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     

肝移植缺血再灌注损伤与细胞粘附分子

自本世纪80年代以来,伴随着手术技巧的提高、新型免疫抑制剂和UW保存液的相继问世,临床肝移植取得了长足的进步。然而,缺血再灌注损伤依然是困扰着肝移植的研究难点,它是引发术后原发性移植物无功能(primary graftnonfunction)的重要原因。而随着近年来对细胞粘附分子研究的不断深入,表明细胞粘附分子恰恰参与并介导了缺血再灌注损伤过程中的各个步骤。本文综述近年来在此领域的研究进展。 一、细胞粘附分子的种类、结构与功能 细胞粘附分子分布极其广泛,涉及生命活动的许多现象,包括细胞分裂、分化以及细胞凋亡的调控等等。根据结构与功能,粘附分子可初步分为5类,即整合素家族、免疫球蛋白超家族、选择素家族、钙粘附蛋白家族和其它粘附分子。前三者是参与肝移植过程中缺血再灌注等炎症反应和免疫应答的重要家族。     

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...     

缺血后处理对再灌注损伤后炎症因子的调节作用

目的探讨缺血后处理(POC)调节肾缺血再灌注损伤(RIPI)后炎症因子的表达水平及其对大鼠肾脏保护作用的机制。方法成年SD大鼠随机分成:假手术组(Sham组)、缺血再灌注组(I/R组)、POC组。Sham组为对照组。I/R组:采用无创动脉夹夹闭左肾动脉45 min,切除右肾,然后去除血管夹,恢复血流灌流。POC组:在I/R组的基础上再进行3个循环的30 s缺血/30 s再灌注的手术干预(共计3 min),最后打开血管夹使血液再灌注。将各组动物于清洁条件下饲养,于第2天及1个月时收集各组动物血清,检测肾脏功能。第2天时,苏木素-伊红(HE)染色观察肾脏组织结构。RT-PCR法检测各组中肿瘤坏死因子(TNF)-α、白细胞介素(IL)-6和IL-10的表达水平。结果再灌注第2天,Sham组血清肌酐(Cr)和血尿酸氮(BUN)的浓度维持在正常水平,而I/R组Cr和BUN的浓度明显增高(P0.01),POC组Cr和BUN的浓度显著低于I/R组(P0.05)。再灌注1个月,三组中Cr的浓度无明显差异(P0.05)。HE染色结果显示,再灌注第2天,Sham组中肾组织形态正常,I/R组肾小管上皮细胞变性,部分脱落,管腔内可见管型,POC组肾组织病变较轻。RT-PCR法检测结果显示,再灌注第2天,Sham组TNF-α、IL-6和IL-10的表达水平很低,I/R组中TNF-α、IL-6的表达水平明显升高,POC组低于I/R组,而IL-10的表达水平明显高于I/R组。结论 POC降低了缺血再灌注后的急性炎症反应,从而对大鼠的肾脏起到了保护作用。     

Kupffer细胞与肝缺血再灌注损伤

Kupffer细胞作为肝脏固有巨噬细胞在炎症反应及肝脏缺血再灌注损伤中发挥重要作用.Kupffer细胞激活后将诱发TNF-α、前列腺素、一氧化氮及氧自由基等各种炎症细胞因子的大量形成,除导致自身功能形态发生改变外,还直接影响邻近的肝细胞、血管内皮细胞以及位于血窦腔内的中性粒细胞等多种细胞,进而启动热缺血或冷缺血后肝脏的缺血再灌注损害.现就Kupffer细胞在肝脏缺血再灌注损伤中的作用机制及对其治疗靶点研究进展作一综述.     

移植肾缺血-再灌注损伤与炎症和微血管病变

移植肾早期不可避免地存在缺血再灌注损伤(IRI),对移植肾的早期恢复和远期预后均有重要影响.缺血-再灌注除损伤肾小管上皮细胞外,还导致间质炎症和徽血管病变;而后者是IRI引起肾功能障碍的关键.缺血后微血管病变以内皮细胞肿胀和随之而来的微血管闭塞为特征,导致再灌注不能顺利进行(无复流现象).阐明内皮细胞功能障碍机制,为移植肾IRI的治疗提供新思路.     

缺血再灌注损伤后大鼠脑神经细胞巢蛋白的表达

将30只成年健康雄性SD大鼠随机分为实验组和对照组.实验组以线栓法建立大脑中动脉缺血后再灌注模型,应用免疫组化SABC法观察再灌注后各观察部位不同时间神经细胞巢蛋白(Nestin)的表达情况.发现缺血再灌注6 h,Nestin阳性细胞少量表达,1 d时数量增多,3 d时明显增多,7 d时Nestin阳性细胞数的量和形态变化最为显著.认为Nestin阳性细胞在正常成年脑组织中广泛表达,再灌注损伤后大脑各部位Nestin阳性细胞的表达呈一致性增强,各部位Nestin阳性细胞数目的 增加量在不同时间又有所不同.     

大鼠移植肝热缺血再灌注损伤的研究

建立大鼠动脉化肝移植胆管外引流模型,术后24 h测胆汁酶学及血清肝功能指标、内皮素-1(ET-1)、超氧化物歧化酶(SOD)、丙二醛(MDA)、一氧化氮(NO)和移植肝细胞间黏附分子-1(ICAM-1)mRNA.结果显示,随着供肝热缺血时间的延长,肝移植后大鼠血清ALT、AST、乳酸脱氢酶(LDH)、GGT、直接胆红素(DBil)、MDA、NO及肝细胞ICAM-1 mRNA显著升高.认为肝移植中供肝热缺血主要损伤肝细胞,SOD、ET-1、NO、ICAM-1参与供肝热缺血造成的移植肝损伤,ICAM-1可能是导致移植肝缺血再灌注时肝细胞损伤的主要因素.     

预处理防治肝缺血再灌注损伤的研究进展

肝脏缺血再灌注损伤(ischemia-reperfusioninjury, I/R)是困扰肝脏外科发展的一大重症,如何防治I/R一直是研究的热点. 预处理通过诱导细胞的内源性保护机制, 对肝脏I/R有明显的防治作用, 本文就各种预处理对抗肝脏I/R的作用机制作一综述, 探讨各种预处理方法的临床应用价值.     

鼠肝缺血再灌注损伤性别差异与一氧化氮有关

女性患者在肝移植或肝细胞肿瘤切除术后较男性患者有更好的生存率。雌激素可通过非基因和（或）基因反应增加内皮细胞一氧化氮合酶（eNOS），催化一氧化氮（NO）产生，而NO在限制全肝缺血再灌注损伤中起着重要作用，本实验观察NO在雌性大鼠肝缺血再灌注中的保护机制。     

热缺血供肝胆管耐受冷保存时限的实验研究

目的探讨有热缺血损伤的供肝及胆管组织耐受冷保存的安全时限,为临床肝移植术后早期肝内外胆管不可逆性坏死和原发性移植肝无功能的防范提供实验依据. 方法在小型猪同种异体原位肝移植模型上,观察供肝血流阻断10 min后移植肝及胆管组织在不同冷保存时间条件下的形态功能改变及其可逆性.结果热缺血10 min,冷保存时间少于16 h组,动物均存活1周以上,且无早期胆管坏死所致的动物死亡;一旦冷保存时间超过16 h,术后早期胆管坏死的发生率显著上升（P＜0.05）,出现因胆管坏死、胆漏所致的动物死亡;随着冷保存时间的进一步延长,将出现原发性移植肝无功能所致的术中、术后早期动物死亡,存活动物均发生胆管坏死.与冷保存16 h以内组比较,16 h以上组术中移植肝胆管组织病理形态学评分和上皮凋亡细胞数显著增高（P＜0.05）,而Na^＋-K^＋-ATP酶及Ca^2＋-ATP酶活力显著降低（P＜0.05）,术后丙氨酸氨基转移酶、天冬氨酸氨基转移酶、γ-谷氨酰转肽酶、碱性磷酸酶恢复较慢.相关分析结果显示,术后胆管坏死率与术中移植肝胆管细胞病理形态学评分及凋亡细胞数呈显著正相关（r值分别为0.931、0.972,P值均＜0.01）,与Na^＋-K^＋-ATP酶和Ca^2＋-ATP酶活力呈显著负相关（r值均为-0.973,P值均＜0.01）.结论有热缺血损伤的供肝及胆管组织,在限定的冷保存时间范围内是可以利用的.若热缺血时间在10 min以内,冷保存时间延长至16 h对移植肝胆管组织仍安全,延长至20 h移植肝仍能发挥功能.     

苦参碱对大鼠原位肝移植冷缺血再灌注损伤的保护作用

目的:探讨苦参碱对大鼠原位肝移植中供肝冷缺血再灌注损伤的保护作用及其机制方法:应用延长保存的大鼠原位肝移植模型, 大鼠224只随机分为对照组、低剂量(40 mg／ kg)、高剂量苦参碱治疗组(80 mg／kg)和假手术组,将供肝在4℃林格液中保存5 h后植入受体,分别观察移植术后1 wk生存率,并且检测移植术后1,2,4,24 h血ALL TNF-α,内毒素 (ET),透明质酸(HA),一氧化氮(NO)及肝组织丙二醛(MDA),超氧化物歧化酶(SOD),细胞间黏附分子-1(ICAM-1)的含量,并观察移植肝脏病理形态学的改变．结果:与对照组比较,苦参碱低剂量、高剂量治疗组术后1 wk生存率显著增加(75％,75％ vs 0,P<0．01),肝功能改善,血清HA(277．62 ±29．06,406．84±95．04 μg／L vs 1109．42± 110．28 μg／L,P<0．01)和肝组织ICAM-1表达均显著减少,血清NO含量增加(53．1±5．1,54．2 ±4．9 μmol/L vs 30．2±2.3 μmol／L,P<0．01), TNF-α(1．69±0．22,1．29±0．33 U／L vs 5．96 ±0．59 U／L,P<0．01)、ET(0．343±0．111, 0_302±0．059 kEU／L vs 0．643±0．110 kEU／L． P<0．01)以及肝组织MDA(0．87±0．41,0．69± 0．22 μmol／g vs 2．35±0．54 μmol／g,P<0．01) 水平均明显降低,肝组织SOD(19．89±1．84, 21．04±1．86 kU／g vs 13．39±0．85 kU／g,P<0．01) 水平均明显升高,肝细胞和肝窦内皮细胞形态也发生改善．结论:苦参碱可以通过减轻再灌注后内毒素血症,抑制库氏细胞激活及释放TNF-α, ICAM-1等炎症性细胞因子,清除氧自由基,促进NO合成等途径,减轻肝细胞及肝窦内皮细胞的损伤．     

热缺血供肝耐受冷保存时限的实验研究

心脏停搏供体是肝移植供肝来源的重要途径之一。有研究表明，热缺血30min以内的供肝可考虑应用，但此类供肝本身存在热缺血损伤，在后续的威斯康星大学溶液（UW液）中能冷保存多久能为临床所用尚未可知。本实验探讨了存在热缺血10min的供肝在UW液中冷保存的安全时限。     

Liver function impairment in liver transplantation and after extended hepatectomy

Extended hepatectomy,or liver transplantation of reduced-size graft,can lead to a pattern of clinical manifestations,namely"post-hepatectomy liver failure"and"small-for-size syndrome"respectively,that can range from mild cholestasis to irreversible organ non-function and death of the patient.Many mechanisms are involved in their occurrence but in the recent past,high portal blood flow through a relatively small liver vascular bed has taken a central role.Therefore,several techniques of inflow modulation have been attempted in cases of portal hyperperfusion first in liver transplantation,such as portocaval shunt,mesocaval shunt,splenorenal shunt,splenectomy or ligation of the splenic artery.However,high portal flow is not the only factor responsible,and before major liver resections,preoperative assessment of the residual liver function is necessary.Techniques such as portal vein embolization or portal vein ligation can be adopted to increase the future liver volume,preventing posthepatectomy liver failure.More recently,a new surgical procedure,that combines in situ splitting of the liver and portal vein ligation,has gradually come to light,inducing remarkable hypertrophy of the healthy liver in just a few days.Further studies are needed to confirm this hypothesis and overcome one of the biggest issues in the field of liver surgery.     

Dynamical changing patterns of glycogen and enzyme histochemical activities in rat liver graft undergoing warm ischemia injury

AIM: To investigate the changing patterns of glycogen and enzyme histochemical activities in rat liver graft under a different warm ischemia time (WIT) and to predict the tolerant time limitation of the liver graft to warm ischemia injury. METHODS: The rats were randomized into five groups, WIT was 0,15,30,45,60 min, respectively, and histochemical staining of liver graft specimens was observed. The recovery changes of glycogen and enzyme histochemistry activities were measured respectively 6 and 24 h following liver graft implantation. RESULTS: The activities of succinic dehydrogenase, cytochrome oxidase, apyrase (Mg++-ATPase) and content of glycogen were decreased gradually after different WIT in a time-dependent manner. The changes were significant when WIT was over 30 min. CONCLUSION: Hepatic injury is reversible within 30 min of warm ischemia injury. Glycogen and enzyme histochemistry activities of liver grafts and their recovery potency after reperfusion may serve as criteria to evaluate the quality of liver grafts.     

Optimized postconditioning algorithm protects liver graft after liver transplantation in rats

Background: Ischemia reperfusion injury(IRI) causes postoperative complications and influences the outcome of the patients undergoing liver surgery and transplantation. Postconditioning(Post C) is a known manual conditioning to decrease the hepatic IRI. Here we aimed to optimize the applicable Post C protocols and investigate the potential protective mechanism.Methods: Thirty Sprague–Dawley rats were randomly divided into 3 groups: the sham group(n = 5),standard orthotopic liver transplantation group(OLT, n = 5), Post C group(OLT followed by clamping and re-opening the portal vein for different time intervals, n = 20). Post C group was then subdivided into 4 groups according to the different time intervals:(10 s × 3, 10 s × 6, 30 s × 3, 60 s × 3, n = 5 in each subgroup). Liver function, histopathology, malondialdehyde(MDA), myeloperoxidase(MPO), expressions of p-Akt and endoplasmic reticulum stress(ERS) related genes were evaluated.Results: Compared to the OLT group, the grafts subjected to Post C algorithm(without significant prolonging the total ischemic time) especially with short stimulus and more cycles(10 s × 6) showed significant alleviation of morphological damage and graft function. Besides, the production of reactive oxidative agents(MDA) and neutrophil infiltration(MPO) were significantly depressed by Post C algorithm. Most of ERS related genes were down-regulated by Post C(10 s × 6), especially ATF4, Casp12, hspa4, ATF6 and ELF2, while p-Akt was up-regulated.Conclusions: Post C algorithm, especially 10 s × 6 algorithm, showed to be effective against rat liver graft IRI. These protective effects may be associated with its antioxidant, inhibition of ERS and activation of p-Akt expression of reperfusion injury salvage kinase pathway.     

Dynamical changing patterns of histological structure and ultrastructure of liver graft undergoing warm ischemia injury from non-heart-beating donor in rats

AIM: To investigate the histological and ultra-structural characteristics of liver graft during different of warm ischemia time (WIT) in rats and to predict the maximum limitation of liver graft to warm ischemia. METHODS: The rats were randomized into 7 groups undergoing warm ischemia injury for 0, 10, 15, 20, 30, 45 and 60 min, respectively. All specimens having undergone warm ischemia injury were investigated dynamically by light and electron microscopy, and histochemistry staining. After orthotopic liver transplantation (OLT), the recovery of morphology of liver grafts after 6, 24 and 48 h was observed. RESULTS: The donor liver from non-heart-beating donors (NHBD) underwent ischemia injury both in the warm ischemia period and in the reperfusion period. Morphological changes were positively related to warm ischemia injury in a time-dependent manner during the reperfusion period. The results demonstrated that different degrees of histocyte degeneration were observed when WIT was within 30 min, and became more severe with the prolongation of WIT, no obvious hepatocyte necrosis was noted in any specimen. In the group undergoing warm ischemia injury for 45 min, small focal necrosis occurred in the central area of hepatic lobule first. In the group undergoing warm ischemia injury for 60 min, patchy or diffused necrosis was observed and the area was gradually extended, while hepatic sinusoid endothe-lial cells were obviously swollen. Hepatic sinusoid was obstructed and microcirculation was in disorder. CONCLUSION: The rat liver graft undergoing warm ischemia injury is in the reversible stage when the WIT is within 30 min. The 45 min WIT may be a critical point of rat liver graft to endure warm ischemia injury. When the WIT is over 60 min, the damage is irreversible.     

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。     

Calcium mobilization in liver transplantation graft with warm ischemia

The influence of warm ischemia on calcium mobilization in liver transplantation was investigated. Twenty-four porcine orthotopic liver transplantations were performed by a temporary portal arterialization technique. Swine were divided into three groups according to warm ischemia time; I (0 min,n=9), II (30 min,n=8), and III (60min,n=7). Ionized calcium was measured in arterial and hepatic venous blood, in initial perfusate, and in initial perfused blood. In group I, all the pigs survived, while in group III all succumbed. In group II, four survived and four died. Ionized calcium level in influx showed no differences, but the level in the initial perfusate in group I was significantly higher than that in group III. The level in the initial perfused blood in group I was significantly higher than levels in groups II and III. Retrospective analysis in group II showed that ionized calcium value in the initial perfused blood in the survivors was significantly higher than that in the non-survivors. A substantial amount of ionized calcium accumulated after revascularization in the graft loaded with warm ischemia, and, in group II, significantly more ionized calcium accumulated in the non-survivors.     

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.