Na~+/H~+交换泵抑制剂EIPA对大鼠肝脏缺血再灌注损伤的影响

目的探讨Na+/H+交换泵抑制剂EIPA对SD大鼠肝缺血再灌注损伤的影响。方法 30只成年SD大鼠随机分成空白组,缺血再灌注组,EIPA预处理组,每组10只。用Pringle's法建立肝缺血模型。比较各组之间的ALT、AST、肝组织湿/干比、肝组织匀浆内髓过氧化物酶(MPO)活性、肝组织Ca2+浓度、肝组织形态学变化及EIPA对上述指标的影响。结果肝缺血再灌注损伤时,血清转氨酶、肝组织Ca2+浓度、湿/干比、MPO活性均明显升高(P<0.05),肝脏呈现不同程度的病理改变;使用EIPA预处理后,上述指标的异常变化均明显减轻,差异有统计学意义(P<0.05)。结论 EIPA可能通过降低细胞内Ca2+超载减轻肝组织水肿,抑制中性粒细胞活性,从而改善缺血肝组织的能量代谢和肝脏组织微循环,对SD大鼠肝脏缺血再灌注损伤产生保护作用。     

中性粒细胞在肝缺血再灌注损伤中的作用及川芎嗪的保护效应

目的探讨肝缺血再灌注损伤时中性粒细胞（ＰＭＮ）的聚集及川芎嗪的保护作用．方法应用家兔肝缺血再灌注损伤模型，观察肝缺血再灌注损伤过程中ＰＭＮ的浸润、脂质过氧化物（ＬＰＯ）、肝细胞形态学变化及川芎嗪的防护效应．结果随着肝缺血再灌注时间的延长，肝组织中ＰＭＮ浸润程度逐渐加重，肝细胞形态学异常变化越发显著，川芎嗪可明显减轻上述的异常变化．结论中性粒细胞聚集、粘附、活化是肝缺血再灌注损伤的重要原因，川芎嗪通过抑制ＰＭＮ聚集、粘附、活化而减轻肝缺血再灌注损伤．     

家兔肝缺血再灌注损伤中脂质过氧化反应及人参多糖的干预

目的 观察肝缺血再灌注损伤时脂质过氧化的变化以及人参多糖的干预作用,并探究其机制.方法 30只家兔随机均分为对照组、缺血再灌注组和人参多糖组.观察血浆及肝组织中丙二醛含量及超氧化物歧化酶、谷胱甘肽过氧化物酶、黄嘌呤氧化酶和丙氨酸氨基转移酶活力变化,光镜下观察肝组织结构变化,并观察人参多糖对上述指标的影响.结果 缺血再灌注组血浆超氧化物歧化酶和谷胱甘肽过氧化物酶活力在肝脏缺血45 min以及再灌注45 min逐步降低,丙氨酸氨基转移酶、黄嘌呤氧化酶活力和丙二醛含量明显升高.人参多糖组血浆超氧化物歧化酶和谷胱甘肽过氧化物酶活力与缺血前比无明显下降,丙氨酸氨基转移酶、黄嘌呤氧化酶活力和丙二醛含量无明显升高,尤其再灌注45 min血浆超氧化物歧化酶活力显著高于缺血再灌注组同期(P<0.01),丙氨酸氨基转移酶、黄嘌呤氧化酶活力和丙二醛含量显著低于缺血再灌注组同期水平(P<0.01).肝组织超氧化物歧化酶、谷胱甘肽过氧化物酶活力缺血再灌注组明显低于对照组,人参多糖组则明显高于缺血再灌注组(P<0.01);黄嘌呤氧化酶活力和丙二醛含量缺血再灌注组明显高于对照组(P<0.05或P<0.01),而人参多糖组则明显低于缺血再灌注组(P<0.05或P<0.01).光镜下发现缺血再灌注组肝组织细胞形态学结构明显异常,人参多糖组肝组织损伤明显减轻.结论 人参多糖能降低黄嘌呤氧化酶活性,减少氧自由基的生成,并且能增强超氧化物歧化酶、谷胱甘肽过氧化物酶等抗氧化酶的活性,清除氧自由基,抑制脂质过氧化反应,从而有效减轻肝缺血再灌注损伤.     

NF-κB对肠缺血再灌注肝损伤P-选择素表达和中性粒细胞浸润的作用

目的:探讨核转移因子-κB(NF-κB)在肠缺血再灌注肝损伤发病机制中的作用及其对P-选择素(P-selectin)表达和中性粒细胞浸润的影响．方法:Wistar大鼠24只随机分成对照(Control 组)、肠缺血再灌注(I／R组)和脯氨酸二硫代氨基甲酸酯(PDTC)治疗组(PDTC组),每组8只．I／ R和PDTC组大鼠行肠系膜上动脉夹闭1 h再灌注2 h．PDTC组于手术前1 h给予20 g／L PDTC 100 mg／kg ip．观察肝组织病理学及其肝功能变化,检测血清IL-6,肝组织匀浆超氧化物歧化酶(SOD)和髓过氧化物酶(MPO)水平．免疫组化法观察肝组织P-selectin和NF-κB表达并采用Western blot法检测肝NF-κB的水平．结果:肠缺血再灌注诱发了肝损伤,表现为肝水肿、出血和炎性粒细胞浸润．与对照组相比,I／R组血清ALT、AST、IL-6水平明显升高 (143．16±53．02至192．31±42．09 U／L,P<0．05; 387．46±78．74至507．56±96．26 U／L,P<0．01; 22．51±6．10至42．85±7．35 ng／L,P<0．01)．肝组织SOD活性降低、MPO含量明显升高(244．87 ±25．11至173．21±16．60 U／mgprot,P<0．01; 2．36±0．56至4.32±0．77 U／g,P<0．01);肝组织的P-selectin和NF-κB表达增强．采用PDTC 预处理,与I／R组相比,肝损伤程度减轻,血清ALT(128．63±38．94 U／L)、AST(462．86± 60．84 U／L)以及IL-6(28．08±7．55 ng／L)水平明显降低(P<0．01,P<0．05,P<0．05);肝脏氧化损伤及白细胞浸润减弱,表现为肝组织SOD活性升高(253．45±25．21 U／mgprot,P<0．01)、MPO 含量降低(3．58±0．49 U／g,P<0．05),同时伴有肝组织中的P-selectin和NF-κB表达减弱．结论:肠缺血再灌注诱发肝损伤,伴有明显的中性粒细胞浸润和肝组织P-selectin的表达增强,NF-κB的活化在此损伤过程中起重要作用． PDTC通过抑制NF-κB活性对肠缺血再灌注肝损伤起保护作用．     

前列腺素E1预处理对胆汁淤积大鼠肝缺血再灌注损伤的保护作用

目的探讨前列腺素E1(PGE1)对胆汁淤积肝脏缺血再灌注损伤的保护机制。方法 36只雄性Wistar大鼠随机分为前列腺素E1组(PGE组)和生理盐水组(NS组)。PGE组肝缺血前15 min至再灌注60 min经门静脉持续泵入PGE1(0.5μg·kg~(-1)·min~(-1)),NS组给予等量生理盐水。结扎胆总管,建立胆汁淤积模型。7 d后Pringle法阻断入肝血流15 min,于再灌注1、6和24 h,检测血清生化酶和胆红素,以及肝组织髓过氧化物酶(MPO)、TNFα、Bcl-2、Bax、热休克蛋白(HSP)70和病理组织学改变。结果再灌注1、6和24 h,2组TBil和DBil水平比较,差异均无统计学意义(P值均0.05)。再灌注1、6和24 h,PGE组ALT、AST、MPO和TNFα水平均显著低于NS组,差异均有统计学意义(P值均0.05)。再灌注1、6和24 h,PGE组Bcl-2水平显著高于NS组,Bax水平显著低于NS组,差异均有统计学意义(P值均0.05)。再灌注1 h和6 h,PGE组HSP70 mRNA表达水平明显高于NS组,差异均有统计学意义(P值均0.05)。再灌注24 h,2组HSP70 mRNA表达水平差异无统计学意义(P0.05)。PGE组肝组织损伤程度均较NS组轻,表现为肝细胞肿胀减轻,肝细胞坏死减少,肝细胞索及肝窦结构比较清晰,肝细胞索排列较规则,肝窦明显增宽。结论 PGE1通过减少中性粒细胞浸润和Bax表达,以及增强HSP70和Bcl-2表达保护胆汁淤积肝脏的缺血再灌注损伤。     

缺血后处理对大鼠肝脏缺血再灌注损伤的保护作用

目的探讨缺血后处理对大鼠肝脏缺血再灌注损伤的保护作用。方法将75只SD大鼠随机分为假手术组、缺血再灌注组和缺血后处理组,建立大鼠肝脏局部缺血再灌注模型。检测大鼠血清、肝组织丙二醛（MDA）、超氧化物歧化酶（SOD）水平,并行肝组织病理学和超微结构检查及免疫组化法检测内源性一氧化氮合成酶（eNOS）的表达。结果与缺血再灌注组相比,缺血后处理组血清ALT和AST水平及肝组织MDA明显降低（P＜0．01）,而SOD水平则显著升高（P〈0．01）;肝组织病理损伤减轻,在再灌注7min时IPO组肝组织eNOS蛋白表达比IR组增强。结论缺血后处理可通过抑制再灌注后氧自由基的过量生成和再灌注损伤保护激酶通路,从而减轻肝细胞损伤。     

川芎嗪对肝缺血再灌注损伤大鼠P-选择素表达的影响

[目的]观察川芎嗪干预肝缺血再灌注损伤大鼠P-选择素表达,探索可能的病理机制,为预防治疗肝细胞缺血再灌注损伤提供依据.[方法]将64只SD大鼠随机分为4组,肉眼观察肝脏形态变化,光镜、电镜观察肝细胞形态变化,免疫组化SABC法检测肝组织中P-选择素表达.[结果]缺血再灌注组可见肝细胞水肿明显,伴空泡形成,间质充血水肿及炎性细胞浸润,再灌注6 h可见肝组织出现明显的点状坏死灶,并可见到灶性坏死;再灌注24 h肝组织可见多发性灶性坏死及片状坏死灶.川芎嗪干预组各时间点肝组织外观与正常肝相似,光镜下肝细胞无明显肿胀,有极少量空泡形成,但无变性或坏死,且间质无明显变化.免疫组化SABC法检测显示,缺血再灌注早期P-选择素即在肝组织中表达,与川芎嗪干预组及假手术组比较,差异有统计学意义(P＜0.01).缺血再灌注组P-选择素表达以1 h时最为明显,与再灌6 h及24 h相比,差异有统计学意义(P＜0.01).[结论]川芎嗪能有效抑制P-选择素的表达,减轻肝缺血再灌注损伤.P-选择素主要在缺血再灌注损伤早期表达.P-选择素介导中性粒细胞滚动黏附,可能是肝缺血再灌注损伤的主要机制之一.     

不同时间的缺血预处理对脂肪肝缺血再灌注损伤的保护作用

目的探讨缺血预处理（IP）对脂肪肝缺血再灌注（IR）损伤的保护作用,以及取得最佳效果的预处理时间。方法通过建立大鼠脂肪肝模型,给予不同时间的IP（5-10、8-10、10-10、15-10 min）和IR（缺血30 min,再灌注30 min）,检测血清AST、ALT、LDH及NO水平,肝组织中MDA、SOD、MPO含量的变化和肝脏病理学变化。以脂肪肝未行IP组和正常肝脏未行IP组及正常肝脏行10-10 min IP作对照。结果 IR后,脂肪肝未行IP组血清肝功能的变化、肝组织病理学改变及炎性浸润程度显著重于正常肝脏未行IP组。在脂肪肝组中,5或8-10 min IP组血清学及肝组织MDA、MPO水平低于其余组和未行IP组,而其SOD水平显著升高（P〈0.05）。各IP组中的NO水平明显高于其对应的IR组（P〈0.05）。脂肪肝IP组中,5或8-10 min IP组血清NO水平明显高于其余组（P〈0.05）。结论脂肪变性加重肝脏IR损伤,IP对脂肪肝的IR损伤具有保护作用,本实验认为5～8 min缺血和10 min再灌注的IP方案可能是中重度脂肪肝时的最佳预处理方案。     

姜黄素对大鼠肝缺血再灌注早期肝组织一氧化氮表达的影响

目的:探讨姜黄素对大鼠肝脏缺血再灌注早期损伤微循环的影响.方法:将大鼠随机分为假手术组、对照组和实验组(姜黄素40 mg/kg,2次给药).通过检测再灌注早期1、3 h血清转氨酶水平、肝组织中一氧化氮(nitricoxide,NO)、一氧化氮合酶(nitricoxide synthase,NOS),诱导型一氧化氮合酶(inducible nitricoxide synthase,iNOS)mRNA及内皮型一氧化氮合酶(endothelium nitricoxide synthase,eNOS)mRNA水平,以及肝组织病理学检查来评价姜黄素对大鼠肝脏缺血再灌注早期损伤微循环的影响.结果:相对于对照组,姜黄素可降低大鼠肝脏缺血再灌注早期损伤1、3 h血清谷丙转氨酶(ALT)的水平(603.8 U/L±64.5 U/L vs 758.1 U/L±114.7U/L,837.1 U/L±33.3 U/L vs 1012.7 U/L±119.8 U/L,均P<0.01)和谷草转氨酶(AST)的水平(605.7 U/L±65.7 U/L vs 779.5 U/L±124.3 U/L,849.6 U/L±36.0 U/L vs 1027.8 U/L±139.8 U/L,均P<0.01);改善肝组织病理学损害;减少肝脏缺血再灌注早期损伤1、3 h肝组织由iNOS产生的NO蛋白水平(0.455±0.056 vs 0.594±0.087.0.492±0.040 vs 0.671±0.079,均P<0.01);降低肝脏缺血再灌注早期损伤1、3 h肝组织iNOS mRNA的表达强度(0.426±0.075 vs 0.569±0.073,0.527±0.066vs 0.702±0.089,均P<0.01).结论:姜黄素可通过减轻肝组织中由iNOS产生的NO生成,来改善肝缺血再灌注早期损伤中微循环的紊乱,从而减少对肝缺血再灌注肝实质细胞的损伤.     

PrxⅥ、SOD、CAT在肝脏缺血再灌注损伤大鼠模型脑内的表达

目的 观察过氧化物酶Ⅵ(PrxⅥ)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)在大鼠肝脏缺血再灌注损伤模型脑内的表达变化.方法 雄性Wistar大鼠随机分为对照组和肝脏缺血再灌注损伤组,通过无损伤血管夹夹闭通往大鼠肝左叶、肝中叶的血管和胆管蒂,30 min后松开血管夹,制造大鼠70％肝脏缺血再灌注损伤模型.6h后取血、肝脏和脑组织.全自动生化分析仪测血清ALT含量,HE法观察大鼠肝脏和脑组织形态学改变,脑组织MDA含量由南京建成试剂盒测定,采用RT-PCR的方法观察大鼠脑内PrxⅥ、SOD、CAT mRNA水平的表达变化,SOD活性采用黄嘌呤氧化酶法测定,PrxⅥ的蛋白水平采用Western印迹测定.结果 与对照组相比,血清中ALT水平和肝脏HE结果均显示肝脏缺血再灌注损伤组大鼠的肝细胞明显受损,证明大鼠肝脏缺血再灌注损伤模型成立.虽然脑组织的HE结果显示脑的形态学结构未发生明显改变,但脑组织内MDA的含量却增加(P＜0.01).同时,PrxⅥmRNA和蛋白水平均升高(P＜0.01),SOD和CAT mRNA水平(P＜0.01)和抗氧化活性(P＜0.01)也都明显增强.结论 在大鼠肝脏发生缺血再灌注损伤后脑内的氧化应激水平也随之增强,而PrxⅥ、SOD、CAT在脑内均发挥了抗氧化应激作用,对脑组织具有一定的保护功能.     

Modulation of liver oxidant-antioxidant system by ischemic preconditioning during ischemia／reperfusion injury in rats

AIM: To investigate effects of ischemic pre-conditioning on the liver endogenous oxidant-antioxidant system during ischemia/reperfusion injury. METHODS: Twenty-four male Sprague-Dawley rats were randomly divided into sham-operated (Sham), ischemia/ reperfusion (I/R), ischemic pre-conditioning plus ischemia/ reperfusion (IPC) groups. Serum ALT, AST and hyaluronic acid levels were assayed and pathologic alterations observed. Liver malondialdehyde (MDA) contents, endogenous antioxidant enzymes, superoxidase dismutase (SOD), catalase (CAT), gultathionine peroxidase (GSH-Px) activities, neutrophils accumulation marker, myeloperoxidase (MPO) activities were measured respectively. RESULTS: Compared with I/R group, sinusoidal endothelial cells as well as hepatocytes damages, as assessed biochemically and histochemically, were improved significantly in IPC group; neutrophils infiltration was also markedly reduced. In IPC group, liver peroxidation, as measured by MDA contents, was significantly decreased when compared with I/R group; endogenous antioxidant enzymes, SOD, CAT and GSH-Px activities were markedly higher than that in I/R group. CONCLUSION: Ischemic pre-conditioning exerts protective effects on both hepatic sinusoidal endothelial cells and hepatocytes during liver I/R injury. Its mechanisms may involve dimunition of neutrophils infiltration and modulation of the imbalance of endogenous oxidant-antioxidant system in the organism.     

大白兔肝缺血再灌注损伤时血浆内毒素的变化及对肝肾功能的影响

目的探讨肝缺血再灌注损伤过程中,肠源性内毒素的动态变化和继发性肝肾功能损害。方法取27只健康成年新西兰大白兔,体重1.4~2.3?,随机分为对照组7只,另外20只作为实验组。以缺血10min(I10min)、缺血20min(I20min)、缺血30min(I30min)和分别再灌注30min(R30min)随机分为3组。对照组取门、腔静脉血测肝肾功能及血浆内毒素,实验组阻断第一肝门造成不同的缺血时段,松开血管夹再灌注30min,其余实验同对照组。结果实验组中血浆谷草转氨酶、谷丙转氨酶、尿素氮、肌苷含量及内毒素浓度均有升高,在I10min/R30min组即有升高,但与对照组相比差异无显著性(P>0.05);而后随着缺血时间的延长这些指标继续明显升高,至I30min/R30min组达最高值,与对照组比差异有显著性(P<0.05~0.01)。肾组织电镜观察发现I10min/R30min组肾脏超微结构无明显改变,而I20min/R30min组和I30min/R30min组肾脏超微结构损害明显。结论肝门阻断后门静脉系统淤血,致肠源性内毒素产生和移位;肝门再开放造成肝缺血再灌注损伤,且随着缺血时间的延长,门、腔静脉血中内毒素水平进行性升高,肝功能进一步损害,最终引起肝肾综合征。     

Effects of Wy14643 on hepatic ischemia reperfusion injury in rats

AIM： To investigate the effects and possible mechanisms of Wy14643 on hepatic ischemiareperfusion （I/R） injury in rats. METHODS： Thirty male Sprague-Dawley rats weighing 220-280 g were randomly divided into five experimental groups： sham group （G1, n = 6）： a sham operation was performed （except for liver I/R）, I/R-untreated group （G2, n = 6）： rats underwent liver ischemia for 90 min followed by reperfusion for 4h; and I/R ＋ Wy14643 groups （G3, G4, G5; n = 6）： after the same surgical procedure as in group 2, animals were pretreated with Wy14643 at the dose of 1, 5 and 10 mg/kg 1 h before ischemia, respectively. Hepatic ischemia-reperfusion （I/R） was induced by clamping blood supply to the left lateral and median lobes of the liver for 90 min, and atraumatic clamp was removed for 4 h reperfusion. Blood samples and liver tissues were obtained at the end of reperfusion to assess serum and hepatic tissue homogenate aminotransferase （ALT）, aspartate aminotransferase （AST）, myeloperoxidase （MPO）, serum interleukin- 1β（IL-1β） and tumor necrosis factor alpha （TNF-α）, as well as activity of superoxide dismutase （SOD） and content of malondialdehyde （MDA） in the hepatic tissue homogenate. RESULTS： Hepatic I/R induced a significant increase in the serum levels of ALT, AST, TNF-α, IL-1β and MPO, as well as the levels of ALT, AST and MDA in the liver tissue homogenate, which were reduced by pretreatment with Wy14643 at the dose of 1, 5 and 10 mg/kg, respectively. The activity of SOD in the liver tissue homogenate was decreased after hepatic I/R, which was enhanced by Wy14643 pretreatment. In addition, serum and liver tissue homogenate ALT and AST in the Wy14643 10 mg/kg group were lower than in the Wy14643 1 mg/kg and 5 mg/kg groups, respectively. CONCLUSION： Wy14643 pretreatment exerts significant protection against hepatic I/R injury in rats. The protective effects are possibly associated with enhancement of anti-oxidant and inhibition inflammation res     

Protective effect of curcumin against liver warm ischemia/reperfusion injury in rat model is associated with regulation of heat shock protein and antioxidant enzymes

AIM： To investigate the hypothesis that the protective effects of curcumin in hepatic warm ischemia/reperfusion （I/R） injury are associated with increasing heat shock protein 70 （Hsp70） expression and antioxidant enzyme activity. METHODS： Sixty Sprague-Dawley male rats were randomly divided into sham, I/R, C ＋ I/R groups. The model of reduced-size liver warm ischemia and reperfusion was used. Curcumin （50 mg/kg） was administered by injection through a branch of superior mesenteric vein at 30 min before ischemia in C ＋ I/R group. Five rats were used to investigate the survival during 1 wk after operation in each group. Blood samples and liver tissues were obtained in the remaining animals after 3, 12, and 24 h of reperfusion to assess serum alanine aminotransferase （ALT）, aspartate aminotransferase （AST）, liver tissue NO2- ＋ NO3-, malondialdehyde （MDA） content, superoxide dismutase （SOD）, catalase （CAT）, nitricoxide synthase （NOS） and myeloperoxidase （MPO） activity, HspT0 expression and apoptosis ratio. RESULTS： Compared with I/R group, curcumin pretreatment group showed less ischemia/reperfusioninduced injury. CAT and SOD activity and Hsp70 expression increased significantly. A higher rate of apoptosis was observed in I/R group than in C ＋ I/R group, and a significant increase of MDA, NO2^- ＋ NO3^- and MPO level in liver tissues and serum transaminase concentration was also observed in I/R group compared to C ＋ I/R group. Curcumin also decreased the activity of inducible NO synthase （iNOS） in liver after reperfusion,but had no effect on the level of endothelial NO synthase （eNOS） after reperfusion in liver. The 7 d survival rate was significantly higher in C ＋ I/R group than in I/R group. CONCLUSION： Curcumin has protective effects against hepatic I/R injury. Its mechanism might be related to the overexpression of Hsp70 and antioxidant enzymes.     

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。     

Effects of propofol on early phase of warm hepatic ischemia/reperfusion injury

BACKGROUND/AIMS: It is still unclear whether propofol may protect the liver against ischemia/ reperfusion injury (IRI) in vivo. METHODOLOGY: The livers of male Sprague-Dawley rats were subjected to 60 minutes of partial normothermic ischemia allowing perfusion to right and caudate lobes and subsequent 45 minutes of reperfusion. Either propofol (Propofol group, n = 11, 10 mg/ kg/h) or saline (Control group, n = 11) was continuously administered. At the end of reperfusion blood and liver samples were taken to analyze malondialdehyde, hepatic injury score, palmitate oxidation rate, serum AST and ALT concentrations. RESULTS: The malondialdehyde concentration (micromol/g tissue, mean +/- SD) was decreased in the Propofol group (1.39 +/- 0.21, perfused lobes and 1.85 +/- 0.27, ischemic reperfused lobes) compared with Control group (1.97 +/- 0.20, perfused lobes and 2.39 +/- 0.28, ischemic reperfused lobes) (P < 0.01). Hepatic injury scores were decreased in Propofol group compared with Control group (P < 0.01), but with mild hepatic injury in both groups. There were no differences of serum AST and ALT concentrations, and palmitate oxidation rate between groups. CONCLUSIONS: Propofol might be effective mainly in attenuation of lipid peroxidation with only minimal hepatocellular protection during the early phase of warm hepatic IRI in vivo.     

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.     

Effect of ischemic preconditioning on P-selectin expression in hepatocytes of rats with cirrhotic ischemia-reperfusion injury

AIM: To investigate the effects and mechanisms of ischemic preconditioning (IPC) on the ischemia/reperfusion (I/R) injury of liver cirrhosis in rats and the effect of IPC on P-selectin expression in hepatocytes.METHODS: Forty male SD rats with liver cirrhosis were randomly divided into sham operation group (SO group),ischemia/reperfusion group (I/R group), ischemic preconditioning group (IPC group), L-Arginine preconditioning group (APC group), L-NAME preconditioning group (NPC group), eight rats in each group. Hepatocellular viability was assessed by hepatic adenine nucleotide level and energy charge (EC) determined by HPLC, ALT, AST and LDH in serum measured by auto- biochemical analyzer and bile output.The expression of P-selectin in the liver tissue was analyzed by immunohistochemical technique. Leukocyte count in ischemic hepatic lobe was calculated.RESULTS: At 120 min after reperfusion, the level of ATP and EC in IPC and APC groups was higher than that in I/R group significantly. The increases in AST, ALT and LDH were prevented in IPC and APC groups. The livers produced more bile in IPC group than in I/R group during 120 min after reperfusion (0.101±0.027 versus 0.066±0.027 ml/g liver,P=0.002). There was a significant difference between APC and I/R groups, (P=0.001). The leukocyte count in liver tissues significantly increased in I/R group as compared with SO group (P＜0.05). The increase in the leukocyte count was prevented in IPC group. Administration of L-arginine resulted in the same effects as in IPC group. However,inhibition of NO synthesis (NPC group) held back the beneficial effects of preconditioning. Significant promotion of P-selectin expression in hepatocytes in the I/R group was observed compared with the SO group (P＜0.01). IPC or L-arginine attenuated P-selectin expression remarkably (P＜0.01). However, inhibition of NO synthesis enhanced Pselectin expression (P＜0.01). The degree of P-selectin expression was positively correlated with the leukocyte counts infiltrating in liver (r=0.602, P=0.000).CONCLUSION: IPC can attenuate the damage induced by I/R in cirrhotic liver and increase the ischemic tolerance of the rats with liver cirrhosis. IPC can abolish I/R induced leukocyte adhesion and infiltration by preventing postischemic P-selectin expression in the rats with liver cirrhosis via a NO-initiated pathway.     

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.