Hemodynamic features of advanced cirrhosis due to chronic bile duct ligation

Intrasplenic Hepatocyte Transplantation Prolonged the Survival in Nagase Analbuminemic Rats with Liver Failure Induced by Common Bile Duct Ligation

It has already been established that hepatocyte transplantation (HTx) in animal models, such as both chemically and surgically induced acute liver failure, liver-based metabolic disease, and cirrhosis, resulted in significant improvement of liver function and survival. However, the efficacy of hepatocyte transplantation in secondary cholestatic liver disease is not well known. In this study, we transplanted hepatocytes into the spleen of Nagase analbuminemic rats (NARs) with common bile duct ligation (CBDL) to evaluate the function of transplanted hepatocytes by both of serum albumin levels and total bilirubin levels. CBDL was carried out on NARs to induce liver failure. Lewis rat hepatocytes were transplanted in NARs 7 days after CBDL. Animals, in groups of four, underwent the following interventions: group 1—intrasplenic transplantation of 30 × 106 primary Lewis rat hepatocytes in NARs with CBDL (n = 4), group 2—intrasplenic injection of 0.5 ml DMEM in NARs with CBDL (n = 4); group 3—CBDL only (n = 4); group 4—intrasplenic transplantation of 30 × 106 primary Lewis rat hepatocytes in NARs (n = 4). Both bilirubin levels and albumin levels in NARs with CBDL were significantly improved post-HTx. Animals receiving hepatocyte transplantation survived longer than animals in nontransplant control groups. This study indicates that hepatocytes can be transplanted to temporarily provide life-supporting liver-specific metabolic function and prolong the survival in recipient rats with liver failure induced by CBDL.

The effect of curcumin on liver fibrosis in the rat model of microsurgical cholestasis

We aimed to determine the effects of curcumin on liver fibrosis and to clarify the role of nuclear factor-κB (NF-κB) and inducible nitric oxide synthase (iNOS) in a model of microsurgical cholestasis in the early stage of extrahepatic biliary atresia.

Ultrasonic diagnosis and vasoactive substances examination in patients with cirrhosis

OBJECTIVE

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).

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Inhibition of nitric oxide synthase in hyperdynamic circulation of rats with early or late cirrhosis secondary to common bile duct ligation

BACKGROUND/AIMS

Preventing internal hemorrhage extends the lifespan of rats with chronic bile duct ligation (CBDL), a common animal model of portal hypertension. We investigated hemodynamics during the early and late stages of cirrhosis caused by CBDL. We also evaluated the hemodynamic influence of NO, which is the chief vasodilator in hyperdynamic syndrome, by administration of an NO synthase inhibitor (N(G)-nitro-L-arginine methyl ester: L-NAME; 10 mg/kg). ANIMALS/METHODS: In 24 Sprague-Dawley rats (9 sham rats and 15 CBDL rats), hemodynamics were assessed under conscious and unrestrained conditions 4 and 8 weeks after surgery. Before and 30 minutes after L-NAME administration, the cardiac index (CI) and regional blood flow were measured with the reference sample method using (141)Ce- and (113)Sn-microspheres (15 µm in diameter).

RESULTS

A hyperdynamic systemic circulation and splanchnic hyperemia were observed after CBDL, and these changes increased with the progression of cirrhosis. L-NAME significantly diminished the hyperdynamic circulation and also reduced splanchnic hyperemia. In 4-week CBDL rats, a low hemoglobin concentration made an important contribution to the hyperdynamic circulation, and the portal collateral system collapsed when inflow to the portal territory was reduced by L-NAME treatment. In 8-week CBDL rats, systemic hemodynamics were closely linked to both the splanchnic circulation and the renal circulation before and after L-NAME administration, apart from hepatic artery blood flow.

CONCLUSION

The distinctive hemodynamic changes of portal hypertension were found in 8-week CBDL rats. Thus, 8-week CBDL rats may be a better animal model of human portal hypertension than 4-week CBDL rats.

An intravital microscopic study of the hepatic microcirculation in cirrhotic mice models: relationship between fibrosis and angiogenesis

This intravital fluorescence microscopy (IVFM) study validates cirrhotic mice models and describes the different intrahepatic alterations and the role of angiogenesis in the liver during genesis of cirrhosis. Cirrhosis was induced by subcutaneous injection of carbon tetrachloride (CCl(4)) and by common bile duct ligation (CBDL) in mice. Diameters of sinusoids, portal venules (PV), central venules (CV) and shunts were measured at different time points by IVFM. Thereafter, liver samples were taken for sirius red, CD31, Ki67, vascular endothelial growth factor (VEGF) and alpha-smooth muscle actin (alpha-SMA) evaluation by immunohistochemistry (IHC). In parallel with fibrogenesis, hepatic microcirculation was markedly disturbed in CCl(4) and CBDL mice with a significant decrease in sinusoidal diameter compared to control mice. In CCl(4) mice, CV were enlarged, with marked sinusoidal-free spaces around CV. In contrast, PV were enlarged in CBDL mice and bile lakes were observed. In both mice models, intrahepatic shunts developed gradually after induction. During genesis of cirrhosis using CD31 IHC we observed a progressive increase in the number of blood vessels within the fibrotic septa area and a progressively increase in staining by Ki67, VEGF and alpha-SMA of endothelial cells, hepatocytes and hepatic stellate cells respectively. In vivo study of the hepatic microcirculation demonstrated a totally disturbed intrahepatic architecture, with narrowing of sinusoids in both cirrhotic mice models. The diameters of CV and PV increased and large shunts, bypassing the sinusoids, were seen after both CCl(4) and CBDL induction. Thus present study shows that there is angiogenesis in the liver during cirrhogenesis, and this is probably due partially to an increased production of VEGF.

Biliary fibrosis in microsurgical extrahepatic cholestasis in the rat

A new model of extrahepatic cholestasis, using a microsurgical technique, is performed as an alternative to the traditional model of the bile duct ligated-rat, in order to study the stage of fibrosis in the long-term. Male Wistar rats were divided into two groups: I (Sham-operated, n = 9) and II [Microsurgical Cholestasis (MC), n = 10]. After 4 weeks, portal pressure, types of portosystemic collateral circulation, mesenteric venous vasculopathy, hepatic function test, and liver histopathology were studied by using the Knodell index and fibrosis was determined by reticulin and Sirius red stains. The animals with MC presented portal hypertension with extrahepatic portosistemic collateral circulation, associated with mesenteric venous vasculopathy and increased plasma levels of bilirubin (6.30 +/- 1.80 vs. 0.22 +/- 0.37 mg/dL; P = 0.0001), alkaline phosphatase (293.00 +/- 82.40 vs. 126.30 +/- 33.42 U/L; P = 0.001), AST (380.00 +/- 78.50 vs. 68.33 +/- 11.74 IU/L; P = 0.0001), ALT (87.60 +/- 22.32 vs. 42.22 +/- 7.89 IU/L; P = 0.0001), and LDH (697.76 +/- 75.13 vs. 384.80 +/- 100.03 IU/L; P = 0.0001). On the contrary, plasma levels of albumin decreased (2.72 +/- 0.12 mg/dl vs. 2.99 +/- 0.10; P = 0.001). The microsurgical resection of the extrahepatic biliary tract in the rat produces an experimental model of hepatic inflammation, characterized by a high Knodell hepatic activity index (4), bile proliferation, and fibrosis.

Experimental obstructive cholestasis: the wound-like inflammatory liver response

Obstructive cholestasis causes hepatic cirrhosis and portal hypertension. The pathophysiological mechanisms involved in the development of liver disease are multiple and linked. We propose grouping these mechanisms according to the three phenotypes mainly expressed in the interstitial space in order to integrate them.Experimental extrahepatic cholestasis is the model most frequently used to study obstructive cholestasis. The early liver interstitial alterations described in these experimental models would produce an ischemia/reperfusion phenotype with oxidative and nitrosative stress. Then, the hyperexpression of a leukocytic phenotype, in which Kupffer cells and neutrophils participate, would induce enzymatic stress. And finally, an angiogenic phenotype, responsible for peribiliary plexus development with sinusoidal arterialization, occurs. In addition, an intense cholangiocyte proliferation, which acquires neuroendocrine abilities, stands out. This histopathological finding is also associated with fibrosis.It is proposed that the sequence of these inflammatory phenotypes, perhaps with a trophic meaning, ultimately produces a benign tumoral biliary process - although it poses severe hepatocytic insufficiency. Moreover, the persistence of this benign tumor disease would induce a higher degree of dedifferentiation and autonomy and, therefore, its malign degeneration.

Comparison of three research models of portal hypertension in mice: macroscopic, histological and portal pressure evaluation

The characterization of mice models of portal hypertension (PHT) is lacking in the literature. Therefore, the aim of the present study was to make a histological approach during development of PHT in two models of cirrhosis with PHT compared with one model of isolated PHT. The model of isolated PHT was developed by partial portal vein ligation (PPVL). Two portal hypertensive cirrhotic mice models were developed either by common bile duct ligation (CBDL) or administration of carbon tetrachloride (CCl(4)) subcutaneously (twice weekly, 1 ml/kg). These models represent, respectively, a secondary biliary cirrhosis and alcoholic cirrhosis. Mice were killed at several time points to evaluate liver changes by histological and ultrastructural methods. A correlation was made with portal pressure measurements. Histology revealed the absence of fibrosis or cirrhosis in PPVL mice. They developed an isolated portal hypertension. After CBDL induction, the mice developed the characteristics of cirrhosis after 6 weeks, with simultaneous increase in portal pressures. Fifty percent of the mice had ascites at that time point. Sixteen weeks after administration of CCl(4), a micronodular cirrhotic aspect of the liver was seen associated with signs of portal hypertension. This is the first descriptive study of three widely used animal models in mice, allowing the study of pathophysiological changes in cirrhosis and portal hypertension. The PPVL in mice leads to a model of isolated portal hypertension. Secondary biliary cirrhosis developed after 6 weeks of common bile duct ligation in 50% of the mice that developed ascites. Subcutaneous injection of CCl(4) for 16 weeks induces cirrhosis and portal hypertension, without ascites. Moreover, the present study is the first description of a cirrhotic model in mice developed by subcutaneous injections of CCl(4). Well-described mice models will facilitate use of knock-out or transgenic mice and lead to a better understanding of the underlying molecular pathways in the field of portal hypertension and cirrhosis.

Effects of chronic L-NAME on nitrotyrosine expression and renal vascular reactivity in rats with chronic bile-duct ligation

In liver cirrhosis, elevated levels of NO and ROS (reactive oxygen species) might greatly favour the generation of peroxynitrite. Peroxynitrite is a highly reactive oxidant and it can potentially alter the vascular reactivity and the function of different organs. In the present study, we evaluated whether peroxynitrite levels are related to the progression of renal vascular and excretory dysfunction during experimental cirrhosis induced by chronic BDL (bile-duct ligation) in rats. Experiments were performed at 7, 15 and 21 days after BDL in rats and in rats 21 days post-BDL chronically treated with L-NAME (NG-nitro-L-arginine methyl ester). Sodium balance, BP (blood pressure), basal RPP (renal perfusion pressure) and the renal vascular response to PHE (phenylephrine) and ACh (acetylcholine) in isolated perfused kidneys were measured. NO levels were calculated as 24-h urinary excretion of nitrites, ROS as TBARS (thiobarbituric acid-reacting substances), and peroxynitrite formation as the renal expression of nitrotyrosine. BDL rats had progressive sodium retention, and decreased BP, RPP and renal vascular responses to PHE and ACh in the time following BDL. They also had increasing levels of NO and ROS, and renal nitrotyrosine accumulation, especially in the medulla. All of these changes were either prevented or significantly decreased by chronic L-NAME administration. In conclusion, these results suggest that the increasing levels of peroxynitrite might contribute to the altered renal vascular response and sodium retention in the development of the experimental biliary cirrhosis. Moreover, the beneficial effects of decreasing NO synthesis are, at least in part, mediated by anti-peroxinitrite-related effects.