潘生丁与阿霉素对兔肝缺血再灌注损伤保护作用的对照研究

为探讨潘生丁对兔肝缺血再灌注损伤保护作用及作用机制。笔者将30只体重2.2～3.0kg的健康新西兰长耳大白兔随机分成3组：对照组(A组)，阿霉素预处理组（B组），潘生丁预处理组（C组），每组10只。实验前3d起B组从耳缘静脉注入阿霉素1mg/kg， 2次/d;C组从耳缘静脉注入潘生丁0.2mg/kg，2次/d;A组从耳缘静脉注入等量的生理盐水。采用Pringle,s方法建立肝脏缺血再灌注模型，留取肝脏标本和下腔静脉血比较3组大白兔肝门阻断前(T1), 肝门阻断30min后(T2)，再灌注2h后（T3）的血小板聚集率(PAGT)、肝功能(AST和ALT) 、肝组织的抗氧化能力（SOD）、脂质过氧化产物丙二醛（MDA）含量、肝指数（湿重/干重％）、组织形态学变化。结果示，在不同时相，与A，B组比较，C组的血小板聚集率下降(P< 0.05);与A组比较，B，C组的肝组织水肿程度较轻(P< 0.05)、肝组织出现较轻的病理学改变，肝功能损害轻、肝组织匀浆超氧化物歧化酶含量高和丙二醛含量减少(P< 0.05); 与B组比较，C组的血小板聚集率下降(P< 0.05) 、肝组织水肿程度较轻(P< 0.05)，A，B两组各项指标之间无显著差异（P>0.05）。提示潘生丁对兔肝缺血再灌注损伤有保护作用，且其作用比阿霉素预处理对肝缺血再灌注损伤的保护作用强。     

Contribution of serotonin to liver injury following canine small-intestinal ischemia and reperfusion.

Intestinal ischemia and reperfusion (I/R) has been shown to be associated with multiple organ damages. Serotonin (5-hydroxytriptamine; 5-HT), which is synthesized in the enterochromaffin cells in the intestine and stored in platelets, is known to play an important role in platelet aggregation and vasoconstriction and may ultimately enhance such organ injuries. The purpose of this study was to investigate the association between liver damage and 5-HT levels in the liver after intestinal I/R. The entire canine small intestine, isolated on a vascular pedicle that consisted of the proximal superior mesenteric artery and superior mesenteric vein, was subjected to 4-h ischemia by clamping these vessels and the marginal arteries supplying the proximal and distal ends of the small intestine. Hepatic blood flow, liver tissue blood flow, bile flow rate, and hepatic venous ketone body ratio (HVKBR) were measured before and at the end of intestinal ischemia and at 5, 15, and 30 min, and 1 and 2 h after reperfusion. 5-HT levels in plasma of the portal vein and hepatic vein were assayed at the same intervals. Time-matched, sham-operated animals served as controls. Intestinal I/R significantly decreased the liver tissue flow, bile flow rate, and HVKBR. Compared to those in controls, 5-HT levels in the portal vein and hepatic vein were markedly increased after reperfusion. Furthermore, intravenous administration of 5-HT receptor antagonists attenuated the liver dysfunction after intestinal reperfusion. These results suggest that intestinal I/R induces continuous disturbance of hepatic microcirculation, leading to liver dysfunction, and that 5-HT may be implicated as one of the mediators of liver dysfunction after intestinal I/R.     

缺血预处理对肺缺血再灌注损伤的影响

目的观察缺血预处理（ＩＰＣ）对肺缺血再灌注（Ｉ／Ｒ）损伤的影响。方法建立兔单肺原位热缺血再灌注损伤模型。３０只兔分Ｉ／Ｒ组、ＩＰＣ组和对照组。对比观察各组平均动脉压、动脉血氧分压、肺组织１２５Ｉ标记牛血清白蛋白漏出量、肺湿干重比、髓过氧化物酶活性。结果经９０分钟缺血１８０分钟再灌注后,ＩＰＣ组肺组织１２５Ｉ标记牛血清白蛋白漏出量、肺湿干重比、髓过氧化物酶活性低于Ｉ／Ｒ组（Ｐ＜０．０５）,平均动脉压、动脉血氧分压高于Ｉ／Ｒ组（Ｐ＜０．０５）。结论ＩＰＣ能减轻肺Ｉ／Ｒ导致的肺毛细血管通透性增高、中性粒细胞浸润,减轻肺Ｉ／Ｒ引起的平均动脉压和动脉血氧分压的下降程度,表明ＩＰＣ能减轻肺Ｉ／Ｒ损伤。     

Warm ischemia and reperfusion injury in diet-induced canine fatty livers

BACKGROUND: Fatty liver is associated with primary nonfunction after liver transplantation, contributing a shortage of suitable liver grafts. Because extensive investigation of mechanisms underlying such nonfunction has been limited largely to rodents, we made a new fatty liver model in dogs and studied primary nonfunction after warm ischemia. METHODS: We developed a diet rich in fat but deficient in choline to induce fatty change in canine liver and investigated effects of 60 min of warm ischemia and reperfusion in dogs with such fatty livers. RESULTS: Microscopically evident steatosis increased with duration of dietary manipulation (up to 12 weeks), as did hepatic total lipid and triglyceride levels. No dog with >30% of steatotic hepatocytes, >445 mg/g hepatic total lipid or >145 mg/g hepatic triglyceride survived after 60 min of warm ischemia. Arterial ketone body ratios decreased and blood endotoxin increased after reperfusion in nonsurvivors. The main histologic finding in livers of nonsurvivors was marked sinusoidal congestion. CONCLUSIONS: Damage to hepatocytes and nonparenchymal cells after warm ischemia and reperfusion was thought to be closely related to sinusoidal microcirculatory disturbances in fatty livers. The canine fatty liver model reported here may be useful in studying the pathology of primary nonfunction and in establishing criteria for allowable degrees of fatty change in potential liver grafts.     

大鼠部分肝缺血再灌注损伤后切除对肝再生的影响

目的 观察大鼠部分肝缺血再灌注损伤后切除对残肝再生的影响.方法 将75只健康雄性SD大鼠随机分为5组:肝脏左叶和中叶(约占全肝70%)切除组(Control组)、肝脏左叶和中叶缺血10min再灌注30min后切除组(I10R30组)、类推得到I60R30组、I90R30组、I90R60组.术后6、12、24h等时间点,测定再生肝重量(RLW);自动生化分析仪检测血清丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)含量;酶联免疫吸附试验(ELISA)检测血清肿瘤坏死因子(TNF)-α含量;通过免疫组织化学法检测残肝增殖细胞核抗原(Ki-67)表达.结果 术后12h,I60R30、I90R30和I90R60组RLW值分别为(1.80±0.03)%、(1.82±0.10)%、(1.87±0.05)%;Ki-67值分别为(58.35±2.18)%、(59.73±3.06)%、(62.65±2.24)%,均明显高于对照组(P<0.05).缺血再灌注干预各组ALT和AST明显高于对照组(P<0.05).术后6h和12h,I60R30、I90R30和I90R60组TNF-α明显高于对照组(P<0.05).结论 大鼠即将被切除的肝脏先缺血再灌注后切除,对残肝再生具有促进作用;诱导产生的TNF-α表达量增多是促进肝再生的原因之一.

Abstract：

Objective To investigate the effects of ischemia reperfusion injury before partial hepatectomy on liver regeneration in rats. Methods Seventy-five male healthy SD rats were randomly classified into 5 groups: group control, in which rats were only subjected to 70% hepatectomy; group I10R30, 70% liver hepatectomy after 10 min of ischemia and 30 min of reperfusion in the resected liver; By analogy, group I60R30, group I90R30 and group I90R60 were constructed. At 6th, 12th and 24th h after operation, RLW was determined; serum alanine aminotransferase (ALT) and aspartate transaminase (AST) activities were measured by using autoanalyzer; the levels of serum tumor necrosis factor (TNF)-α were determined by ELISA and the expression level of Ki-67 was detected by using immunohistochemical methods in the residual liver tissues. Results At 12th h after partial hepatectomy, the rate of RLW in group I60R30, group I90R30 and group I90R60 was (1.80±0.03)%, (1.82±0.10)%, (1.87±0.05)% respectively; the rate of Ki-67 was (58.35±2.18)%, (59.73±3.06)%, (62.65±2.24)% respectively, which was significantly higher than that in the group control (P<0.05). The levels of ALT and AST in rats with ischemia reperfusion injury were higher than in the group control (P<0.05). At 6th h and 12th h after operation, the expression levels of TNF-α in groups I60R30, I90R30 and I90R60 were significantly higher than those in the group control (P<0.05). Conclusion Ischemia reperfusion injury in the resected liver before partial hepatectomy could improve liver regeneration of the remnant liver in rats. The high expression of induced TNF-α may be one of the reasons.     

肝脏热缺血再灌注损伤对胆道系统的影响

肝移植已经成为治疗终末期肝病的重要手段而广泛应用于临床,但是胆道并发症尤其是缺血型胆道病变已成为影响患者长期生存和生活质量的重要因素.本文就近年来肝脏缺血再灌注引发胆道系统损伤的发生机制及其研究进展作一综述.     

乌司他丁对失血性休克大鼠肝脏缺血再灌注损伤保护作用的研究

目的：探讨乌司他丁对失血性休克大鼠肝脏缺血再灌注损伤的保护作用及机制。方法：24只雄性Wista大鼠随机分为假手术组、生理盐水治疗组、乌司他丁治疗组,每组8只。建立大鼠失血性休克模型。乌司他丁治疗组,予以乌司他丁25000U·kg-1加入2mL生理盐水静脉推注,并完成液体复苏;生理盐水治疗组予以2mL生理盐水静脉推注,并完成复苏;假手术组,除不放血和输液外,其他处理与模型相同。观察3h后处死大鼠,取血液离心分离血浆检测肝功能指标、血清肿瘤坏死因子（TNF-α）;取肝右叶2块肝组织,1块用于肝组织病理改变和肝细胞凋亡观察;1块用于肝组织匀浆,离心取上清液进行肝组织MDA、SOD、髓过氧化物酶（MPO）检测。结果：失血性休克大鼠肝脏再灌注3h后,生理盐水治疗组肝组织发生了严重缺血再灌注损伤,肝细胞水样变,肝窦淤血变窄,间质大量炎性细胞浸润,而乌司他丁治疗组仅有轻度再灌注损伤。乌司他丁治疗组肝细胞凋亡、肝功能指标ALT、AST、血清TNF-α水平、肝组织MDA含量、MPO活性较生理盐水治疗组均有不同程度的减少（P〈0.05）,SOD活性较生理盐水治疗组升高（P〈0.05）。结论：乌司他丁对大鼠失血性休克再灌注后肝脏损伤具有保护作用,其机制可能与抑制中性粒细胞浸润、抑制氧自由基的形成、抗肝细胞凋亡相关。     

血管紧张素转换酶在大鼠原位肝移植缺血再灌注损伤中的作用

目的 通过研究血管紧张素转换酶(ACE)在大鼠原住肝移植(OLT)中的表达情况及其与OLT后缺血再灌注损伤(IRI)的相关性,初步探讨肾素-血管紧张素系统在肝移植缺血再灌注损伤中的可能作用.方法 将OLT大鼠分为无冷保存组(NCP)及冷保存组(CP),假手术组作对照,组织学检查及血ALT检测观察缺血再灌注损伤程度,Real-time PCR,Western blot和免疫组化分别检测ACE的mRNA,蛋白表达及其组织定位,以上指标同时在术后多个时间点作动态观察.结果 OLT后,肝组织ACE在mRNA及蛋白水平均显著高于对照组(P<0.05,P<0.01),且CP组明显高于NCP组(P<0.05);CP组血清ALT水平显著高于NCP组,组织损伤更明显;动态观察显示ACE水平与血清ALT水平及组织损伤程度有很好的相关性.结论 ACE与冷保存导致的OLT后IRI的炎症损伤密切相关,肾素-血管紧张素系统可能在OLT后的IRI中有重要作用.     

Role of cyclic nucleotides in ischemia and reperfusion injury of canine livers

BACKGROUND: In a series of canine liver ischemia experiments, we have shown that amelioration of hepatic injury is achievable by the inhibition of vasoconstriction, cytokine production, platelet aggregation, and neutrophil infiltration. Cyclic adenosine diphosphate (cAMP) was considered to be involved in most of these events. In our study, we tested our hypothesis that augmentation of endogenous cAMP by phosphodiesterase (PDE) 3 inhibitor, amrinone (AM), or adenylate cyclase stimulator, NKH477 (NKH), could attenuate ischemia and reperfusion injury of the liver. METHODS: Thirty-six beagle dogs were used. They were divided into group CT (untreated control), group AM, group NKH, and group CB (treated by both agents). AM or NKH were administered i.v. 1 hr before ischemia (group preAM and group preNKH) or 15 min before reperfusion (pos-AM and postNKH). Combination group animals were treated only before ischemia. Animal survival, hepatic tissue blood flow, liver enzymes, platelet counts, energy metabolism, hepatic cAMP and cyclic guanosine 3',5'-cyclic monophosphate levels, and histopathology were analyzed. RESULTS: Two-week animal survival was significantly improved by pre- or posttreatment with either agent. After reperfusion, hepatic tissue blood flow, liver enzyme release, platelet counts, energy metabolism, tissue cAMP levels, and histological architecture were also ameliorated markedly. Combination of both agents induced severe liver damage and lethal hypotension. AM treatment exhibited more protective effects than NKH, particularly when it was given before ischemia. Interestingly, not only cyclic guanosine 3',5'-cyclic monophosphate, were also restored at higher levels after reperfusion by preischemia treatment. CONCLUSIONS: Administration of amrinone or NKH477 maintained hepatic tissue concentrations of cyclic nucleotides, and attenuated ischemia and reperfusion injury of the liver. Thus, regulation of hepatic tissue cyclic nucleotides is an important alternative for prevention of hepatic damage in liver preservation and surgery.     

灯盏花素预处理供肝减轻大鼠肝移植后早期缺血再灌注损伤

目的 研究应用灯盏花素对供肝进行预处理,减轻大鼠肝移植术后早期缺血再灌注损伤的作用.方法 以SD大鼠作为肝移植供、受者,采用随机数字表法将受鼠分为4组.A组和C组供肝未经灯盏花素预处理,B组和D组供肝经含20 mg/L灯盏花素的UW液预处理;A组和B组供肝冷缺血时间为30～40 min,C组和D组为12 h.术后检测各组受鼠的凝血功能、肝功能、血清血栓调节蛋白(TM)含量、凋亡蛋白酶-3 (Caspase-3)活性及核因子-kB(NF-kB)相对表达量,观察各组移植肝组织病理学变化和肝细胞凋亡情况.结果 术后3d,C组与D组受鼠死亡率分别为40.0％(8/20)和29.4％(5/17),差异无统计学意义(P＞0.05);术后4组间凝血功能无明显变化(P＞0.05).与C组比较,术后早期D组肝功能、肝组织病理学改变及肝细胞凋亡均明显改善(P＜0.01),血清TM含量、Caspase-3活性及NF-kB表达量均明显降低(P＜0.01).术后A组和B组的缺血再灌注损伤明显较轻,两组间上述指标的差异均无统计学意义(P＞0.05).结论 应用灯盏花素对供肝进行预处理,能够减轻大鼠肝移植术后由冷保存时间较长引起的缺血再灌注损伤,其机制可能与抑制凋亡相关的信号通路和减轻肝脏微循环内皮细胞损伤有关.     

氟比洛芬酯对肝叶切除术后缺血再灌注损伤患者的影响

目的:探讨分析氟比洛芬酯对肝叶切除患者肝缺血再灌注损伤的保护机制。方法:将60例肝癌患者随机分为对照组和氟比洛芬酯组,在手术开始前10 min,氟比洛芬酯组静脉注射氟比洛芬酯,对照组注射相同容量的0.9%氯化钠溶液。对比两组患者麻醉诱导前10 min(T_0)、肝门阻断前(T_1)、肝脏再灌注1 h(T_2)、6 h(T_3)以及术后第1、3、5天(T__4、T_5、T_6)的天门冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)、总胆红素(TBIL)、血清肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)、白细胞介素8(IL-8)、丙二醛(MDA)、超氧化物歧化酶(SOD)浓度。结果:与T_0比较,两组T_(2-6)AST、ALT、TBIL(TBIL除外T_3)、TNF-α、IL-6、IL-8水平均有所增高(P0.05);术后第1、3、5天AST、ALT、TNF-α、IL-6、IL-8水平氟比洛芬酯组明显低于对照组(P0.05);与T_0比较,氟比洛芬酯组MDA逐渐降低,SOD逐渐增高,对照组则呈相反变化,两组MDA、SOD浓度在T_2-6与T_0比较,差异具有统计学意义(P0.05);氟比洛芬酯组MDA在T_(4-6)明显低于对照组(P0.05),SOD浓度也明显高于对照组(P0.05)。结论:氟比洛芬酯对肝叶切除患者肝缺血再灌注损伤具有保护作用,可减轻围术期炎症反应和提高患者免疫力。     

肝脏缺血再灌注损伤分子机制的研究进展

缺血再灌注损伤(IRI)是肝移植术中不可避免的病理生理变化,是引起肝损伤的一个重要原因,可能导致肝功能衰竭,影响肝移植受者术后的近、远期疗效。参与肝脏缺血再灌注的分子进程复杂多样,所涉及的机制在很大程度上尚未阐明,并不断有新的复杂机制更新。本综述旨在总结一些重要的分子机制在肝脏IRI中的研究进展,同时概述减轻IRI的新兴策略,为临床提高肝移植疗效及移植肝生存率,提供理论和科学依据。     

移植肝再灌注损伤的发生机制

目的：介绍有关移植肝再灌注损伤发生机制的研究动向,方法：复习有关文献并进行综述性报告。结果：移植肝冷保存后的再灌注损伤的发生机制主要有：（1）内皮细胞损伤和Kupffer细胞激活,导致一系列细胞因子的产生,引起移植肝损伤,并引发全身炎症反应综合征。（2）白细胞,血小板与肝血窦壁的粘附而损害肝细胞,并可阻塞肝血窦造成“无复流”现象;（3）pH值的变化,再灌注后移植肝的代谢恢复正常后,组织内pH值的改变可引起肝细胞损伤,并可造成线粒体的肿胀,使肝细胞的功能降低,（4）复氧损伤,主要与白细胞释放活性氧（ROS）有关,结论：移植肝再灌注损伤是多种因素综合作用的结果,在再灌注前后提高肝细胞和内皮细胞的活性,抑制Kupffer细胞的激活,减少ROS及肿瘤坏死因子（TNF）的产生将是今后预防移植肝再灌注损伤研究的关键。     

肝脏缺血再灌注损伤的研究进展

肝脏缺血再灌注损伤是肝脏外科常见的病理生理过程,是集肝窦血管内皮损伤、氧化应激、炎症反应、细胞凋亡与自噬等多种机制共同作用的结果,对于肝切除、肝移植等肝脏外科手术后肝功能恢复和围手术期安全具有显著影响.然而,迄今为止,其具体的损伤机制尚未完全阐明,在临床上也始终缺乏有效的干预手段.因此,对于肝脏缺血再灌注损伤发病机制以及防御举措的深入研究具有重要的临床意义.笔者结合近年来最新文献报道,对该领域的实验研究进展予以简要综述.     

Kallistatin对大鼠肝缺血再灌注损伤的保护及机制研究

目的:探讨Kallistatin对大鼠肝缺血再灌注后肝损伤的保护作用及机制。方法:建立大鼠肝脏缺血再灌注模型,随机将Wistar大鼠分成假手术组(S组)、缺血再灌注组(I/R组)、空壳腺病毒组(O组)和Kallistatin组(K组)。测定血清丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)水平评价肝功能。HE染色观察肝组织病理学改变。TUNEL法观察肝细胞凋亡情况。Westen-blot法检测肝组织中Caspase-3、Bcl-2、Bax的表达。结果:与S组比较,I/R组AST、ALT水平明显升高(P<0.05),病理损伤严重,Cas-pase-3和Bax表达也相应增加(P<0.05),而Bcl-2表达减少(P<0.05)。与I/R组比较,K组各项指标均明显改善(均为P<0.05)。O组与I/R组间无明显差别(P>0.05)。结论:Kallistatin对大鼠肝脏缺血再灌注后具有明显的保护作用,其机制可能通过促进Bcl-2表达、抑制Bax表达实现。