促红细胞生成素预处理在心肌缺氧复氧损伤中对凋亡相关基因表达影响的研究

目的：观察促红细胞生成素（erythropoietin,EPO）预处理在大鼠心肌缺氧复氧损伤（hypoxia/reoxygenation,H/R）中的抗凋亡效应以及对凋亡相关基因bcl-2及bax表达的影响。方法：Wistar成年雄性大鼠60只,分为2组,分别为对照组,EPO预处理组（EPO组）,每组30只,EPO组大鼠经腹腔注射5000U/kg重组人促红细胞生成素（Recombinant human erythropoietin,RHuEPO）,对照组注射同体积生理盐水。2组各15只大鼠于给药24h后,检测各项指标,其余15只大鼠置于常压缺氧环境中（O27%）12h后,移至常压常氧环境中2h,予H/R损伤,之后采取心肌标本,DNA末端转移酶标记法（TUNEL法）检测心肌细胞凋亡,免疫组化检测凋亡效应酶胱天蛋白酶-3（caspase-3）、凋亡相关基因B细胞淋巴瘤/白血病-2（B-cell lymphoma/leukemia-2,bcl-2）及B细胞淋巴瘤/白血病相关x蛋白（Bcl-associated x protein,bax）蛋白表达水平,计算bcl-2/bax比值。结果：H/R损伤前2组心肌细胞凋亡率,caspase-3以及bax蛋白表达水平无显著性差异（P〉0.05）,EPO组bcl-2蛋白表达水平、bcl-2/bax比值显著高于对照组（P〈0.01）。H/R损伤后2组心肌细胞凋亡率,caspase-3、bax及bcl-2蛋白表达水平显著高于损伤前（P〈0.01）,而bcl-2/bax比值显著低于损伤前（P〈0.01）,EPO组的心肌细胞凋亡率、caspase-3蛋白表达水平显著低于对照组（P〈0.05,P〈0.01）,而bcl-2蛋白表达水平以及bcl-2/bax比值显著高于对照组（P〈0.05,P〈0.01）,2组bax蛋白表达水平差异无显著性（P〉0.05）。结论：EPO预处理在心肌H/R损伤中具有显著的抗凋亡效应;这一效应与其上调抗凋亡基因bcl-2的表达有关。     

脑缺血再灌注后bcl-2、caspase-3 mRNA水平表达与大脑皮质及纹状体区炎性细胞浸润

目的探讨大鼠脑缺血再灌注后bcl-2蛋白、caspase-3 mRNA的表达及炎性细胞浸润与神经细胞凋亡的关系。方法将54只Wistar大鼠随机分为二组：假手术组，缺血再灌注组。采用原位末端标记(TUNEL)、免疫组化和原位杂交技术分别观察脑缺血再灌注后不同时间点神经细胞凋亡及损伤的变化与bcl-2、caspase-3 mRNA表达。结果bcl-2表达于缺血再灌注12～24h达高峰，再灌注2—4d呈下降趋势，至16d略高于假手术组；caspase-3 mRNA于缺血再灌注12—24h达高峰，2—4d呈降低趋势，至16d略高于假手术组。结论脑缺血再灌注后细胞凋亡介导神经细胞损伤、坏死是一个渐进的动态演变过程。bcl-2蛋白、caspase-3 mRNA表达在抑制细胞凋亡和介导神经细胞损伤等方面起非常重要的作用。     

苦参碱对大鼠供肝冷保存再灌注损伤中肝细胞凋亡及调控基因表达的影响

目的:探讨苦参碱对大鼠原位肝移植供肝冷保存再灌注损伤中肝细胞凋亡及调控基因表达的影响.方法:应用延长保存的大鼠原位肝移植模型,大鼠84只随机分为对照组、低剂量苦参碱治疗组(40mg/kg)、高剂量苦参碱治疗组(80mg/kg)和假手术组,将供肝在4℃林格液中保存5h后植入受体,各组大鼠于再灌注后4和24h后取样.采用TUNEL法分别检测移植术后肝细胞凋亡,流式细胞仪检测凋亡相关基因Bcl-2,FasL蛋白的表达,光镜下观察移植肝脏病理形态学的改变.结果:与对照组比较,苦参碱低、高剂量治疗组术后肝脏细胞凋亡指数显著降低(6.07±1.68,6.17±0.83vs14.87±2.10,P<0.01),肝组织Bcl-2表达增加(59.32±14.09,58.90±16.70vs17.00±8.01,P<0.01),但FasL表达量无显著差异(P>0.05),肝细胞凋亡指数、Bcl-2和FasL表达在苦参碱低、高剂量组间也无显著差异.对照组肝细胞损伤的病理表现相当严重,而治疗组的病理表现显著改善.结论:苦参碱通过促进抑制凋亡基因Bcl-2的表达来抑制冷保存再灌注导致的肝细胞凋亡.     

促红细胞生成素预处理在心肌缺氧复氧损伤中对凋亡相关基因表达影响的研究

目的:观察促红细胞生成素(erythropoietin,EPO)预处理在大鼠心肌缺氧复氧损伤(hypoxia/reoxygenation,H/R)中的抗凋亡效应以及对凋亡相关基因bcl-2及bax表达的影响。方法:Wistar成年雄性大鼠60只,分为2组,分别为对照组,EPO预处理组(EPO组),每组30只,EPO组大鼠经腹腔注射5000U/kg重组人促红细胞生成素(Recombinant human erythropoietin,RHuEPO),对照组注射同体积生理盐水。2组各15只大鼠于给药24h后,检测各项指标,其余15只大鼠置于常压缺氧环境中(O27%)12h后,移至常压常氧环境中2h,予H/R损伤,之后采取心肌标本,DNA末端转移酶标记法(TUNEL法)检测心肌细胞凋亡,免疫组化检测凋亡效应酶胱天蛋白酶-3(caspase-3)、凋亡相关基因B细胞淋巴瘤/白血病-2(B-cell lymphoma/leukemia-2,bcl-2)及B细胞淋巴瘤/白血病相关x蛋白(Bcl-associated x protein,bax)蛋白表达水平,计算bcl-2/bax比值。结果:H/R损伤前2组心肌细胞凋亡率,caspase-3以及bax蛋白表达水平无显著性差异(P>0.05),EPO组bcl-2蛋白表达水平、bcl-2/bax比值显著高于对照组(P<0.01)。H/R损伤后2组心肌细胞凋亡率,caspase-3、bax及bcl-2蛋白表达水平显著高于损伤前(P<0.01),而bcl-2/bax比值显著低于损伤前(P<0.01),EPO组的心肌细胞凋亡率、caspase-3蛋白表达水平显著低于对照组(P<0.05,P<0.01),而bcl-2蛋白表达水平以及bcl-2/bax比值显著高于对照组(P<0.05,P<0.01),2组bax蛋白表达水平差异无显著性(P>0.05)。结论:EPO预处理在心肌H/R损伤中具有显著的抗凋亡效应;这一效应与其上调抗凋亡基因bcl-2的表达有关。     

银杏叶对脑缺血再灌注损伤大鼠神经细胞凋亡、bcl-2和Bax表达的影响

目的分析银杏叶对脑缺血再灌注损伤大鼠神经细胞凋亡、bcl-2和Bax表达的影响。方法选取40只健康合格的雌性SD大鼠,分为假手术组、模型组、低剂量组、高剂量组。脑缺血再灌注24 h,分别对4组大鼠的脑梗死体积百分比、凋亡细胞数、bcl-2、Bax及bcl-2/Bax进行测定。结果模型组大鼠的脑梗死无论在体积百分比、凋亡细胞数都明显高于假手术组,差异具有统计学意义(P0.05);低剂量组、高剂量组梗死体积的百分比和凋亡细胞数明显少于模型组,且高剂量组大鼠脑梗死体积百分比、凋亡细胞数较低剂量组的大鼠降低显著(P0.05);4组大鼠脑缺血再灌注24 h后,模型组bcl-2、Bax显著高于假手术组(P0.05),低剂量组大鼠bcl-2、bcl-2/Bax高于模型组大鼠而Bax低于模型组大鼠,高剂量组大鼠bcl-2、bcl-2/Bax高于模型组大鼠,而Bax低于模型组大鼠,且bcl-2/Bax高于低剂量组(P0.05)。结论银杏叶对脑缺血再灌注具有抑制神经细胞凋亡、减少脑梗死体积作用,且高剂量效果显著,增加脑缺血再灌注24 h后bcl-2的表达,降低Bax表达,对脑缺血再灌注损伤起到保护作用,但是对于bcl-2和Bax表达与剂量无关。     

苦参碱对大鼠小体积肝移植缺血再灌注损伤的保护作用

目的: 探讨苦参碱对大鼠小体积肝移植缺血再灌注损伤的保护作用及机制.方法:采用大鼠30%小体积肝移植模型, ♂SD大鼠322只随机分为假手术组、小体积肝移植对照组和高、低剂量苦参碱治疗组(60、40 mg/kg). 观察术后1 wk生存率, 检测移植术2h、4 h、1 d、2 d、3d、7 d后ALT、AST及LDH值. 光镜及电镜下评估移植肝病理形态学改变, ELISA法检测肝脏IL-6, TNF-α表达.结果: 与对照组比较, 苦参碱高、低剂量治疗组术后1 wk生存率显著增加(80%, 70% vs 50%, 均P<0.05), 术后2h、4h、1d ALT、AST及LDH明显降低(P<0.01). 苦参碱治疗组中肝细胞和肝窦内皮细胞凋亡减少、细胞形态明显改善, 苦参碱治疗组术后2 h、4 h、1 d肝脏组织中IL-6, TNF-α水平明显降低(P<0.01). 结论:苦参碱可减轻肝细胞及肝窦内皮细胞的损伤, 改善小体积肝移植术后缺血再灌注损伤, 其机制可能与苦参碱抑制肝移植术后IL-6、TNF-α等炎症因子的释放有关.     

参附注射液对脑缺血再灌注大鼠bcl-2、p53表达的影响

目的 研究参附注射液(SFI)对脑缺血再灌注损伤神经元凋亡、bcl-2、p53蛋白表达的影响及对脑缺血再灌注损伤的保护作用机制.方法 健康大鼠分为缺血对照组和SFI治疗组,再灌注开始时治疗组大鼠腹腔注射SFI,对照组注射生理盐水,于再灌注6、12、24 h处死大鼠取脑组织制切片,分别进行bcl-2、p53蛋白及凋亡细胞检测.结果 TUNEL染色结果各组均有阳性细胞表达,SFI治疗组凋亡细胞数与缺血对照组比较显著减少.bcl-2蛋白结果显示治疗组bcl-2阳性细胞数均明显高于对照组.p53蛋白检测结果显示治疗组阳性细胞数均明显低于对照组.结论 SFI能抑制脑缺血再灌注损伤神经元凋亡,其抗凋亡机制可能与上调bcl-2蛋白及下调p53蛋白表达有关.     

大鼠局灶性脑缺血再灌注后雌二醇的保护作用及其对caspase-3表达的影响

目的观察雌二醇对大鼠局灶性脑缺血再灌注后神经细胞凋亡与caspase-3表达的影响。方法雄性Wistar大鼠72只随机分为假手术组（n=8）、手术对照组和雌二醇组。后两组又根据再灌注时间的不同各分为3、6、12、24h四个小组,每小组8只。线栓法制作脑缺血-再灌注（I/R）损伤模型。缺血2h分别再灌注3、6、12、24h后断头取脑,应用TUNEL染色及SP免疫组织化学方法观察并测定梗死灶体积、凋亡细胞数及caspase3的表达。结果假手术组未发现脑梗死灶和凋亡细胞及caspase-3阳性细胞。雌二醇组较手术对照组脑梗死体积显著缩小（P〈0.05）,凋亡细胞数减少（P〈0.05）;caspase-3表达减弱（P〈0.05）。结论雌二醇通过下调caspase-3的表达抑制脑细胞凋亡,具有脑保护作用。     

原位肝移植缺血再灌注损伤对大鼠肾脏组织细胞凋亡的影响

目的对比研究大鼠原位肝移植缺血再灌注损伤对肾脏组织细胞凋亡的影响。方法参照Kamada"二袖套法",建立Wistar大鼠原位肝移植动物模型,并以假手术组大鼠为对照组。分别于术后1、3、6、12、24h处死两组动物,检测血清尿素氮(BUN)和肌酐(CREA)水平变化。应用免疫组化(SP)法检测肾脏凋亡细胞的Fas蛋白表达,应用流式细胞技术检测肾脏细胞凋亡。结果肝移植组及对照组中BUN及CREA从术后1h开始上升,12h时达到高峰。两组肾脏组织细胞术后1h即出现细胞凋亡,12h时达到高峰。结论原位肝移植缺血再灌注损伤可致肾脏细胞凋亡,是肾脏细胞早期死亡的主要形式。     

熊果酸抑制神经细胞凋亡降低局灶性脑缺血再灌注损伤的实验研究

目的探讨熊果酸不同剂量对脑缺血再灌注损伤的保护作用及其机制。方法采用线栓法复制局灶性脑缺血再灌注大鼠模型,随机分为假手术组、模型组及熊果酸低剂量组(20 mg/kg)、中剂量组(40 mg/kg)、高剂量组(80 mg/kg),每组20只再灌注前30min腹腔注射给药,24 h后行盲法神经功能评分,测定各组脑组织含水量和脑梗死体积;观察神经细胞凋亡并计算凋亡指数(AI),检测脑组织中bcl-2 mRNA、Bax mRNA表达及caspase-3、核转录因子-κB(NF-κB)蛋白表达。结果熊果酸中、高剂量组大鼠神经功能评分较模型组降低,神经功能症状明显改善,脑组织含水量和梗死体积均降低,差异有统计学意义(P0.05或P0.01);熊果酸各剂量组神经细胞凋亡状况呈不同程度好转,中、高剂量组AI降低(P0.05或P0.01);熊果酸中、高剂量组脑组织Bax mRNA表达下调、bcl-2 mRNA上调、bcl-2/Bax比值升高,caspase-3、NF-κB蛋白表达下调,差异有统计学意义(P0.05或P0.01)。结论熊果酸中、高剂量可能通过抑制神经细胞凋亡而起到降低局灶性脑缺血再灌注损伤的作用。     

血红素氧合酶对大鼠肝脏缺血再灌注损伤细胞凋亡及相关基因的影响

目的通过应用血红素氧合酶（HO）的诱导剂氯高血红素和抑制剂锌原卟啉（ZnPP），探讨HO对大鼠肝脏缺血再灌注（IR）细胞凋亡及其相关基因的影响。方法将96只Sprague—Dawley大鼠采用钳夹法制备肝脏IR模型，随机分为假手术组、IR组、氯高血红素组和ZnPP组，检测再灌注0、1．5、4h和8h各个时间点大鼠肝脏功能以及病理学改变，流式细胞法测定肝细胞凋亡率、TUNEL法观察再灌注后4h大鼠肝细胞的凋亡情况，Western blot法检测再灌注后8h Bcl-2和Caspase-3的表达。结果在IR组各时间点均可见ALT和AST增高，病理学检查可见肝细胞肿胀，肝窦变窄，嗜中性粒细胞浸润和片状坏死等变化，肝组织中细胞凋亡率明显升高，Bcl-2的表达减少，而Caspase-3的表达增加。在氯高血红素组再灌注后1．5、4h和8h ALT和AST值明显降低，肝脏病理学改善，凋亡细胞减少及细胞凋亡率降低，肝脏Bcl-2的表达增加，Caspase-3的表达减少。ZnPP组则显示与之相反的结果。结论HO在肝脏IR损伤中具有保护作用，这种保护作用可能与抑制细胞凋亡有关。     

Mechanism of cell death during warm hepatic ischemia-reperfusion in rats: apoptosis or necrosis?

Reperfusion injury can cause liver dysfunction after cold storage and warm ischemia. Recently it has been suggested that more than 50% of hepatocytes and sinusoidal endothelial cells (SEC) are undergoing apoptosis during the first 24 hours of reperfusion. The aim of our study was to quantify apoptotic and necrotic hepatocytes and apoptotic SEC after 60 or 120 minutes of warm, partial no-flow ischemia and 0 to 24 hours reperfusion in male SD rats. Apoptotic cells were identified by TUNEL assay in combination with morphological criteria. After 60 minutes of ischemia and 1 hour of reperfusion there was a significant increase of apoptotic hepatocytes (0.7 +/- 0.1% vs. 0.3 +/- 0.1% in controls) and SEC (1.5 +/- 0.6% vs. 0.3 +/- 0.1% in controls). The number of apoptotic SEC and hepatocytes was not different from controls at 6 hours or 24 hours of reperfusion. In contrast, the number of necrotic hepatocytes was quantified as 12 +/- 2% at 1 hour, 34 +/- 6% at 6 hours, and 57 +/- 11% at 24 hours. These results correlated with the increase in plasma ALT levels at these time points. Longer (120 min) ischemia times did not affect the number of apoptotic cells but increased hepatocellular necrosis to 58 +/- 4% at 6 hours reperfusion. No significant increase in caspase-3 activity and processing was detectable in any of these livers. Moreover, the caspase inhibitor Z-Asp-cmk (2 mg/kg IV) had no significant effect on reperfusion injury. Our results suggest that only a small minority of SEC and hepatocytes undergo apoptosis after 60 to 120 minutes of warm ischemia followed by 0 to 24 hours of reperfusion. Oncotic necrosis appears to be the principal mechanism of cell death for both cell types.     

The Strategy of Combined Ischemia Preconditioning and Salvianolic Acid-B Pretreatment to Prevent Hepatic Ischemia-Reperfusion Injury in Rats

Background Ischemia-reperfusion injury (IRI) is a serious complication of liver surgery, especially for extended hepatectomy and liver transplantation. The aim of this study was to evaluate the protective effect of combined ischemic preconditioning (IPC) and salvianolic acid-B (Sal-B) pretreatment against IRI-induced hepatocellular injury. Methods Sixty male Wistar rats weighing around 200 g were randomized into five groups (n = 12): sham group: only anesthesia and laparotomy; IR group: 90 min sustained ischemia by blocking the left portal vessels; IPC group: 10 min ischemia and 10 min reperfusion prior to the sustained ischemia; Sal-B group: 10 mg/kg injection of Sal-B intravenously 10 min prior to the sustained ischemia; IPC + Sal-B group: same IPC procedure as in IPC group, but proceeded by intravenous administration of Sal-B 10 min prior to sustained ischemia. After 5 h of reperfusion, serum levels of ALT and AST were measured; the amount of malondialdehyde (MDA) and adenine nucleotides in liver tissue was determined; the expression of Bcl-2 and caspase-3 was detected by immunofluorescent and western blotting techniques; the severity of apoptosis and pathological alterations was evaluated by TUNEL and H&E staining, respectively. Results The serum aminotransferases, hepatic MDA concentration, and apoptotic index in groups IPC, Sal-B, and IPC + Sal-B were significantly lower than those in the IR group (P < 0.001), while the IPC + Sal-B group had the lowest values among these groups (P < 0.05). Compared with the IR group, groups IPC and Sal-B not only had statistically higher ATP levels and energy charge (EC) values (P < 0.01), but also had upregulated Bcl-2 expression and downregulated cleaved caspase-3 expression in liver tissue. All these effects were further augmented in the IPC + Sal-B group. Liver histopathological findings were consistent with these results. Conclusions Based on these results, the combined IPC and Sal-B pretreatment had a synergistically protective effect on liver tissue against IRI, which might be due to decreased post-ischemic oxidative stress, improved energy metabolism, and reduced hepatocellular apoptosis.     

Utility of adenovirus-mediated Fas ligand and bcl-2 gene transfer to modulate rat liver allograft survival

Introduction Fas-mediated apoptosis has recently been found to be associated with the phenomenon of immune privilege.[1] Although Fas ligand (FasL) isprimarily expressed by T lymphocytes after activation, constitutive expression of FasL, which has also been observed in the ocular tissue surrounding the anterior chamber, is believed to be responsible for inducing apoptosis of infiltrating lymphocytes, thus mediating immune privilege.[1] Similarly, the expression of Fas ligand by Sertoli cell…     

缺血预处理对移植肝缺血再灌注损伤中细胞凋亡的影响

目的 探讨细胞凋亡在移植肝缺血再灌注损伤中的作用及缺血预处理对其影响。方法 通过对移植肝进行 因预处理,用全自动生化分析仪检测肝功能、比色法测定移植肝组织的ＭＤＡ、用流式细胞仪结合原位标记技术检测细胞调７亡。结果 移植肝再灌注后血中ＡＳＴ、ＡＬＴ、ＬＤＨ和肝组织中ＭＤＡ均明显升亮,肝细胞调亡明显增加,经缺血预处理后,血中ＡＳＴ,ＡＬＴ,ＬＤＨ和肝组织中ＭＤＡ均降低,肝细胞调亡亦明显减少,结论 缺血     

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.     

Effect of normothermic liver ischemic preconditioning on the expression of apoptosis-regulating genes C-jun and Bcl-XL in rats

AIM: To explore the expression of apoptosis-regulating genes C-jun and Bcl-XL after normothermic liver ischemic preconditioning and its protective effect on hepatocytes in the rat. METHODS: Wistar rats are randomly divided into sham operation group (S group, n = 10), ischemic reperfusion group (IR group, n = 10) and ischemic preconditioning group (IP group, n = 10). After dissection of the hepatoduodenal ligament in S group, and after 30-min reperfusion in IR group and in IP group, the samples of liver tissue were taken for studying the hepatocellular apoptosis, the expressions of C-jun mRNA, Bcl-XL mRNA and their proteins, and morphologic changes at 0, 3, 6, 20 h. Meanwhile the venous blood samples were drawn at 3, 6 and 20 h for testing ALT, AST and LDH. RESULTS: The levels of ALT, AST and LDH in IR group and IP group were significantly higher than those in S group. Hepatocellular apoptosis was significantly increased in both IR group and IP group, especially in IR group. Expressions of C-jun mRNA and protein were significantly increased in IR group compared with those in both IP group and S group, but no significant difference between IP group and S group (P>0.05). Expressions of Bcl-XL mRNA and protein in IR group and S group were not significant (P>0.05), but were significantly increased in IP group compared with those in both S group and IR group. Patch necrosis of hepatocytes because of severe injury could be seen in IR group microscopically, and the ultrastructural changes were irreversible. Meanwhile in IP group, no hepatocellular necrosis occurred, and the ultrastructural changes were reversible because of mild injury. CONCLUSION: (1) IP can protect the rat liver from normothermic IR injury by modulation of the expression of apoptosis-regulating genes C-jun and Bcl-XL; (2) IR injury may activate the apoptosis of hepatocytes by increasing the expression of apoptosis-inducing gene C-jun; (3) IP may prohibit the apoptosis of hepatocytes by increasing the expression of apoptosis-inhibitory gene Bcl-XL.     

Effect of cold-ischemia time on nuclear factor-κB activation and inflammatory response in graft after orthotopic liver transplantation in rats

AIM: To study the mechanism and effect of nuclear factor-κB (NF-κB) activation and inflammatory response on the extended cold-preserved graft injury after orthotopic liver transplantation (OLT). METHODS: OLT was performed in rats with varying time of cold ischemia grafts (6, 18 and 24 h in University Wisconsin solution at 4 ℃). We determined the time of NF-κB activation and expression of tumor necrosis factor-α (TNF-α), cytokineinducible neutrophil chemoattractant (CINC), and intercellular adhesion molecule-1 (ICAM-1) within 6 h after reperfusion. Serum alarming aminotransferase (ALT), neutrophil sequestration, circulating neutrophil CD11b and L- selectin expression were also evaluated. RESULTS: The accumulation of neutrophils in the graft was significantly increased in the 18 h and 24 h cold-ischemia groups within 0.5 h after reperfusion, compared with the 6 h group. But the strongly activated neutrophils was slightly increased at 2 h after reperfusion and remained at high levels 4 h after reperfusion, which was synchronized with the common situation of recipients after transplantation. Prolonged cold-preservation did not affect neutrophil accumulation and activation. NF-κB activation preceded the expression of TNF-α, CINC, and ICAM-1 in the liver, which was significantly increased with prolonged cold preservation. In prolonged cold preserved grafts, prominently elevated NF-κB activation occurred at 0.5 h and 1 h, compared with that at 2 h after reperfusion, which was consistent with greatly increased intrahepatic TNF-α response. CONCLUSION: NF-κB activation is correlated with the expression of TNF-α, CINC, and ICAM-1 in vivo in OLT rats. Extended cold preservation of grafts might up-regulate TNF-α, CINC, and ICAM-1 expression in the grafts, most probably through elevated NF-κB activation, and might contribute to neutrophil infiltration in the grafts after reperfusion. Elevated NF-κB activity is harmful to inflammatory response in the grafts, and inhibited NF-κB activity might protect against early graft injury after liver transplantation.     

Role of mitochondria in cell apoptosis during hepatic ischemia-reperfusion injury and protective effect of ischemic postconditioning

AIM: To investigate the role of mitochondria in cell apoptosis during hepatic ischemia-reperfusion injury and protective effect of ischemic postconditioning (IPC). METHODS: A rat model of acute hepatic ischemia-reperfusion was established, 24 healthy male Wistar rats were randomly divided into sham-operated group, ischemia-reperfusion group (IR) and IPC group. IPC was achieved by several brief pre-reperfusions followed by a persistent reperfusion. Concentration of malondialdehyde (MDA) and activity of several antioxidant enzymes in hepatic tissue were measured respectively. Apoptotic cells were detected by TdT-mediated dUTP-biotin nick end labeling (TUNEL) and expression of Bcl-2 protein was measured by immunohistochemical techniques. Moreover, mitochondrial ultrastructure and parameters of morphology of the above groups were observed by electron microscope. RESULTS: Compared with IR group, the concentration of MDA and the hepatocellular apoptotic index in IPC group was significantly reduced (P<0.05), while the activity of antioxidant enzymes and OD value of Bcl-2 protein were markedly enhanced (P<0.05). Moreover, the injury of mitochondrial ultrastructure in IPC group was also obviously relieved. CONCLUSION: IPC can depress the synthesis of oxygen free radicals to protect the mitochondrial ultrastructure and increase the expression of Bcl-2 protein that lies across the mitochondrial membrane. Consequently, IPC can reduce hepatocellular apoptosis after reperfusion and has a protective effect on hepatic ischemia-reperfusion injury.     

白细胞介素-10与减体积大鼠肝移植后肝再生的关系

目的 探讨白细胞介素-10(IL-10)与减体积大鼠肝移植术后移植肝再生的关系。方法 建立减体积大鼠肝移植模型,实验分为:肝切除组、全肝移植组和减体积肝移植组,分别于术后1、2、4、7d取肝组织,免疫组织化学检测各组IL-10的表达,流式细胞仪检测移植肝的增殖活性。结果 肝切除组、全肝移植组和减体积肝移植组肝细胞增生活跃,术后4d增殖高峰分别为26.3±0.9、35.8±2.2、32.4±1.8。IL-10与移植后肝再生呈负相关(r=-0.58,P<0.01)。结论 减体积肝移植和全肝移植术后肝脏具有同样的增殖活性,但增殖峰值较肝切除延迟。IL-10对移植肝肝再生具有明显的调控作用,同时受免疫系统产生的其它细胞因子和激素的影响。