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A surgical connection between portal and inferior cava veins was performed to generate an experimental model of high circulating ammonium and hepatic hypofunctioning. After 13 weeks of portacaval anastomosis (PCA), hyperammonemia and shrinkage in the liver were observed. Low glycemic levels accompanied by elevated levels of serum alanine aminotransferase were recorded. However, the activity of serum aspartate aminotransferase was reduced, without change in circulating urea. Histological and ultrastructural observations revealed ongoing vascularization and alterations in the hepatocyte nucleus (reduced diameter with indentations), fewer mitochondria, and numerous ribosomes in the endoplasmic reticulum. High activity of hepatic caspase-3 suggested apoptosis. PCA promoted a marked reduction in lipid peroxidation determined by TBARs in liver homogenate but specially in the mitochondrial and microsomal fractions. The reduced lipoperoxidative activity was also detected in assays supplemented with Fe2+. Only discreet changes were observed in conjugated dienes. Fluorescent probes showed significant attenuation in mitochondrial membrane potential, reactive oxygen species (ROS), and calcium content. Rats with PCA also showed reduced food intake and decreased energy expenditure through indirect calorimetry by measuring oxygen consumption with an open-flow respirometric system. We conclude that experimental PCA promotes an angiogenic state in the liver to confront the altered blood flow by reducing the prooxidant reactions associated with lower metabolic rate, along with significant reduction of mitochondrial content, but without a clear hepatic dysfunction.

Background Glycogen storage disease (GSD) is an inherited disorder leading to abnormal glucose metabolism and glycogen accumulation, and is associated with various complications including hepatic adenoma and hepatocellular carcinoma. The aim of this study was to analyze the risk factors for hepatic adenoma and its malignant change, and the hepatocellular carcinoma-free survival rate in patients with GSD who developed adenoma. Methods A total of 72 patients with GSD who were enrolled from March 1982 to September 2013 at Seoul National University Children's Hospital were retrospectively analyzed, and the median follow-up period was 19.2 years. Results Thirty-two patients (44.4%) developed hepatic adenoma at an age range of 7.9–26.3 years (median, 14.3 years). Among the 32 patients with hepatic adenoma, 4 patients (12.5%) developed hepatocellular carcinoma on an average interval of 6.7 years between the diagnosis of adenoma and the development of hepatocellular carcinoma. GSD type I and portacaval shunt operation were found to be the risk factors for hepatic adenoma development. The hepatocellular carcinoma-free survival rate at 10 years from adenoma development was 82%. Conclusion The present study found that portacaval shunt operation increases the risk of development of hepatic adenoma in GSD patients, especially in GSD type I. The hepatic adenoma in GSD patients has a potential of malignant transformation, which should be keep in mind in follow-up process of the disease., Graphical Abstract

The etiopathogenesis of primary sclerosing cholangitis is unknown. Genetic variants of fucosyltransferase 2 (FUT2) have been identified in genome-wide association studies as risk factors for primary sclerosing cholangitis. We investigated the role of Fut2 in murine liver pathophysiology by studying Fut2(-/-) mice. Fut2(-/-) mice were viable and fertile, had lower body weight than wild-type (wt) littermates and gray fur. Half of the Fut2(-/-) mice showed serum bile salt levels 40 times higher than wt (Fut2(-/-)(high) ), whereas the remainder were normocholanemic (Fut2(-/-)(low) ). Fut2(-/-) mice showed normal serum liver tests, bile flow, biliary bile salt secretion, fecal bile salt loss, and expression of major hepatocellular bile salt transporters and cytochrome P450 7a1, the key regulator of bile salt synthesis, indicating that elevated serum bile salts in Fut2(-/-)(high) mice were not explained by cholestasis. Fut2(-/-)(high) mice, but not Fut2(-/-)(low) mice, were sensitive to hydrophobic bile salt feeding (0.3% glycochenodeoxycholate); they rapidly lost weight and showed elevation of serum liver tests (alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase) and areas of liver parenchymal necrosis. Histomorphological evaluation revealed the presence of paraportal shunting vessels, increased numbers of portal vascular structures, wall thickening of some portal arteries, and periductal fibrosis in Fut2(-/-)(high) mice more than Fut2(-/-)(low) mice and not wt mice. Unconjugated bilirubin and ammonia were or tended to be elevated in Fut2(-/-)(high) mice only. Portosystemic shunting was demonstrated by portal angiography, which disclosed virtually complete portosystemic shunting in Fut2(-/-)(high) mice, discrete portosystemic shunting in Fut2(-/-)(low) mice, and no shunting in wt littermates. Liver pathology in Fut2(-/-) mice is dominated by consequences of portosystemic shunting resulting in microcirculatory disturbances, mild (secondary) periductal fibrosis, and sensitivity toward human bile salt toxicity. (Hepatology 2017;66:542-554)

Ammonia is neurotoxic, and chronic hyperammonemia is thought to be a major contributing factor to hepatic encephalopathy in patients with liver disease. Portacaval shunting of rats is used as an animal model to study the detrimental metabolic effects of elevated ammonia levels on body tissues, particularly brain and testes that are deleteriously targeted by high blood ammonia. In normal adult rats, the initial uptake of label (expressed as relative concentration) in these organs was relatively low following a bolus intravenous injection of [13N]ammonia compared with lungs, kidneys, liver, and some other organs. The objective of the present study was to determine the distribution of label following intravenous administration of [13N]ammonia among 14 organs in portacaval-shunted rats at 12 weeks after shunt construction. At an early time point (12 s) following administration of [13N]ammonia the relative concentration of label was highest in lung with lower, but still appreciable relative concentrations in kidney and heart. Clearance of 13N from blood and kidney tended to be slower in portacaval-shunted rats versus normal rats during the 2–10 min interval after the injection. At later times post injection, brain and testes tended to have higher-than-normal 13N levels, whereas many other tissues had similar levels in both groups. Thus, reduced removal of ammonia from circulating blood by the liver diverts more ammonia to extrahepatic tissues, including brain and testes, and alters the nitrogen homeostasis in these tissues. These results emphasize the importance of treatment paradigms designed to reduce blood ammonia levels in patients with liver disease.

Background The term hepatopulmonary syndrome typically applies to cyanosis that results from “intrapulmonary vascular dilatation” due to advanced liver disease. Similar findings may result from a congenital portosystemic shunt without liver disease. An adverse consequence of such shunts is intrapulmonary vascular dilatation, which affects the microvascular gas exchange units for oxygen. Case presentation Here, we describe a toddler with chronic cyanosis, exercise intolerance, and finger clubbing due to a malformation shunt between the portal vein and the inferior vena cava. A transcatheter embolization of the shunt resulted in resolution of his findings. Conclusions Congenital portosystemic shunts need to be considered in the differential diagnosis of cyanosis. Electronic supplementary material The online version of this article (10.1186/s12890-019-0788-8) contains supplementary material, which is available to authorized users.

Budd-Chiari syndrome (BCS) refers to hepatic venous outflow obstruction that in severe cases can lead to acute liver failure prompting consideration of revascularization or transplantation. Here, a 22 year old female with angiographically proven BCS secondary to JAK2/V617F positive Polycythemia vera on therapeutic warfarin presented with acute liver failure (ALF). Imaging revealed a new, near complete thrombotic occlusion of the main portal vein with extension into the superior mesenteric vein. An emergent direct intrahepatic portocaval shunt (DIPS) was created and liver function promptly normalized. She has been maintained on rivaroxaban since that time. Serial assessment over 1 year demonstrated continued shunt patency and improved flow in the mesenteric vasculature on ultrasound as well as normal liver function. DIPS is a viable alternative in the treatment of ALF from BCS when standard recanalization is not feasible. Improved blood flow may also improve portal/mesenteric clot burden. While further investigation is needed, new targeted anticoagulants may be viable as a long term anticoagulation strategy.

Pruritus is a common symptom in chronic liver diseases, which may also alter thermal sensitivity. The underlying mechanisms remain unclear and treatments are not satisfactory. Portal-systemic shunting has been proposed to alter thermal sensitivity in cirrhotics. Inflamma-tion-induced enhanced activity of the Transient Receptor Potential Vanilloid 1 (TRPV1) may contribute to pruritus and thermal hyperalgesia. Sildenafil reduces neuroinflam-mation in portacaval shunt (PCS) rats. The aims were to assess whether: (1) PCS rats show enhanced scratching or thermal sensitivity; (2) TRPV1 activity is enhanced in PCS rats; (3) treatment with sildenafil reduces TRPV1 activation, scratching and thermal hyperalgesia. Rats were treated with sildenafil beginning 3 weeks after surgery. The number of scratches performed were counted. Thermal hyperalgesia was analyzed using the Hargreaves' Plantar Test. TRPV1 activation by measuring the increase in Ca2+ induced by capsaicin in dorsal root ganglia neurons. PCS rats show enhanced scratching behavior, reaching 66 +/- 5 scratches/ h (p < 0.01) at 21 days after surgery, while controls show 37 +/- 2 scratches/ h. PCS rats show thermal hyperalgesia. Paw withdrawal latency was reduced (p < 0.05) to 10 +/- 1 s compared to controls (21 +/- 2 s). Capsaicin-induced calcium increase was higher in dorsal root ganglia cultures from PCS rats, indicating TRPV1functional increase. PCS rats show enhanced scratching behavior and thermal sensitivity and are a good model to study these alterations in chronic liver diseases. Enhanced sensitivity and activity of TRPV1 channel underlies these alterations. Treatment with sildenafil reduces TRPV1 channel sensitivity and activity and normalizes scratching behavior and thermal sensitivity.

Portacaval anastomoses spontaneously appear during liver insufficiency and lead to chronic hyperammonemia and hepatic encephalopathy. Ammonium induces oxidative stress in the brain. Here, we compared the state of the antioxidant system in different rat brain areas and studied the manner in which it is affected by portacaval shunting. At 4 weeks after the surgical operation, we measured the activities of catalase, Cu,Zn-superoxide dismutase, glutathione peroxidase, glutathione reductase, and glutathione transferase in cytoplasm and content of oxidized proteins in mitochondria of the neocortex, cerebellum, hippocampus, and striatum. All four brain regions differed according to the ammonium content and activity of each antioxidant enzyme. The activity of glutathione peroxidase decreased as compared to the control only in the cerebellum and striatum of animals with portacaval shunt. After portacaval shunting, the activities of catalase, Cu,Zn-superoxide dismutase, glutathione peroxidase, and glutathione reductase did not differ from the control in all the brain regions we studied. An inverse correlation between the content of oxidized proteins and activity of glutathione transferase suggests that the diminished activity of glutathione peroxidase in the cerebellum and striatum, but not other antioxidant enzymes and other brain regions, may play a role in the pathogenesis of hepatic encephalopathy.

Summary Aim Rats with portacaval shunt (PCS) are useful experimental models of human hepatic encephalopathy in chronic liver dysfunction. We have previously shown that PCS modifies amine neurotransmitter systems in the CNS and increases voluntary alcohol intake by rats. Hepatocyte transplantation, used in acute liver failure, has recently also been applied to chronic liver diseases, which prompted us to investigate whether the altered brain amine system and the drinking behavior in long-term shunted rats could be normalized by hepatocyte transplants. Methods Hepatocytes, isolated from syngeneic donors by collagenase digestion, were injected (3 × 106 cells/rat) into the pancreatic tail region, 6 months after PCS. Hepatic function was evaluated by measuring urine urea and plasma L-histidine concentrations. A free choice test with two bottles (tap water and 10% ethyl alcohol) was performed for 3 days to assess the rats’ preference for alcohol. The rats were euthanized 2 months posttransplantation. Brain histamine and 5-hydroxyindoleacetic acid (5-HIAA) levels were measured by radioenzymatic assay and by HPLC-EC, respectively, N-tele-methylhistamine by GC/MS while MAOA and MAOB activities by isotopic procedures. Results Portacaval shunt rats with hepatocyte transplants gave more urea than before transplantation, with lower plasma L-His levels and higher body weight versus the PCS counterparts. Also, those rats consumed less alcohol. The CNS amines and 5-HIAA concentrations, as well as MAO-B activity, being abnormally high in untreated PCS rats, significantly reduced after PCS hepatocyte treatment. Conclusions The results support the therapeutic values of hepatocyte transplants in chronic liver diseases and the temporary character of PCS-exerted CNS dysfunctions.

Background & Aims The pathogenesis of hepatic encephalopathy (HE) is multifactorial and often associated with the development of brain oedema. In addition to ammonia playing a central role, systemic oxidative stress is believed to aggravate the neuropsychological effects of ammonia in patients with chronic liver disease (CLD). The aim of this study was to (i) induce systemic oxidative stress in hyperammonaemic portacaval anastomosed (PCA) rats by inhibiting the antioxidant glutathione using Dimethyl maleate (DEM) and (ii) investigate whether a synergistic relationship between ammonia and oxidative stress contributes to the pathogenesis of brain oedema in CLD. Methods Four-week PCA and sham-operated rats received DEM (0.4–4 mg/kg/day) for the last 10 days before sacrifice when oxidative stress markers [reactive oxygen species (ROS) and malondialdehyde (MDA)] were assessed in blood and frontal cortex. Brain water content was measured using a specific gravimetric technique. Results Dimethyl maleate induced an increase in ROS and MDA in the blood, but not in the brain, of the PCA rats, compared with non-treated PCA rats. This was accompanied with an increase in brain water content (PCA+DEM: 78.45 ± 0.13% vs. PCA: 77.38 ± 0.11%, P

Neuroinflammation plays a main role in neurological deficits in rats with minimal hepatic encephalopathy (MHE) due to portacaval shunt (PCS). Treating PCS rats with SB239063, an inhibitor of MAP-kinase-p38, reduces microglial activation and brain inflammatory markers and restores cognitive and motor function. The translocator protein-(18-kDa) (TSPO) is considered a biomarker of neuroinflammation. TSPO is increased in brain of PCS rats and of cirrhotic patients that died in hepatic coma. Rats with MHE show strong microglial activation in cerebellum and milder in other areas when assessed by MHC-II immunohistochemistry. This work aims were assessing: 1) whether binding of TSPO ligands is selectively increased in cerebellum in PCS rats; 2) whether treatment with SB239063 reduces binding of TSPO ligands in PCS rats; 3) which cell type (microglia, astrocytes) increases TSPO expression. Quantitative autoradiography was used to assess TSPO-selective (3)H-(R)-PK11195 binding to different brain areas. TSPO expression increased differentially in PCS rats, reaching mild expression in striatum or thalamus and very high levels in cerebellum. TSPO was expressed in astrocytes and microglia. Treatment with SB239063 did not reduces (3)[H]-PK11195 binding in PCS rats. SB239063 reduces microglial activation and levels of inflammatory markers, but not binding of TSPO ligands. This indicates that SB239063-induced neuroinflammation reduction in PCS rats is not mediated by effects on TSPO. Also, enhanced TSPO expression is not always associated with cognitive or motor deficits. If enhanced TSPO expression plays a role in mechanisms leading to neurological alterations in MHE, SB239063 would interfere these mechanisms at a later step.

PURPOSE: To investigate the intraoperative microcirculatory changes of the affected organs (small bowel, liver and kidney) during the making of a modified selective portacaval (PC) shunt. METHODS: On ten anaesthetized Sprague-Dawley rats the selective end-to-side mesocaval anastomosis was performed, where only the rostral mesenteric vein is utilized and the portal vein with the splenic vein are left intact. Morphometric and microcirculatory investigations using a LDF device determining flux units (BFU) were carried out. RESULTS: After completing the shunts the microcirculatory flux values did not recover in the same manner on the surface of the small intestine, the liver or the kidney. BFU values showed deterioration in the small intestine and in the liver (p

There is functional zonation of metabolism across the liver acinus, with glutamine synthetase restricted to a narrow band of cells around the terminal hepatic venules. Portacaval anastomosis, where there is a major rerouting of portal blood flow from the portal vein directly to the vena cava bypassing the liver, has been reported to result in a marked decrease in the activity of glutamine synthetase. It is not known whether this represents a loss of perivenous hepatocytes or whether there is a specific loss of glutamine synthetase. To answer this question, we have determined the activity of glutamine synthetase and another enzyme from the perivenous compartment, ornithine aminotransferase, as well as the immunochemical localization of both glutamine synthetase and ornithine aminotransferase in rats with a portacaval shunt. The portacaval shunt caused a marked decrease in glutamine synthetase activity and an increase in ornithine aminotransferase activity. Immunohistochemical analysis showed that the glutamine synthetase and ornithine aminotransferase proteins maintained their location in the perivenous cells. These results indicate that there is no generalized loss of perivenous hepatocytes, but rather, there is a significant alteration in the expression of these proteins and hence metabolism in this cell population.

Background and Aims Bleeding esophageal varices is responsible for much of the high mortality rate in cirrhosis. An important objective of management of bleeding varices is to develop reliable tools for predicting survival, controlling bleeding and encephalopathy, and improve quality of life. This study compared two widely used prognostic tools, the model for end-stage liver disease (MELD) and the Child-Turcotte (C-T) score, in a randomized controlled trial of emergency treatment of bleeding varices. Methods We randomized 211 unselected consecutive patients with cirrhosis and bleeding varices to endoscopic sclerotherapy (n = 106) or emergency portacaval shunt (n = 105). Diagnosis and treatment were accomplished within 20 hours. Follow-up was 100% for 10 y. We compared the prognostic powers of MELD and C-T upon entry, and then monthly for the first year and every 3 months thereafter. Statistical analysis included computation of receiver operating curves, the area under the curve, and the proportion of variability. Results In baseline determinations of MELD versus C-T, there were no significant differences in predicting survival, recurrent encephalopathy, and rebleeding. The Child-Turcotte score was a stronger predictor than MELD of hospital readmissions and readmission days. In serial determinations over years, the prognostic power of both MELD and C-T was substantial, but C-T was significantly more effective in predicting survival and time to recurrent encephalopathy. Conclusions In this first long-term comparison of MELD versus C-T in cirrhosis with bleeding varices, C-T was consistently as effective as MELD in predicting survival, encephalopathy, rebleeding, hospital readmissions, and readmission days. In some measures, C-T was a more effective prognostic tool than MELD.

Cirrhotic patients with recurrent variceal bleeds who have failed prior medical and endoscopic therapies and are not transjugular intrahepatic portosystemic shunt candidates face a grim prognosis with limited options. We propose that mesocaval shunting be offered to this group of patients as it has the potential to decrease portal pressures and thus decrease the risk of recurrent variceal bleeding. Mesocaval shunts are stent grafts placed by interventional radiologists between the mesenteric system, most often the superior mesenteric vein, and the inferior vena cava. This allows flow to bypass the congested hepatic system, reducing portal pressures. This technique avoids the general anesthesia and morbidity associated with surgical shunt placement and has been successful in several case reports. In this paper we review the technique, candidate selection, potential pitfalls and benefits of mesocaval shunt placement.

To study the frequency of risk factors for hepatic encephalopathy in patients of chronic liver disease. This is a retrospective, non interventional hospital based observational case study between April 2002 to April 2003 carried out in North Medical Ward, Mayo Hospital, Lahore. Two hundred consecutive patients of chronic liver disease presenting with hepatic encephalopathy were studied. The frequency of risk factors was 47%, due to infections, 30% due to GIT bleeding, 19% due to constipation, 4% due to miscellaneous factors. Early recognition of the precipitating factors improves the prognosis and final outcome.

The increased deposition of iron in gastric mucosa is known as gastric siderosis. It is believed that the only regulated step of the iron metabolism cycle occurs during absorption in the small intestine. Once this system becomes overwhelmed due to either local or widespread iron levels, then iron can be absorbed very quickly by a passive concentration-dependent mechanism. This excess iron is initially stored in the liver but later can be found in the pancreas, heart and joints. Excess iron is not expected to deposit in the gastric mucosa. This gastric deposition has been found in association with hemochromatosis, oral iron medications, alcohol abuse, blood transfusions, hepatic cirrhosis and spontaneous portacaval shunt with esophageal varices. The precise mechanism of this iron deposition in gastric epithelial and stromal cells is still not well understood; thus, identification of iron in gastric mucosa raises many questions. On histology, the pattern of deposition is variable, and recognition of the pattern is often useful to choose the appropriate workup for the patient and to diagnose and possibly treat the cause of iron overload. In this article, we have described a well-referenced review of this rare clinical entity with different histological patterns, diagnostic tests and the clinical significance of the different patterns of iron deposition.

Hyperammonemia and sarcopenia (loss of skeletal muscle) are consistent abnormalities in cirrhosis and portosystemic shunting. We have shown that muscle ubiquitin-proteasome components are not increased with hyperammonemia despite sarcopenia. This suggests that an alternative mechanism of proteolysis contributes to sarcopenia in cirrhosis. We hypothesized that autophagy could be this alternative pathway since we observed increases in classic autophagy markers, increased LC3 lipidation, beclin-1 expression, and p62 degradation in immunoblots of skeletal muscle protein in cirrhotic patients. We observed similar changes in these autophagy markers in the portacaval anastamosis (PCA) rat model. To determine the mechanistic relationship between hyperammonemia and autophagy, we exposed murine C2C12 myotubes to ammonium acetate. Significant increases in LC3 lipidation, beclin-1 expression, and p62 degradation occurred by 1 h, whereas autophagy gene expression (LC3, Atg5, Atg7, beclin-1) increased at 24 h. C2C12 cells stably expressing GFP-LC3 or GFP-mCherry-LC3 constructs showed increased formation of mature autophagosomes supported by electron microscopic studies. Hyperammonemia also increased autophagic flux in mice, as quantified by an in vivo autophagometer. Because hyperammonemia induces nitration of proteins in astrocytes, we quantified global muscle protein nitration in cirrhotic patients, in the PCA rat, and in C2C12 cells treated with ammonium acetate. Increased protein nitration was observed in all of these systems. Furthermore, colocalization of nitrated proteins with GFP-LC3-positive puncta in hyperammonemic C2C12 cells suggested that autophagy is involved in degradation of nitrated proteins. These observations show that increased skeletal muscle autophagy in cirrhosis is mediated by hyperammonemia and may contribute to sarcopenia of cirrhosis.

BACKGROUND: Disability has not been studied after emergency treatment of bleeding esophageal varices (BEV). We created a disability index (DI) in a randomized controlled trial comparing emergency endoscopic therapy (EST) versus emergency portacaval shunt (EPCS). METHODS: There were 211 unselected, consecutive patients with cirrhosis and acute BEV who were randomized to EST (n = 106) or EPCS (n = 105). Diagnostic work-up and treatment were performed within 8 hours. Ninety-six percent underwent more than 10 years follow-up evaluation. Disability was measured by assessing 9 factors to create a DI. RESULTS: Ten-year survival was 8% after EST versus 51% after EPCS (P < .001). EPCS had a significantly better DI. The EST and EPCS values were as follows: liver function improvement: not applicable and ++; worsening liver function, ++ and not applicable; portal-systemic encephalopathy (PSE) incidence, 36 and 15; PSE episodes, 179 and 94; packed red blood cell units, 1,005 and 320; hospital readmissions, 387 and 292; and number of readmission days, 9.6 and 4.7. All of the P values were less than .001. CONCLUSIONS: EPCS resulted in a markedly better DI than EST, a significantly higher survival rate, better control of bleeding, and a lower incidence of PSE. EPCS is an effective first-line emergency treatment of BEV.

a b s t r a c t Mast cells are involved in various liver diseases and appear to play a broader pathogenic role than orig- inally thought. They may participate in the splanchnic alterations related to a porto-systemic shunt. To verify this hypothesis we studied the serum and hepatic histological changes in rats four weeks after an end-to-side portacaval shunt. In this experimental model of chronic liver insufficiency we also assessed the mucosal mast cells (MMC) and connective tissue mast cells (CTMC) in the liver, mesenteric lymph nodes and small intestine, as well as the serum levels of rat mast cell protease-II (RMCP-II). The results show liver and testes atrophy, with hypoalbuminemia (p = 0.0001), hyperbilirubinemia (p = 0.0001) and increase in aspartate aminotransferase (p = 0.004) and alanine aminotransferase (p = 0.0001). Hepatic histopathology demonstrates hepatocytic necrosis and apoptosis, portal inflammation, biliary prolifera- tion, steatosis and fibrosis. There is a decrease of MMCs and CTMCs in the liver, while in the ileum CTMCs increase and MMCs decrease. These results suggest the involvement of mast cells in the pathophysio- logical splanchnic impairments in this experimental model. In particular, the decreased number of liver mast cells may be associated with the hepatic atrophy. If this is the case, we propose that the disruption of the hepato-intestinal axis after a portocaval shunt in the rat could inhibit the ability of the liver to developing an appropriate repair response mediated by mast cells.

The aim of this study was to investigate the pathophysiology of pancreatitis after major hepatectomy. The study used ten female pigs. Three served as sham animals (sham group) and were killed after laparotomy to obtain normal tissue samples. Seven animals were subjected to major hepatectomy (70–75%), using the Pringle maneuver for 150 min, after constructing a portacaval side-to-side anastomosis (hepatectomy group). Duration of reperfusion was 24 h. Pancreatic tissue sampled 24 h after reperfusion had increased necrosis and edema in comparison to sham group and to tissue sampled at 12 h. Tissue malondialdehyde (MDA) did not differ significantly between samples at 12 and 24 h but was increased in the hepatectomy group in comparison to sham animals. Percentage increase in portal MDA content during reperfusion was greater at 12 h of reperfusion in comparison to the increase after 24 h. Portal pressure increased significantly after 12 h of reperfusion. Serum amylase and C-peptide increased during reperfusion in comparison to baseline levels. The findings suggest that intraoperative portal congestion is not the only cause of the development of pancreatitis after major hepatectomy. The oxidative markers suggest that reactive oxygen species produced during vascular control may be responsible as well.

Although there are many models for animal testing, the ideal model for chronic liver disease involving hepatic encephalopathy has not been described yet. Different problems associated with the models have led researchers to develop their own, sometimes unique experimental models, which makes difficult the comparison between the results of the conducted studies (1). Hepatic encephalopathy (HE) definition, nomenclature, diagnosis and quantification consensus were published in 2002 (2) where three types of HE were considered: type A, associated with acute liver failure, type B, associated with the existence of porto-systemic communication (by-pass) without intrinsic liver disease and type C, associated to liver cirrhosis. HE type C, in turn, is classified according to their form of presentation as spontaneous or episodic HE, in relation to precipitating factors, persistent HE is subdivided into mild (HE grade I), severe (HE II-IV) or treatment-dependent (early developed after abolition of treatment) and finally, the minimal HE, as the first manifestation of HE. HE type C is the most common form and from a clinical point of view, the episodic HE type because of liver cirrhosis decompensation is the most typical and relevant. The ideal model of HE should reproduce most of the clinical features of this syndrome in humans, as occurring mainly in patients with chronic liver disease, being precipitated by defined factors, it should be reversible with the correction of precipitating factors and improved using rifaximin or ammonia lowering-drugs, being strongly associated with altered nitrogen metabolism and showing a wide spectrum of severity. Because most patients with HE also suffer from chronic liver disease, porto-systemic shunts, developed hyperammonemia and systemic inflammation it is highly desirable that animal models would include these facts (Fig. 1).

Introduction There is accumulating clinical evidence that acute liver failure may be regularly associated with myocardial injury. To test this hypothesis in a standardized experimental setting, we used two porcine models of ALF. Material and methods In 14 domestic pigs ALF was induced by either a) surgical devascularization of the liver (DV group, n = 7), or b) partial (70-75%) hepatectomy and ischaemia/reperfusion of the liver remnant for 150 min (I/R group, n = 7). Four additional animals constituted the sham operation group. All animals were monitored for a 12-h period, at the end of which their hearts were harvested. Plasma troponin I (cTnI) and malondialdehyde (MDA) were measured before the operation (baseline) and at 6 h and 12 h postoperatively. The harvested hearts were histologically analysed, appointing a score from 0 (no injury) to 3 (maximum injury) to selected injury indicators. Results In the sham group, all cTnI measurements and total myocardial injury score were zero in all animals. In both ALF groups, plasma cTnI levels increased by the 6th and remained elevated up to the 12th postoperative hour (p < 0.01 vs. sham animals). Total myocardial injury score and total histological score revealed some extent of myocardial injury. The rise of MDA levels suggests an underlying oxidative mechanism. Conclusions Our study provides direct evidence of early myocardial injury in the setting of acute liver failure in pigs. The mechanism of injury remains to be elucidated.

The effect of portacaval shunting on the antioxidant status of the cerebellum and hippocampus has been studied in rats using standard methods of enzymatic analysis. Endogenous ammonia levels and activities of eight antioxidant enzymes were shown to be unequal in these two brain regions and to respond differently to intrahepatic portosystemic shunt surgery.

Background Bleeding esophageal varices (BEV) in cirrhosis has been considered an indication for liver transplantation (LT). This issue was examined in a randomized controlled trial (RCT) of unselected, consecutive patients with advanced cirrhosis and BEV that compared endoscopic sclerotherapy (EST; n = 106) to emergency direct portacaval shunt (EPCS; n = 105). Methods Diagnostic work-up and treatment were initiated within 8 hours. Patients were evaluated for LT on admission and repeatedly thereafter; 96% underwent over 10 years of regular follow-up. The analysis was supplemented by 1300 unrandomized cirrhotic patients who previously underwent portacaval shunt (PCS) with 100% follow-up. Results In the RCT long-term bleeding control was 100% following EPCS, only 20% following EST. Also, 3-, 5-, 10-, and 15-year survival rates were 75%, 73%, 46%, and 46%, respectively, following EPCS compared with 44%, 21%, 9%, and 9% following EST, respectively (P < .001). Only 13 RCT patients (6%) were ultimately referred for LT mainly because of progressive liver failure; only 7 (3%) were approved for LT and only 4 (2%) underwent LT. The 1- and 5-year LT survival rates were 0.68% and 0, respectively, compared with 81% and 73%, respectively, after EPCS. In the 1300 unrandomized PCS patients, 50 (3.8%) were referred and 19 (1.5%) underwent LT. The 5-year survival rate was 53% compared with 72% for all 1300 patients. Conclusions If bleeding is permanently controlled, as occurred invariably following EPCS, cirrhotic patients with BEV seldom require LT. PCS is effective first-line and long-term treatment. Should LT be required in patients with PCS, although technically more demanding, numerous studies have shown that PCS does not increase mortality or complications. EST is not effective emergency or long-term therapy.

Current treatment of chronic hepatoportal encephalopathy with dietary protein restriction is not always sufficient, and long-term administration of antibiotics may lead to some undesirable side-effects. The present study of three patients with encephalopathy and surgical portacaval shunt demonstrates the favourable effect of a synthetic disaccharide (lactulose, Duphalac). This study also demonstrates clearly that there is a close interrelation between the EEG and the metabolism of the brain. Thus the EEG analysis can be used as a method for checking the effects of therapy in hepatic encephalopathy.

— Besides the spontaneous occurrence of portacaval shunts in chronic liver diseases and the performance of shunt to cure portal hypertension, shunts are now proposed for the treatment of some metabolic diseases, especially in children. The portacaval shunt model in the rat, known to induce liver atrophy related to hepatocyte loss and atrophy, was used to investigate morphological liver changes occurring in cholestasis. Two weeks after portacaval or sham portacaval shunt, the bile duct was ligated and livers were examined by light and electron microscopy at 5 h, 20 h, 4 days and 8 days. Portal inflammatory reaction and proliferation of bile ducts were identical but areas of patchy hepatic necrosis were more numerous in shunted rats. Hepatocyte size decreased in the sham group but increased in the other group. Hepatocyte ultrastructural changes were similar in the two groups. At 5 h, the number of bile canaliculi sections increased (X2) and 95% of them were normal. As time elapsed, the ratio of dilated bile canaliculi without microvilli and of bile canaliculi filled with cytoplasmic blebs increased but in no case reached 50% of the total. These results show that in the rat, cholestasis induced by bile duct ligation has approximately the same characteristics in control or shunted animals.

We have evaluated the link between haemostatic abnormalities and immune dysfunction in liver disease by evaluating parameters of cellular and humoral immunity in conjunction with coagulation profiles in rats following portacaval anastomosis, induction of portal hypertension by portal vein stenosis or by sham surgical procedures. Twelve weeks following surgery, portacaval shunted rats were markedly anaemic (8.9 +/- 0.6 g/dl; controls 12.3 +/- 1.4 g/dl, p < 0.05), had low plasma fibrinogen levels (0.6 +/- 0.3 g/l, controls 2.5 +/- 0.2 g/l p < 0.05) and markedly elevated fibrin(ogen) degradation products (FDP) titres (1/40-1/80; controls < 1/10. p < 0.05). Portal vein stenosed rats were less anaemic (11.5 +/- 0.8 g/dl), had near normal fibrinogen levels (2.1 +/- 0.3 g/l) but elevated FDP levels (1/40-1/80). Both portacaval shunted and portal vein stenosed rats had elevated serum IgG levels (35.1 +/- 14.1 g/l; 29.2 +/- 13.9 g/l respectively; control values 20 +/- 5.9 g/l p < 0.05 for comparison with both experimental groups). Intrinsic lymphocyte proliferation to T and B cell mitogens was markedly depressed in the portacaval anastamosed rats when compared to controls. Serum factors inhibitory to control lymphocyte proliferation were noted in the shunted rats. Phagocytosis of complement and immunoglobulin sensitised sheep RBC by Kupffer cells purified from rats that had undergone portacaval shunting was markedly reduced (p < 0.05). The increased degree of phagocytosis following exposure to LPS-endotoxin (50 micrograms/ml) was proportionate in degree to the control group. Spontaneous release of bioactive lymphocyte activating factors (IL-1 and IL-6) by purified rat sinusoidal cell populations was decreased in the portacaval shunted group, and decreased still further following stimulation with LPS (50 micrograms/ml) in vitro. The observation that many of the haemostatic and immunological abnormalities associated with chronic liver disease are present in rats with surgically created portacaval shunts or with induced portal hypertension, lends credence to the hypothesis that shunting of portal blood is, at least in part, responsible for many of the systemic manifestations associated with chronic liver disease.

Hepatorenal syndrome (HRS) is a functional renal failure that frequently develops in patients with advanced cirrhosis and severe impairment in systemic circulatory function. Traditionally it has been considered to be the consequence of a progression of the splanchnic arterial vasodilation occurring in these patients. However, recent data indicate that a reduction in cardiac output also plays a significant role. There are two different types of HRS. Type-2 HRS consists of a moderate and steady or slowly progressive renal failure. It represents the extreme expression of the circulatory dysfunction that spontaneously develops in patients with cirrhosis. The main clinical problem in these patients is refractory ascites. Type-1 HRS is a rapidly progressive acute renal failure that frequently develops in closed temporal relationship with a precipitating event, commonly spontaneous bacterial peritonitis. In addition to renal failure, patients with type-1 HRS present deterioration in the function of other organs, including the heart, brain, liver, and adrenal glands. Type-1 HRS is the complication of cirrhosis associated with the worst prognosis. However, effective treatments of HRS (vasoconstrictors associated with intravenous albumin, transjugular intrahepatic portacaval shunt, albumin dialysis) that can improve survival have recently been introduced.

All of the methods proposed for measuring portal blood flow are either invasive, estimate total rather than nutrient flow, and none has proved reliable in cirrhotic patients. A method has been derived from pharmacokinetic principles used for the calculation of bioavailability of drugs according to the route of administration (i.v. or p.o.) and tested experimentally in 20 pigs. A tracer dose of [14C]ursodeoxycholic acid, a biliary acid with a high-liver first-pass effect, is administered in the duodenum, and serial peripheral blood samples are taken. Later, the same dose of the same drug is administered i.v. The shunt fraction of portal blood F is obtained by the ratio of the areas under the plasma level vs. time curves ("AUC") after p.o. and i.v. administrations: (see formula in text). The pigs were divided into three experimental groups. (i) Group I: undisturbed portal flow; (ii) Group II: total diversion of portal blood with an end-to-side portacaval shunt, and (iii) Group III: partial diversion of portal blood through a side-to-side portacaval shunt. Portal flow was measured during surgery with an electromagnetic flowmeter above and below the shunt and the degree of shunting calculated. Results show that the shunt fraction measured with ursodeoxycholic acid is well-correlated with hemodynamic data. No overlap between Groups I and III is observed. It is concluded that the shunt fraction of nutrient portal blood can be measured with this noninvasive method. Minute amounts of ursodeoxycholic acid were used in order to be completely metabolized by the liver, even in spite of hepatocellular dysfunction. Therefore, this method should be valid in cirrhotic patients and be useful to decide the type of portasystemic shunt to propose for the decompression of gastroesophageal varices.

We examined the temporal relationship between portacaval anastamosis (PCA), weight gain, changes in skeletal muscle mass and molecular markers of protein synthesis, protein breakdown, and satellite cell proliferation and differentiation. Male Sprague-Dawley rats with end to side PCA ( n = 24) were compared with sham-operated pair-fed rats ( n = 24). Whole body weight, lean body mass, and forelimb grip strength were determined at weekly intervals. The skeletal muscle expression of the ubiquitin proteasome system, myostatin, its receptor (the activin 2B receptor) and its signal, cyclin-dependant kinase inhibitor (CDKI) p21, insulin-like growth factor (IGF)-I and its receptor (IGF-I receptor-α), and markers of satellite cell proliferation and differentiation were quantified. PCA rats did not gain body weight and had lower lean body mass, forelimb grip strength, and gastrocnemius muscle weight. The skeletal muscle expression of the mRNA of ubiquitin proteasome components was higher in PCA rats in the first 2 wk followed by a lower expression in the subsequent 2 wk ( P < 0.01). The mRNA and protein of myostatin, activin 2B receptor, and CDKI p21 were higher, whereas IGF-I and its receptor as well as markers of satellite cell function (proliferating nuclear cell antigen, myoD, myf5, and myogenin) were lower at weeks 3 and 4 following PCA ( P < 0.05). We conclude that PCA resulted in uninhibited proteolysis in the initial 2 wk. This was followed by an adaptive response in the later 2 wk consisting of an increased expression of myostatin that may have contributed to reduced muscle protein synthesis, impaired satellite cell function, and lower skeletal muscle mass.

This study was undertaken to report variceal rebleeding and survival after small-diameter prosthetic H-graft portacaval shunts (HGPCS) and to compare actual to predicted survival after shunting. Since 1987 we have prospectively followed patients after undergoing HGPCS to treat bleeding varices failing/not amenable to sclerotherapy/banding. One hundred and seventy patients underwent shunting. Cirrhosis was because of alcohol in 56%, hepatitis in 12%, both in 11%, and other causes in 21%. Child class was A for 10%, B for 28%, and C for 62%. Thirty-three patients died by 6 months, 54 by 24 months, 87 by 60 months, and 112 by 10 years, generally because of liver failure. Fifty-one patients are alive at a median of 48.3 months, 76 months +/- 57.8 (mean +/- SD). Variceal rehemorrhage was documented in 3 (2%) patients. By child class, 5-year/10-year survival rates were as follows: A 66.7/33.3%, B 48.6/15.6%, and C 29.2/7.0%. Actual survival was superior to predicted survival (Model for End-Stage Liver Disease [MELD]), (p0.001). Variceal rehemorrhage in patients undergoing small-diameter prosthetic H-graft portacaval shunting was very uncommon. Actual survival was superior to predicted survival (MELD). Long-term survival paralleled degree of hepatic function, although long-term survival was possible even with very advanced cirrhosis. Application of HGPCS is encouraged.

This study was undertaken to evaluate the ability to predict survival after 8 mm prosthetic H-graft portacaval shunts (HGPCS).Since 1988, 170 patients have been prospectively followed after HGPCS. Using preshunt data, predictors of survival after shunting [MELD Score, Emory Score, Child Pugh Score, Discriminant Function (DF), and Child Class] were determined and related to actual survival.Child Class was: (a) 10%, (b) 28%, and (c) 62%. Actual 5- and 10-year survival by Child Class was: (a) 67% and 33%, (b) 49% and 16%, (c) 29% and 7%. Survival correlated with all predictors of survival (p0.01 for each). Actual survival was better than predicted by MELD (p0.001). By Multiple Variable Regression Analysis--Computed Model, explained variation in survival was greatest for Child Class (18%), followed by MELD (14%), with DF, Emory Score, and Child Pugh Score not significantly contributing.After HGPCS, actual survival is better than predicted by MELD. Child Class explains only a minor variation in survival, although it better explains survival than MELD, Emory Score, Child Pugh Score, or DF. Conventional predictors of survival poorly and underpredict survival after HGPCS and should be used with caution.

Background: Liver failure in experimental animals or in human cirrhosis elicits neuroinflammation. Prolyl oligopeptidase (PREP) has been implicated in neuroinflammatory events in neurodegenerative diseases: PREP protein levels are increased in brain glial cells upon neuroinflammatory insults, but the circulating PREP activity levels are decreased in multiple sclerosis patients in a process probably mediated by bioactive peptides. In this work, we studied the variation of PREP levels upon liver failure and correlated it with several inflammatory markers to conclude on the relation of PREP with systemic and/or neuroinflammation. Methods: PREP enzymatic activity and protein levels measured with immunological techniques were determined in the brain and plasma of rats with portacaval shunt (PCS) and after treatment with ibuprofen. Those results were compared with the levels of PREP measured in plasma from cirrhotic patients with or without minimal hepatic encephalopathy (MHE). Levels of several pro-inflammatory cytokines and those of NO/cGMP homeostasis metabolites were measured in PCS rats and cirrhotic patients to conclude on the role of PREP in inflammation. Results: In PCA rats, we found that PREP levels are significantly increased in the hippocampus, striatum and cerebellum, that in the cerebellum the PREP increase was significantly found in the extracellular space and that the levels were restored to those measured in control rats after administration of an anti-inflammatory agent, ibuprofen. In cirrhotic patients, circulatory PREP activity was found to correlate to systemic and neuroinflammatory markers and had a negative correlation with the severity of the disease, although no clear relation to MHE. Conclusions: These results support the idea that PREP levels could be used as indicators of cirrhosis severity in humans, and using other markers, it might contribute to assessing the level of neuroinflammation in those patients. This work reports, for the first time, that PREP is secreted to the extracellular space in the cerebellum most probably due to glial activation and supports the role of the peptidase in the inflammatory response.

The concentrations of many of the large neutral amino acids (LNAA) are elevated in the brain of animals after portacaval shunt (PCS) and in the cerebrospinal fluid of patients with liver cirrhosis. High brain levels of the LNAA may be related to hepatic encephalopathy. Several investigators have reported that the transport of LNAA across the blood-brain barrier is more rapid in rats after PCS; however, no data characterizing the changes in the kinetic parameters of blood-brain transport (Vmax, Km or the apparent diffusion constant Kd) have been reported. Information about the specific changes in transport are important in identifying their cause. We estimated the kinetic parameters of the blood-brain transport of 14C-leucine in 50 male Sprague-Dawley rats 20 days after PCS and in 40 control rats. The carotid artery single-injection technique of Oldendorf was used with 3H2O as diffusible reference. Unlabeled leucine was added to a constant amount of 14C-leucine in the injection solution to produce leucine concentrations ranging from 0.003 to 8.0 mM. Fifteen seconds after carotid injection, brain tissue was dissected and its radioactivity was determined. Kinetic parameters were estimated using a nonlinear regression program. The results are shown in the following table I.

BACKGROUND Portacaval shunt (PCS) prevent hepatotrophic factors from flowing into the liver, but they enter directly the systemic circulation and worsen liver injury. This study was designed to investigate the effects of hepatotrophic factors through the portal vein on the liver in rats with portal hypertension after portacaval shunt. METHODS Intrahepatic portal hypertension (IHPH) was induced by intragastric administration of carbon tetrachloride, and end-to-side PCS was performed. Eight normal rats served as controls, and eight rats with IHPH served as IHPH model (IHPH group). Another 32 rats with IHPH-PCS were randomly subdivided into 4 groups: normal saline (NS) given to 8 rats, hepatocyte growth factor (HGF) 8, insulin (INS) 8, hepatocyte growth factor and insulin (HGF + INS) 8. Hepatotrophic factors were infused into the portal vein through an intravenous catheter. Portal venous pressure (PVP) was measured. The levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were tested biochemically and those of hyaluronic acid (HA) and laminin (LN) were measured by radioimmunoassay. Hepatic fibrosis was assessed histologically and the expression of collagens type I and III were detected immunohistochemically. Ultrastructural change of hepatocytes and the number of mitochondria were observed under an electron microscope. The data were compared between groups and subgroups by Student-Newman-Keuls procedure with SPSS10.0. RESULTS PVP was significantly higher in the IHPH rats than in the control rats (P < 0.05). The levels of serum ALT, AST, HA, and LN, hepatic fibrosis score, the amount of collagen deposition, collagens type I and III increased more significantly in the IHPH group than in the control rats (P < 0.05). The number of mitochondria decreased more significantly in the IHPH rats than in the control rats (P < 0.05). The levels of serum ALT, AST, HA and LN as well as hepatic fibrosis score, the amount of collagen deposition, and the amount of collagens type I and III in the HGF and HGF + INS rats were significantly lower than those in the NS rats (P < 0.05). The damage to hepatocyte ultrastructure was markedly alleviated and the number of mitochondria was increased more significantly in the HGF and HGF + INS rats than in the NS rats under an electron microscope. CONCLUSIONS Perfusion of exogenous hepatotrophic factors through the portal vein can alleviate liver injury, minimize the damage to the ultrastructure of hepatocyte, protect liver function, and lessen hepatic fibrosis in rats with portal hypertension after PCS.

In hepatic disorders, abnormal plasma amino acid profiles are observed. In this study, we examined whether soy protein isolate (SPI) improved plasma methionine concentration in the model animals. Portacaval shunt (PCS) increased alanine aminotransferase (ALT) activity and methionine concentration in blood of rats fed a 40% casein diet supplemented with 0.6% methionine (casein-M diet). A 40% SPI diet supplemented with 1.28% methionine (SPI-M diet), which contained the same amount of methionine as that in 40% casein-M diet, normalized plasma ALT activity and methionine level in PCS rats. These effects of a SPI diet may be due to its amino acid composition, since an amino acid mixture diet mimicking a 40% SPI-M diet was also effective to hypermethioninemia of PCS rats. To find key enzymes for the beneficial effect of soy protein, we examined effects of a 40% SPI-M or casein-M diet on the activities of three methionine-metabolizing enzymes in liver of PCS rats. A SPI-M diet stimulated only the activity of cystathionine gamma-lyase, compared with a casein-M diet. A SPI diet has a preventive effect on hypermethioninemia, at least in part, by stimulating cystathionine gamma-lyase activity in liver and may be used for nutritional management of liver disorders with hypermethioninemia.

Proliferation and differentiation of satellite cells are critical in the regeneration of atrophied muscle following immobilization and aging. We hypothesized that impaired satellite cell function is responsible for the atrophy of skeletal muscle also seen in cirrhosis. Myostatin and insulin-like growth factor 1 (IGF1) have been identified to be positive and negative regulators, respectively, of satellite cell function. Using a rat model of cirrhosis [portacaval anastamosis (PCA)] and sham-operated controls, we examined the expression of myostatin, its receptor activinR2b, and its downstream messenger cyclin-dependant kinase inhibitor p21 (CDKI p21) as well as IGF1 and its receptor in the gastrocnemius muscle. Expression of PCNA, a marker of proliferation, and myogenic regulatory factors (myoD, myf5, and myogenin), markers of differentiation of satellite cells, were also measured. Real- time PCR for mRNA and Western blot assay for protein quantification were performed. PCA rats had lower body weight and gastrocnemius weight compared with sham animals ( P < 0.05). PCNA and myogenic regulatory factors were lower in PCA rats ( P < 0.05). Myostatin, activinR2b, and CDKI p21 were higher in the PCA animals ( P < 0.05). The expression of IGF1 and its receptor was lower in liver and skeletal muscle of PCA animals ( P < 0.05). These data suggest that skeletal muscle atrophy seen in the portacaval shunted rats is a consequence of impaired satellite cell proliferation and differentiation mediated, in part, by higher myostatin and lower IGF1 expression.

Cerebral hyperemia is an important contributor to the development of brain edema in fulminant hepatic failure. Rats receiving an ammonia infusion after portacaval anastomosis (PCA) demonstrate a rise in cerebral blood flow (CBF) with brain edema at 180 min. Vasopressin (VP), a systemic vasoconstrictor which in the rat dilates cerebral vessels through V(2) receptors, was used to ascertain the effects of increasing CBF.Changes in CBF were measured with Laser Doppler flowmetry (LDF). Absolute CBF was measured with radioactive microspheres to calculate oxygen and ammonia uptake.Compared to the NH(3)+Vehicle group, VP+NH(3) infusion accelerated the rise in CBF (117+/-21 vs. -6+/-12%, P0.01), and the development of brain edema (81.09+/-0.17 vs. 80.29+/-0.06%, P0.01). Radioactive microspheres confirmed these results (254+/-44 vs. 106+/-9.5 ml/min/100 g, P0.01). Oxygen uptake was similar. Ammonia uptake was more than twofold higher in the VP+NH(3) group. A V(1) antagonist negated the higher mean arterial pressure (MAP) that occurs with VP but cerebral hyperemia still occurred. A V(2) antagonist resulted in similar systemic pressures, CBF and brain water compared to the VP+NH(3) group.In this model, an increase in CBF with VP hastens the development of brain edema while increasing ammonia delivery to the brain.

The aim of the current study was to examine morphological and ultrastructural changes in the rat liver in an experimental model of chronic liver disease (end-to-side portacaval shunt). The surgical procedure providing an end-to-side portacaval shunt (PCS) was performed in Wistar rats. The liver and pancreas weights were determined 8 weeks after the operation, when liver histology and ultrastructural patterns of hepatocytes were examined. Body weights were not significantly different between the groups 8 weeks after the operation. Liver weight was significantly lower in PCS rats than in control and sham operated (SHAM) rats. The same was observed when liver weight was expressed as a percentage of body weight. Pancreas weight was significantly greater in PCS than in control and SHAM rats. Liver histology in rats with PCS showed glycogen depletion and sinusoidal dilatation around the hepatic vein. Kupffer's cells were filled with haemosiderin. The hepatocytes surrounding the portal space exhibited degenerative and microvesicular fatty changes. Multiplication of the biliary ductules in the portal space was present. Atrophy of hepatocytes occurred in other parenchymal zones and apoptopic hepatocytes were seen more frequently in rats with PCS. The ultrastructural characteristics of hepatocyte cell lesions in rats with PCS at the end point of our experiment included reduction and fragmentation of rough endoplasmic reticulum with destroyed or dilated cisternae and few polysomes accompanied by proliferation of smooth endoplasmic reticulum. The present study suggests that end-to-side PCS in rats causes liver atrophy and that the morphological and ultrastructural changes in the hepatocytes partially explain the metabolic and endocrine abnormalities.

Patients with chronic hepatic encephalopathy (HE) may present affective symptoms and antidepressant drug treatment in this condition is not uncommon. The present microdialysis study investigated treatment with the chronic antidepressant venlafaxine (VEN) in experimental HE with regard to tentative changes in pharmacokinetic and/or pharmacodynamic parameters. Three weeks after portacaval shunt (PCS) or sham operation in rats, VEN (10 mg/kg daily) was administered by implanted osmotic minipumps. VEN treatment for 14 days resulted in higher concentrations of VEN in PCS rats than in sham controls in serum and brain compartments, and the VEN levels in serum and brain were strongly inter-correlated. The serum N-desmethylvenlafaxine concentration did not differ between the groups, but correlated with the serum VEN levels. The other VEN metabolites were below the quantification limits. VEN treatment for 9-12 days significantly stimulated locomotion and rearing in the open field in sham controls, but failed to do so in the PCS rats. The concentrations of noradrenaline, dopamine, 5-HT, and 5-HIAA in neocortical dialysates were higher in PCS than in sham rats after 14 days of VEN treatment, but the elevations reached statistical significance only in the case of dopamine and 5-HIAA. In summary, there were significant pharmacokinetic and pharmacodynamic alterations in rats with experimental HE as compared to controls. The described experimental HE model may be useful for continued pharmacokinetic/pharmacodynamic interaction studies to unravel the pathophysiological consequences of HE on the CNS.

Identifying the gene expression changes induced by hepatic encephalopathy (HE) leads to a better understanding of the molecular mechanisms of HE-induced neurological dysfunction. Using GeneChip® and real-time PCR, the present study evaluated the gene expression profile of rat cerebral cortex at 4 weeks after portacaval shunting. Among 1,263 transcripts represented on the chip, mRNA levels of 31 transcripts were altered (greater than twofold; 16 increased and 15 decreased) in the portacaval shunted (PCS) rat compared to sham control. Changes observed by GeneChip® analysis were confirmed for 20 transcripts (8 increased, 7 decreased, and 5 unchanged in PCS rat brain) by real-time PCR. Neurotransmitter receptors, transporters, and members of the second messenger signal transduction are the major groups of genes altered in PCS rat brain. Of importance was that the increased heme oxygenase-1 and decreased Cu,Zn-superoxide dismutase expression observed raise the possibility of oxidative stress playing a pathogenic role in chronic HE. © 2002 Wiley-Liss, Inc.

Some metabolic and endocrine consequences of portacaval shunt were examined in rats eight weeks after the operation. Plasma levels of insulin, glucagon somatostatin, such as pancreatic content of insulin, glucagon, and somatostatin were determined by radioimmunoassay. Numerous biochemical parameters, such as the concentration of serum ammonia, transaminase (AST and ALT), urea bilirubin, total plasma protein and plasma albumin levels were determined by standard biochemical tests. Normal plasma levels of insulin and somatostatin hyperglucagonaemia were observed in rats with portacaval shunt. After portacaval shunt there was a highly significant increase (p

Hepatic vein thrombosis is caused by one or several thrombogenic conditions, of which myeloproliferative disorders are the most frequent. Thrombosis and its fibrous sequelae can affect the veins diffusely or locally. Severity is determined by the extent and velocity of the thrombotic process. Development of venous collateral vessels is an important compensatory mechanism. Some patients can be totally free of symptoms. Major complications are intractable ascites, liver insufficiency, and gastrointestinal bleeding. Diagnosis can be made via ultrasonography or magnetic resonance imaging in a majority of cases. The main prognostic factors are age, Child-Pugh score, and response of ascites to diuretics. Medical therapy includes control of causal factors, anticoagulation, and nonspecific treatment of complications. Procedures aiming to restore outflow of hepatic blood are indicated in patients with uncontrolled manifestations. Percutaneous angioplasty, followed by portosystemic shunt (including a transjugular intrahepatic portosystemic stent shunt) and eventually liver transplantation can be proposed in a graded manner. The current 10-year survival rate is about 75%.

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 [plusmn] 6.5 pg/mL) and portal (19.2 [plusmn] 7 pg/mL) ET-1 levels increased, whereas they decreased after reperfusion (systemic, 11.8 [plusmn] 7.1 pg/mL; portal, 13.2 [plusmn] 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 [plusmn] 6.9 v 15.1 [plusmn] 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. (Liver Transpl 2002;8:27-33.)