瑞芬太尼对肝硬化大鼠肝脏缺血再灌注损伤的影响

目的 探讨瑞芬太尼对肝硬化大鼠肝脏缺血再灌注损伤的影响.方法 成年健康雄性SD大鼠30只,体重260～300 g,采用随机数字表法,将其随机分为3组(n=10):肝硬化组(C组)、肝硬化+肝缺血再灌注组(I/R组)和瑞芬太尼组(R组).C组、I/R组和R组采用四因素综合法制备大鼠肝硬化模型,I/R组和R组在肝硬化模型制备成功后1周制备大鼠70％肝脏缺血再灌注模型,R组于缺血前10 min开始静脉输注瑞芬太尼1μg·kg-1·min-至再灌注结束.于再灌注4h时取静脉血样和肝组织,测定血清ALT和AST活性、肝细胞Bcl-2和Bax表达及肝细胞凋亡情况,计算细胞凋亡指数,光镜下观察肝组织病理学结果.结果 与C组比较,I/R组血清ALT和AST的活性升高,肝细胞Bcl-2表达下调,Bax表达上调,细胞凋亡指数升高(P＜0.05);与I/R组比较,R组血清ALT和AST的活性降低,肝细胞Bcl-2表达上调,Bax表达下调,细胞凋亡指数降低(P＜0.05).R组肝组织病理学损伤轻于I/R组.结论 瑞芬太尼可减轻肝硬化大鼠肝脏缺血再灌注损伤,其机制与平衡肝细胞Bcl-2与Bax表达而抑制肝细胞凋亡有关.     

Relationship Between Ischemia/Reperfusion Injury and Acute Rejection of Allogeneic Liver Transplant in Rats

Objective

This study aimed to investigate the relationship between the severity of ischemia/reperfusion (I/R) injury and the acute rejection (AR) of allogeneic liver transplants in rats.

Methods

The experimental rats were divided in different groups: normal control group (sham group, group I); syngeneic liver transplant control group (similar gene group, group II); and allogeneic liver transplant groups (groups III to VI). The rats were humanely killed at 1, 3, 5, and 7 days after transplantation or sham operation to determine the severity of I/R injury, rejection classification, and hepatocyte apoptosis. Messenger RNA (mRNA) and protein expression levels of Fas, perforin, and granzyme B were assessed in the liver tissues using real-time polymerase chain reaction and immunohistochemistry, respectively.

Results

The rejection scores of the transplanted liver tissues gradually increased until these scores were proportional to the severity of I/R injury in groups III, IV, and V. The maximum scores were reached at 7 days after transplantation as the duration of transplantation was extended. The mRNA and protein expression levels of Fas, perforin, and granzyme B were significantly increased at 1, 3, 3, 5, and 7 days after liver reperfusion in groups III, IV, and V compared with those in groups I, II, and VI (P < .05).

Conclusion

The occurrence of AR after allogeneic liver transplantation in rats was positively correlated with the severity of I/R injury. Given that I/R injury caused serious damage to the transplanted liver, the occurrence of AR consequently decreased.     

治疗性高碳酸血症对大鼠移植肝脏缺血再灌注损伤的影响

目的 探讨治疗性高碳酸血症对大鼠移植肝脏缺血再灌注损伤的影响.方法 清洁级雄性Wistar大鼠32只,6周龄,体重220～280 g,采用完全随机设计的方法两两配对实施肝脏原位移植16只.采用随机数字表法,将受体鼠随机分为2组(n=8):肝移植组(LT组)和治疗性高碳酸血症组(TH组).LT组再灌注即刻吸入50％ O2-50％N2混合气体2 h;TH组再灌注即刻吸入O2-N2-CO2混合气体lh,调节气体浓度和呼吸频率,维持FiO2 50％、PaCO2 80～ 100 mm Hg,而后继续吸入50％O2-50％N2混合气体lh.再灌注期间记录MAP、PaO2和PaCO2.再灌注2h时,取动脉血样,测定血清ALT、AST、TNF-α、IL-1和IL-6的水平;取肝组织,测定NF-κB活性,计算凋亡指数,观察肝组织病理学结果.结果 与LT组比较,TH组血清ALT、AST、TNF-α、IL-1和IL-6水平、肝组织NF-κB活性和凋亡指数降低,MAP、PaO2和PaCO2升高(P＜0.05).TH组肝组织病理学损伤较LT组减轻.结论 治疗性高碳酸血症可减轻大鼠移植肝脏缺血再灌注损伤,机制与抑制炎性反应和细胞凋亡有关.     

雌激素对大鼠肝缺血再灌注损伤中SOD和MDA及细胞凋亡的影响

目的：探讨雌激素对大鼠切除肝缺血再灌注损伤的肝脏超氧化物歧化酶（SOD）、丙二醛（MDA）及细胞凋亡的影响。方法：制作肝切除缺血再灌注损伤动物模型,雄性SD大鼠随机分为3组,即假手术组（Sham组）,肝切除缺血再灌注组（I/R组）和肝切除缺血再灌注＋雌激素组（I/R＋E2组）。分别在缺血再灌注后1、3、6 h于光学显微镜下观察肝组织病理学改变,检测血清ALT的水平、肝组织MDA的含量及SOD的活性,并应用流式细胞仪检测细胞凋亡率。结果：I/R＋E2组在各时相点血清ALT、肝组织MDA和SOD及肝细胞凋亡率的变化幅度明显低于I/R组。在光学显微镜下观察I,/R组肝小叶结构紊乱,肝窦淤血,肝细胞水肿变性,肝细胞片状坏死。Sham组和I/R＋E2组上述改变明显减轻。结论：雌激素对肝切除缺血再灌注损伤有显著保护作用,其作用机制可能与雌激素减少氧自由基产生、减轻脂质过氧化反应及抑制细胞凋亡有关。     

Genistein预处理对大鼠肝缺血再灌注损伤的保护作用

目的：探讨genistein预处理对肝脏缺血再灌注损伤的保护作用及其机制。
方法：54只SD大鼠完全随机分成3组。A组为I/R组:70%热缺血60 min及再灌注;B组为I/R
 genistein（GST）预处理组;C组为假手术组。于成模后2,6,12 h取大鼠血清和肝组织,检测血清AST,ALT浓度和肝组织MDA浓度,免疫组化法检测肝组织casepase-3蛋白的表达,光镜下观察肝脏组织病理变化。
结果：与I/R组相比,genistein预处理血清中AST及ALT浓度明显降低,肝组织病理损伤明显减轻。肝组织casepase-3蛋白表达及MDA浓度显著降低（均P＜0.05）。
结论：genistein预处理对大鼠肝脏热缺血再灌注具有保护作用,其机制与清除氧自由基,抑制细胞凋亡有关。     

Effect of Shenfu Injection （ ginesenoside and aconite alkaloid） on the apoptosis of intestinal mucosal epithelial cells and its mechanism during ischemia-reperfusion in rats

hegutisnotonlyatargetorganfortraumaandshockbutalsoasatriggerforsystemicinflammationresponsesyndrome .Intestinalmucosalischemiaandreperfusioninjuryisanimportantandessentialetiologicalbasisleadingtomultipleorgandisfunctionsyndrome (MODS) .1Howtopreventandtreatshock ,trauma ,aswellastheischemiaandreperfusioninjuryofthegastrointestinaltracthasbecomethecruxtostudy .Ithasbeenprovedthatcellapoptosisisthemainpatternforthedeathofintestinalepithelialcellsduringischemiaandreperfusion .2 Ithasbeenincrea…     

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。     

血红素氧合酶-1减轻老龄大鼠供肝缺血再灌注损伤

目的诱导血红素氧合酶-1,提高老龄大鼠供肝的抗氧化能力,观察其能否减轻老龄大鼠供肝缺血再灌注损伤。方法　老龄SD大鼠为供者,成年SD大鼠为受者,随机分为实验组和对照组。实验组:供者供肝切取前24 h腹腔注射血晶素;对照组:供者供肝切取前24 h腹腔注射生理盐水。受者肝移植后3、6、12、24、48 h分别取移植肝组织,检测抗氧化酶、抗氧化剂、凋亡细胞和凋亡因子的表达情况。结果　实验组移植肝组织中超氧化物歧化酶(SOD)和维生素E、维生素C含量较对照组明显增加,丙氨酸转氨酶(ALT)则较对照组明显降低;另外,实验组较对照组凋亡细胞数量减少,BCL-2表达增加,半胱氨酸蛋白酶-3(Caspase 3)表达降低。结论诱导血红素氧合酶-1可以减轻老龄大鼠供肝缺血再灌注损伤,其机制与抑制细胞凋亡有关。     

白术多糖对缺血再灌注损伤大鼠肝脏的保护作用

目的：探讨白术多糖对大鼠肝脏缺血再灌注（I/R）损伤的保护作用。
方法：成年雄性SD大鼠随机分成3组：假手术组,I/R组,白术多糖预处理缺血再灌注组（PC组）,分别于成模后1,6,24 h 3个时段分别检测3组大鼠血清谷丙转氨酶（ALT）和谷草转氨酶（AST）水平;检测肝组织中ICAM-1 mRNA含量及IL-1的表达。
结果：PC组及I/R组ALT,AST水平以及ICAM-1 mRNA含量和IL-1表达均高于假手术组（P＜0.05）,但PC组上述4个指标均较I/R组显著降低,差异有统计学意义（P＜0.05）。
结论：白术多糖可能通过降低ICAM-1的含量而减少炎症因子IL-1的生成,从而对肝脏I/R损伤起保护作用。     

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。     

雌激素对大鼠肝切除肝缺血再灌注损伤中核因子-κB/IκB传导通路的影响及保护作用

目的 观察雌激素对大鼠肝切除肝缺血再灌注损伤中核因子-κB(NF-κB)/抑制蛋白(IκB)传导通路影响.方法 制作肝切除肝缺血再灌注损伤动物模型,雄性SD大鼠随机分为3组:假手术组(Sham组);肝切除肝缺血再灌注组(I/R组);肝切除肝缺血再灌注+雌激素组(I/R+ E2 组).分别在缺血再灌注后1、3、6h光镜下观察肝组织病理学改变,检测血清天冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)的水平和肝组织丙二醛(MDA)的含量及超氧化物岐化酶(SOD)的活性,免疫组织化学法测定肝组织NF-κB的表达,Western blot检测NF-κB抑制蛋白(IκB-α)和细胞间黏附分子-1(ICAM-1)表达,流式细胞仪检测细胞凋亡率.结果 再灌注后I/R组在各时相血清ALT、AST均显著高于I/R +E2组,并于6h达到峰值(P＜0.05).与I/R+E2组和Sham比较,I/R组肝细胞凋亡率显著升高(P＜0.01);肝组织中IκB-α表达降低,而NF-κB表达增高(P＜0.05);ICAM-1 和MDA的结果变化和NF-κB表达水平变化类似,SOD呈相反变化.在光镜下观察,I/R组肝小叶结构紊乱,肝窦淤血,肝细胞水肿变性,肝细胞片状坏死,在Sham组和I/R +E2组上述病理学变化明显改善.结论 雌激素对肝切除肝脏缺血再灌注损伤有显著保护作用,其作用机制可能与雌激素影响NF-κB/IκB传导通路、减轻脂质过氧化反应、减少炎症介质释放及抑制细胞凋亡有关.     

葛根素对大鼠肝缺血再灌注损伤脑组织c-fos和Bcl-2表达的影响

目的：观察肝缺血再灌注损伤时c-fos、Bcl-2与脑细胞凋亡的关系及葛根素对其影响的可能机制。方法：建立肝缺血再灌注损伤动物模型。选健康雄性SD大鼠56只,随机分为对照组、缺血30min组（I组）、缺血30min即刻再灌注组（I/R组）、缺血30min再灌注1h组（I/R1h）、缺血30min再灌注2h组（I/R2h）、30min再灌注4h组（I/R4h）及葛根素预处理组（PUE＋I/R4h组）,每组8只。观缺血察各组肝、脑HE染色;应用免疫组织化学方法测定各组大鼠脑组织c-fos、Bcl-2的表达;应用原位细胞凋亡法测定脑细胞凋亡。结果：I/R2h组、I/R4h组肝组织中散在分布大量炎症细胞,肝细胞明显肿胀,有的呈空泡状变性,肝脏结构紊乱;PUE＋I/R4h组上述改变明显改善。I/R2h、I/R4h组脑组织水肿明显,PUE＋I/R4h组明显改善。与对照组比较,其余各组脑组织c-fos表达均增高﹙P〈0.01）,I/R4h组水平最高,PUE＋I/R4h组较I/R1h组、I/R2h组、I/R4h组明显降低（P〈0.01）。与对照组比较,其余各组脑组织Bcl-2表达增高（P〈0.01）,I/R4h组与I/R2h组差异无统计学意义﹙P〉0.05）,PUE＋I/R4h组较对照组、组表达增多（P〈0.01）,较I/R1h组、I/R2h组、I/R4h组明显降低（P〈0.01）。I组、I/R组细胞I凋亡指数较对照组明显增加（P〈0.01）,随着再灌注时间的延长细胞凋亡指数逐渐增加。PUE＋I/R4h组较I/R2h组、I/R4h组明显降低（P〈0.01）。结论：肝缺血再灌注损伤可引起脑组织的损伤及脑细胞凋亡。随着再灌注时间的延长,脑组织中c-fos表达增高,脑细胞凋亡与c-fos的表达有关。Bcl-2在缺血期发挥了抑凋亡的作用,随着再灌注时间的延长,其作用减弱,脑细胞凋亡指数增加。葛根素可能通过抑制c-fos的表达、增加Bcl-2的表达发挥减轻肝缺血再灌注损伤所致脑细胞凋亡的作用。     

Apoptosis and regeneration of sinusoidal endothelial cells after extended cold preservation and transplantation of rat liver

BACKGROUND: Sinusoidal endothelial cells (SECs) are particularly susceptible to cold ischemia-reperfusion (I/R) injury. We have examined the process of injury and recovery of graft after cold-preserved liver transplantation, with special focus on the proliferation of SECs and regulatory mechanisms involved. METHODS: Male SD rats were divided into two groups according to length of cold preservation time in University of Wisconsin [UW] solution of graft: UW1h group and UW12h group. Graft function, incidence of apoptosis, proliferation of SECs and the expression of related regulatory factors were assessed after orthotopic liver transplantation (OLT). RESULTS: SECs are more sensitive to apoptosis induced by cold I/R injury compared with hepatocytes. Using bromodeoxyuridine and rat endothelial cell antigen-1 double immunostaining assay, SECs exhibited a delayed proliferation in comparison with hepatocytes, reaching a peak at 72 hr in UW1h group and 96 hr in UW12h group, respectively. Vascular endothelial growth factor increased at 24 hr after reperfusion, and peaked at 72 hr in both groups. Flt-1 and flk-1 expression was found to be mainly limited to SECs, with a peak in expression occurring between 72 and 96 hr, which coincided with the peak in SEC proliferation in UW1h group. However, flt-1 was found to be reduced significantly at any time throughout the experiments in UW12h group compared to sham. CONCLUSION: The delayed recovery of rat liver after extended cold preservation and transplantation correlates with a retarded regeneration of SECs due to increased apoptosis and reduced expression of flt-1. These results suggest that SECs play an important role in cold-preserved liver transplantation.     

饮食中亚硝酸盐对大鼠肝缺血再灌注损伤的保护作用

目的 探讨饮食中亚硝酸盐对大鼠肝脏缺血再灌沣(I/R)损伤的保护作用.方法 Wistar 大鼠随机分为I/R组(对照组)、亚硝酸钠预处理组(实验组)和假手术组.建立大鼠肝脏部分I/R模型,实验组的饮水中加入少量亚硝酸盐并喂养7 d后建模,检测血清谷丙转氨酶(ALT)和谷草转氨酶(AST)的水平,测定肝组织中超氧化物歧化酶(SOD),丙二醛(MDA),一氧化氮(NO),一氧化氮合酶(NOS)含量及活性.用Hoechst染色法检测细胞凋亡,并观察各组病理形态学的改变.结果 对照组AST,ALT,MDA水平和细胞凋亡的程度均明显异常.实验组上述指标的异常变化均明显减轻,NO明显高于对照组,差异有统计学意义(P＜0.01);但NOS并未增多,与对照组差异无统计学意义.结论 饮食中的亚硝酸盐对大鼠肝脏I/R损伤有明显的保护作用.     

异丙酚后处理联合缺血后处理对大鼠肝脏缺血再灌注损伤的影响

目的 探讨异丙酚后处理联合缺血后处理对大鼠肝脏缺血再灌注损伤的影响.方法 健康雄性sD大鼠30只,体重200～250 g,随机分为5组(n=6),假手术组(Ⅰ组)仅开腹;缺血再灌注组(11组)肝脏缺血1 h再灌注4 h;缺血后处理组(Ⅲ组)肝脏缺血1 h后,再灌注10 8,缺血10 8,重复6次进行缺血后处理;异丙酚后处理组(Ⅳ组)肝脏缺血1 h后经尾静脉注射异丙酚10 mg/kg,随后静脉输注异丙酚40 mg·kg~(-1)·h~(-1) h;异丙酚后处理+缺血后处理组(V组)肝脏缺血1 h后进行异丙酚后处理及缺血后处理.于再灌注4 h时测定血清ALT活性、肝组织MDA含量、SOD活性、Bcl-2及Bax的蛋白表达水平,电镜下观察肝细胞超微结构.结果 与Ⅰ组比较,Ⅱ组～Ⅴ组血清ALT活性及肝组织MDA含量升高,肝组织Bcl-2蛋白表达上调,Ⅲ组-Ⅴ组肝组织SOD活性升高,Ⅱ组、Ⅲ组及Ⅴ组肝组织Bax蛋白表达上调(P<0.05或0.01);与Ⅱ组比较,Ⅲ组-Ⅴ组血清ALT活性及肝组织MDA含量降低,肝组织SOD活性升高,Bcl-2蛋白表达上调,Bax蛋白表达下调(P<0.05或0.01);与Ⅲ组比较,Ⅳ组血清ALT活性及肝组织MDA含量降低(P<0.05或0.01).Ⅲ组-Ⅴ组肝组织病理学损伤较Ⅱ组明显减轻.结论 异丙酚后处理联合缺血后处理可减轻大鼠肝脏缺血再灌注损伤,与异丙酚后处理单独应用时效果相同,其机制可能与抑制肝组织脂质过氧化反应及细胞凋亡有关.     

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。     

巨噬细胞炎性蛋白-2在大鼠原位肝移植后的表达

目的：研究趋化因子巨噬细胞炎性蛋白－2（MIP－2）在大鼠同种原位肝移植后的表达。方法：采用大鼠原位肝移植模型,将供肝用乳酸林格氏液保存4h,随机分为两组,即移植后1h组和移植后4h组,同时用假手术组作对照,对肝组织中的MIP－2mRNA的表达,血清MIP－2的表达,肝组织中的中性粒细胞浸润、血清丙氨酸转氨酶（ALT）做了测定。结果移植组MIP－2mRNA的表达和血清蛋白表达较假手术对照组显著升高,4h 组高于1h组（P＜0．01）,并且它的mRNA表达和血清蛋白表达与肝中中性粒细胞浸润。血清ALT变化呈正相关。结论MIP－2在大鼠肝移植的缺血／再灌注损伤中起重要的上调作用,成为肝移植植再灌注损伤的重要因素之一。     

Caspase-8 and caspase-3 small interfering RNA decreases ischemia/reperfusion injury to the liver in mice

BACKGROUND: Ischemia/reperfusion injury (I/R injury) of the liver remains a significant problem during liver surgery and transplantation. I/R injury is associated with liver apoptosis, which is mediated by death receptors such as Fas and tumor necrosis factor alpha (TNF-alpha), and/or mitochondrial dysfunction induced by cellular stress. Caspase-8 is presumed to be the apex of the death-mediated apoptosis pathway, whereas caspase-3 belongs to the "effector" proteases in the apoptosis cascade. Synthetic small interfering RNAs (siRNAs) specifically suppress gene expression by RNA interference. Therefore, we evaluated the therapeutic efficacy of caspase-8 and caspase-3 siRNA in a murine model of liver I/R injury. METHODS: In C57BL/6 mice, 45% or 70% of the liver mass was clamped for 90 minutes. For survival analysis, total hepatic ischemia was induced for 45 minutes. In vivo delivery of siRNA was performed via the portal vein by high-volume injection (0.5 nmol of siRNA in 1 mL containing 10% lipiodol) 60 minutes before ischemia. As a control, animals received either vehicle or non-sense siRNA (siRNA-scrambled). RESULTS: Liver uptake of siRNA was analyzed in transgenic mice who express beta-galactosidase (beta-gal) (C57BL/6J-TgN(MTn-LacZ)204Bri) after administration of siRNA-LacZ. A 3- to 4-fold decrease in beta-gal activity was accomplished at 0.5 nmol. No significant change in beta-gal activity was demonstrated in mice receiving non-sense siRNA. Immunohistochemical studies found that 60% of the liver cells efficiently took up siRNA. Significant reduction in serum aspartate transaminase was found in animals treated with siRNA caspase-8 or caspase-3 compared with siRNA-scrambed or vehicle-treated controls. More than a 60% reduction in caspase-8 and caspase-3 gene expression and activities was accomplished after siRNA administration. Animals treated with siRNA presented lower infiltration of polymorphonuclear leukocytes and better preservation of the liver architecture compared with controls. All of the control mice subjected to total liver ischemia died within 5 days. In contrast, 30% of the animals given siRNA caspase-8 and 50% of those treated with siRNA caspase-3 survived indefinitely (>30 days). CONCLUSIONS: Small interfering RNA targeted to caspase-8 and caspase-3 provided significant protection against I/R injury to the liver. This approach could be therapeutic in liver transplantation and other conditions associated with I/R injury to the liver.