Enhanced expressions of apelin on proliferative hepatic arterial capillaries in human cirrhotic liver

Aim: Apelin (APLN), the endogenous ligand of angiotensin-like receptor 1 (APJ), is a peptide necessary for embryonic and tumor angiogenesis. Little is known about the localization and changes of APLN expression including the sinusoids in human cirrhotic liver, which might contribute to portal hypertension. This study was designed to elucidate the localization and change of APLN expression in human liver during the progression of cirrhosis. Methods: Twelve normal liver specimens, eight specimens of Child–Pugh grade A cirrhosis, and 10 specimens of Child–Pugh grade C cirrhosis were studied. APLN protein and gene expression was examined by immunohistochemistry, western blotting, immunoelectronic microscopy, and laser captured microdissection (LCM) followed by polymerase chain reaction (PCR) in sinusoid. Results: In control liver tissue, APLN was localized mainly on arterial endothelial cells and hepatic arterioles in the portal tract. In cirrhotic liver tissue, aberrant APLN expression was observed in periportal capillary endothelial cells corresponding to capillarized sinusoids, and in proliferated arterial capillaries in the fibrotic septa. Significant overexpression of APLN at protein level in cirrhotic liver was demonstrated by western blotting (P < 0.01 Child–Pugh A and C versus control, P < 0.01 Child–Pugh A versus C). APLN mRNA expression in the sinusoid was confirmed by LCM-PCR. Conclusion: In humans, APLN protein and gene were overexpressed in cirrhotic liver compared with normal liver, and the magnitude increased as cirrhosis progressed. Especially in end-stage cirrhosis, APLN was strongly expressed in proliferated arterial capillaries directly connected with the sinusoids, suggesting a role of APLN in the proliferation of arterial capillaries in cirrhosis.     

Endothelin-induced vasoconstriction in isolated perfused liver preparations from normal and cirrhotic rats

Isolated, perfused rat liver preparations (IPRL), obtained from rats with carbon tetrachlorideinduced cirrhosis and normal controls, were used to investigate responses to the vasoactive peptide endothelin-1 (ET-1). The mean perfusion resistance (R) of cirrhotic IPRL was significantly greater than that of controls (2.63 ± 0.24 vs 1.54 ± 0.14 mmHg/mL per min per g; P < 0.01). Both control and cirrhotic IPRL demonstrated a concentration-related increase in resistance (ΔR) in response to ET-1, with a minimum effective concentration of approximately 3 × 10⁻¹¹ mol/L. The EC₅₀ (-log of the 50% effective concentration) was not significantly different between cirrhotic and control IPRL (8.48 ± 0.19 and 8.79 ± 0.11, respectively); however, the maximum response to ET-1 was significantly greater in cirrhotic preparations (R: 10.4 ± 2.2 vs 4.4 ± 0.5 mmHg/mL per min per g, P < 0.01; DR, 7.8 ± 2.1 vs 2.8 ± 0.4 mmHg/mL per min per g, P < 0.01). Following maximal stimulation by ET-1, the mean portal-hepatic venous pressure gradient at a physiological flow rate of 1 mL/min per g was approximately 90% greater across cirrhotic IPRL than that across normal IPRL (11.2 ± 2.0 vs 5.9 ± 0.9 mmHg, respectively; P < 0.05). These results support the hypothesis that endogenously released ET-1 has a significant influence on the portal vascular resistance of cirrhotic liver in vivo and has an important role in the pathogenesis of portal hypertension.     

Effect of interferon gamma on intrahepatic haemodynamics of the cirrhotic rat liver

Sublethal injury of the liver with carbon tetrachloride (CCI₄) induces the modulation of hepatic stellate cells to their myofibroblast (MFB) phenotype. Pretreatment or concomitant treatment with interferon gamma (IFNγ) has been shown to inhibit this phenomenon. The aim of this study was to investigate the influence of IFNγ treatment (50 000 IU s.c. each day for 5 days) in rats with an established cirrhosis. Cirrhosis was induced with nine doses of CCI⁴. Comparison of biopsies before and after treatment with IFNγ showed that the number of MFB present, identified by their α-smooth muscle actin immunoreactivity, was markedly reduced. Pressure-flow curves were constructed in isolated perfused liver preparations from IFNγ-treated and saline-treated cirrhotic rats and analysed to obtain the extrapolated zero-flow intercept (P⁰, an index of hepatic vascular distensibility) and the vasodilator-induced change in resistance at a flow rate of 1 mL/min per g (ΔR₁ an indication of the level of intrinsic vascular tone). In IFNγ-treated rats, portal venous pressure measured in vivo was significantly reduced compared with controls (11.9±1.2 vs 16.0 ± 0.5 mmHg, P < 0.05), P₀ was lower (2.03 ± 0.18 vs 2.87 ± 0.32 mmHg, P < 0.05) and ΔR₁ was decreased (0.39 ± 0.15 vs 1.02 ± 0.19 mmHg/mL per min per g, P < 0.05). The findings indicate that treatment with IFNγ is effective in reducing MFB density in established CCI₄-cirrhosis in the rat and results in a marked improvement in intrahepatic haemodynamics.     

A distinct nitric oxide and adenosine A1 receptor dependent hepatic artery vasodilatatory response in the CCl4‐cirrhotic liver

Increase of portal venous vascular resistance is counteracted by decrease of hepatic arterial vascular resistance (hepatic arterial buffer response). This process is mediated by adenosine in normal livers. In cirrhosis, hepatic arterial vascular resistance is decreased but the involvement of adenosine in this process is unknown. The aim of our study was to identify the signalling pathway responsible for the decreased hepatic arterial resistance in cirrhotic livers. Methods: Cirrhosis was induced by CCl₄. Using a bivascular liver perfusion dose–response curves to adenosine of the HA were performed in the presence and the absence of pan‐adenosine blocker (8‐SPT), A1 blocker (caffeine) or nitric oxide synthase‐blocker (l ‐NMMA) after preconstriction with an α1‐agonist (methoxamine). Western blot of the HA were used to measure the density of the A1 and A2a receptors. Results: Adenosine caused a dose dependent relaxation of the hepatic artery of both cirrhotic and control animals that were blocked in both groups by 8‐SPT (P<0.02). The response to adenosine was greater in cirrhotic rats (P=0.016). Both l ‐NMMA (P=0.003) and caffeine reduced the response to adenosine in cirrhotic but not in control animals. Western blot analysis showed a higher density of A1 and a lower density of A2a receptor in cirrhotic animals (P<0.05). Conclusion: The adenosine‐induced vasodilatation of the HA is increased in cirrhotic rats suggesting a role for adenosine‐NO in the decreased hepatic arterial vascular resistance found in cirrhosis. This significantly greater response in cirrhosis by the A1 receptor follows the same pathway that is seen in hypoxic conditions in extra‐hepatic tissues.     

卡维地洛与普萘洛尔降低肝硬化门静脉高压患者肝静脉压力梯度效果的对比分析

目的探讨卡维地洛和普萘洛尔降低肝硬化门静脉高压患者肝静脉压力梯度(HVPG)的幅度、应答率以及用药后不良反应的差异,对卡维地洛降低门静脉压力的有效性和安全性进行评价。方法收集2010年10月-2012年1月在山东大学附属省立医院确诊的64名肝硬化门静脉高压患者,随机分为2组:普萘洛尔组(n=33)和卡维地洛组(n=31),根据血压和心率调整剂量,疗程7 d,均于治疗前后行HVPG测定及肝肾功能指标检测,比较2组患者HVPG降低的幅度及应答率,并观察患者低血压、腹水、肾损伤等不良反应的发生情况。计量资料组间比较采用t检验,计数资料组间比较采用χ2检验或Fisher精确概率法。结果卡维地洛组和普萘洛尔组的HVPG均明显降低,降低幅度分别为(28.30±22.19)%和(12.38±24.09)%,其中卡维地洛组降低更明显,差异有统计学意义(t=0.223 4,P=0.032)。2组应答率分别为:卡维地洛组56.7%(17/30),普萘洛尔组41.9%(13/31),2组差异无统计学意义(χ2=1.324,P=0.250)。卡维地洛组平均动脉压的降低较普萘洛尔组明显,差异有统计学意义(t=2.338,P=0.024),但患者未出现明显低血压的不良反应;2组患者胆红素、血肌酐和尿素氮在治疗前后无明显升高,亦无腹水生成或加重的趋势。结论本研究提示在短期内卡维地洛降低HVPG的作用较普萘洛尔显著,且无明显不良反应;其用于肝硬化门静脉高压的治疗是安全有效的。     

肝星状细胞活化在大鼠肝硬化门脉高压形成中的作用

[目的]探讨肝星状细胞(HSC)活化在大鼠肝硬化门脉高压形成中的作用.[方法]采用二甲基亚硝胺(DMN)4周12次腹腔注射制作大鼠肝硬化模型,分别于造模后1 d、2 d、3 d、1周、2周、4周、6周、8周作为动态观察时相点,免疫组化染色观察肝组织α-平滑肌肌动蛋白(α-SMA)、Ⅳ型胶原(ColⅣ)、层黏连蛋白(LN)表达,电镜观察肝组织超微结构,肠系膜前静脉分支插管法测门脉压力(Ppv).[结果]造模2、3 d后肝窦壁α-SMA染色逐渐增强,4周时阳性表达最为明显;模型大鼠肝窦壁ColⅣ阳性染色呈现先弱后强,LN的沉积随造模时间的延长而进行性增加,4周时表达最为明显,电镜下可见肝窦内皮失窗孔和基底膜形成;DMN大鼠HSC中α-SMA表达量与Ppv高低呈显著正相关(P＜0.05).[结论]活化的HSC通过分泌大量的ColⅣ和LN形成肝窦内皮下基底膜以及因表达α-SMA而收缩力增强,是肝硬化肝窦阻力增加和门脉高压形成的重要病理细胞学基础.     

Clinical impact of right accessory hepatic artery injury in deceased donor livers

Background

Right accessory hepatic artery (RAHA) injury at retrieval is a rare complication of deceased liver procurement. Arterial reconstruction is often required under these circumstances which could potentially increase the risk of hepatic artery thrombosis (HAT). The aim of this study is to investigate whether RAHA injury affects the incidence of HAT, early biliary complications, or 3-month graft and patient survival rates.

Methods

All adult liver transplants performed between 1994 and February 2007 at Addenbrooke’s Hospital, Cambridge, UK were considered for inclusion in the study. Grafts were divided into three groups depending on the presence of RAHA and injury (Group 1: normal anatomy and single hepatic artery anastomosis; Group 2: RAHA requiring reconstruction; Group 3: RAHA injury requiring reconstruction).

Results

Eight hundred and forty-four liver transplants were included in the study (Group 1: 654 grafts; Group 2: 63 grafts; Group 3: 14 grafts). The incidence of HAT (Group 1, 2.9%; Group 2, 6.4%; Group 3, 14.3%) was significantly different between the three groups (P?=?0.01); biliary complications at 3?months (Group 1, 7.1%; Group 2, 11.1%; Group 3, 7.1%) were not significantly different. Graft and patient survival at 3?months were significantly worse in Group 3 when compared with Group 2 (61.5 vs. 88.3%, P?=?0.01; 81.8 vs. 98.2%, P?=?0.02).

Conclusion

This is the first study analysing the clinical impact of RAHA injury during liver procurement. We conclude that the use of liver grafts with RAHA injury does result in a higher HAT rate and is also associated with lower graft and patient survival rates at 3?months.     

肝硬化患者结肠镜下表现及其相关因素分析

目的探讨肝硬化患者结肠镜下表现,及这些病变与肝功能Child-Pugh分级、食管静脉曲张程度、肝纤维化指标（APRI指数）等相关因素的关系。方法回顾性分析本院2009年1月至2012年5月收治的172例肝硬化住院患者临床资料,23例患者行结肠镜检查,同时分析肠镜表现与肝功能,食管静脉曲张程度以及APRI指数的关系。结果 172例患者中共23例患者行结肠镜检查,最常见病变为门静脉高压性结肠病（PHC）（9/23,39.1%）,完全正常比例仅有8.7%（2/23）。PHC的发生与患者中重度食管静脉曲张有相关趋势（P=0.086）,与患者严重肝纤维化（APRI指数大于1.08）和肝功能Child-Pugh评分无关。结论多达91.3%的肝硬化患者结肠镜表现异常,39.1%患者表现为PHC,需要对肝硬化患者进行结肠镜检查。     

Relationship between hepatic blood flow,liver tests,haemodynamic values and clinical characteristics in patients with chronic liver disease*

Although hepatic blood flow (HBF) has been measured in patients with liver disease for many years, the results of these studies have not provided clear information concerning the usefulness of this measurement. Hepatic blood flow was measured in 392 patients with either cirrhosis (n= 356) or hepatic fibrosis (n= 36). The control group included 59 subjects with normal liver architecture. Hepatic clearance of indocyanine green (ICG) was markedly reduced in patients with cirrhosis and hepatic fibrosis compared with controls (182±5, 276±22 and 421±25 mL/min, respectively). In patients with cirrhosis, ICG clearance and extraction were significantly correlated, but were not correlated to HBF. Although HBF did not differ between patients with cirrhosis and controls (1.26±0.04 vs 1.35±0.07 L/min, respectively), patients with hepatic fibrosis had lower HBF (1.04±0.07 L/min; P< 0.05). In patients with cirrhosis, no correlation was observed between HBF and cardiac output, mean arterial pressure, azygos blood flow, the hepatic venous pressure gradient or Pugh's score. However, a significant difference in HBF was observed in patients with and without hepatic encephalopathy (1.00±0.09 vs 1.28±0.03 L/min, respectively; P<0.05). In conclusion, the present study shows that, in patients with cirrhosis, HBF is normal and is not related to other haemodynamic values or liver tests. These results discourage the measurement of HBF in the evaluation of patients with cirrhosis.     

部分脾动脉栓塞术对肝硬化门静脉高压症血流动力学的影响

目的探讨部分脾动脉栓塞术（PSE）治疗肝硬化门静脉高压症的临床疗效及应用价值。方法 23例不同原因肝硬化门静脉高压患者行PSE治疗,PSE术前及术后1周、1、3、6个月彩色多普勒分别检测患者门静脉和脾静脉的内径、血流速度,计算血流量,并与PSE术前配对分析。结果术后各期患者脾静脉、门静脉血流速度及血流量较术前降低（P〈0.05）;脾静脉内径术后各期与术前相比明显缩小（P〈0.05）;而门静脉主干内径术后6个月内缩小不明显（P〉0.05）。结论 PSE能有效的降低门静脉压力。     

Effect of early bosentan administration on the development of esophageal varices in cirrhotic rats: experimental study in Wistar rats

Background  This study was conducted to investigate the effect of chronic bosentan administration on the development of esophageal varices in carbon tetrachloride-induced cirrhosis in rats. Methods  For the development of liver cirrhosis and esophageal varices, 60 rats underwent ligation of the left adrenal vein, followed by phenobarbital and carbon tetrachloride administration. Two weeks after the beginning of carbon tetrachloride administration, rats were separated into two groups. In group I, comprising 30 rats, bosentan was continuously administered throughout the study, whereas in group II, also 30 rats, placebo instead of bosentan was continuously administered. Hemodynamic studies and morphometric analysis of the lower esophagus were performed after complete induction of cirrhosis. The total number of veins counted in the submucosa, the number of submucosal veins/mm² of submucosa, the total submucosal area occupied by vessels, the mean cross-sectional vessel area, the relative submucosal area (percentage) occupied by vessels, and the area of the single most-dilated submucosal vein were studied. Results  Bosentan induced a significant (P < 0.05) decrease in portal pressure, while morphometric analysis revealed a significant reduction (P < 0.05) of all parameters studied in bosentan-treated rats, except in the total and relative number of submucosal veins. Conclusions  Bosentan administration seemed to significantly attenuate dilation of submucosal veins in the lower esophagus of cirrhotic rats. This effect was mainly attributed to a decrease in the portal pressure induced by chronic bosentan administration.     

Comparison of Doppler ultrasonography and the hepatic venous pressure gradient in assessing portal hypertension in liver cirrhosis

BACKGROUND AND AIM: This prospective study aimed to determine whether Doppler ultrasonography can represent the hepatic venous pressure gradient (HVPG) as an assessment of the severity of portal hypertension and the response to terlipressin, which reduces the portal pressure in liver cirrhosis. METHODS: The HVPG and the Doppler ultrasonographic parameters, such as the portal venous velocity and the splenic venous velocity, the pulsatility and the resistive index of the hepatic, splenic and renal arteries were measured in 138 patients with liver cirrhosis. The changes in the HVPG and the portal venous velocity after administering terlipressin were evaluated in 43 of the 138 patients. The patients who showed a reduction in the HVPG of more than 20% of the baseline were defined as responders to terlipressin. RESULTS: None of the Doppler ultrasonographic parameters correlated with the HVPG. Both the HVPG (28.0 +/- 19.8%) and the portal venous velocity (29.7 +/- 13.2%) showed a significant reduction after terlipressin administration. However, the portal venous velocity decreased significantly, not only in the responders (31.0 +/- 12.0%) but also in the non-responders (25.2 +/- 16.4%). CONCLUSIONS: Doppler ultrasonography does not represent the HVPG, and is therefore not suitable for replacing HVPG as a means of assessing the severity of portal hypertension and the response to drugs which reduce the portal pressure in liver cirrhosis.