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Liver cirrhosis and portal hypertension are accompanied by portal-systemic collaterals formation and lethal complications. Angiogenesis participates in the development of collaterals. Spironolactone is an aldosterone receptor antagonist used to control fluid overload in cirrhotic patients although recent studies suggest that it also inhibits angiogenesis. This study investigated the effect of spironolactone on abnormal angiogenesis and portal-systemic collaterals in cirrhosis. Liver cirrhosis was induced in Sprague-Dawley rats by common bile duct ligation (BDL), and sham-operated rats were the controls. The BDL and sham rats received spironolactone (20 mg/kg/d, oral gavage) or vehicle from day 15 to 28 after the operations. Spironolactone did not influence the portal and systemic hemodynamic, and the renal and hepatic biochemistry data, but it significantly ameliorated hepatic fibrosis, portal-systemic shunting, and mesenteric angiogenesis. Plasma vascular endothelial growth factor (VEGF) levels and the mesenteric protein expression of VEGF and phosphor-vascular endothelial growth factor receptor 2 (VEGFR-2) decreased in the spironolactone group. Spironolactone did not affect motor activity or plasma ammonia levels. The down-regulation of VEGF pathway participates, albeit partly, in the antiangiogenic effect of spironolactone. Thus, spironolactone treatment in patients with liver cirrhosis may provide additional benefits aside from ascites control.

Background and rationale. The control of Endothelin-1 (ET-1)-mediated intrahepatic vasoconstriction in cirrhosis is beneficial for the alleviation of relevant complications. Cirrhosis is accompanied by hypogonadism and altered sex hormone status. Besides, sex hormones have vasoactive effects, but it is unknown if they influence vascular function in cirrhosis. This study aimed to investigate the roles of sex hormones in hepatic vascular reactions to ET-1 in cirrhosis. Liver cirrhosis was induced in Spraque-Dawley male and female rats with common bile duct ligation (BDL). Sham-operated (Sham) rats were controls. On the 43rd day after operations, intrahepatic vascular concentration-response curves to ET-1 were obtained with the following preincubatioins: 1) vehicle; 2) 17β-estradiol; 3) progesterone; 4) testosterone. Livers from sham and BDL rats were dissected for real-time polymerase chain reaction analysis of estrogen, progesterone and testosterone receptors. Results. Compared with sham males perfused with vehicle, sham females presented higher perfusion pressure changes to ET-1 which was reversed only by 17β-estradiol. In cirrhosis, compared with males, 17β-estradiol no longer attenuated vascular responsiveness to ET-1 in females. In females, BDL rats had lower hepatic estrogen receptor α(ERα) mRNA expression than that in sham rats. Conclusions. The sham females showed a stronger intrahepatic vascular constrictive effect to ET-1 than sham males, which could be reversed by 17β-estradiol. However, the influence of 17β-estradiol was lost in cirrhotic females, which may be attributed, at least partly, to intrahepatic ERα down-regulation in females with cirrhosis.

Background: Evidence has demonstrated that overproduction of prostacyclin (PGI2) is critical in the pathogenesis of splanchnic hyposensitivity to vasoconstrictors in the cirrhotic state. The biosynthesis of PGI2 is through cyclooxygenase (COX). This study evaluated which isoform of COX is dominant in the mechanism of collateral vascular reactivity of biliary cirrhotic rats. Methods: Three groups of formalin-injected common bile duct-ligated (FBDL) induced cirrhotic rats received two doses of: (1) selective COX-1 inhibitor (SC-560 2 mg/kg); (2) COX-2 inhibitor (NS-398 2 mg/kg); (3) dimethyl sulfoxide (control). Subsequently, the rats were kept in metabolic cages for 24 hours to collect urine. Thereafter, the systemic and portal hemodynamics and renal function were measured. In another series, using in-situ collateral perfusion model, the collateral vascular responses to arginine vasopressin (AVP) were measured in the subject rats after preincubation of vehicle (Krebs solution), SC-560 (5 mM) or NS-398 (10 mM). Results: The mean arterial pressure, heart rate, and portal pressure were similar among SC-560-treated, NS-398-treated, and control groups. Additionally, there was no significant difference in the calculated creatinine clearance rates among these three groups. SC-560 preincubation significantly enhanced the pressor effect of AVP at the concentration of 3M � 10 � 9 M (11.0 � 1.0 mmHg vs. 6.4 � 0.6 mmHg, p ¼ 0.002) in the cirrhotic rats. Conclusion: There was no significant hemodynamic change and renal toxicity after acute administration of COX inhibitor in the FBDL-induced cirrhotic rats. Preincubation of selective COX-1, but not COX-2, inhibitor could enhance collateral vascular response to AVP, indicating that COX-1 plays a major role in the collateral vascular reactivity. Copyright 2013 Elsevier Taiwan LLC and the Chinese Medical Association. All rights reserved.

HPS (hepatopulmonary syndrome) is characterized by oxygen desaturation in patients with chronic liver disease. The initiation of HPS comes from abnormal pulmonary vasodilatation and/or angiogenesis. In the present study, we evaluated anti-angiogenesis therapy using sorafenib in experimental HPS animals. HPS was induced by CBDL (common bile duct ligation) in rats. A 2-week 10 mg·(kg of body weight) − 1 ·day − 1 treatment regimen of sorafenib or distilled water (control) was initiated 2 weeks after the surgical procedure. Haemodynamics, liver biochemistry, plasma VEGF (vascular endothelial growth factor) measurements and blood gas analysis of the CBDL rats were performed. The livers of the CBDL rats were dissected for histopathology examination, and the lungs were examined by immunohistochemical staining, real-time PCR and Western blot analysis. In another two parallel groups, intrapulmonary shunts were determined. The AaPO2 (alveolar–arterial O2 gradient) and plasma VEGF levels were reduced after sorafenib treatment [AaPO2 ,7 .2+ 3.4 mmHg in sorafenib-treated rats compared with 15.3 + 4.2 mmHg in controls (P = 0.004); VEGF, 45.3 + 2.7 pg/ml in sorafenib-treated rats compared with 54.4 + 7.7 pg/ml in controls (P = 0.021)]. Sorafenib attenuated pulmonary VEGF mRNA and VEGF, VEGFR-2 (VEGF receptor 2), phospho-VEGFR-2 and Akt protein expression. In addition, sorafenib significantly attenuated intrapulmonary angiogenesis and decreased the degree of intrapulmonary shunting by 33.7 % (11.2 + 5.7 % in sorafenib-treated rats compared with 16.9 + 5.9 % in controls; P = 0.003). Our findings suggest that sorafenib attenuates intrapulmonary shunting and decreases the AaPO2 in CBDL rats, implicating the improvement of HPS in this experimental animal model. The beneficial effect may be attributed to the reduction in intrapulmonary angiogenesis through inhibition of the VEGF/VEGFR-2/Akt pathway.

Angiogenesis in liver cirrhosis leads to splanchnic hyperemia, increased portal inflow, and portosystemic collaterals formation, which may induce lethal complications, such as gastroesophageal variceal hemorrhage and hepatic encephalopathy. Cannabinoids (CBs) inhibit angiogenesis, but the relevant influences in cirrhosis are unknown. In this study, Spraque-Dawley rats received common bile duct ligation (BDL) to induce cirrhosis. BDL rats received vehicle, arachidonyl-2-chloroethylamide (cannabinoid receptor type 1 [CB1] agonist), JWH-015 (cannabinoid receptor type 2 [CB2] agonist), and AM630 (CB2 antagonist) from days 35 to 42 days after BDL. On the 43rd day, hemodynamics, presence of CB receptors, severity of portosystemic shunting, mesenteric vascular density, vascular endothelial growth factor (VEGF), VEGFR-1, VEGFR-2, phospho-VEGFR-2, cyclooxygenase (COX)-1, COX-2, and endothelial nitric oxide synthase (eNOS) expressions as well as plasma VEGF levels were evaluated. Results showed that CB1 and CB2 receptors were present in left adrenal veins of sham rats, splenorenal shunts (the most prominent intraabdominal shunts) of BDL rats, and mesentery of sham and BDL rats. CB2 receptor was up-regulated in splenorenal shunts of BDL rats. Both acute and chronic JWH-015 treatment reduced portal pressure and superior mesenteric arterial blood flow. Compared with vehicle, JWH-015 significantly alleviated portosystemic shunting and mesenteric vascular density in BDL rats, but not in sham rats. The concomitant use of JWH-015 and AM630 abolished JWH-015 effects. JWH-133, another CB2 agonist, mimicked the JWH-015 effects. JWH-015 decreased mesenteric COX-1, COX-2 messenger RNA expressions, and COX-1, COX-2, eNOS protein expressions. Furthermore, JWH-015 decreased intrahepatic angiogenesis and fibrosis. Conclusions :C B 2 agonist alleviates portal hypertension (PH), severity of portosystemic collaterals and mesenteric angiogenesis, intrahepatic angiogenesis, and fibrosis in cirrhotic rats. The mechanism is, at least partly, through COX and NOS down-regulation. CBs may be targeted in the control of PH and portosystemic collaterals. (HEPATOLOGY 2012;56:248-258)

Prostaglandin plays an important role in the pathogenesis of hepatic encephalopathy. This study investigated the therapeutic effects of selective cyclooxygenase (COX) inhibitor on hepatic encephalopathy in thioacetamide-induced fulminant hepatic failure (FHF) rats. The selective COX-1 inhibitor (SC-560), COX-2 inhibitor (NS-398) or distilled water (control) was administered in the normal and FHF rats. The mortality rates were calculated and severity of hepatic encephalopathy was evaluated using Opto-Varimex activity sensors. Besides, the levels of blood ammonia, 6-keto-prostaglandin-F(1α) (PGF(1α), active metabolite of prostacyclin), tumor necrosis factor α (TNF-α) and liver biochemistry tests were measured. The hepatic mRNA expressions of nitric oxide synthase and COX were determined, and the liver histopathological changes were examined. The liver biochemistries and motor activities were similar among COX-1, COX-2 treated and control groups. SC-560 treatment improved the survival of FHF rats (mortality rates: SC-560 group 0%, control 33%; P=0.037). Besides, SC-560 treatment improved hepatic encephalopathy and decrease plasma levels of PGF(1α), but did not change TNF-α levels. There were no significant differences in liver biochemistry and ammonia levels except that the aspartate aminotransferase levels were lower in the NS-398 treated group. Both hepatic COX-1 and COX-2 mRNA expressions were attenuated after SC-560 treatment. The decreased COX-2 and increased constitutive nitric oxide synthase mRNA expressions were found after NS-398 treatment. Besides, the histopathology of liver got improved after selective COX inhibition. In conclusion, COX-1 inhibition by SC-560 decreases the mortalities and improves motor activities, suggesting COX-1, rather than COX-2, plays a major role in hepatic encephalopathy of FHF rats.

Eur J Clin Invest 2011 Abstract Background Nitric oxide (NO) inhibition aggravates hepatic damage and encephalopathy and increases mortality in rats with thioacetamide (TAA)-induced acute liver failure. Statins enhance NO production but whether they influence the above parameters are unknown. Material and methods Male Sprague-Dawley rats were used. In the first series, TAA (350 mg/kg per day, i.p. for 3 days) was administered to induce acute liver failure. Control rats received saline. Rats received distilled water or pravastatin (20 mg/kg per day, p.o.) from 2 days before to 3 days after TAA or saline injection. In the second series, liver cirrhosis was induced by common bile duct ligation (BDL). Sham-operated rats served as controls. Rats received distilled water or pravastatin for 5 or 14 days until the 42nd day after operation. On the last day of treatment, survival, motor activities, serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, ammonia and brain histology were evaluated. Results Thioacetamide and BDL rats showed higher ALT, AST, bilirubin and ammonia levels and lower motor activity counts compared with their corresponding control groups. In TAA rats, pravastatin elicited higher total and ambulatory motor activity counts and lower AST and total bilirubin levels. Survival was improved, whereas brain H&E staining was not significantly different in TAA rats with or without pravastatin treatment. In BDL groups, rats with or without pravastatin treatment were not different in motor activity counts and liver biochemistry. Conclusions Pravastatin ameliorates hepatic encephalopathy and liver biochemistry and improves survival in rats with acute liver failure, but not in those with cirrhosis.

Background and Aim: Inflammation plays a pivotal role in liver injury. Gabexate mesilate (GM, a protease inhibitor) inhibits inflammation by blocking various serine proteases. This study examined the effects of GM on hepatic encephalopathy in rats with acute and chronic liver failure. Methods: Acute and chronic liver failure (cirrhosis) were induced by intraperitoneal TAA administration (350 mg/kg/day for 3 days) and common bile duct ligation, respectively, in male Sprague-Dawley rats. Rats were randomized to receive either GM (50 mg/10 mL/kg) or saline intraperitoneally for 5 days. Severity of encephalopathy was assessed by the Opto-Varimex animal activity meter and hemodynamic parameters, mean arterial pressure and portal pressure, were measured (only in chronic liver failure rats). Plasma levels of liver biochemistry, ammonia, nitrate/nitrite, interleukins (IL) and tumor necrosis factor (TNF)-α were determined. Results: In rats with acute liver failure, GM treatment significantly decreased the plasma levels of alanine aminotransferase (P = 0.02), but no significant difference of motor activity, plasma levels of ammonia, IL-1β, IL-6, IL-10 and TNF-α or survival was found. In chronic liver failure rats, GM significantly lowered the plasma TNF-α levels (P = 0.04). However, there was no significant difference of motor activity, other biochemical tests or survival found. GM-treated chronic liver failure rats had higher portal pressure (P = 0.04) but similar mean arterial pressure in comparison with saline-treated rats. Conclusions: Chronic GM treatment does not have a major effect on hepatic encephalopathy in rats with TAA-induced acute liver failure and rats with chronic liver failure induced by common bile duct ligation.

Background and Aims: The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor can enhance endothelial nitric oxide synthase expression and induce vasodilatation. The vasodilatory effect may be detrimental to portal-systemic collaterals due to aggravating the shunting degrees. The present study investigated the effects of pravastatin, a HMG-CoA reductase inhibitor, on the collateral vascular responsiveness to endothelin-1 (ET-1) and portal-systemic shunting in portal hypertensive rats. Methods: The partial portal vein-ligated (PVL) rats received either pravastatin (25 mg/kg per day) or distilled water since 2 days prior to until 7 days after ligation. On the 8th day following hemodynamic measurements, the collateral vascular responsiveness to ET-1 was evaluated by an in situ collateral perfusion model. The shunting degrees of collaterals were evaluated by constructing vascular flow-pressure curves and color microsphere study, respectively. PVL rats underwent pre-incubation with: (i) Krebs solution (control); or Krebs solution plus (ii) 2 × 10−5 M pravastatin; (iii) pravastatin + Nω-nitro-L-arginine (10−4 M); and (iv) pravastatin + indomethacin (10−5 M), followed by ET-1 (10−10–10−7 M) administration to evaluate the collateral vascular responsiveness. Results: In chronic study, pravastatin did not modify systemic and portal hemodynamics and collateral vascular responsiveness to ET-1. The resistances of flow-pressure curves and the microsphere study demonstrated similar shunting degrees between both groups. Furthermore, pravastatin pre-incubation didn't reduce collateral perfusion pressure to ET-1. Conclusion: Chronic pravastatin administration does not induce detrimental effects on hemodynamics and collaterals in PVL rats, nor does it influence the shunting degree. In addition, it does not modify the vasoconstrictive effect of ET-1 on the collaterals of PVL rats.

Background and Aim: Portal-systemic collateral vascular resistance and vasoconstrictor responsiveness are crucial in portal hypertension and variceal bleeding control. Statins enhance vasodilators production, but their influence on collaterals is unknown. This study aimed to survey the effect of simvastatin on collaterals. Methods: Partially portal vein-ligated rats received oral simvastatin (20 mg/kg/day) or distilled water from −2 to +7 day of ligation. After hemodynamic measurements on the eighth postoperative day, baseline perfusion pressure (i.e. an index of collateral vascular resistance) and arginine vasopressin (AVP, 0.1 nM–0.1 µM) responsiveness were evaluated with an in situ perfusion model for collateral vascular beds. RT-PCR of endothelial NO synthase (eNOS), inducible NOS (iNOS), cyclooxygenase-1 (COX-1), COX-2, thromboxane A2 synthase (TXA2-S) and prostacyclin synthase genes was performed in parallel groups for splenorenal shunt (SRS), the most prominent intra-abdominal collateral vessel. To determine the acute effects of simvastatin, collateral AVP response was assessed with vehicle or simvastatin. SRS RT-PCR of eNOS, iNOS, COX-1, COX-2 and TXA2-S, and measurements of perfusate nitrite/nitrate, 6-keto-PGF1α and TXB2 levels were performed in parallel groups without AVP. Results: Acute simvastatin administration enhanced SRS eNOS expression and elevated perfusate nitrite/nitrate and 6-keto-PGF1α concentrations. Chronic simvastatin treatment reduced baseline collateral vascular resistance and portal pressure and enhanced SRS eNOS, COX-2 and TXA2-S mRNA expression. Neither acute nor chronic simvastatin administration influenced collateral AVP responsiveness. Conclusion: Simvastatin reduces portal-systemic collateral vascular resistance and portal pressure in portal hypertensive rats. This may be related to the enhanced portal-systemic collateral vascular NO and prostacyclin activities.

Background and Aim: Nitric oxide (NO) inhibition aggravates hepatic damage and encephalopathy and increases mortality in rats with thioacetamide (TAA)-induced acute liver failure. Statins enhance NO synthase expression beyond their lipid-lowering capability, but the impact on encephalopathy remains unexplored. The aim of this study was to assess the effects of simvastatin on rats with TAA-induced acute liver damage and hepatic encephalopathy. Methods: Sprague–Dawley rats received TAA (350 mg/kg/day) or normal saline (NS) by intraperitoneal injection for 3 consecutive days. Two days before injections, each group was divided into three subgroups, taking (i) distilled water; (ii) simvastatin (20 mg/kg/day); or (iii) simvastatin plus NG-nitro-l-arginine methyl ester (L-NAME, 25 mg/kg/day) by oral gavage for 5 days. On the fifth day, severity of encephalopathy was assessed and plasma levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin and ammonia were measured. Results: The TAA subgroups showed higher ALT, AST, bilirubin and ammonia levels and lower motor activity counts as compared with the NS subgroups. Among the TAA-treated subgroups, rats with simvastatin treatment exerted higher motor activity counts and survival rate (P = 0.043), and a trend of lower ALT, AST, bilirubin and ammonia levels than those receiving saline. All rats that underwent simvastatin plus L-NAME treatment died during or after TAA injections. Conclusions: Simvastatin improved encephalopathy and survival in TAA-administered rats. The beneficial effect was offset by L-NAME, suggesting the role of NO in liver damage and encephalopathy.

Background and Aim: Nitric oxide (NO) plays a significant role in the vascular hyposensitivity to vasoconstrictors in cirrhosis. Chronic NO inhibition improves the portal-systemic collateral responsiveness to arginine8-vasopressin (AVP) and ameliorates shunting degree in rats with prehepatic portal hypertension. This study investigated whether long-term NO inhibition by NG-nitro-L-arginine methyl ester (L-NAME) enhances the collateral vascular responsiveness to AVP and alleviates the severity of shunting in cirrhotic rats. Methods: Bile duct-ligated (BDL) rats received L-NAME in tap water (25 mg/kg/day) or tap water only (control) for 1 week from the 36th day after BDL. On the 43rd day, the mean arterial pressure and portal pressure were measured. With an in situ perfusion model of portal-systemic collateral vasculature, different concentrations of AVP (10−10−10−7 mol/L) with a constant flow rate (12 mL/min) were applied to assess the perfusion pressure changes of collaterals. In addition, flow pressure curves were obtained with different flow rates (6–18 mL/min): the slopes serve as indices of collateral vascular resistance and the higher resistance indicates less collateral. Results: The mean arterial pressure was significantly increased after L-NAME treatment (P

BackgroundLiver cirrhosis is often accompanied by portal-systemic collateral formation with hemorrhage and encephalopathy. Prostacyclin participates in hyperdynamic circulation and vascular hyporeactiveness to vasoconstrictors in cirrhosis. It has been shown that arginine vasopressin (AVP) induces direct collateral vasoconstriction in portal hypertensive rats, which is potentiated by indomethacin preincubation. However, the influence of chronic indomethacin administration in cirrhosis remains unexplored.MethodsThis study was performed on male Sprague-Dawley rats with liver cirrhosis induced by common bile duct ligation. They received subcutaneous indomethacin (5 mg/kg/day) or distilled water (control) injection from the 36th to 42nd day after operation. On the 43rd day, systemic and portal hemodynamics were evaluated and the following experiments were performed with an in situ collateral perfusion model: in the first series, concentration-response curves to AVP (10−10−10−7 M) were obtained; in the second series, flow-pressure curves were plotted (Krebs solution, 6–18 mL/min), where the slope represents an index of collateral vascular resistance (the higher the resistance, the smaller the amount of shunting vessels, that is, the lower the degree of shunting).ResultsThe mean arterial pressure and portal pressure were similar between indomethacin and control groups (p > 0.05). Indomethacin elevated the collateral perfusion pressure to AVP (3 × 10−9, 10−8 M, p < 0.05) but did not influence the slope of the flow-pressure curve (p > 0.05).ConclusionIn bile duct-ligated cirrhotic rats, indomethacin improves the portal-systemic collateral vascular responsiveness to AVP without alleviating the severity of shunting.

Background: Hepatic encephalopathy is neuropsychiatric derangement secondary to hepatic decompensation or portalsystemic shunting. Nitric oxide (NO) synthase inhibition aggravates encephalopathy and increases mortality in rats with thioacetamide (TAA)-induced acute liver failure, suggesting a protective role of NO. This study investigated the roles of endothelium-derived constitutive NO synthase (eNOS) and inducible NOS (iNOS) in the liver of rats with fulminant hepatic failure and encephalopathy. Methods: Male Sprague-Dawley rats (300–350 g) were randomized to receive TAA 350 mg/kg/day, by intraperitoneal injection or normal saline for 3 days. Severity of encephalopathy was assessed with the Opto-Varimex animal activity meter. Plasma levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, and bilirubin were measured. Hepatic iNOS and eNOS RNA and protein expressions were assessed by reverse transcription–polymerase chain reaction and Western blot analyses, respectively. Results: The TAA group showed lower motor activity counts than the normal saline group. Hepatic eNOS, but not iNOS, mRNA and protein expressions were enhanced in the TAA group. In addition, hepatic eNOS mRNA expression was negatively correlated with total movement but positively correlated with ALT and AST. Protein expression of hepatic eNOS was positively correlated with ALT, AST and bilirubin. Conclusion: Upregulation of hepatic eNOS was observed in rats with TAA-induced fulminant hepatic failure and encephalopathy, which might play a regulatory role. [J Chin Med Assoc 2007;70(1):16–23]

Portal-systemic collaterals lead to dreadful consequences in patients with cirrhosis. Angiogenesis participates in the development of liver fibrosis, hyperdynamic circulation, and portal-systemic collaterals. 2'-Hydroxyflavanone (2'-HF), one of the citrus fruits flavonoids, is known to have antiangiogenesis effect without adverse response. However, the relevant effects in liver fibrosis have not been surveyed.Male Wistar rats received thioacetamide (TAA, 100 mg/kg tiw, i.p.) for 6 weeks to induce liver fibrosis. On the 29th to 42nd day, rats randomly received 2'-HF (100 mg/kg, qod, i.p.) or vehicle (corn oil). On the 43rd day, after hemodynamic measurements, the followings were surveyed: (i) severity of collaterals; (ii) mesenteric angiogenesis; (iii) mesenteric proangiogenic factors protein expressions; (iv) Mesenteric vascular endothelial cells apoptosis; and (v) Mesenteric expressions of proteins regulating apoptosis.Compared with the vehicle group, 2'-HF did not significantly change body weight, mean arterial pressure, heart rate, and portal pressure in TAA rats. 2'-HF significantly alleviated the severity of collaterals, but the mesenteric phospho-ERK, ERK, phospho-Akt, Akt, COX1, COX2, VEGF, and VEGFR-2 protein expressions were not altered. The apoptotic index of 2'-HF group was significantly higher and the mesenteric protein expressions of pro-apoptotic factors, NFkB 50, NFkB 65, Bax, phospho-p53, 17 kD cleaved caspase 3, and 17 kD casepase 3 were up-regulated.2'-HF does not influence the hemodynamics but alleviated the severity of collaterals in rats with liver fibrosis and early portal hypertension. This is, at least partly, attributed to enhanced apoptosis of mesenteric vascular endothelial cells.

Background: Catecholamine exerts profound vascular effects on vascular smooth muscle, and serum norepinephrine (Nepi) and sympathetic nervous activity are increased in cirrhosis. The vascular response of Nepi and acetylcholine (Ach) in portal–systemic collaterals of cirrhotic rats is unknown. The purpose of the present study was to investigate the effects of Nepi and Ach on portal–systemic collaterals of common bile duct-ligated (BDL) cirrhotic rats. Methods: Perfusion studies were performed 6 weeks after BDL when hepatic cirrhosis was induced. Three series of experiments were performed in BDL rats: (i) the Nepi (10−10 mol/L−10−5 mol/L) vasoconstrictory responses with (n = 6) and without (n = 5) α1- (phentolamine, 5 × 10−6 mol/L) or β- (propranolol, 10−5 mol/L) receptor antagonist (n = 6 and 5, respectively); (ii) the Ach (10−8 mol/L−10−5 mol/L) vasodilatory responses in Nepi- preconstricted portal–systemic collaterals in the absence (n = 7) or presence (n = 8) of Nϖ- l-nitro-arginine (NNA, 10−4 mol/L); and (iii) the effect of indomethacin (10−5 mol/L; n = 6) on Nepi responses. The collateral vascular responses were evaluated by the in situ collateral perfusion. Results: Norepinephrine significantly increased the perfusion pressure and was inhibited by phentolamine (P 0.05). Acetylcholine produced >50% relaxation of the Nepi-preconstricted collateral vessels and was inhibited by NNA (P

Background and Aims: Endotoxin has been proposed to participate in the development of hepatic encephalopathy. However, there is no published data concerning the effects of endotoxin neutralization on the degree of hepatic encephalopathy. The present study investigated the effect of chronic intraperitoneal injection of polymyxin B, a neutralizing antagonist of endotoxin, on hepatic encephalopathy in rats with thioacetamide (TAA)-induced fulminant hepatic failure. Methods: Male Sprague-Dawley rats weighing 300–350 g were used. Fulminant hepatic failure was induced by intraperitoneal injection of TAA (350 mg/kg/day) for 3 days. Two series of rats were designed to compare the effects of low dose (0.1 mg) or high dose (0.2 mg) intraperitoneal polymyxin B administration versus normal saline (NS) on hepatic encephalopathy. The injection was twice daily started from 2 days prior to TAA administration and lasted for 5 days. Severity of encephalopathy was assessed by the counts of motor activity in an Opto-Varimex animal activity meter. Plasma levels of endotoxin and tumor necrosis factor-α (an index of liver injury) were measured by Limulus assay and the ELISA method, respectively. Results: Neutralization of endotoxin by either low dose or high dose polymyxin B administration did not significantly alleviate the degree of hepatic encephalopathy, as represented by the counts of motor activities (P > 0.05). Plasma levels of endotoxin and tumor necrosis factor-α were comparable between rats treated with polymyxin B or NS (P > 0.05). Conclusion: Our findings do not support the notion that endotoxin plays a major role in the pathogenesis of hepatic encephalopathy in rats with TAA-induced fulminant hepatic failure.

Background Peptic ulcer disease may occur in the absence of dyspeptic symptoms. The pathogenesis of dyspepsia in peptic ulcer disease is unclear. Whether the presence of Helicobacter pylori infection or use of non-steroidal anti-inflammatory drugs affects dyspeptic symptoms in patients with peptic ulcer disease has not been determined. The aim of the study was to determine the frequency and risk factors for peptic ulcer disease in a cohort of asymptomatic, unselected patients undergoing routine screening EGD. Methods This was a prospective study of a cohort of Chinese subjects undergoing screening EGD as part of a routine health maintenance program. Routine EGD screening was performed in 6457 consecutive subjects who underwent a self-paid, health evaluation. Those with endoscopy-confirmed peptic ulcer disease were enrolled to assess the risk factors that distinguish asymptomatic patients with peptic ulcer disease from patients with symptoms because of peptic ulcer disease. Results A total of 704 (10.9%) patients were found to have peptic ulcer disease, of which two thirds (n=496) were asymptomatic. Both uni- and multivariate analysis showed that the asymptomatic patients tended to have a larger body mass index, to be habitual tea drinkers, and to have an ulcer that was less than 1 cm in diameter and in a healing stage. Gender, blood group, history of hypertension and/or diabetes, ulcer location, Helicobacter pylori status, use of non-steroidal anti-inflammatories or sedative medications, habitual coffee drinking, and habits with respect to smoking of tobacco or ingestion of alcohol, had no association with symptoms. Conclusions The results of this study suggest that silent peptic ulcer disease is common in Taiwan. Dyspeptic symptoms because of peptic ulcer disease may be influenced by intrinsic (body mass index and ulcer characters) and extrinsic (habitual tea drinking) factors. Non-steroidal anti-inflammatory drug use and Helicobacter pylori status had no significant effect on the symptomatology of peptic ulcer disease. These findings may contribute to the understanding of the pathogenesis in the visceral symptoms of peptic ulcer disease.

Background/aims Endothelin-1 (ET-1) may induce intrahepatic vasoconstriction and consequently increase portal pressure. Endothelin-1 has been shown to exert a direct vasoconstrictive effect on the collateral vessels in partially portal vein-ligated rats with a high degree of portal-systemic shunting. This study investigated the collateral vascular responses to ET-1, the receptors in mediation and the regulation of ET-1 action by nitric oxide and prostaglandin in cirrhotic rats with a relatively low degree of portal-systemic shunting. Methods The portal-systemic collaterals of common bile duct-ligated (BDL) cirrhotic rats were tested by in situ perfusion. The concentration-response curves of collaterals to graded concentrations of ET-1 (10(-10)-10(-7) m) with or without BQ-123 (ET(A) receptor antagonist, 2 x 10(-6) m), BQ-788 (ET(B) receptor antagonist, 10(-7) m) or both were recorded. In addition, the collateral responses to ET-1 with preincubation of N(omega)-nitro-L-arginine (NNA, 10(-4) M), indomethacin (INDO, 10(-5) M) or in combination were assessed. Results Endothelin-1 significantly increased the perfusion pressures of portal-systemic collaterals. The ET-1-induced constrictive effects were inhibited by BQ-123 or BQ-123 plus BQ-788 but not by BQ-788 alone. The inhibitory effect was greater in the combination group. Pretreatment of NNA or NNA plus INDO equivalently enhanced the response of ET-1 while pretreatment of INDO alone exerted no effect. Conclusion Endothelin-1 has a direct vasoconstrictive effect on the collaterals of BDL cirrhotic rats, mainly mediated by ET(A) receptor. Endogenous nitric oxide may play an important role in modulating the effects of ET-1 in the portal-systemic collaterals of BDL cirrhotic rats.

Summary Background : Irritable bowel syndrome is a common condition seen in Western countries. In Asia, however, it is less known and even less studied. Aim : To determine the prevalence and social impact of irritable bowel syndrome as well as the health-seeking behaviour of irritable bowel syndrome patients in Taiwan Methods : Using the modified Rome II questionnaire, a survey was carried out in a population receiving physical check-up (n = 2865). Results : The prevalence of irritable bowel syndrome in Taiwan was 22.1% and 17.5% (κ = 0.73) according to the Rome II and I criteria, respectively. No gender difference was found between subjects with and without irritable bowel syndrome symptoms. Irritable bowel syndrome subjects were likely to undertake an excessive number of physician-visits (P

Background Prostacyclin mediates, at least partly, the splanchnic vascular hyporesponsiveness to glypressin in bleeding portal hypertensive rats. This study investigated the relative contribution of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) in the splanchnic hyposensitivity to glypressin in rats with portal hypertension induced by partial portal vein ligation (PVL). Methods Fourteen days after the operation, the rats were divided into without- and with-bleeding groups. Three series of PVL rats were used to investigate (i). the haemodynamic effects of glypressin (0.07 mg x kg(-1) intravenously), (ii). COX-1/COX-2 mRNA expression over abdominal aorta and superior mesenteric artery and (iii). plasma levels of 6-keto-prostaglandin-F1alpha. In rats with a hypotensive haemorrhage, 4.5 mL of blood was withdrawn and 50% of the withdrawn blood was re-infused before blood and vessel sampling or the administration of glypressin. Results Splanchnic hyposensitivity to glypressin was demonstrated in the haemorrhage-transfused PVL rats with enhanced COX-1 expression of superior mesenteric artery and increased plasma levels of 6-keto-prostaglandin-F1alpha. There were no differences in the COX-2 expression of superior mesenteric artery and COX-1 and COX-2 expressions of abdominal aorta between without- and with-bleeding groups. Conclusion In portal hypertensive rats with acute haemorrhage, COX-1 over-expression in the superior mesenteric artery plays a role in mediating the splanchnic hyposensitivity to glypressin.

Endoscopic retrograde cholangiopancreatography (ERCP)-induced pancreatitis provides a model to study the time course of cytokine release during the initiation phase of pancreatitis. The early changes of inflammatory cytokines after ERCP have been unclear.To evaluate the early changes in serum levels of proinflammatory and antiinflammatory cytokines after ERCP and to assess their value in the early recognition of post-ERCP pancreatitis.Seventy-eight consecutive patients undergoing ERCP were prospectively studied. The serum concentrations of tumor necrosis factor alpha, interleukin-1beta, interleukin-6, interleukin-8, and interleukin-10 were determined immediately prior to and 1, 4, 8, and 24 hours after ERCP.Seven of 78 patients (9.0%) developed post-ERCP pancreatitis. Serum levels of tumor necrosis factor alpha, interleukin-1beta, interleukin-6, interleukin-8, and interleukin-10 significantly increased at 8 and 24 hours but not at 1 and 4 hours after ERCP in patients with post-ERCP pancreatitis, in comparison with patients without pancreatitis. Using a cutoff level of 36 pg/mL for interleukin-6 at 8 hours after ERCP, we found that the sensitivity and specificity for recognition of post-ERCP pancreatitis were 100% and 87%, respectively. Serum levels of interleukin-6 and interleukin-8 modestly increased from baseline values, 1 to 24 hours after uncomplicated ERCP.Proinflammatory and antiinflammatory cytokines significantly increased in the early stage after ERCP-induced pancreatitis. Among the inflammatory cytokines, interleukin-6 is the most useful for recognition of post-ERCP pancreatitis.

Background Chronic portal hypertension is associated with the development of portal-systemic collaterals. Long-term octreotide treatment has been shown to enhance the constrictive response to vasopressin in the mesenteric arteries of portal hypertensive rats. This study investigated the effects of long-term octreotide treatment on the response of portal-systemic collaterals to vasopressin in portal hypertensive rats. Methods Partially portal vein-ligated rats were divided into two groups to receive subcutaneous injection of either placebo (5% dextrose in water) or octreotide (30 µg kg−1) twice daily for 7 days. Two series of experiments were performed to measure: (a) the systemic and portal hemodynamics and cumulative concentration-response curves of collateral vessels to vasopressin (10−10 to 10−7 M) and (b) the slopes of the flow-pressure curves of collaterals (an index of portal-systemic shunting). The cumulative concentration-response curves and flow pressure curves were determined by the in situ collateral perfusion. Results Long-term octreotide treatment significantly lowered the portal pressure without changes in the mean arterial pressure. Vasopressin significantly and similarly increased the perfusion pressure of collateral vessels in both the placebo- and octreotide-treated groups. In addition, long-term octreotide treatment exerted no effect on the EC50 of vasopressin (−8·25 ± 0·19 vs. –8·20 ± 0·10, P > 0·05) and the slopes of flow-pressure curves (0·97 ± 0·02 vs. 0·94 ± 0·04, P > 0·05) in the collaterals. Conclusion Despite lowering the portal pressure, long-term octreotide treatment did not enhance the vasoconstrictive effect of vasopressin in the collateral vessels of portal hypertensive rats and ameliorate the degree of portal-systemic shunting.

Background/Aims : Somatostatin and its long-acting analogue, octreotide, have been used to cease variceal bleeding with uncertain mechanisms. This study investigated whether somatostatin and octreotide have a direct vasoconstrictive effect on the portal-systemic collaterals of portal-hypertensive rats and potentiate the vasoconstriction induced by endothelin-1 in these vascular beds. Methods : The vascular responses of collateral vessels to graded concentrations of somatostatin (10 −9 –10 −5 mol/l), octreotide (10 −10 –10 −6 mol/l), norepinephrine (10 −9 –10 −5 mol/l) and vehicle (Krebs solution) were evaluated in perfused collateral vascular beds of rats with portal hypertension induced by partial portal vein ligation. In addition, the perfusion pressure changes of collateral vessels to endothelin-1 (10 −8 mol/l) in the presence of vehicle(control), somatostatin (10 −6 mol/l) and octreotide (10 −6 mol/l) were tested. Results : Compared with the vehicle group, norepinephrine significantly increased the perfusion pressure of collateral vessels at concentrations between 10 −7 and 10 −5 mol/l. In contrast, neither somatostatin nor octreotide significantly changed the perfusion pressure. Somatostatin and octreotide significantly enhanced the endothelin-1-induced vasoconstrictive effect on the collaterals. Conclusions : Somatostatin and octreotide exert no direct vasoconstrictive effect on the collateral vessels of portal hypertensive rats. In the presence of endothelin-1, somatostatin and octreotide exert a local vasoconstrictive effect on these vascular beds.

Chronic gastroesophageal reflux disease is closely associated with esophageal adenocarcinoma and gastric cardia carcinoma, and esophageal adenocarcinoma and gastric cardia carcinoma have both been increasing in Western countries recently. Gastroesophageal reflux disease is not rare in Taiwan, but the frequency of occurrence of esophageal adenocarcinoma or gastric cardia carcinoma has not been studied here to date. Patients diagnosed with esophageal and gastric cancers at this hospital between 1981 and 1995 were recruited using the hospital tumor registry database. There were 45, 1546, 970, and 4167 patients diagnosed with esophageal adenocarcinoma, esophageal squamous cell carcinoma, gastric cardia carcinoma, and gastric noncardia adenocarcinoma, respectively. The ratios of esophageal adenocarcinoma versus esophageal squamous cell carcinoma among the three cohorts were 0.030, 0.016, and 0.041, respectively (trend, P = 0.086). The corresponding values for gastric cardia carcinoma versus gastric noncardia adenocarcinoma were 0.252, 0.232, and 0.218, respectively (trend, P = 0.256). The ratios of esophageal adenocarcinoma versus esophageal squamous cell carcinoma and of gastric cardia carcinoma versus gastric noncardia adenocarcinoma have not risen in the three cohorts. Unlike the situation in Western countries, the incidence of esophageal adenocarcinoma and gastric cardia carcinoma versus esophageal squamous cell carcinoma and gastric noncardia adenocarcinoma have not increased over the past 15 years among the Chinese in Taiwan. Although gastroesophageal reflux disease is common here, its definite pathogenesis leading to esophageal adenocarcinoma or gastric cardia carcinoma remains unresolved.

The hepatopulmonary syndrome (HPS) is characterized by hypoxia and increased intrapulmonary shunts in cirrhotic patients. Emerging evidence showed promising results of treating HPS by abolishment of intrapulmonary inflammation and angiogenesis. Rosuvastatin is a kind of 3-hydroxy-methyl-3-glutamyl coenzyme A reductase inhibitor. In addition to lipid-lowering effects, it has anti-inflammation and anti-angiogenesis properties. We postulated that rosuvastatin treatment can ameliorate HPS. Common bile duct ligation (CBDL) was applied in an experimental HPS animal model. CBDL rats received 2-week rosuvastatin (20 mg/kg/day) treatments from the fifteenth day after operation. The haemodynamic data, blood gas analysis, liver biochemistries, tumour necrosis factor-α (TNF-α) and vascular endothelial growth factor (VEGF) were examined after rosuvastatin treatment. The liver and lung tissues were dissected for histopathological studies and protein analyses. In the parallel groups, intrapulmonary shunts were determined. The haemodynamic and liver biochemistries were not changed after rosuvastatin treatment in CBDL rats, but the alveolar-arterial oxygen pressure gradient was significantly decreased, implying that HPS-induced hypoxia was reversed after rosuvastatin treatment. In addition, rosuvastatin treatment reduced intrapulmonary shunts and plasma levels of VEGF and TNF-α. Besides, the intrapulmonary protein expression of nuclear factor kappa B (NF-κB), VEGF receptor (VEGFR)-1,2 and Rho-associated A kinase were significantly down-regulated and the intrapulmonary angiogenesis was ameliorated. We concluded that rosuvastatin alleviates experimental HPS through blockade of pulmonary inflammatory angiogenesis via TNF-α/NF-κB and VEGF/Rho-associated A kinase pathways down-regulation.

Background Angiogenesis plays a pivotal role in splanchnic hyperaemia and portosystemic collateral formation in cirrhosis. Endothelin-1 (ET-1), an endothelium-derived vasoconstrictor, has also been implicated in the pathogenesis of cirrhosis and portal hypertension. Design This study aimed to survey the influences of ET-1 in cirrhosis-related angiogenesis. Common bile duct ligation was performed on Spraque–Dawley rats to induce cirrhosis. Since the 14th day after the operation, rats randomly received distilled water (DW, control), bosentan [a nonselective ET receptor (ETR) blocker] or ambrisentan (a selective ETAR blocker) for 4 weeks. On the 43rd day, portal and systemic haemodynamics, liver biochemistry, portosystemic shunting degree, mesenteric vascular density, mRNA and/or protein expressions of relevant angiogenic factors were evaluated. Results In cirrhotic rats, bosentan significantly reduced portal pressure. Ambrisentan did not influence haemodynamics and liver biochemistry. Both of them significantly improved the severity of portosystemic collaterals and decreased the mesenteric vascular density. Compared with the DW-treated cirrhotic rats, splenorenal shunt and mesenteric inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX2), vascular endothelial growth factor mRNA expressions and mesenteric iNOS, COX2, VEGF, phospho-VEGF receptor 2, Akt and phospho-Akt protein expressions were down-regulated in both groups. Conclusions In rats with liver cirrhosis, both nonselective and selective ETAR blockade ameliorate the severity of portosystemic shunting and mesenteric angiogenesis via the down-regulation of VEGF pathway and relevant angiogenic factors. ET receptors may be targeted to control the severity of portosystemic collaterals and associated complications in cirrhosis.

Portal hypertension (PH), a pathophysiological derangement of liver cirrhosis, is characterized by hyperdynamic circulation, angiogenesis, and portosystemic collaterals. These may lead to lethal complications, such as variceal bleeding. Caffeine has been noted for its effects on liver inflammation, fibrogenesis, and vasoreactiveness. However, the relevant influences of caffeine in cirrhosis and PH have not been addressed. Spraque-Dawley rats with common bile duct ligation–induced cirrhosis or sham operation received prophylactic or therapeutic caffeine treatment (50 mg/kg/day, the first or 15th day since operation, respectively) for 28 days. Compared to vehicle (distilled water), caffeine decreased cardiac index, increased systemic vascular resistance, reduced portal pressure (PP), superior mesenteric artery flow, mesenteric vascular density, portosystemic shunting (PSS), intrahepatic angiogenesis, and fibrosis without affecting liver and renal biochemistry. The beneficial effects were reversed by selective adenosine A1 agonist N6-cyclopentyladenosine (CPA) or A2A agonist GCS21680. Both prophylactic and therapeutic caffeine treatment decreased portal resistance and PP in thioacetamide (200mg/kg, thrice-weekly for 8 weeks)-induced cirrhotic rats. Caffeine down-regulated endothelial nitric oxide synthase, vascular endothelial growth factor (VEGF), phospho-VEGFR2, and phospho–Akt mesenteric protein expression. Caffeine adversely affected viability of hepatic stellate and sinusoidal endothelial cells, which was reversed by CPA and GCS21680. On the other hand, caffeine did not modify vascular response to vasoconstrictors in splanchnic, hepatic, and collateral vascular beds. Conclusions: Caffeine decreased PP, ameliorated hyperdynamic circulation, PSS, mesenteric angiogenesis, hepatic angiogenesis, and fibrosis in cirrhotic rats. Caffeine may be a feasible candidate to ameliorate PH-related complications in cirrhosis. (Hepatology 2015;61:1672-1684)

Background Hepatic encephalopathy is a complex neuropsychiatric syndrome seen secondary to acute liver failure, chronic parenchymal liver disease, or portal-systemic anastomosis. Vasodilatation induced by nitric oxide (NO) may be involved in the development of hepatic coma. However, there are no comprehensive data concerning the effects of NO inhibition on the severity of hepatic encephalopathy. Methods Male Sprague-Dawley rats weighing 300-350 g were used. Fulminant hepatic failure was induced by intraperitoneal injection of thioacetamide (TAA, 350 mg kg -1 day -1 ) for 3 days. Rats were divided into two groups to receive either N G -nitro-L-arginine methyl ester (L-NAME, 20 mg kg -1 day -1 via intragastric gavage) or normal saline (N/S) from 2 days prior to TAA administration for 5 days. Severity of encephalopathy was assessed by counts of motor activity and neurobehaviour test scores. Plasma levels of endotoxin, tumour necrosis factor-α and nitrate/nitrite were determined by the chromogenic Limulus assay, enzyme-linked immunosorbent assay and colorimetric assay, respectively. Results Compared with N/S-treated rats, the mortality rate was significantly higher in rats receiving L-NAME (59% vs. 18%, P < 0.01). Inhibition of NO had detrimental effects on the counts of motor activities (P < 0.05) and neurobehaviour score (P < 0.01). Rats treated with L-NAME had significantly higher plasma levels of endotoxin (26.7 ± 3.8 pg mL -1 ) and tumour necrosis factor-α (29.4 ± 6.5 pg mL -1 ) compared with rats treated with N/S (13.2 ± 2.7 pg mL -1 and 11.2 ± 2.6 pg mL -1 , respectively, P < 0.01). Plasma levels of endotoxin and tumour necrosis factor-α, but not of nitrate/ nitrite, were significantly correlated with the severity of hepatic encephalopathy (P < 0.05). Conclusion Chronic L-NAME administration had detrimental effects on the severity of encephalopathy in TAA-treated rats, suggesting a protective role of NO in the development of fulminant hepatic failure.

Background Prostacyclin (PGI 2 ) is an important contributor to the mediation of hyporeactivity to vasoconstrictors and the development of hyperdynamic circulation in portal hypertensive states. Inhibition of PGI 2 synthesis in haemorrhage-transfused partially portal vein-ligated rats could ameliorate the splanchnic hyposensitivity to glypressin, a long-acting vasopressin analogue. This study investigated whether the hyposensitivity to glypressin also exists in rats with common bile duct ligation (BDL) and whether the inhibition of PGI 2 synthesis by indomethacin could potentiate the portal-hypotensive effect of glypressin in bleeding BDL rats. Methods Two series of BDL rats were used. Series 1 investigated the haemodynamic effects of low dose glypressin (0.07 mg kg -1 ) in BDL rats with or without bleeding by catheterization. In series 2, haemodynamic parameters were measured in stable or bleeding BDL rats that were receiving intravenously high dose glypressin (0.2 mg kg -1 ) or indomethacin (5 mg kg -1 ) followed by high dose glypressin. In rats with a hypotensive haemorrhage, 4.5 mL of blood was withdrawn and 50% of the withdrawn blood was reinfused before the administration of glypressin or indomethacin. Results Splanchnic hyposensitivity to glypressin was demonstrated in haemorrhage-transfused BDL rats receiving high, but not low, doses of glypressin. Indomethacin infusion did not cause significant systemic and portal haemodynamic changes in bleeding BDL rats (P > 0.05). The addition of indomethacin significantly enhanced the portal-hypotensive effects of glypressin (P < 0.05) and potentiated the increases in mean arterial pressure induced by glypressin infusion (P < 0.001) in bleeding BDL rats. Conclusion Splanchnic hyposensitivity to glypressin observed in haemorrhage-transfused BDL rats could be ameliorated by the addition of indomethacin, suggesting a role of endogenous PGI 2 in its pathophysiology.

Hyposensitivity to vasopressin is a well documented phenomenon in animals with portal hypertension and patients with cirrhosis subject to haemorrhage. Haemorrhage is associated with the endogenous release of bradykinin, which may subsequently stimulate the formation of nitric oxide (NO). The present study investigated the relative contribution of NO synthase (NOS) isoforms and the role of bradykinin in the pathogenesis of splanchnic hyposensitivity to a long-acting vasopressin analogue, glypressin, in rats with portal hypertension induced by partial portal vein ligation (PVL). At 14 days after the operation, systemic and portal haemodynamics were measured in stable or bleeding PVL rats receiving an intravenous infusion of glypressin (0.07 mg/kg). In the treatment groups, NG-nitro-L-arginine methyl ester (L-NAME; a non-selective NOS inhibitor), L-canavanine (a specific inhibitor of inducible NOS) or HOE 140 (a bradykinin B2 receptor antagonist) was administered 45 min before the infusion of glypressin. In rats with a hypotensive haemorrhage, 4.5 ml of blood was withdrawn and 50% of the withdrawn blood was re-infused before the administration of glypressin or various inhibitors. Splanchnic hyposensitivity to glypressin was demonstrated in the haemorrhage/transfused PVL rats. The infusion of L-NAME elevated the mean arterial pressure in the bleeding PVL rats without the modulation of portal pressure. The addition of L-NAME or HOE 140, but not L-canavanine, significantly and similarly potentiated the portal-hypotensive effects of glypressin. It is concluded that constitutive NOS and bradykinin are responsible, at least partly, for the splanchnic hyposensitivity to glypressin observed in the early stages of the haemorrhage/transfused rat model of portal hypertension.

To delineate the clinical roles of plasma cytokine or endotoxin levels in the natural course of infection in patients with decompensated cirrhosis, 66 cirrhotic patients were studied within a 1.5-year period. Plasma levels of tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, IL-8 and endotoxin were determined on days 1, 4 and 7 after admission when hospital infection was suspected and 4 months later. A total of 24 patients (36.4%) were proven to be infected during hospitalization (group A), while 42 others were not infected (group B). Fever occurred in a very high proportion (22/24) of group A patients. Baseline levels of TNF-α (37.7±15.2 compared with 8.7±1.2 pg/ml; P < 0.01) and IL-6 (180.5±20.5 compared with 24.6±7.5 pg/ml; P < 0.0001) were higher in group A patients, while IL-1β, IL-8 and endotoxin levels were not significantly different between the two groups. For patients with hospital infection, IL-6 levels determined during the episode were significantly higher than baseline levels. Using IL-6 > 80 pg/ml as a baseline cut-off level to diagnose bacterial infection, the sensitivity, specificity and accuracy were 87.5, 100 and 95.5% respectively. The one-year cumulative probability of mortality (61.1% compared with 23.7%; P < 0.001) and of bacterial re-infection (72.2% compared with 18.4%; P < 0.0001) was higher in group A than in group B. Plasma TNF-α and IL-6 levels determined at 4 months were not different between the two groups. In conclusion, fever or elevated plasma IL-6 levels in patients with decompensated cirrhosis calls for early antibiotic treatment to prevent life-threatening bacterial infection. Bacterial infection is likely to recur in those patients with increased IL-6 levels, while severe episodes of infection occur in patients with increased TNF-α levels.

Protein C deficiency is one of the causes of curable or preventable portal vein thrombosis. We report two patients of portal vein thrombosis associated with hereditary protein C deficiency. The first patient presented with continuous right upper quadrant pain and high fever. The abdominal sonography revealed normal liver parenchyma but portal vein and superior mesenteric vein thrombosis. Based on a 55% (normal 70-140%) plasma protein C level, he was diagnosed as having protein C deficiency. A trace of his family history showed that his elder brother also had protein C deficiency with a 50% plasma C level. Both patients received anticoagulant therapy. The younger brother showed good response. Unfortunately, the elder one suffered from recurrent episodes of variceal bleeding and received a life-saving splenectomy and devascularization. We herein remind clinicians that early screening and therapy are helpful in preventing late complications of protein C deficiency with portal vein thrombosis.

Gall-bladder wall thickening is commonly seen in patients with cirrhosis, but its exact causes have not been well established. We evaluated clinical, biochemical and haemodynamic data of patients with cirrhosis with respect to the presence of thickening of the gall-bladder wall. After excluding patients who presented with gallstones, acute or chronic cholecystitis, heart failure, a serum creatinine level greater than 2 mg/dL and/or a serum alanine aminotransferase level greater than 400 U/L, 77 patients with cirrhosis (75 male, two female; mean age 58 +/- 8 years) were enrolled in the study. Clinical, biochemical, ultrasound and haemodynamic data were obtained in every patient. Forty-one (53%) of 77 patients with cirrhosis had gall-bladder wall thickening (> 4 mm). Compared with patients with a normal gall-bladder wall, patients with gall-bladder wall thickening had significantly lower serum albumin levels (3.6 +/- 0.6 vs 2.9 +/- 0.7 gm/dL, respectively; P < 0.05), a longer prothrombin time (13 +/- 6 vs 16 +/- 6 s, respectively; P < 0.05), more patients with Child-Pugh class C (6 vs 37%, respectively; P < 0.05) and more patients with ascites (8 vs 50%, respectively; P < 0.05). In addition, compared with patients with a normal gall-bladder wall, those patients with gall-bladder wall thickening had a higher hepatic venous pressure gradient (13.9 +/- 4.5 vs 17.1 +/- 4.1 mmHg, respectively; P < 0.01) and a lower systemic vascular resistance (SVR; 1144 +/- 332 vs 1010 +/- 318 dyn.s/cm5, respectively; P < 0.05). Using a multivariate analysis, the presence of ascites and SVR lower than 900 dyn.s/cm5 were independently correlated with the presence of gall-bladder wall thickening, while a hepatic vein pressure gradient greater than 10 mmHg had only a marginally significant association. The presence of ascites, decreased SVR and portal hypertension are related to the occurrence of gall-bladder wall thickening in patients with cirrhosis, indicating that the development of gall-bladder wall thickening may be multifactorial.

To realize the roles of peripheral vasodilatation and atrial natriuretic peptide in the formation of cirrhotic ascites, the effects of long-term administration of octreotide on carbon tetrachloride-induced cirrhotic rats were evaluated.Urine sodium excretion, hemodynamics, plasma atrial natriuretic peptide levels, renin activities and aldosterone concentrations were compared between cirrhotic and control rats (protocol 1); and between octreotide- (65 micrograms/kg, twice daily for 10 days, subcutaneously) and placebo-treated (5% dextrose) cirrhotic rats (protocol 2). In an in vitro experiment, right atrial tissue of cirrhotic rats was incubated with different concentrations of octreotide to evaluate the release of atrial natriuretic peptide (protocol 3).Cirrhotic rats had significantly lower urine sodium excretion and systemic vascular resistance, and significantly higher plasma atrial natriuretic peptide levels, renin activities and aldosterone concentrations than control rats. Compared with placebo-treated cirrhotic rats, octreotide caused increased urine sodium excretion (-10 +/- 4% vs. 13 +/- 8% from baseline values, p0.05) and systemic vascular resistance (2.6 +/- 0.1 vs. 3.3 +/- 0.3 mmHg.min.100 g.ml-1, p0.05); and decreased plasma atrial natriuretic peptide levels (166.7 +/- 24.8 vs. 234.0 +/- 19.2 pg/ ml, p0.05), renin activities (2.45 +/- 0.49 vs. 4.36 +/- 0.53 ng.ml-1.h-1, p0.01) and aldosterone concentrations (290.2 +/- 40.0 vs. 483.3 +/- 82.6 pg/ml, p0.05). In the in vitro experiment, right atrial release of atrial natriuretic peptide of cirrhotic rats was not significantly changed when incubated with different concentrations of octreotide.Octreotide ameliorates renal sodium retention and suppresses plasma levels of atrial natriuretic peptide of ascitic cirrhotic rats with a novel mechanism via, at least partly, the modification of peripheral vascular resistance.

Endotoxemia has frequently been observed in patients with cirrhosis. Previous studies have shown that cirrhotic patients with endotoxemia have a higher mortality than those without. We evaluated the clinical value of plasma endotoxin level in predicting short-term (3 months) and long-term (2 years) survival among cirrhotic patients and compared it with the Child-Pugh score.Plasma endotoxin levels were determined in 102 cirrhotic patients without clinical evidence of infection by a quantitative Limulus assay. The patients were followed up for 3 months to assess short-term survival and for 2 years for long-term survival.Plasma endotoxin levels increased progressively as liver function deteriorated. In short-term survival analysis, plasma endotoxin levels were significantly higher in non-survivors than those in survivors (10.6 +/- 2.2 pg/ml versus 5.8 +/- 0.5 pg/ml; P0.05). Both plasma endotoxin and serum bilirubin levels, but not the Child-Pugh score, were significant factors in predicting short-term survival in multivariate analysis. In long-term survival analysis, plasma endotoxin levels did not differ significantly between survivors and non-survivors (6.1 +/- 0.6 pg/ml versus 7.3 +/- 1.1 pg/ml; P0.05) and was not an independent predictor of long-term survival. In contrast, both Child-Pugh score and serum bilirubin levels were significant predictors of long-term survival in multivariate analysis.In patients with cirrhosis, plasma endotoxin levels progressively increase as liver function deteriorates and may be useful in predicting short-term survival.

Abnormal angiogenesis in liver cirrhosis often leads to severe complications such as variceal haemorrhage and encephalopathy. Furthermore, splanchnic angiogenesis elevates portal pressure, in which angiogenic factors play pivotal roles. GTP (green tea polyphenol) extracted from Camellia sinensis has anti-angiogenic properties, but the effects on the parameters described above in cirrhosis have not been investigated. The aim of the present study was to determine the effects of GTP in cirrhosis and to investigate the underlying mechanism. Liver cirrhosis was induced in Spraque–Dawley rats by common BDL (bile duct ligation). They randomly received GTP or DW (distilled water, vehicle) for 28 days, then haemodynamic parameters, portosystemic shunting, mesenteric window vascular density, intrahepatic angiogenesis, liver fibrosis, plasma VEGF (vascular endothelial growth factor) concentration, mesenteric angiogenic factor and receptor protein expression, and serum and mesenteric oxidative stress parameters were assessed. Compared with the DW group, GTP significantly decreased portosystemic shunting, liver fibrosis, intrahepatic angiogenesis, mesenteric window vascular density, VEGF concentration and down-regulated the mesenteric HIF (hypoxia-inducible factor)-1α, VEGF and phospho-Akt expression. In conclusion, GTP ameliorates the severity of portosystemic shunting and mesenteric angiogenesis via the suppression of HIF-1α, Akt activation and VEGF. GTP appears to be an appropriate agent in controlling portal hypertension-related complications via anti-angiogenesis. Abbreviations: ALT, alanine aminotransferase; AST, aspartate transaminase; BDL, bile duct ligation; CAT, catalase; COX, cyclo-oxygenase; DW, distilled water; EGCG, (−)-epigallocatechin-3-gallate; eNOS, endothelial NO synthase; ERK, extracellular-signal-regulated kinase; GPx, glutathione peroxidase; GTP, green tea polyphenol; HE HIF, hypoxia-inducible factor; HR, heart rate; HUVEC, human umbilical vein endothelial cell; iNOS, inducible NO synthase; MAP, mean arterial pressure; MDA, malondialdehyde; PDGF, platelet-derived growth factor; PP, portal pressure; SOD, sodium dismutase; TBS-T, TBS containing 1% (v/v) Tween 20; TEAC, trolox equivalent antioxidant capacity; VEGF, vascular endothelial growth factor

Background & Aims Cirrhosis is characterized by increased intrahepatic vascular resistance and enhanced vasocontractile responsiveness that impedes portal inflow and elevates portal pressure, in which endothelin-1 (ET-1) plays a role. Diabetes and glucose influence vasoresponsiveness but their impact on the intrahepatic vascular bed in cirrhosis is unknown. To investigate intrahepatic ET-1 vasoresponsiveness in cirrhotic rats with and without diabetes and to explore the underlying mechanisms. Methods Spraque-Dawley rats received common bile-duct ligation (BDL) to induce cirrhosis. Streptozotocin was injected to induce diabetes in the BDL rats (BDL/STZ). In situ liver perfusion was performed to obtain the ET-1 concentration-response curves. The basic hemodynamics and hepatic protein expressions of ET-1 receptors, pERK, ERK, pAkt, Akt, iNOS, eNOS, peNOS and calmodulin were evaluated. The circulating concentrations of N-terminal pro-brain natriuretic peptide (NT-ProBNP), blood urea nitrogen (BUN) and creatinine were also determined. Results Body weight, mean arterial pressure, heart rate and survival rate were significantly decreased in the BDL/STZ rats. The perfusion pressure changes in response to ET-1 were higher in the BDL/STZ group for all perfusates. ETA receptor and pERK expressions were enhanced in the BDL/STZ group. The circulating concentrations of NT-ProBNP, BUN and creatinine, as well as SMA flow, were not significantly different between the BDL and BDL/STZ groups. Conclusion Cirrhotic rats with diabetes showed higher intrahepatic ET-1 vasoresponsiveness than normoglycemic cirrhotic rats. This effect is not affected by changes in perfused glucose concentration and may be related, at least in part, to intrahepatic ETAR receptor and pERK over-expression.

Plasma glucagon concentrations were measured in 160 cirrhotic patients (Pugh's grade A in 52 patients, Pugh's grade B in 64 patients and Pugh's grade C in 44 patients). These values were compared with plasma glucagon concentrations in 57 age and sex-matched healthy subjects. Systemic and portal haemodynamic measurements, effective renal plasma flow and creatinine clearance were recorded for each patient. Plasma glucagon levels were significantly increased in cirrhotic patients compared with healthy subjects. In addition, plasma glucagon levels were higher in cirrhotic patients with ascites than in those without ascites and were increased in relation to the severity of cirrhosis as assessed by Pugh's score. Multiple linear regression found that only Child-Pugh's score was estimated to be an independent predictor of hyperglucagonaemia in cirrhotic patients. However, in patients with different degrees of oesophageal varices and in patients without oesophageal varices, plasma glucagon concentrations were no different among the different groups of patients, but were still higher than plasma glucagon concentrations in healthy subjects. In contrast, plasma glucagon levels were negatively correlated with mean arterial pressure and systemic vascular resistance. The results of the present study suggest that impairment of liver function plays, in part, a role in increased plasma glucagon levels observed in patients with cirrhosis. In addition, these data support the hypothesis that hyperglucagonaemia may contribute, at least in part, to the pathogenesis of peripheral arterial vasodilatation in cirrhosis with portal hypertension.

Metabolic bone disease has long been recognized in chronic liver disease, especially cholestatic or alcoholic liver diseases. The aim of the present study was to investigate the prevalence and severity of osteodystrophy in cirrhotic men and the correlation of its incidence with the clinical severity of cirrhosis in an endemic area of post-necrotic hepatitis. We measured serum levels of osteocalcin, 25-hydroxyvitamin D, parathyroid hormone mid-molecule, calcium and testosterone in 74 cirrhotic men (Child-Pugh's classification grade A n = 30, B n = 21 and C n = 23) and 16 healthy controls. Standard X-rays and bone mineral densities of lumbar spine were performed in 30 patients with post-necrotic cirrhosis and 10 healthy controls. Serum levels of osteocalcin, parathyroid hormone and testosterone were significantly lower in patients with cirrhosis than in controls. Changes paralleling an increased severity of cirrhosis were found in serum levels of 25-hydroxyvitamin D and testosterone, but not in the serum levels of osteocalcin and parathyroid hormone. The lumbar bone mineral density was significantly lower in patients with post-necrotic cirrhosis than in controls (0.97 +/- 0.13) vs 1.07 +/- 0.12 g/cm2, P < 0.05) and was correlated with serum 25-hydroxyvitamin D levels (r = 0.467; P < 0.005). There was no correlation between the bone mineral density and serum osteocalcin or the clinical severity of cirrhosis. The prevalence of spinal osteoporosis, as defined by a lumbar bone mineral density greater than two standard deviations below the mean value of the controls, was 20% in cirrhotic patients compared with 10% in controls. Two (6.7%) patients (both grade C) had spinal compression fractures compared with none in the control group. In conclusion, serum osteocalcin and lumbar bone mineral density were significantly lower in cirrhotic men than in controls. However, they were not correlated with each other or the clinical severity of cirrhosis.

epatocellular carcinoma (HCC) is one of the most common cancers H in Taiwan and in the world.',' The overall prognosis of HCC is very poor. Surgical resection is the only potentially curative treatment for HCC and is most effective for small turn or^.^-^ Unfortunately, many HCC patients have tumor recurrence after surgery and most patients are not eligible for surgery because of advanced stage at presentation. Other treatments, such as conventional radiotherapy"' or chemotherapy,*-'O are ineffective and the results unsatisfactory. Embolization for HCC may be palliative.'' Most of these treatments may have significant side effects. New, effective, and less toxic methods of treatment for patients with advanced HCC are urgently needed. HCC may be a hormone-dependent tumor and hormonal therapy has been recommended for further clinical investigations by several HCC may be an androgen-dependent tumor. Patients with aplastic anemia who developed HCC after long term therapy with androgenic steroids were first reported by Johnson et al." Thereafter, many androgeninduced HCCs were reported.16-" HCC was strongly associated with androgen in vitro and in vivo. Several rat hepatoma cell lines were reported to be androgen-dependent and contained cytoplastic androgen receptors IAR)." Androgen stimulates the growth of HCC cells implantated in rats when compared with controls.20 AR were positive in 74% of male and 33% of female HCC patients.''~22 Androgen may interact with AR of human HCC and enhance tumor growth and invasiveness. The recurrence rates

This study investigated the role of endotoxaemia in the development of hyperdynamic circulation observed in rats with extrahepatic (high collateralization) or intrahepatic (low collateralization) portal hypertension. Compared with sham-operated rats, decreased mean arterial pressure and systemic vascular resistance were detected on days 1, 4, and 14 following partial portal vein ligation. By day 1, the cardiac index of portal vein-ligated rats was similar to that of sham-operated rats and progressively increased, thereafter, reaching statistically higher values days 4 and 14. No differences in plasma endotoxin levels were found between portal vein-ligated and sham-operated rats throughout the observation period. Both carbon tetrachloride-induced cirrhotic rats with and without ascites had a higher cardiac index and lower systemic vascular resistance. Plasma endotoxin levels were higher in cirrhotic rats with ascites (8.6 +/- 2.0 pg/mL; P < 0.01) than those of control rats (2.2 +/- 0.3 pg/mL) and cirrhotic rats without ascites (2.4 +/- 0.6 pg/mL). These results suggest that factors other than endotoxaemia play a role in the development of hyperdynamic circulation observed in rats with extrahepatic portal hypertension and cirrhotic rats without ascites, but that endotoxaemia may contribute to the maintenance of hyperdynamic circulation found in cirrhotic rats with ascites. The severity of liver disease may be a more important factor than the presence of portosystemic shunting for the development of endotoxaemia in portal hypertensive states.

Background: Liver cirrhosis with portal hypertension is associated with hyperdynamic circulation characterized by generalized vasodilatation and increased cardiac output and regional blood flows. Patients with liver cirrhosis present with increased levels of interleukin-6 (IL-6), which may inhibit vascular smooth-muscle contraction. We investigated whether increased plasma IL-6 levels contribute to the pathogenesis of hyperdynamic circulation observed in cirrhotic patients and whether they are correlated with plasma tumor necrosis factor-α (TNF-α) and endotoxin concentrations. Methods: In 58 consecutive cirrhotic patients and 34 healthy subjects the plasma concentrations of TNF-α and IL-6 were measured with enzyme-linked immunosorbent assay, and endotoxin determinations with a limulus assay. In addition, 52 cirrhotic patients underwent a hemodynamic study using Swan-Ganz catheterization. Results: Plasma TNF-α, IL-6, and endotoxin levels were significantly higher in cirrhotic patients than in healthy subje...

Plasma endotoxin levels were investigated using a quantitative Limulus assay in patients with chronic liver diseases and correlated with the severity of liver diseases, the presence of esophageal varices, and hemodynamic parameters. The plasma endotoxin levels were significantly higher in chronic hepatitis patients with acute exacerbation (10.1 +/- 1.3 pg/ml, n = 13, p0.05) and patients with cirrhosis (7.0 +/- 0.7 pg/ml, n = 126, p0.05) than in healthy subjects (2.9 +/- 0.2 pg/ml, n = 45). Chronic hepatitis patients (n = 30) had plasma endotoxin levels which were similar to those in healthy subjects (4.6 +/- 0.5 vs. 2.9 +/- 0.2 pg/ml, p0.05) but lower than those in chronic hepatitis patients with acute exacerbation (4.6 +/- 0.5 vs. 10.1 +/- 1.3 pg/ml, p0.05). Endotoxemia (plasma endotoxin level5.7 pg/ml) was found in 27%, 85% and 41% of patients with chronic hepatitis, chronic hepatitis with acute exacerbation, and cirrhosis, respectively. In patients with cirrhosis, the plasma endotoxin levels progressively increased in relation to the severity of liver dysfunction (Pugh's class A/B/C = 4.9 +/- 0.5/7.9 +/- 1.4/10.2 +/- 2.0 pg/ml, p0.05). In contrast, plasma endotoxin levels were comparable between patients with cirrhosis with and without esophageal varices (p0.05). Chronic hepatitis patients with acute exacerbation (no collaterization) had much higher plasma endotoxin levels than those in patients with cirrhosis and large varices (p0.05), whereas compensated patients with cirrhosis and large esophageal varices had plasma endotoxin levels similar to those seen in chronic hepatitis patients (no collaterization) (p0.05).(ABSTRACT TRUNCATED AT 250 WORDS)