Pentoxifylline contributes to the hepatic cytoprotective process in rats undergoing hepatic ischemia and reperfusion injury.

AIM: Considerable efforts have been made to find and/or eliminate the underyling causes of hepatic ischemia-reperfusion injury, but many points are still unclear. Pentoxifylline-related cytoprotection is one of these unclear points. Our study tests the effects of pentoxifylline on the hepatic cytoprotective process in an experimental model. MATERIALS AND METHODS: The animals were divided into two groups: (1) placebo-pretreated rats and (2) pentoxifylline-pretreated rats. After pretreatment, all rats underwent the hepatic ischemia-reperfusion procedure which was performed by clamping the hepatoduodenal ligament. To evaluate the liver injury, serum levels of alanine transaminase (ALT) and aspartate transaminase (AST), and liver tissue levels of prostaglandin E(2) (PGE(2)) were measured before ischemia, immediately after ischemia and immediately after reperfusion. RESULTS: Before ischemia and immediately after ischemia, there were no significant differences between ALT and AST levels of groups 1 and 2 (p >0.05). However, at the end of reperfusion, ALT and AST levels of group 2 were significantly decreased when compared with group 1 (p < 0.05 and p < 0.01, respectively). Additionally, tissue levels of PGE(2) that were obtained before ischemia, immediately after ischemia and immediately after reperfusion in group 2 were significantly higher than those of group 1 (p < 0.001). CONCLUSION: Pentoxifylline reduces reperfusion injury of the liver through significantly decreased transaminase levels, and contributes to hepatic cytoprotection by increasing tissue levels of PGE(2) significantly. These effects reflect the role of tissue PGE(2) in pentoxifylline-related hepatoprotection against ischemia-reperfusion injury of the liver.     

Reduction of post-ischemic lung reperfusion injury by fibrinolytic activity suppression

BACKGROUND: Although extensive studies on the detailed mechanisms of ischemia-reperfusion injury have been conducted, the implication of the fibrinolytic system has not been known. To determine the role of the fibrinolytic system in ischemia-reperfusion injury, we used tranexamic acid, a synthetic specific plasmin and tissue-type plasminogen activator inhibitor, to suppress fibrinolytic activity in a rabbit lung ischemia-reperfusion model. METHODS: New Zealand White rabbits were randomly divided into two groups: a simple ischemia group and a group injected with tranexamic acid before left hilar occlusion. After 2 hours of warm ischemia, plasma was collected from pulmonary vessels. Fibrin zymography was used to ascertain fibrinolytic activity, and enzyme-linked immunosorbent assay was used to determine soluble thrombomodulin levels as a marker for endothelial cells damage. Changes in left pulmonary function including arterial oxygen tension, peak airway pressure, and pulmonary vascular resistance were recorded during reperfusion after the 2 hours of warm ischemia. RESULTS: Fibrinolytic activity and soluble thrombomodulin levels increased in the vessels of the ischemic lung, indicating endothelial cell injury. The increased fibrinolytic activity and the rise in soluble thrombomodulin were suppressed by the preadministration of tranexamic acid, resulting in remarkably improved pulmonary function during reperfusion. After 2 hours of reperfusion, the wet-to-dry weight ratios and histological studies showed reduced pulmonary edema in the group that had received tranexamic acid. CONCLUSION: These findings suggest that the fibrinolytic system is involved in the onset mechanism of ischemia-reperfusion injury through induced endothelial cell damage and increased vascular permeability.     

肝细胞凋亡在肝硬化大鼠肝缺血再灌注损伤中的意义

目的 研究肝硬化大鼠肝缺血再灌注（I／R）损伤和硬化肝比正常肝更容易损伤的机制是否与肝细胞凋亡有关？方法 建立原位肝I／R模型，将肝硬化大鼠随机分为2组：A组：缺血时间（I）＝20min;B组：I＝30min;C组：正常大鼠，I＝30min，比较灌注前后各组血清AST、ALT的变化和肝细胞凋亡的百分数。结果 肝硬化大鼠肝I／R后，AST、ALT明显升高，以灌注后6h为高峰，灌注24、72h后逐渐下降。灌注6h后，B组的血清转氨酶为3组中最高（P＜0．05），说明B组肝损伤最严重。肝细胞凋亡在I／R后明显增多，以灌注后6h为高峰，随后逐渐下降，变化与转氨酶一致。灌注后6h，B、A、C组肝细胞凋亡的百分数分别为20．9％、13．5％和10．7％，B组明显高于A、C两组（P＜0．01）。再灌注72h内未见明显肝细胞坏死。结论 肝细胞凋亡是肝硬化大鼠I／R损伤肝细胞死亡的主要形式，肝细胞凋亡与肝缺血时间密切相关，肝硬化肝细胞比正常肝细胞容易发生凋亡是硬化肝对缺血敏感的重要原因。     

大黄素对大鼠肝脏缺血再灌注损伤的预防作用

目的:探讨大黄素对肝脏缺血-再灌注损伤的保护作用及其机制.方法:将45只成年雄性SD大鼠随机分成三组:假手术对照组(A组)15只,肝缺血30 min、再灌注90min组(B组)15只,术前5 d给予大黄素灌胃60mg/(kg·d),5次 肝缺血30 min、再灌注90min(C组)15只;观察血清谷丙转氨酶(ALT)、谷草转氨酶(AST)、透明质酸酶(HA)、肝组织丙二醛(MDA)含量的变化及肝脏组织病理学改变情况,同时测定各组大鼠胆汁流量情况.结果:C组与B组相比,MDA含量显著降低(P＜0.05),HA浓度明显降低(P＜0.01),胆汁流量显著增加(P＜0.01),同时C组的肝细胞功能明显改善,且肝脏超微结构改变也较轻.结论:大黄素对肝脏缺血-再灌注损伤具有保护作用,该作用与减轻肝脏缺血再灌注后脂质过氧化程度和肝窦内皮细胞损伤有关.     

Prolonged continuous or intermittent vascular inflow occlusion during hemihepatectomy in pigs

OBJECTIVE: To assess ischemia and reperfusion (I/R) injury in a hemihepatectomy model in pigs after prolonged continuous or intermittent vascular inflow occlusion in the liver. SUMMARY BACKGROUND DATA: Massive intraoperative blood loss during liver resections can be prevented by temporary vascular inflow occlusion, consequently leading to ischemia and reperfusion injury in the remnant liver. Previously, in a pig liver resection model in which only limited I/R injury was induced during brief (90 min) vascular inflow occlusion, the authors demonstrated reduced I/R injury after continuous (CNT) occlusion, compared to intermittent (INT). This liver resection study on pigs was undertaken to assess I/R injury after prolonged (120 min) CNT or INT occlusion. METHODS: In pigs (37.0 +/- 1.5 kg), liver ischemia during 2 hours was CNT (n = 6) or INT (n = 6) (eight subsequent periods of 12 min ischemia and 3 min recirculation), followed by 6 hours of reperfusion. A left hemihepatectomy (45.5% +/- 1.4%) was performed within the first 12 minutes of ischemia. No hepatic pedicle clamping or liver resection was performed in control experiments (n = 6). Microvascular damage was assessed by hyaluronic acid (HA) uptake capacity of the liver (parameter of early sinusoidal endothelial cell damage) and restoration of intrahepatic tissue pO2 during reperfusion. Hepatocellular damage was tested by plasma concentrations of aspartate aminotransferase (AST), alanine aminotransferase, and lactate dehydrogenase (LDH). RESULTS: Hyaluronic acid uptake after 6 hours of reperfusion, compared to preischemic uptake, was unaltered in the control group, but was significantly reduced in both resection groups. However, more HA was taken up after INT occlusion, compared to CNT (60.4% +/- 5.6% and 39.5% +/- 3.7%, respectively; ANOVA: p = 0.001). Intrahepatic tissue pO2 distribution after 6 hours of reperfusion more closely returned to preischemic configuration in the INT group than in the CNT group, indicating reduced microcirculatory disturbances after INT occlusion. Release of AST and LDH after 6 hours of reperfusion was significantly increased in both CNT and INT groups. Lower AST levels, however, were found after INT occlusion than after CNT occlusion (267.0 +/- 74.7 U/l and 603.3 +/- 132.4 U/l, respectively; p = 0.06). CONCLUSIONS: Intermittent hepatic vascular inflow occlusion during prolonged liver ischemia in pigs resulted in less microcirculatory and hepatocellular injury, compared to continuous occlusion. Intermittent clamping is preferable when prolonged periods of vascular inflow occlusion are applied during liver resections.     

七氟醚预处理对右肝癌切除患者肝脏缺血再灌注损伤的保护作用

目的：探讨七氟醚预处理对右肝癌切除患者肝脏缺血再灌注损伤的保护作用及其机制。方法：择期全麻下行右肝癌手术切除患者40例．ASAI或II级,术中经第一肝门阻断．血流阻断时间10～30min．随机分为2组（n=20）：缺血再灌注组（IR组）和七氟醚预处理组（S组）。两组麻醉维持期间均保持脑电双频谱指数40-50。s组麻醉诱导后吸入1MAC七氟醚（呼气末浓度）．30min后洗脱15min。于麻醉诱导前（T0）、缺血再灌注即刻（T1）、1h（T2）、6h（T3）抽血测血清中谷丙转氨酶（ALT）．谷草转氨酶（AST）,乳酸脱氢酶（LDH）的含量以及肝脏组织匀浆中丙二醛（MDA）含量和超氧化物岐化酶（SOD）活性,并行肝组织病理学观察。结果：与麻醉诱导前比较．两组缺血再灌注即刻．1h、6h血清ALT．AST,LDH含量均显著增加（P〈0．05）;与IR组比较,s组肝脏缺血再灌注后相应各时点血清ALT．AST、LDH含量均降低．肝组织匀浆MDA含量减少,SOD活性增加（P〈0．05）;肝组织病理学损伤减轻。结论：七氟醚预处理对右肝癌切除患者肝脏缺血再灌注损伤有保护作用．可能与其抑制氧自由基生成．减少脂质过氧化有关。     

间断低氧预适应对大鼠肝切除缺血再灌注肝脏凋亡相关蛋白Bcl-2、Bax表达的影响

目的 观察术前间断低氧预适应对大鼠70％肝切术后缺血再灌注损伤肝脏凋亡相关蛋白Bcl-2和Bax表达的影响。方法 健康清洁级SD大鼠54只,用SPSS软件随机分为3组,每组18只：（1）肝切除组（PH组）,切除肝脏的左叶和中叶（约占总肝重的70％）;（2）缺血再灌注组（IR组）,即在肝门阻断下切除肝脏的左叶和中叶,肝门阻断20 min后开放血流,残余肝脏发生了缺血再灌注过程;（3）间断低氧预适应组（IHP组）,术前1周将大鼠置于氧气体积分数为10％的低氧环境中,每天1h。1周后在肝门阻断下行肝切除术（同IR组）。各组分别于术后12、24、48 h进行取材检测,用全自动生化分析仪检测血清谷丙转氨酶（ALT）、谷草转氨酶（AST）含量,采用免疫组化方法检测残余肝组织Bcl-2、Bax表达情况。结果 在术后各时间点,IR组和IHP组血清ALT和AST水平均显著高于PH组,但IHP组明显低于IR组。与IR组相比,IHP组术后各时间点肝脏Bcl-2蛋白表达显著升高,而Bax蛋白表达显著下降。差异均有统计学意义（P＜0.05）。结论 间断低氧预适应对残余肝脏缺血再灌注损伤具有保护作用,其途径可能是通过促进抗凋亡蛋白Bcl-2表达和抑制促凋亡蛋白Bax表达,来减少肝细胞凋亡。     

山莨菪碱对肝脏缺血再灌注损伤的保护作用

目的 探讨山莨菪碱对肝脏缺血再灌注损伤的保护作用。方法 将雄性Wistar大鼠制成肝脏缺血再灌注模型，随机分为正常对照组、缺血再灌注组、生理盐水组和山莨菪碱组，观察肝脏缺血60min再灌注1、3、6、12及24h后血浆和／或肝组织中内皮素－1（ET－1）、透明质酸（HA）、丙氨酸转氨酶（ALT）、丙二醛（MDA）和再灌注1h后肝细胞内游离Ca^2 ([Ca^2 ]i)、ATP含量变化以及肝组织病理学改变。结果 肝脏缺血再灌注后血浆和／或肝细胞中ET－1、HA、ALT、MDA和肝细胞内[Ca^2 ]u含量均显著升高，而肝组织中ATP含量明显降低；肝脏缺血再灌注前应用山莨菪碱2.0mg/kg者，血浆HA和肝细胞内[Ca^2 ]i含量明显降低，肝组织中MDA也有不同程度的降低，而肝组织中ATP含量明显升高，同时肝酶的漏出减少，肝组织病理学损害明显减轻。结论 山莨菪碱对肝脏缺血再灌注损伤具有保护作用。     

肠腔分流条件下巴马小型猪缺血再灌注肝功及病理变化

目的探讨肝缺血再灌注过程中肝功能及病理变化规律。方法将18头正常小型猪随机分为A组(入肝血流阻断90min)、B组(入肝血流阻断100min),对照观察两组动物在缺血前、复流前、复流1h及术后各时相点ALT、AST及肝组织病理的变化情况。结果(1)A组长期存活率为100%,B组长期存活率为44.4%;(2)两组动物于缺血及复流1hALT水平变化较术前无明显变化(P>0.05),至术后2、3d均显著高于术前水平(P<0.05),术后4d与术前无显著差异(P>0.05),术后2、3d时B组水平均显著高于A组(P<0.05);(3)两组动物于复流1h时AST水平达到峰值(P<0.05),此后AST水平逐渐下降,到术后3d与术前无显著性差异(P>0.05),复流1h,术后1、2d时B组水平显著高于A组(P<0.05);(4)两组动物肝组织病变随着缺血时间的延长而更加严重,在复流1h时肝组织损伤最为严重,随后肝组织损伤逐渐减轻,存活动物于术后4d肝组织结构基本恢复正常,死亡动物尸检见肝组织大片溶解坏死;(5)对比ALT、AST与肝组织病理学变化的关系可以看到,在肝IR过程中,ALT水平变化与肝组织变化趋势不一致,而AST水平变化与肝组织病理改变情况基本一致。结论(1)在长时间缺血过程中如发现肝组织出现灶性坏死、细胞广泛气球样变、脂肪变性将提示组织损伤难以恢复,动物难以耐受肝缺血再灌注损伤;(2)在肝脏缺血过程中检测血清ALT、AST并不能用于判断肝缺血再灌注损伤的预后情况,但再灌注过程中血清AST水平能较好的反映肝组织的受损程度。     

海藻糖对肝脏缺血再灌注损伤的保护作用及机制研究

目的探讨海藻糖是否对肝脏缺血再灌注损伤具有保护作用及其相关机制。方法C57BL/6J小鼠数字随机分为无缺血组、缺血再灌注组、海藻糖处理组和生理盐水对照组,缺血90 min后于再灌注的0h和6h,收集血液和肝组织,通过分离血清测丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)肝功能指标及肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)和白细胞介素-2(IL-2)炎症因子水平和肝组织病理改变研究海藻糖在肝脏缺血再灌注损伤中的作用;AML12小鼠肝细胞系构建缺糖缺氧-复糖复氧细胞模型,分为实验组和对照组,实验组根据给予的海藻糖浓度不同分为低剂量组和高剂量组,对照组无海藻糖,收集细胞,流式细胞仪检测凋亡水平以研究海藻糖对肝脏缺血再灌注损伤诱导的细胞凋亡的影响,蛋白印迹法检测Caspase-3、Cleaved Caspase-3和Bcl-2蛋白水平以研究海藻糖在肝脏缺血再灌注损伤诱导的细胞凋亡中的分子机制。结果体内动物实验显示肝脏缺血再灌注后,缺血再灌注组ALT、AST及TNF-α、IL-1β和IL-2等肝功能指标及炎症因子水平升高(P<0.05),且肝组织发生坏死;而在给予海藻糖处理后,ALT、AST、TNF-α、IL-1β和IL-2等水平较生理盐水对照组降低且肝组织坏死面积也减少(P<0.05)。体外细胞实验显示与对照组相比,实验组肝细胞凋亡水平下降;且实验组活化的促凋亡蛋白Cleaved Caspase-3水平下降、抗凋亡蛋白Bcl-2水平升高。结论在体内和体外条件下海藻糖对肝脏缺血再灌注损伤有保护作用,其机制可能是通过抑制肝脏缺血再灌注损伤诱导的炎症发生和抑制Caspase-3的活化并促进Bcl-2的表达,减轻细胞凋亡,从而保护肝脏缺血再灌注损伤。     

Controlled vasoregulation of postischemic liver microcirculation--a therapeutic approach.

One of the changes produced by ischemia and reperfusion is endothelin (ET)-mediated constriction of the hepatic vascular bed. This leads to microcirculatory disturbances and reduced blood flow, thereby causing local hypoxia and liver damage. Our aim was to induce stepwise changes of microvascular vessel diameters so as to define the best protective vessel width that could be produced by drug therapy and thereby to minimize ischemia/reperfusion injury. The mixed ET receptor antagonist bosentan was used in different dosages in a rat liver ischemia/reperfusion model with splenocaval shunt. In vivo microscopy was performed 30-90 min after reperfusion and local hepatic tissue pO2 was determined, together with aspartate aminotransferase/alanine aminotransferase (AST/ALT). After ischemia, sinusoidal diameters were significantly reduced to 76 +/- 7% of those in the control group. After the administration of bosentan in dosages of 0.1, 1, and 10 mg/kg body weight iv and 10 mg/kg body weight intraportally we found diameters of 83 +/- 4, 98 +/- 2, 109 +/- 6, and 137 +/- 19%, respectively. Perfusion rate and leukocyte-endothelium interactions showed dependence on sinusoidal diameters, with the best results in the group where preischemic sinusoidal vessel width had been maintained. Local tissue pO2 and transaminase levels also showed that oxygen supply was sufficient and that hepatocellular injury was most minimized in this group. Graduated blocking of ET receptors allows stepwise regulation of sinusoidal and postsinusoidal venular vessel width and offers a treatment strategy for pathophysiological situations that are associated with ET-induced vasoconstriction. The results suggest that maintenance of preischemic microvascular diameter is the best therapeutic approach.     

川芎嗪对大鼠肝脏缺血-再灌注损伤保护作用的机理研究

目的　研究川芎嗪注射液对大鼠肝脏缺血再灌注损伤的保护作用。方法　96 只SD大鼠被随机均分为假手术组、肝脏缺血再灌注组(I/R组)和肝脏缺血+川芎嗪再灌注组(简称治疗组)3 组,分别于术前及术后30 min、6 h及24 h检测血浆丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)及乳酸脱氢酶(LDH),观察每组大鼠1周存活情况及肝脏病理组织学变化,并行肝细胞凋亡指数检测。结果　治疗组术后1 周大鼠存活情况好于I/R组(P<0.05); 治疗组及I/R组血浆ALT、AST及LDH均明显高于假手术组(P<0.05),但治疗组低于I/R组(P<0.05)。光镜下见,缺血再灌注后肝血窦和中央静脉明显瘀血,肝细胞坏死I/R组重于治疗组。肝细胞凋亡指数I/R组高于治疗组(P<0.05)。结论　川芎嗪对大鼠肝脏缺血再灌注损伤具有明显的保护作用。     

硫化氢对大鼠肝缺血再灌注损伤的影响

目的 评价硫化氢对大鼠肝缺血再灌注损伤的影响.方法 健康雄性SD大鼠30只,体重220～250 g,采用随机数字表法,将其随机分为假手术组(S组)、缺血再灌注组(IR组)和不同剂量硫化氢组(H2S1～3组),每组6只.S组仅暴露肝门,不夹闭动、静脉;IR组采用夹闭左、中叶肝蒂、门静脉和肝动脉支1h恢复灌注的方法制备大鼠肝缺血再灌注模型;H2S1～3组于再灌注前5min分别腹腔注射14、28、56 μmol/kg硫化氢钠.于再灌注6h时抽取下腔静脉血样并取肝组织,采用全自动生化分析仪测定血清谷丙转氨酶(ALT)和谷草转氨酶(AST)活性,采用二硫代二硝基苯甲酸法测定肝组织谷胱甘肽(GSH)含量,光镜下观察肝组织病理学结果.结果 与S组相比,IR组血清ALT和AST活性升高,肝组织GSH含量下降(P＜0.05);与IR组相比,H2S1～3组ALT和AST活性降低,肝组织GSH含量升高(P＜0.05);H2S1～3组肝病理学损伤较IR组明显减轻.结论 H2S可减轻大鼠肝缺血再灌注损伤.     

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。     

大鼠脂肪干细胞对自体肝移植缺血再灌注损伤的保护机制研究

目的探讨大鼠脂肪干细胞在大鼠自体肝移植缺血再灌注(ischemia-reperfusion,IR)损伤模型中的保护作用机制。方法分离并培养大鼠脂肪干细胞(adipose-derived stem cells,ADSCs),构建稳定细胞株。SD大鼠随机分为假手术组、自体肝移植缺血再灌注组(IR组)、自体肝移植缺血再灌注+脂肪干细胞回填组(ADSCs组),每组10只。假手术组上腹正中切口,暴露并离断肝脏韧带,不做其他处理。IR组用动脉夹夹闭肝门阻断血流,肝素注射液灌注15 min,不给药。ADSCs组在肝素注射液灌注后30 min尾静脉注射1×106 ADSCs。手术后24 h后处死大鼠,检测各组大鼠血清中天冬氨酸氨基转移酶(AST)、丙氨酸转氨酶(ALT)、肝脏超氧化物歧化酶(SOD)、丙二醛(MDA)含量,以及线粒体活性;苏木素-伊红染色(HE)观察肝脏病理学改变;免疫印迹法(Western blotting)检测细胞间黏附分子-1(ICAM-1)、Bax基因表达情况。结果与假手术组相比,IR组AST和ALT水平、MDA含量较高,SOD含量较低(P0.05),线粒体活性较弱。病理切片结果显示,IR组肝细胞出现坏死,炎性细胞浸润严重。Western blotting结果显示IR组较假手术组ICAM-1、Bax表达增多。与IR组相比,ADSCs组AST和ALT水平、MDA含量较低,SOD含量较高(P0.05),线粒体活性较强,炎性细胞浸润较少,ICAM-1、Bax表达减少。结论大鼠脂肪干细胞对大鼠自体肝移植缺血再灌注损伤模型有保护作用,其作用机制可能是通过减少炎症反应和氧化应激程度进而减轻肝脏缺血再灌注损伤。     

高渗氯化钠羟乙基淀粉40注射液高容量血液稀释对大鼠肝脏缺血再灌注损伤的影响

目的 探讨高渗氯化钠羟乙基淀粉40注射液高容量血液稀释对大鼠肝脏缺血再灌注损伤的影响.方法 雄性Wistar大鼠30只,体重300～350 g,随机分为3组(n=10):假手术组(S组)、缺血再灌注组(IR组)和高容量血液稀释组(HH组).S组仅开腹,不阻断血管;IR组阻断肝门静脉和左肝动脉30 min,再灌注2 h;HH组30 min内经尾静脉输注高渗氯化钠羟乙基淀粉40注射液10 ml/kg进行高容量血液稀释,输注完毕后15 min,行肝脏缺血再灌注.再灌注2 h时,下腔静脉取血样,测定血清谷丙转氨酶(ALT)和谷草转氨酶(AST)的活性;取左肝叶组织,光镜下观察病理学结果,采用比色法测定丙二醛(MDA)含量,采用黄嘌呤氧化酶法测定超氧化物歧化酶(SOD)活性.结果 与S组比较,IR组和HH组血清ALT和AST的活性、肝组织MDA含量升高,肝组织SOD活性降低(P<0.01),肝组织病理学损伤明显;与IR组比较,HH组血清ALT和AST的活性、肝组织MDA含量降低,肝组织SOD活性升高(P<0.01),肝组织病理学损伤减轻.结论 高渗氯化钠羟乙基淀粉40注射液高容量血液稀释可减轻大鼠肝脏缺血再灌注损伤,可能与氧自由基生成减少有关.     

一氧化氮对大鼠肝缺血-再灌注损伤中肝细胞凋亡的影响

目的探讨一氧化氮对肝缺血-再灌注损伤及肝细胞凋亡的影响。方法在一氧化氮合酶（NOS）增强剂和抑制剂条件下,观察大鼠肝缺血-再灌注后1、3、6、24h肝的血清门冬氨酸氨基转移酶（AST）和丙氨酸氨基转移酶（ALT）变化,同时进行肝细胞胞浆诱导型一氧化氮合酶（iNOS）表达及肝细胞凋亡的免疫组织化学分析。结果在再灌注6h点AST、ALT、肝细胞凋亡水平上,L-精氨酸（L-arg）组值分别为（341.88±111.24）IU/L、（311.75±139.41）IU/L和2.80±1.79,显著低于L-硝基精氨酸甲酯（L-NAME）组（2080.88±241.98）IU/L、（1153.00±110.92）IU/L和5.50±0.71（P值均＜0.05）。而L-arg组的肝细胞内iNOS表达灰度值152.07±3.46显著高于L-NAME组灰度值180.45±4.46（P＜0.05）。结论一氧化氮可减少肝缺血-再灌注损伤后肝酶的释放,抑制肝细胞的凋亡,改善肝缺血-再灌注损伤。     

S-腺苷蛋氨酸对大鼠缺血再灌注肝脏能量代谢的影响

目的研究S-腺苷蛋氨酸(SAM)预处理对大鼠肝脏缺血再灌注损伤线粒体功能的影响。方法54只大鼠按随机数字表法随机均分为对照组、缺血再灌注组(I/R组)和SAM组,SAM组大鼠肝脏在缺血前2h行腹腔注射SAM预处理。3组动物在阻断肝门30min后(对照组仅做分离,不阻断肝门)复流,并于再灌注后0、1和6h抽取下腔静脉血检测ALT及AST,切取肝组织检测线粒体SOD、MDA、ATP及EC,并制备病理切片在电镜下观察线粒体的超微结构。结果再灌注后0、1及6h,I/R组ALT、AST和MDA明显高于对照组(P<0.01),SOD(除0h外)、ATP及EC明显低于对照组(P<0.01);SAM组ALT、AST及MDA(除0h外)明显低于I/R组(P<0.01),SOD(除0h外)、ATP及EC明显高于I/R组(P<0.05,P<0.01)。超微结构观察,I/R组线粒体较对照组有明显的损伤,线粒体数量减少,肿胀明显,嵴模糊不清,基质密度低;而SAM组与I/R组相比损伤程度明显减轻。结论SAM能抑制线粒体脂质过氧化反应,提高ATP的产生,最终提高线粒体的能量代谢水平,有效地减轻肝脏的缺血再灌注损伤。     

上调肝脏HO-1抑制肥大细胞脱颗粒减轻大鼠肝脏缺血再灌注损伤

目的 探索HO-1对肝脏缺血再灌注损伤中肥大细胞脱颗粒的影响。方法 将20只SD大鼠随机分成4组：假手术组（Sham组）,缺血再灌注损伤组（I/RI组）,HO-1诱导剂钴原卟啉组(CoPP组,术前24h给予CoPP,5 mg/kg)及HO-1抑制剂锌原卟啉组(ZnPP组,术前24h给予ZnPP,20 mg/kg)。建立大鼠缺血再灌注损伤模型,各组于再灌注后2h收集标本。RT-PCR检测肝脏组织HO-1 mRNA表达,Western blot检测肝脏组织HO-1蛋白表达;测定血清中ALT、AST水平;肝脏组织甲苯胺蓝染色检测肥大细胞脱颗粒数量,HE染色评价肝脏组织损伤情况。结果 与Sham组相比,I/RI组、CoPP组、ZnPP组大鼠组织HO-1 RNA和蛋白表达增加,血清ALT、AST水平升高,肥大细胞脱颗粒数量增多,肝脏细胞损伤加重。CoPP组与I/RI组相比,HO-1 mRNA和蛋白表达增加,血清ALT、AST水平减低,肥大细胞脱颗粒数量减少,肝细胞损伤减轻。ZnPP组与I/RI组相比,HO-1 mRNA和蛋白表达减少,血清ALT、AST水平升高,肥大细胞脱颗粒数量增多、肝细胞损伤严重。组间比较差异具有统计学意义(P＜0.05)。结论 HO-1过表达能减轻肝脏I/RI,其机制可能与抑制肝脏组织中肥大细胞脱颗粒有关。     

UTI和丹参在鼠肝脏缺血再灌注中对肝窦内皮细胞损伤保护效应的实验研究

目的：探讨UTI和丹参在肝脏缺血再灌注中对肝窦内皮细胞损伤的保护作用。方法：将大鼠肝脏缺血再灌注模型30只大鼠分为5组，A组为空白对照组（n=3），B组为缺血再灌注组（n=7），C组为UTI组（n=6），D组为丹参组（n=6），E组为UTI＋丹参组（n=8）。除A组外，在缺血30min再灌注120min后分别取血检测AST、ALT、LDH、HA及ET，并取肝组织行光镜和电镜观察。结果：C组、D组较B组各指标明显下降（P〈0．01），E组各指标较C组或D组均有下降，（P〈0．05）。光镜和电镜观察形态学损伤程度，B组最重，C组、D组次之，E组最轻。结论：UTI、丹参在缺血再灌注中能有效减轻对肝窦内皮细胞的损伤，二药合用有协同作用。