with life-threatening complications or end-stage liver disease. Decompensated cirrhosis is not a single organ illness but a complex multi-system disorder typified by impaired immunity, malnutrition and multi-organ failure and presents a significant challenge to the critical care physician. In this article we describe the epidemiology, aetiology and pathophysiology of decompensated liver disease and describe the management strategies of a range of resulting clinical complications.     

Alcoholic liver cirrhosis. Screening for hepatocellular carcinoma in liver cirrhosis

HIGH INCIDENCE: Because of the high incidence of hepatocellular carcinoma (HCC) in patients with cirrhosis (3 to 5% per year) and the fact that curative treatment is currently available only for small sized tumors careful screening is warranted in this high risk population. Earlier screening attempts produced disappointing results in terms of cure and survival, particularly in Europe. Progress in ultrasonography, a better understanding of the risk of developing HCC, and most importantly the advent of local percutaneous treatments have greatly affected the data which should be reexamined. SCREENING METHODS: Patients with cirrhosis, particularly alcoholic or viral cirrhosis, should undergo regular ultrasound examinations, every six months for most screening protocols although the best timing remains unknown. Assay of serum alpha-fetoprotein is of limited use due to its low sensitivity and specificity. Diagnosis of HCC is basically based on helicoidal computed tomography and/or magnetic resonance imaging findings, with or without pathological proof (ultrasound-guided biopsy) that may be difficult to obtain. A probabilistic diagnosis is therefore retained if necessary, based on the presence of risk factors and arterial hypervascularization of a liver nodule. EARLY TREATMENT: With ultrasound screening, the diagnosis of HCC can generally be established early, when curative transplantation, resection or local percutaneous destruction are still feasible. The percutaneous methods use chemical or physical agents to destroy the tumor. There are few contraindications so curative treatment can be proposed for large number of patients. Large-scale prospective studies will be completed in the upcoming years and are expected to provide evidence validating the principle of screening and early treatment.     

Carbon tetrachloride-induced experimental cirrhosis in the rat: a reappraisal of the model

The goal of this study was to evaluate the presence of extrahepatic damage and the uniformity and reversibility of the histological findings in CCl4-induced liver cirrhosis in the rat. To verify these findings rats were sacrificed 2 and 10 weeks after a treatment consisting of ten intragastric doses of CCl4, administered weekly. All treated rats developed an irreversible micronodular cirrhosis with no damage to the brain, kidney and pancreas. Moreover, rats sacrificed 2 weeks after the last CCl4 dose showed a number of functional alterations usually observed in man. In particular, low branched chain/aromatic amino acids (BCAA/AAA) plasma ratio, high ammonia, low zinc and high insulin with normal blood glucose were obtained.     

Neurological complications of liver cirrhosis and orthotopic liver transplant

Neurological complications are common in cirrhotic patients with end-stage liver failure. They comprise a wide array of etiologies, which may originate before, during, or after liver transplantation. The objective of this study was to describe the nature of the main neurological complications in patients with end-stage liver failure. Several toxins including ammonia, manganese, benzodiazepine-like substances, gamma-aminobutyric acid-like substances, and impaired dopaminergic neurotransmission are at the top of the list of candidates for hepatic encephalopathy, subclinical encephalopathy, and extrapyramidal signs before liver transplantation. Central pontine myelinolysis, cerebrovascular autoregulation impairment, and paradoxical cerebral embolism are probably responsible for the neurological complications during liver transplantation. Neurological complications represented by alterations of mental status, seizures, and focal motor deficits have been described after liver transplantation. These complications have been attributed to several pathogenetic factors, such as a poorly functioning graft, an intracranial hemorrhage, a cerebral infarction, an infection, or the toxicity of immunosuppressants.     

Portal hypertension in liver cirrhosis

Portal hypertension is a dramatic complication in liver cirrhosis by efraction of the varices localized more frequently in the esophagus. It has been an actual subject due to physiopathological research (endotelin system, nitric system etc), diagnosis (echoendoscopy, color Doppler), and therapeutically progress. Propranolol, available at a low cost, is efficient and unanimously accepted in the prophylactic treatment of medium and large varices which have never bled as well as in the hemorrhage due to variceal efraction which stopped therapeutically or spontaneously. This drug diminishes the risk of rebleeding. Besides the pharmacological treatment, terlipresine, octreotid, sclerotherapy and bandlegation are used in active hemorrhage due to variceal efraction. If this fails other methods for haemostasis are used: portosystemic transjugular shunt, mechanical tamponade, selective surgery and ideally hepatic transplant. Except for the hepatic transplant, none of the mentioned methods can improve the rate of survival in-patients, which depends on the state of the hepatic failure.     

Focal cirrhosis of the liver

The experience in treatment of 14 patients with focal cirrhosis of the liver is summarized. Clinical and morphological data is presented. It is noted that clinical picture is poor and non-specific. Ultrasonic examination is the main diagnostic tool. It is demonstrated that histological examination of removed specimen is often necessary for final diagnosis. Method of choice in the treatment of patients is surgical one. The scope of surgery depends on intraoperative features, extended hepatic resection is not usually indicated.