己酮可可碱预处理对大鼠供肝冷缺血损伤影响的实验研究

目的　探讨已酮可可碱预处理供者及肝脏对供肝冷缺血损伤的影响。方法　Wistar大鼠按处理方法的不同分为 4组 :对照组、供者预处理组 (实验 1组 )、供肝预处理组 (实验 2组 )、供者及供肝联合预处理组 (实验 3组 ) ,预处理使用己酮可可碱。各组动物均在供肝冷保存 6h后行原位肝移植 ,门静脉血流恢复后第 30min、3h及 2 4h取门静脉血测定肿瘤坏死因子 (TNF α)、丙氨酸转氨酶(ALT)、天冬氨酸转氨酶 (AST)及谷胱甘肽S转移酶 (GST)的水平。结果　门静脉复流后 30min、3h时血清TNF α水平 ,各实验组明显低于对照组 ,实验 3组显著低于实验 1组及实验 2组 (P <0 .0 5) ;30min及 3h时血清GST水平 ,各实验组明显低于对照组 (P <0 .0 5) ,实验 3组显著低于实验 1组及实验 2组 (P <0 .0 5) ;30min及 3h时血清ALT水平 ,各实验组明显低于对照组 ,实验 3组显著低于实验1组及实验 2组 (P <0 .0 5) ;2 4h时前述各指标各实验组明显低于对照组 ,实验 3组显著低于实验 2组 (P <0 .0 5) ;30min时血清AST水平 ,各实验组明显低于对照组 ,实验 3组显著低于实验 1组及实验 2组 (P <0 .0 5)。结论　己酮可可碱预处理对供肝的冷缺血再灌注损伤有一定的保护作用     

己酮可可碱在肺缺血-再灌注损伤中的作用

目的　探讨己酮可可碱 (PTX)对肺缺血 -再灌注损伤的保护作用。　方法　 72只大鼠随机分为 3组 ,每组 2 4只。 组 :未行缺血及再灌注处理 ; 组 :行左肺缺血和再灌注处理 ; 组 :行左肺缺血和再灌注处理 ,并给予己酮可可碱。采用在体肺温缺血 -再灌注损伤的模型 ,于缺血 45分钟、再灌注 1小时、2小时和 4小时进行动脉血气分析、肺组织含水量、支气管肺泡灌洗液白蛋白含量、血浆和左肺组织丙二醛、左肺组织和支气管肺泡灌洗液髓过氧化物酶(MPO)活性测定。　结果　 组再灌注 2小时和 4小时动脉血氧分压显著降低 ,各时间点左肺含水量、支气管肺泡灌洗液白蛋白含量、血浆丙二醛、左肺组织、支气管肺泡灌洗液中髓过氧化物酶均显著升高 ,PTX可改善上述指标变化。结论　 PTX通过抑制中性粒细胞肺内聚集 ,减轻肺血管内皮细胞损伤程度 ,而防止损伤的发展     

己酮可可碱对肝脏缺血再灌注损伤保护作用的实验研究

目的　观察大鼠肝脏缺血再灌注后肿瘤坏死因子 -α (TNF α)早期释放及核因子κB(NFκB )活化对炎性介质表达和中性粒细胞浸润的影响。探讨其对肝缺血再灌注损伤的意义。方法　建立大鼠肝脏部分热缺血模型 ,己酮可可硷 (PTX )组于缺血前 1h腹腔注射PTX 5 0mg/kg ,对照组同法等量生理盐水注射 ,另设假手术组。结果　对照组相比 ,PTX组TNF α浓度、NFκBp65含量 (IOD )、巨噬细胞炎性蛋白 -2 (MIP 2 )和细胞间黏附因子 -1(ICAM 1)mRNA表达量 (IOD )、髓过氧化物酶(MPO )活性 (U/g)均明显降低 (均P <0 .0 5 )。再灌注 6hPTX组天门冬氨酸转氨酶 (AST)、丙氨酸转氨酶 (ALT)、乳酸脱氢酶 (LDH )含量 (U/L)和湿重 /干重 (W /D )水平也显著降低 (均P <0 .0 5 )。结论　PTX通过减少TNF α的早期释放 ,抑制NFκB活化 ,从而下调趋化因子、黏附分子表达和减少中性粒细胞浸润 ,从而得以减轻肝脏缺血再灌注损伤。     

己酮可可碱对肠缺血再灌注致多器官损伤的保护作用

研究多形核中性粒细胞在多器官损伤中的作用及ＰＭＮ活化的抑制剂己酮可可碱对器官损伤的保护作用。方法；采用大鼠肠缺血再灌注致多器官损伤的损伤的模型。结果；肠缺血再灌注可导致肠及远端器官肝，肺中ＰＭＮ聚集明显增加，并伴有这些器官的损伤，己酮可可碱可明显抑制肠缺血再灌注引起的ＰＭＮ聚集，同时肠，肝，肺组织损伤的指标明显改善。     

供肝缺血预处理对大鼠肝移植缺血再灌注损伤的保护性作用

目的：探讨供肝热缺血预处理对大鼠供肝冷缺血再灌注（I/R）损伤中的保护作用及其机制。方法：采用SD大鼠建立原位肝移植动物模型，供肝冷缺血期为120 min，受体无肝期16～20min。随机分为3组：假手术组，获取供肝前仅作肝脏周围韧带的解剖;肝移植组，获取供肝前不作肝门阻断;缺血预处理（IPC）组，获取供肝前阻断肝门5min，再灌注5min。术后2，4，24，72h检测血清ALT、抗氧化酶活力、血清NO水平及细胞因子TNF-α。结果：肝移植组及IPC组术后ALT及过氧化物含量均明显高于假手术组，而IPC组低于肝移植组(P﹤0.05)，其抗氧化酶活力较移植组明显升高（P﹤0.05）; NO水平在IPC术后2，4，24，72h均显著高于假手术组，72h时肝移植组明显高于IPC组及假手术组(P﹤0.05)，而IPC组高于假手术组;肝移植组血清中TNF-α释放明显高于假手术组(P﹤0.05);IPC组TNF-α的释放显著低于肝移植组(P﹤0.05)。结论：供肝热缺血预处理对大鼠供肝冷缺血I/R损伤具有明显保护作用;其机制可能是IPC快速提高并稳定了血清中NO水平，降低了炎性细胞因子TNF-a的产生，从而减少移植肝细胞的损害。     

己酮可可碱对沙鼠全脑缺血／再灌注的保护作用

目的　观察己酮可可碱 (PTX)对沙鼠全脑缺血 /再灌注模型的作用效果 ,并对其作用机制进行初步探讨。方法　夹闭双侧颈动脉 ,诱导沙鼠全脑缺血 ,30分钟后松夹 ,再灌注 90min。在缺血诱导时 ,静脉给予 2 5mg·kg-1,或者 5 0mg·kg-1的PTX ;另一组于再灌注开始时静脉输注 2 5mg·kg-1的PTX。假手术组和对照组输入相同容积的 0 9%NaCl。再灌注开始时以 0 2 %伊文思兰 1ml·10 0g-1对所有沙鼠腹腔注射。实验结束时断头取脑 ,- 70℃冰箱保存 ,进行脑水肿定量、脑组织超氧化物歧化酶 (SOD)活性、丙二醛 (MDA)含量测定及脑组织伊文思兰含量测定。结果　与对照组相比 ,在缺血诱导时或再灌注开始时输注 2 5mg·kg-1PTX明显减轻沙鼠脑水肿的程度 (P <0 0 5或0 0 1) ,脑组织脂质过氧化产物MDA含量显著降低 (P <0 0 5或 0 0 1) ,脑组织中SOD的活性明显升高 (P <0 0 5或 0 0 1) ,脑组织伊文思兰含量显著降低 (P <0 0 5或 0 0 1)。 5 0mg·kg-1PTX输注对沙鼠脑缺血 /再灌注损伤无保护作用 ,其中 3只沙鼠死于低血压休克。结论　在血液动力学稳定的前提下 ,PTX对脑缺血 /再灌注损伤的保护作用可能与其提高脑血流量 ,抑制超氧阴离子产生 ,以及对血管内皮细胞的保护作用有关     

维拉帕米对大鼠脂肪肝热缺血再灌注损伤的保护作用

目的 探讨脂肪肝缺血再灌注损伤过程中丙二醛、谷丙转氨酶、内皮素、肿瘤坏死因子的变化,以及维拉帕米对脂肪有趣 缺血再灌注（I／R）损伤的保护作用。方法 通过建立脂肪肝动物模型,观察脂肪肝大鼠在 因前门静脉压力,缺血前、缺血15min和30min再灌注60min后血清谷丙转氨酶（ALT）,肿瘤坏死因子（TNFα）,内皮素（ET－1）和肝组织中丙二醛（MDA）的变化,以及维拉帕米对I／R损伤的保护作用。结果 缺血前及I／R损伤后,脂肪肝组大鼠肝组织中MDA及血清ET－1、TNFα、ALT呈升高趋势,药物组则明显降低。结论 （1）肝脂肪变性可导致肝窦狭窄和不规则,门静脉压升高。（2）含大量 质的肝细胞对I／R损伤敏感性增高,通过产生过多的MDA,ET－1,TNFα,导致肝细胞破坏,血清ALT升高。（3）缺血前应用维拉帕米,对脂肪肝I／R损伤起保护作用。     

缺血后处理对大鼠移植肝缺血再灌注损伤的保护作用

目的探讨在体条件下缺血后处理对大鼠移植肝缺血再灌注损伤的保护作用及其可能机制。方法采用SD大鼠原位肝移植模型,供肝冷保存时间100min,无肝期控制于18min以内,60只雄性健康SD大鼠随机分为3组,对照组12只,缺血再灌注损伤组和后处理组各24只。对照组开腹后仅游离肝周韧带;缺血再灌注损伤组受体大鼠供肝切除前仅以肝素化生理盐水经门静脉灌注;后处理组供肝植入后完全再灌注前,给予多次短暂复灌复停作为缺血后处理。缺血再灌注损伤组、后处理组受体一半（6只）于再灌注后2h留取血液及肝组织,另一半（6只）于再灌注后6h留取肝组织。对照组于关腹后相应时间留取血液及肝组织。各组分别检测肝功能,采用酶联免疫吸附法测定血清肿瘤坏死因子Or．和中性粒细胞弹性蛋白酶。根据酶促反应原理,利用分光光度仪测定肝脏谷胱甘肽过氧化物酶、丙二醛、髓过氧化物酶、超氧化物歧化酶。肝组织HE染色后光镜下观察组织学变化。结果缺血再灌注损伤组和后处理组血清肝功能指标、炎性细胞因子水平及肝组织过氧化物含量均高于对照组（P〈0．05）,而后处理组较缺血再灌注损伤组则明显低（P〈0．05）;缺血再灌注损伤组和后处理组肝组织抗氧化酶活力显著低于对照组（P〈0．05）,而后处理组较缺血再灌注损伤组则明显高（P〈0．05）。结论缺血后处理对大鼠移植肝的缺血再灌注损伤有明显的保护作用。提高组织的抗氧化能力和降低炎性细胞因子水平可能是缺血后处理保护作用的机制之一。     

心脏停搏供体肝移植时供肝己酮可可碱预处理对移植肝的保护效应

目前，如何减轻心脏停搏供体（NHBDS）肝移植时供肝的冷热缺血及再灌注损伤达到移植肝的保护，从而最大限度地利用和改善此类供肝以取得满意的疗效正成为肝移植研究的重要课题。本实验旨在探讨己酮可可碱（PTX）供肝预处理在NHBDs肝移植时对移植肝脏的保护效应及其相关机制。     

不同胆道灌洗方法对大鼠肝内胆管冷保存再灌注损伤的影响

目的观察不同胆道灌洗方法对大鼠移植肝肝内胆管冷保存再灌注损伤的影响。方法应用大鼠原位肝移植模型，将88只SD大鼠随机分为假手术组、胆道非灌洗组、UW液胆道灌洗组、生理盐水（NS）胆道灌洗＋UW液肝内胆道灌注保存组、HTK液胆道灌洗＋UW液肝内胆道灌注保存组、HTK液胆道灌洗＋HTK液肝内胆道灌注保存组。移植肝置于4℃林格液中保存2h后行原位肝移植。移植肝再灌注后24h，检测血清总胆红素（TB）、直接胆红素（DB）、碱性磷酸酶（AKP）、γ-谷酰转肽酶（GGT）及胆汁中GGT、葡萄糖（Glu）含量。在光镜及电镜下观察肝内胆管上皮细胞的形态学变化。结果与非灌洗组比较，胆道灌洗组术后各项指标明显改善（P〈0．01）；HTK液及NS灌洗组较UW液灌洗组术后指标改善明显（P〈0．05）。病理检测发现非灌洗组胆道损伤明显，各灌洗组胆道损伤程度明显改善，HTK液灌洗＋UW或HTK液灌注组对胆管上皮细胞的损伤较轻。结论移植肝冷保存前进行胆道灌洗可以明显减轻胆管上皮细胞的损伤，4℃HTK液灌洗＋4℃UW或HTK液灌注保存效果比较理想。     

灯盏花素预处理供肝减轻大鼠肝移植后早期缺血再灌注损伤

目的 研究应用灯盏花素对供肝进行预处理,减轻大鼠肝移植术后早期缺血再灌注损伤的作用.方法 以SD大鼠作为肝移植供、受者,采用随机数字表法将受鼠分为4组.A组和C组供肝未经灯盏花素预处理,B组和D组供肝经含20 mg/L灯盏花素的UW液预处理;A组和B组供肝冷缺血时间为30～40 min,C组和D组为12 h.术后检测各组受鼠的凝血功能、肝功能、血清血栓调节蛋白(TM)含量、凋亡蛋白酶-3 (Caspase-3)活性及核因子-kB(NF-kB)相对表达量,观察各组移植肝组织病理学变化和肝细胞凋亡情况.结果 术后3d,C组与D组受鼠死亡率分别为40.0％(8/20)和29.4％(5/17),差异无统计学意义(P＞0.05);术后4组间凝血功能无明显变化(P＞0.05).与C组比较,术后早期D组肝功能、肝组织病理学改变及肝细胞凋亡均明显改善(P＜0.01),血清TM含量、Caspase-3活性及NF-kB表达量均明显降低(P＜0.01).术后A组和B组的缺血再灌注损伤明显较轻,两组间上述指标的差异均无统计学意义(P＞0.05).结论 应用灯盏花素对供肝进行预处理,能够减轻大鼠肝移植术后由冷保存时间较长引起的缺血再灌注损伤,其机制可能与抑制凋亡相关的信号通路和减轻肝脏微循环内皮细胞损伤有关.     

参附注射液对肠缺血-再灌注大鼠肿瘤坏死因子α的影响

目的观察肿瘤坏死因子α(TNF-α)在大鼠肠缺血-再灌注损伤过程中的作用及参附注射液对TNF-α的影响,探讨参附注射液防治肠缺血-再灌注损伤机制。方法 SD大鼠随机分为肠缺血-再灌注组(IR组)、参附注射液预处理组(SF组)和假手术组(C组)。采用阻断肠系膜上动脉(SMA)的方法制造肠缺血-再灌注模型。分别测定各组动物血浆、肠组织TNF-α含量及血液动力学变化;光镜观察肠粘膜损伤情况。结果IR组再灌注后MAP下降,与C组和SF组比有显著性差异(P<0.01);SF组肠粘膜损伤程度减轻,与IR组比有显著性差异(P<0.01);SF组血浆及肠组织TNF-α水平降低,与IR组比有显著性差异(P<0.01)。结论参附注射液可明显防治大鼠肠缺血-再灌注导致的肠粘膜损伤,这种作用可能是通过抑制TNF-α的释放实现的。     

去铁胺对自体肝移植大鼠肝脏缺血再灌注损伤的保护作用

目的 探讨去铁胺预处理对大鼠自体肝移植缺血再灌注损伤的保护作用及其可能机制.方法 建立大鼠自体肝移植模型,将96只健康雄性SD大鼠随机分为去铁胺预处理(deferoxamine,D组),注射用水对照组(control group,C组)和假手术模型(shsm operation,S组)各32只.分别于术后0.5 h、2 h、6 h、24 h各时间点处死大鼠,检测血清ALT和AST水平和肝组织SOD活性与MDA含量;做病理组织学检查,免疫组化检测HIF-1α、TNF-α及IL-1蛋白的表达.结果 在30 min、2 h、6 h及24 h各个时间点,D组大鼠血清ALT及AST水平、肝组织MDA含量及IL-1、TNF-α蛋白表达量明显低于C组,再灌注后2 h、6 h、24 h,D组大鼠肝组织SOD含量(411±70;384±53;379±46)和各时间点HIF-1α蛋白表达量(0.0413±0.0040;0.0684±0.0032;0.0583±0.0032;0.0491±0.0026)明显高于C组[SOD(341±21;323±25;303±25)和HIF-1α(0.0254±0.0024;0.0312±0.0022;0.0381±0.0022;0.0257±0.0015)](F>59.881;P<0.01).结论 去铁胺预处理对大鼠自体肝移植缺血再灌注损伤具有保护作用,可能与促进HIF-1α表达上调,减轻氧化损伤和降低炎性因子水平有关.     

Attenuation of skeletal muscle ischemia/reperfusion injury by inhibition of tumor necrosis factor

Purpose: Tumor necrosis factor α (TNF-α) has been shown to play a role in pulmonary injury after lower-extremity ischemia/reperfusion (I/R). However, its role in direct skeletal muscle injury is poorly understood. The hypothesis that endogenous TNF production contributes to skeletal muscle injury after hindlimb I/R in rats was tested. Methods: Juvenile male Sprague-Dawley rats underwent 4 hours of bilateral hindlimb ischemia and 4 hours of reperfusion (IR) or sham operation (SHAM). A subset was treated with a soluble TNF receptor I construct (STNFRI, 10 mg/kg) 1 hour before ischemia (PRE) or at reperfusion (POST). Direct skeletal muscle injury (SMII) and muscle endothelial capillary permeability (MPI) were quantified by means of Tc⁹⁹ pyrophosphate and I¹²⁵ albumin uptake. Pulmonary neutrophil infiltration and hepatocellular injury were assessed by means of myeloperoxidase content (MPO) and aspartate aminotransferase (AST) concentrations, respectively. Serum TNF bioactivity was measured with the WEHI bioassay. Results: Hindlimb I/R (IR vs SHAM) resulted in a significant (P < .05) increase in the SMII (0.52 ± 0.06 vs 0.07 ± 0.01) and MPI (0.35 ± .04 vs 0.06 ± 0.01). Pretreatment with STNFRI (PRE vs IR) significantly ameliorated both SMII (0.30 ± 0.05 vs 0.52 ± 0.06) and MPI (0.23 ± 0.02 vs 0.35 ± 0.04), whereas treatment at reperfusion (POST vs IR) had no effect. Hindlimb I/R (IR vs SHAM) resulted in both significant pulmonary neutrophil infiltration (MPO 16.4 ± 1.06 U/g vs 11.3 ± 1.4 U/g) and hepatocellular injury (AST 286 ± 45 U/mL vs 108 ± 30 U/mL), but neither was inhibited by pretreatment with STNFRI before ischemia. Detectable levels of TNF were measured during ischemia in a significantly higher percentage of the IR group compared with SHAM (9 of 12 vs 3 of 12), and the maximal TNF values were also significantly greater (51.1 ± 12.6 pg/mL vs 5.5 ± 2.9 pg/mL). No TNF was detected in any treatment group during reperfusion nor after administration of the STNFRI. Conclusion: Acute hindlimb IR initiates a systemic TNF response during the ischemic period that is partly responsible for the associated skeletal muscle injury. (J Vasc Surg 1999;29:370-6.)     

Mycophenolate mofetil attenuates liver ischemia/reperfusion injury in rats

Mycophenolate mofetil (MMF) has been gradually introduced into clinical liver transplantation in recent years. However, the effects of MMF on hepatic ischemia/reperfusion (I/R) injury and the potential mechanisms involved are not totally understood. We aimed to evaluate whether MMF could attenuate hepatic I/R injury. MMF (20 mg/kg) or vehicle was administered to Wistar rats by gavage. The rats were then subjected to hepatic ischemia. Liver cell apoptosis and the levels of aspartate aminotransferase, myeloperoxidase (MPO), xanthine oxidase (XOD) and malondialdehyde (MDA) were determined. Expression of vascular cell adhesion molecule-1 (VCAM-1) and activation of mitogen-activated protein kinases (MAPKs) were also investigated. Furthermore, the hepatic microcirculation was observed by intravital fluorescence microscopy. Rats pretreated with MMF exhibited significant alleviation of their postischemic liver function. Liver cell apoptosis and the tissue MPO, XOD and MDA levels were decreased by MMF pretreatment. MMF also improved I/R-induced hemodynamic turbulence, as evidenced by reduced hepatic perfusion failure and decreased numbers of rolling and adherent leukocytes. I/R injury induced activation of the MAPKs pathway while expression of VCAM-1 was downregulated by MMF pretreatment. In summary, MMF attenuates hepatic I/R injury through suppression of the production of reactive oxygen species and amelioration of postischemic microcirculatory disturbances.     

Atorvastatin donor pretreatment prevents ischemia/reperfusion injury in renal transplantation in rats: possible role for aldose-reductase inhibition

BACKGROUND: The aim of the present study was to evaluate the effect of donor pretreatment with atorvastatin on ischemia/reperfusion (I/R) injury in renal transplantation in rats. METHODS: Donor rats were pretreated orally with atorvastatin or vehicle 2 days prior to explantation. Kidneys were stored for 24 hr at 4 degrees C in University of Wisconsin solution and transplanted into isogeneic or allogeneic recipients. RESULTS: Donor treatment with atorvastatin improved initial graft function, reduced renal inflammation, and the number of TUNEL-positive cells in renal tissue after prolonged cold storage and isogeneic transplantation. In the allogeneic transplantation model, donor treatment with atorvastatin reduced renal inflammation in grafts harvested after 5 days, but no improvement of long-term graft survival (24 weeks) could be observed. A genome wide gene expression profile of donor kidneys from atorvastatin treated or vehicle treated rats revealed a fivefold downregulation of aldose reductase in all atorvastatin treated animals (P<0.01). Donor treatment with an aldose-reductase inhibitor improved kidney function and reduced renal inflammation after prolonged cold storage and isogeneic transplantation. CONCLUSION: Our data suggest that downregulation of aldose reductase in renal tissue might underlie the protective effect of donor atorvastatin treatment. Donor pretreatment with a statin or an aldose reductase inhibitor could offer a new treatment strategy to prevent transplantation associated tissue injury.     

Influence of donor pretreatment with N-acetylcysteine on ischemia/reperfusion injury in rat kidney grafts

PURPOSE: N-acetylcysteine (NAC) has been shown to ameliorate ischemic acute renal failure. We determined the effect of donor pretreatment with NAC on ischemia reperfusion (I/R) injury in rat kidney grafts. MATERIALS AND METHODS: Lewis rats were divided into 3 groups (8 per group) and treated with saline, mannitol (1 gm/kg) or NAC (1 gm/kg intravenously) prior to donor nephrectomy. Cold stored kidneys (24 hours in UW solution) were transplanted into bilaterally nephrectomized recipients. Blood and graft tissue samples were taken 24 hours after transplantation for assessment of metabolic changes, histological damage and renal function. Metabolites associated with renal I/R injury were quantified in blood and renal tissue by magnetic resonance spectroscopy. RESULTS: The degree of histological damage was similar between the treatment groups. Of the counted tubules 60%were mildly damaged, whereas 40% showed moderate damage. Measurement of the metabolites allantoin and trimethylamine-N-oxide (TMAO) indicated a beneficial effect of NAC treatment. In graft tissue and recipient blood allantoin, a uric acid metabolite, was significantly lower in the NAC group vs the mannitol and saline groups (p <0.05). In recipient blood TMAO, an established marker of renal medullary injury, was significantly decreased in the NAC group vs mannitol and saline (p <0.05). Serum creatinine levels were not different between treatment groups. CONCLUSIONS: Donor pretreatment with NAC preserves renal metabolism and may improve outcomes of I/R injured kidney transplants. Allantoin and TMAO are sensitive metabolic markers of renal I/R injury that can be detected before the onset of functional and morphological changes.