血红素氧合酶-1与肝脏缺血再灌注

血红素氧合酶(HO)是催化分解血红素生成一氧化碳、胆绿素和二价铁离子的限速酶。近来研究发现,HO-1与肝脏缺血再灌注损伤关系密切,此文从HO-1抗氧化、抗凋亡、抗炎症、改善微循环方面概述其与肝脏缺血再灌注的关系。     

血红素加氧酶-1在肝脏缺血再灌注损伤研究中新进展

肝脏缺血再灌注损伤(hepatic ischemia reperfusion injury,HIRI)的分子机制迄今尚未完全清楚。血红素加氧酶-1(heme oxygenase-1,HO-1)是体内血红素降解的起始酶和限速酶,在体内分解血红素生成一氧化碳(CO)、胆绿素和自由铁。HO-1系统具有抗炎、抗氧化、抗凋亡和促进细胞存活、循环稳定和免疫调节的作用,在HIRI中发挥着至关重要的作用。通过药物或基因工程的方法诱导产生HO-1,能减轻HIRI,目前这一方向已经成为该领域的研究热点。     

The effect of estrogen on hepatic microcirculation after ischemia/reperfusion

Background and aims Gender dimorphism in clinical manifestation of sepsis, hemorrhage, and trauma is still under investigation. Several experimental studies have indicated a protective effect of estrogen. Nonetheless, the effect of gender on hepatic ischemia/reperfusion remains controversially discussed, and the influence of estrogen is still unclear. In the present study, we investigated whether hepatic ischemia/reperfusion (I/R) injury is gender-dependent and if hepatic microvascular reperfusion injury can be prevented by estrogen. Materials and methods Eight female and eight male Sprague-Dawley rats were subjected to 90 min left lobar ischemia followed by 60 min reperfusion. Additional six males were pretreated with 17β-estradiol 24 h before I/R. Six female and six male rats served as nonischemic sham animals. By means of intravital microscopy, sinusoidal perfusion, leukocyte–endothelial cell interaction, and Kupffer cell activity were analyzed. Finally, arterial blood and liver tissue samples were taken for histomorphological analysis and liver enzyme determination. Results After hepatic ischemia/reperfusion, animals revealed a significant gender-specific impairment of hepatic microcirculation, whereas Kupffer cell depression, sinusoidal perfusion failure, leukocyte–endothelial cell interaction within post sinusoidal venules, and parenchymal liver cell damage were more pronounced in male animals. Pretreatment with estrogen caused a normalization of Kupffer cell dysfunction and an amelioration of sinusoidal perfusion failure and venular leukocyte–endothelial cell interaction. However, estrogen did not protect from manifestation of post ischemic parenchymal cell damage. Conclusion Hepatic ischemia and reperfusion generate a gender-specific occurrence of microvascular injury, which seems to be partially mediated by estrogen. However, additional factors may contribute to the initial post ischemic parenchymal cell damage. M. Burkhardt and J.E. Slotta equally contributed to this work.     

Heme oxygenase-1 and gut ischemia/reperfusion injury: A short review

Ischemia/reperfusion (I/R) injury of the gut is a significant problem in a variety of clinical settings and is associated with a high morbidity and mortality. Although the mechanisms involved in the pathogenesis of gut I/R injury have not been fully elucidated, it is generally believed that oxidative stress with subsequent inflammatory injury plays an important role. Heme oxygenase (HO) is the rate-limiting enzyme in the catabolism of heme, followed by production of CO, biliverdin, and free iron. The HO system is believed to confer cytoprotection by inhibiting inflammation, oxidation, and apoptosis, and maintaining microcirculation. HO-1, an inducible form of HO, serves a vital metabolic function as the rate-limiting step in the heme degradation pathway, and affords protection in models of intestinal I/R injury. HO-1 system is an important player in intestinal I/R injury condition, and may offer new targets for the management of this condition.     

促红细胞生成素与心肌缺血再灌注损伤

近年来促红细胞生成素(erythropoietin,EPO)的非造血生物作用逐渐引起关注。研究表明,EPO 可以减轻缺血缺氧时心肌细胞的损伤,减少心肌细胞的调亡,从而使其可能成为预防和治疗心肌缺血再灌注损伤的一条途径。     

Caspase recruitment domain 6 protects against hepatic ischemia/reperfusion injury by suppressing ASK1

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Prophylaxis with carnosol attenuates liver injury induced by intestinal ischemia/reperfusion

AIM： To investigate the possible protective effects of carnosol on liver injury induced by intestinal ischemia reperfusion （I/R）.
METHODS： Rats were divided randomly into three experimental groups： sham, intestinal I/R and carnosol treatment （n = 18 each）. The intestinal I/R model was established by clamping the superior mesenteric artery for 1 h. In the carnosol treatment group, surgery was performed as in the intestinal I/R group, with intraperitoneal administration of 3 mg/kg carnosol 1 h before the operation. At 2, 4 and 6 h after reperfusion, rats were killed and blood, intestine and liver tissue samples were obtained. Intestine and liver histology was investigated. Serum levels of aspartate aminotransferase （AST）, alanine aminotransferase （ALT） and interleukin （IL）-6 were measured. Liver tissue superoxide dismutase （SOD） and myeloperoxidase （IvIPO） activity were assayed. The liver intercellular adhesion molecule-1 （ICAM-1） and nuclear factor κB （NF-κB） were determined by immunohistochemical analysis and western blot analysis.
RESULTS： Intestinal I/R induced intestine and liver injury, characterized by histological changes, as well as a significant increase in serum AST and ALT levels. The activity of SOD in the liver tissue decreased after I/R, which was enhanced by carnosol pretreatment. In addition, compared with the control group, carnosol markedly reduced liver tissue MPO activity and serum IL-6 level, which was in parallel with the decreased level of liver ICAI-1 and NF-κB expression.
CONCLUSION： Our results indicate that carnosol pretreatment attenuates liver injury induced by intestinal I/R, attributable to the antioxidant effect and inhibition of the NF-κB pathway.     

肝缺血再灌注损伤对肿瘤增殖、转移的影响

肝缺血再灌注损伤(hepatic ischemia/reperfusion injury,HIRI)是肝脏外科常见的病理生理过程.HIRl通过引起趋化因子、黏附分子、基质金属蛋白酶、血管内皮细胞生长因子等细胞因子表达改变,对血液中残留肿瘤细胞的迁移、黏附、定植、生长等步骤有着重要的影响.与肝癌术后的复发、转移关系密切.     

Toll样受体参与小鼠肝脏缺血再灌注损伤

目的探讨Toll样受体是否参与小鼠肝脏缺血再灌注损伤及其机制. 方法用Toll样受体缺损小鼠(C3H/Hej,Hej组)和野生型(C3H/Heouj,Heouj组)小鼠复制部分肝脏缺血再灌注损伤模型,于缺血45min,再灌注1h和3h处死动物,检测血清天门冬氨酸氨基转移酶(AST)和血清肿瘤坏死因子α(TNFα)的含量;并以northern blot及髓过氧化物酶(MPO)试验分别检测缺血肝组织TNFα mRNA的表达和MPO的含量. 结果 (1)再灌注1、3h,与假手术组相比,小鼠血浆AST明显升高,但Hej组明显低于Heouj组(661.83U/L±106.09U/L和1215.5U/L±174.03U/L,t＝-6.65,P<0.01;1145.17U/L±132.43U/L和2958.17U/L±186.81U/L,t＝-5.57,P<0.01);(2)再灌注3h时,与假手术组相比,Hej组和Heouj组小鼠血清TNFα浓度明显升高,且前者明显低于后者(152.39pg/ml±43.3pg/ml和249.12pg/ml±51.89pg/ml,t＝-3.13,P<0.05);(3)再灌注1h,除假手术组外,Hej组和Heouj组小鼠缺血肝组织内可见TNFα mRNA的表达,但前者的表达水平明显低于后者,杂交带密度分析显示两者之间差异有显著性 (80.3±28.8与189.4±24.6,t＝-3.25,P<0.05);(4)再灌注3h,与假手术组相比,Hej组和Heouj组小鼠缺血肝组织内MPO含量明显升高,且前者含量明显低于后者(0.059±0.004和0.173±0.025,F＝33.49,P<0.01). 结论 Toll样受体可能通过其介导的炎性通路参与了小鼠肝脏缺血再灌注损伤.     

Effect of remote ischemic preconditioning on hepatic microcirculation and function in a rat model of hepatic ischemia reperfusion injury

Background:

Liver transplantation involves a period of ischemia and reperfusion to the graft which leads to primary non-function and dysfunction of the liver in 5–10% of cases. Remote ischemic preconditioning (RIPC) has been shown to reduce ischemia reperfusion injury (IRI) injury to the liver and increase hepatic blood flow. We hypothesized that RIPC may directly modulate hepatic microcirculation and have investigated this using intravital microscopy.

Methods:

A rat model of liver IRI was used with 45 min of partial hepatic ischemia (70%) followed by 3 h of reperfusion. Four groups of animals (Sham, IRI, RIPC+IRI, RIPC+Sham) were studied (n= 6, each group). Intravital microscopy was used to measure red blood cell (RBC) velocity, sinusoidal perfusion, sinusoidal flow and sinusoidal diameter. Neutrophil adhesion was assessed by rhodamine labeling of neutrophils and cell death using propidium iodide.

Results:

RIPC reduced the effects of IRI by significantly increasing red blood cell velocity, sinusoidal flow and sinusoidal perfusion along with decreased neutrophil adhesion and cell death.

Conclusions:

Using intravital microscopy, this study demonstrates that RIPC modulates hepatic microcirculation to reduce the effects of IRI. HO-1 may have a key role in the modulation of hepatic microcirculation and endothelial function.     

逆灌注对移植肝缺血再灌注损伤的影响

目的:探讨原位肝移植中经下腔静脉逆行灌注对移植肝缺血再灌注损伤的影响.方法:36例大鼠肝移植随机分为3组,每组12例.门静脉组即经门静脉顺行灌注,肝动脉+门静脉组即同时开放肝动脉及门静脉顺行灌注,下腔静脉组即先吻合下腔静脉后开放逆行灌注,然后吻合门静脉及肝动脉.分别检测术后1、6及24 h的血清转氨酶、移植肝病理变化及...     

锌对缺血再灌注损伤家兔心肌金属硫蛋白-1基因表达的影响

目的研究锌对家兔心肌缺血再灌注损伤的保护作用。方法采用RT-PCR技术,检测分析金属硫蛋白-1(MT-1)基因在家兔缺血再灌注损伤心肌的表达及锌对其基因表达的调节。结果各组家兔心肌组织中均有MT-1基因的表达,缺血再灌注组MT-1基因的表达较正常对照组明显下降(P<0.01),补锌再灌注组MT-1基因的表达较缺血再灌注组明显上调(P<0.01)。结论锌对家兔心肌缺血再灌注损伤的分子机制中,调节其心肌组织中MT-1基因转录水平的表达可能是一条重要途径。     

Splenectomy-reduced hepatic injury induced by ischemia/reperfusion in the rat

Abstract: In the present study, we investigated the role of the spleen in experimental hepatic ischemia/reperfusion in the rat. After a 90-min period of ischemia in the left and middle hepatic lobes, the ischemia was released and the liver was reperfused for up to 24 h. Plasma alanine aminotransferase reached a peak 3 h after the onset of reperfusion, and gradually decreased thereafter. A histological examination revealed evidence of hepatocellular necrosis and degeneration, especially 24 h after the onset of reperfusion. In addition, there was a noticeable accumulation of polymorphonuclear cells in the liver following ischemia/reperfusion. A splenectomy performed just prior to ischemia/reperfusion reduced both biochemical and histological hepatocellular injury. The number of polymorphonuclear cells in the liver following ischemia/reperfusion was significantly reduced in rats subjected to splenectomy, suggesting that the increase in polymorphonuclear cells may contribute to liver injury. The number of mononuclear cells also increased in the marginal zones of the spleen following ischemia/reperfusion, and appeared to be derived from the splenic monocyte/macrophage population, based on immunohistochemical studies. The spleen plays an important role in the pathogenesis of hepatic ischemia/reperfusion injury and the splenic monocyte/macrophage population contributes to liver damage.     

Reduced severity of liver ischemia/reperfusion injury following hepatic resection in humans is associated with enhanced intrahepatic expression of Th2 cytokines.

BACKGROUND: Based on previous studies in experimental models, pro-inflammatory Th1 cytokines (i.e. TNF-alpha and IFN-gamma) are thought to play a pathogenic role in hepatic ischemia/reperfusion injury, while anti-inflammatory Th2 cytokines (i.e. IL-4 and IL-10) have been associated with reduced liver disease severity. To test the relevance of these concepts in humans, cytokine expression profiles were characterized in liver biopsies from patients undergoing hepatic resection following intermittent portal clamping. METHODS: Twelve patients were analyzed for the intrahepatic expression of TNF-alpha, IFN-gamma, IL-4 and IL-10 before and about 90min after the last reperfusion. In addition, parameters of liver damage including sALT and serum levels of TNF-alpha were analyzed at 2, 24 and 48h after surgery. RESULTS: When compared with pre-reperfusion liver specimens, all post-reperfusion biopsies showed significantly increased levels of TNF-alpha and IFN-gamma mRNAs. Conversely IL-4 and IL-10 mRNA levels were significantly increased in only seven patients. A negative correlation was observed between Th2 cytokines (IL-4, IL-10) and ALT and serum levels of TNF-alpha. Furthermore, the presence of hepatic steatosis was significantly associated with lower intrahepatic contents of IL-4 and IL-10. CONCLUSIONS: The results suggest that the local early expression of Th2 cytokines may contribute to attenuate liver injury following ischemia reperfusion in humans. The early imbalance between pro- and anti-inflammatory cytokines seen in steatotic liver subjected to I/R could explain, at least partially, the decreased tolerance of steatotic livers to I/R injury.     

缺血预处理对大鼠脑缺血再灌注损伤神经细胞的保护作用

目的探讨大鼠局灶性脑缺血预处理对脑缺血再灌注损伤后神经元的保护作用。方法健康雄性SD大鼠60只,随机分为3组:假手术组、大脑中动脉缺血再灌注(MCAO)组、预处理(BIP)组,每组按照再灌注后12 h、1、2、3 d四个时间点平均分为4个亚组,制备缺血预处理模型,分别用流式细胞术和ELISA法观察脑缺血预处理对缺血再灌注大鼠缺血半暗带神经细胞凋亡率及血清神经元特异性烯醇化酶(NSE)含量的影响。结果大鼠脑缺血再灌注后12 h,MCAO组细胞凋亡发生率及血清中NSE的含量较假手术组显著增加(P<0.01),1 d时达到高峰,以后时间点逐渐下降,但仍高于假手术组(P<0.01);BIP组各个时间点神经元凋亡发生率及血清NSE较MCAO组显著降低(P<0.05,P<0.01)。结论大鼠局灶性脑缺血预处理对脑缺血再灌注神经元损伤有保护作用。     

异氟烷预处理对离体大鼠心肌缺血再灌注损伤的影响

目的:采用Langendorff离体心脏灌注模型,研究异氟烷预处理对离体大鼠心肌缺血再灌注损伤的影响。方法:24只SD大鼠随机分为4组,每组6只,分别为缺血再灌注损伤组(IR组)、异氟烷预处理1组(IsoP 1组)、异氟烷预处理2组(IsoP 2组)和异氟烷预处理3组(IsoP 3组)。监测复灌后心功能恢复情况、冠脉流出液中磷酸肌酸激酶(CK)、乳酸脱氨酶(LDH)的释放量和心肌存活面积的变化。结果:复灌期间3组IsoP心脏各对应时间点的LVEDP均显著低于对照组(P<0.05~<0.01);再灌注30 min时IsoP各组LVDP的恢复均高于IR组(P<0.05),IsoP3组±dp／dtmax在再灌注30 min时的恢复百分比均高于IR组(P<0.05),IsoP1组+dp／dt max高于IR组(P<0.05);复灌后异氟烷预处理组各时间点的CK、LDH释放量均低于IR组(P<0.01);IsoP2组、IsoP1组和IsoP3组心肌存活面积百分比均高于IR组(P<0.01);预处理各组之间比较无显著性差异(P>0.05)。结论:IsoP对大鼠离体缺血再灌注心肌有保护作用,可以显著减轻心肌细胞的损伤,改善心功能,增加心肌存活面积。     

心肌缺血/再灌注损伤后的肺组织损伤

目的初步探讨心肌缺血／再灌注损伤对肺组织损伤的可能机制。方法选取雄性成年SD大鼠（4～6月龄）,体重130～160g,建立成年大鼠缺血／再灌注模型。运用CK和MPO试剂盒检测肌酸激酶（CK）和髓过氧化物酶（MPO）的含量,运用双抗体夹心ABC—ELISA法检测细胞间黏附分子-1（ICAM-1）的含量。结果与伪手术组相比,缺血／再灌注大鼠的AN／AAR比值明显增高（P〈0．05）,CK在心肌缺血／再灌注大鼠血清中的含量明显升高（P〈0．05）,MPO与ICAM-1在心肌缺血／再灌注组大鼠血清和肺组织中含量明显升高（P〈0．05）。结论大鼠心肌缺血再灌注损伤后肺组织受到一定的损伤,可能与体循环中炎性介质的作用及肺组织的炎性应激有关。     

一氧化氮与肺缺血再灌注损伤的研究进展

一氧化氮（nitricoxide，NO）是一种活性很强的自由基，具有广泛的生物学活性。多项研究提示NO在急性肺缺血／再灌注（ischemia／reperfusion，I／R）损伤中具有重要作用。本文重点描述有关一氧化氮在肺I／R损伤中作用的研究进展。     

茶多酚对大鼠肝脏缺血-再灌注损伤的保护作用

目的探讨茶多酚对大鼠肝脏缺血再灌注损伤的保护作用及其机制。方法健康雄性SD大鼠30只，随机均分为4组：假手术正常对照组6只；肝脏缺血再灌注损伤模型组8只；茶多酚低浓度于预组8只（75mg／kg）；茶多酚高浓度于预组8只（150mg／kg）．缺血30min再灌注60min检测肝组织MDA含量、GSH-PX活性及血浆ALT含量。光镜下比较各组肝组织损伤情况。结果肝缺血再灌注模型组ALT、MDA含量明显高于假手术正常对照组（P〈0．01），GSH-PX活力则降低（P〈0．01）；茶多酚低浓度及高浓度组ALT，MDA含量均明显低于肝缺血再灌注模型组（P〈0．01），而GSH-Px活力均高于肝缺血再灌注模型组（P〈0．01）；光镜观察茶多酚低浓度及高浓度预处理组肝细胞损伤明显小于肝缺血再灌注模型组。结论茶多酚对大鼠肝脏缺血再灌注损伤具有显著的保护作用。