小体积肝移植和辅助性原位小体积肝移植治疗猪急性肝功能衰竭的近期疗效观察

目的观察小体积肝移植和辅助性原位小体积肝移植治疗猪急性肝功能衰竭的近期疗效。方法急性肝功能衰竭猪随机分为3组接受肝移植治疗:A组行全肝移植(n=5);B组行小体积肝移植(n=5);C组行辅助性原位小体积肝移植(n=5)。各组动物开腹后即刻、切脾后即刻和再灌注后30 min分别监测门静脉压力,并观察术后生化指标变化、病理改变和1周生存率。结果A、B和C三组的移植肝重量与受体体重之比分别为(2．44±0．30)％、(0．76±0．02)％和(0．75±0．03)％。再灌注后30 min,B组移植肝门静脉压力显著高于其它两组(A:B:C=13．3:17．5:12．2 cmH2O, P<0．01),C组原肝门静脉压力显著高于移植肝门静脉压力(14．3:12．2 cmH2O,P<0．05)。A组和C组术后第2天起血清天冬氨酸转氨酶、总胆红素、凝血酶原时间、乳酸和血氨水平明显下降,术后第7天基本恢复至正常水平。B组术后上述生化指标一直维持在较高的水平,术后第2～4天明显高于其它两组(P<0．01)。A组、B组和C组1周生存率分别为100％、20％和80％,B组明显低于其它两组(P<0．05)。结论辅助性原位小体积肝移植治疗急性肝功能衰竭近期疗效优于小体积肝移植,术中不必干预原肝门静脉。     

附加门体分流术对小体积移植肝保护作用的实验研究

目的 研究附加门体分流术对小体积移植肝的保护效果.方法 建立巴马小型猪小体积肝移植模型,将15只小型猪平均分为3组:(1)A组,小体积肝移植组(对照组);(2)B组,远端脾肾分流术+小体积肝移植组;(3)C组,肠腔H形分流术+小体积肝移植组.手术后观察动物7 d存活率,动态监测肝功能生化指标、自由门静脉压、门静脉血流量(PBF)以及移植肝组织病理学改变.结果 动物7 d存活率分别为:A组1/5,B组3/5,C组5/5.A组动物移植肝复流后自由门静脉压立即升高,高峰达(28.6±2.07)mm Hg(1 mm Hg=0.133 kPa),复流1 h后单位肝组织PBF达(3.56±0.1 1)ml·min-1·g-1;移植肝组织病理学改变严重,包括肝细胞气球样变或肝细胞坏死、肝窦淤血、肝实质出血.B、c组中动物肝功能酶学指标有所改善.移植肝复流后自由门静脉压显著低于A组水平(P<0.05),PBF保持相对平稳.移植肝组织病理学病变明显减轻.结论 附加门体分流术可能可以避免小体积移植肝的损伤.     

大鼠小体积肝移植物再灌注早期EGR-1的表达及其意义

目的探讨早期生长因子(EGR-1)在大鼠小体积肝移植物早期损伤中的表达及意义。方法雄性SD大鼠随机分成3组:假手术组(SO组),小体积肝移植物组(30%供肝组),全肝移植物组(100%供肝组)。采用两袖套法建立肝移植模型,比较再灌注24 h内3组肝功能指标变化、肝脏组织病理学改变及肝移植物内EGR-1和内皮素-1(ET-1)表达的变化。结果假手术组AST水平明显低于其余两组(P0.01),而100%供肝组AST水平低于30%供肝组,其中6,24 h时点上,两者差异具有统计学意义(P0.01)。光镜检查显示24 h 30%供肝的肝窦明显扩张,肝窦内衬细胞崩解、分离。假手术组未见EGR-1和ET-1表达,30%供肝组EGR-1和ET-1表达明显强于100%供肝组。结论小体积肝移植物早期损伤与EGR-1高表达及受其调控的ET-1表达上调有关。     

血清α谷胱甘肽-S-转移酶监测移植肝缺血再灌注损伤的临床研究

目的 探讨应用血清α-GST、监测肝移植术后移植肝缺血再灌注损伤的临床价值。方法采用酶联免疫测定法(EIA)对30例原位肝移植受体移植肝恢复再灌注72h内血清α-GST水平的动态变化进行监测，并与常规肝功能指标(AST、ALT、LDH)比较。结果 移植肝恢复再灌注后血清α-GST水平迅速上升、迅速下降，达到高峰及降至正常的时间明显早于肝功能指标，平均每小时变化率及平均峰值幅度也明显大于同期肝功能指标。结论 血清α-GST、监测肝移植术后移植肝缺血再灌注损伤较常规肝功能指标更具敏感性，能更及时判断移植肝功能损害的发生与终止。     

大鼠脊髓缺血再灌注损伤后MMP-9的基因表达变化

目的 研究脊髓缺血再灌流损伤过程中的脊髓神经细胞MMP-9表达的变化.方法 30只成年Wistar大鼠,解剖分离腹主动脉,按缺血和再灌流各时间段分别阻断开放腹主动脉,造成脊髓腰尾段缺血,假手术组不阻断腹主动脉,取缺血前、缺血30min、缺血60min,缺血30min再灌注2、6、10h后,分别造成脊髓缺血再灌注损伤模型,每个时相点5只.对局部脊髓逆转录PCR(RT-PCR)及荧光定量PCR检测基质金属蛋白酶9(MMP-9)的表达水平.结果 正常对照组(缺血前)脊髓可见少量MMP-9表达,而实验组(缺血30min、缺血60min)MMP-9基因表达明显增加,再灌注2、6、10h,MMP-9mRNA表达逐渐增加,且MMP-9的基因表达较缺血期明显增加,各组之间存在明显的差异(P＜0.05).结论 MMP-9在脊髓缺血再灌注中起一定作用,再灌注期细胞内MMP-9基因表达明显多于缺血期,MMP-9与缺血再灌注时间之间存在时效关系,表明MMP-9可能参与脊髓再灌流损伤,是脊髓再灌注损伤过程中一个重要的病理学环节,研究结果对于揭示脊髓继发性损伤的发病机理具有积极意义.     

骨髓间充质干细胞促进大鼠小体积肝移植后肝再生的实验研究

目的 探讨骨髓间充质干细胞能否促进大鼠小体积肝移植后移植肝的再生.方法 体外分离、培养、鉴定大鼠骨髓间充质干细胞.在30％大鼠部分肝移植的模型基础上,实验分为对照组(30％ PLT)和骨髓间充质干细胞干预组(30％PLT+ MSC).比较两组肝移植术后的存活率,分析肝功能的变化,通过免疫组化来观察移植肝标本Cyclin D1和PCNA的表达,并对移植肝组织结构进行电镜观察.结果 骨髓间充质干细胞的干预,能够改善小体积肝移植术后肝功能状况,减轻组织学损伤,并能够提高存活率,30％ PLT组与30％ PLT+ MSC组一周存活率分别为16.7％和58.3％.而在Cyclin D1和PCNA的免疫组化表达中,30％ PLT组表达明显抑制,30％ PLT+ MSC组表达上调.结论 骨髓间充质干细胞可以存进大鼠小体积肝移植后移植肝的再生,改善肝功能,并提高存活率.     

丙氨酰谷氨酰胺对肝移植术后移植肝功能和结构的影响

目的 探讨传统全胃肠外营养及添加丙氨酰谷氨酰胺(Ala-Gln)的TPN对肝移植后移植肝功能和结构的影响.方法 将24例肝移植病人随机分为两组:不添加Ala-Gln的TPN组(TPN组),添加Ala-Gln的TPN组(Gln组).术后第2天予以等热量(每千克体重104.6 kJ)、等氮量(每千克体重0.16 g)共7d.监测术后第2天、第9天肝功能指标;观察供肝冉灌注后、术后第9人移植肝结构的变化.结果 术后第9天Gln组与TPN组比较,APOB与CHE增高幅度大且差异有统计学意义(P＜0.05);AST的降低幅度大且差异有统计学意义(P＜0.05).Gln组移植肝细胞超微结构改善优于TPN组.结论 肝移植后添加Ala-Gln的TPN比传统TPN有利于移植肝缺血再灌注损伤的恢复.     

经典原位肝移植术中逆灌注法对移植肝缺血再灌注损伤的影响

目的 探讨经典原位肝移植术中逆灌注法对移植肝缺血再灌注损伤的影响.方法 35例经典原位肝移植患者随机分为试验组和对照组.试验组17例,采用经下腔静脉逆灌注法,在吻合门静脉前先开放下腔静脉,然后再吻合门静脉、肝静脉;对照组18例,采用常规经门静脉正向灌注法,先开放门静脉,再开放下腔静脉,然后吻合肝动脉.分别测定两组的以下指标:复温缺血时间(RWIT);移植术后1h及术后1、2、3、5、7天血清丙氨酸转氨酶(ALT)、谷氨酰转肽酶(GGT)、总胆红素(TB)、凝血酶原时间(PT);无肝期结束后2h下腔静脉血中的肿瘤坏死因子-α(TNF-α)和白细胞介素-1(IL-1)的浓度;无肝期结束后3h取肝组织活检行光镜检查,高倍镜下计算肝细胞水变性及坏死细胞百分比.结果 试验组的RWIT显著短于对照组(P＜0.05);术后1小时,术后1、2天试验组TB显著低于对照组(P＜0.05),术后3、5、7天两组无差异(P＞0.05);术后1、2天试验组ALT显著低于对照组(P＜0.05),术后1h、术后3、5、7天两组无差异(P＞0.05);术后1h,术后1、3天试验组GGT显著低于对照组(P＜0.05),术后2、5、7天两组无差异(P＞0.05);两组PT术后无差异(P＞0.05);无肝期结束后2h,试验组下腔静脉血中TNF-α,IL-l的浓度显著低于对照组(P＜0.05);病理组织学检查显示试验组肝细胞缺血再灌注损伤较对照组轻;无肝期结束后3h,试验组肝细胞水变性及坏死细胞百分比显著低于对照组(P＜0.05).结论 经典原位肝移植术中逆灌注法可减轻移植肝缺血再灌注损伤,改善移植肝早期肝功能.     

大鼠肺早期缺血再灌注损伤时线粒体DNA的表达及意义

目的 探讨线粒体DNA(mtDNA)在大鼠肺缺血再灌注损伤过程中的表达变化及意义.方法 32只雄性SD大鼠,分为4组:缺血再灌注1组(IR1组)大鼠按照原位缺血再灌注模型的制作方法缺血1h,再灌注0.5 h;缺血再灌注2组(IR2组),采用相同方法,缺血1h,再灌注1h;假手术对照1组(Con1组),开胸1.5h;假手术对照2组(Con2组),开胸2h.实验结束时分别处死各组大鼠,心脏采血,完整取下左肺.行HE染色,观察各组肺组织病理变化;测量肺湿重/干重,计算肺含水量;提取外周血DNA,荧光定量实时聚合酶链法测定各组大鼠外周血循环mtDNA表达量;酶联免疫吸附法测定各组大鼠肺组织中基质金属蛋白酶9(MMP-9)和单核细胞趋化蛋白1(MCP-1)含量.结果 与Con1组和Con2组相比较,IR1组和IR2组大鼠肺组织损伤加重,炎症细胞浸润、肺泡腔内渗出显著增多,肺水含量也升高(P＜0.01).IR1组大鼠外周血中mtDNA含量高于Con1组,IR2组大鼠外周血中mtDNA含量高于Con2组,差异均有统计学意义(P＜0.01,P＜0.01).与Con1组相比较,IR1组大鼠肺组织MMP-9和MCP-1的表达的差异无统计学意义(P＞0.05);而与Con2组相比较,IR2组大鼠肺组织MMP-9和MCP-1的表达升高(P＜0.01).结论 大鼠原位肺缺血再灌注损伤早期,循环中mtDNA明显升高,其表达与肺组织中MMP-9、MCP-1的表达具有相关性.     

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.     

Liver regeneration is suppressed in small-for-size liver grafts after transplantation: involvement of c-Jun N-terminal kinase, cyclin D1, and defective energy supply

BACKGROUND: Small-for-size liver grafts have decreased survival compared to full-size grafts. This study investigated mechanisms of suppression of liver regeneration in small-for-size grafts. METHODS: Rat liver explants were reduced in size to 50% and implanted into recipients of different body weights, resulting in graft weight/standard liver weights of approximately 50% (half-size) and approximately 25% (quarter-size). RESULTS: Hepatic cellular 5-bromo-2'-deoxyuridine (BrdU) incorporation increased from 0.2% after sham operation to 2%, 18%, and 1.2% in full-size, half-size, and quarter-size grafts, respectively. Graft weight did not increase in full- and quarter-size grafts but increased 40% in half-size grafts. By contrast, apoptosis remained low (< or =0.7%) and stem cells did not increase in all conditions. Phospho-c-Jun increased 27-fold in half-size grafts but only sevenfold in quarter-size grafts. Activating protein-1 activation increased 14-fold in half-size grafts but only fivefold in quarter-size grafts. Cyclin D1 (CyD1), which was barely detectable in full- and quarter-size grafts, increased 8.3-fold in half-size grafts. Adenosine 5'-triphosphate (ATP) per gram tissue decreased 70% in quarter-size grafts. Treatment of quarter-size grafts with radical scavenging C. sinenesis polyphenols (20 microg/ml) increased BrdU labeling and weight gain to 35% and 56%, respectively, reversed inhibition of CyD1 expression, c-Jun phosphorylation, and AP-1 activation in quarter-size grafts compared to half-size grafts, and restored ATP levels to 75%. CONCLUSIONS: Liver regeneration is stimulated in half-size grafts but suppressed in quarter-size grafts. Defective liver regeneration in small grafts is associated with an inhibition of the c-Jun N-terminal kinase/c-Jun and CyD1 pathways and compromised energy production.     

Ischemic preconditioning prevents free radical production and mitochondrial depolarization in small-for-size rat liver grafts

BACKGROUND: Ischemic preconditioning (IP) renders tissues more tolerant to subsequent longer episodes of ischemia. This study tested whether IP attenuates injury of small-for-size liver grafts by preventing free radical production and mitochondrial dysfunction. METHODS: IP was induced by clamping the portal vein and hepatic artery for 9 min. Livers were harvested 5 min after releasing the clamp. Mitochondrial polarization and cell death were assessed by intravital confocal/multiphoton microscopy of rhodamine 123 (Rh123) and propidium iodide. Free radicals were trapped with alpha-(4-pyridyl 1-oxide)-N-tert-butylnitrone and measured using electron spin resonance. RESULTS: After quarter-size liver transplantation, alanine aminotransferase, serum bilirubin, necrosis, and apoptosis all increased. IP blocked these increases by more than 58%. 5-Bromo-2'-deoxyuridine labeling and increases of graft weight were only approximately 3% and 0.2% in quarter-size grafts without IP, respectively, but increased to 32% and 60% in ischemic-preconditioned grafts, indicating better liver regeneration. Eighteen hours after implantation, viable cells with depolarized mitochondria in quarter-size grafts were 15 per high power field, and dead cells were less than 1 per high power field, indicating that depolarization preceded necrosis. A free radical adduct signal was detected in bile from quarter-size grafts. IP decreased this free radical formation and prevented mitochondrial depolarization. IP did not increase heat shock proteins 10, 27, 32, 60, 70, 72, 75 and Cu/Zn-superoxide dismutase (SOD) but increased heat shock protein-90, a chaperone that facilitates protein import into mitochondria, and mitochondrial Mn-SOD. CONCLUSION: Taken together, IP decreases injury and improves regeneration of small-for-size liver grafts, possibly by increasing mitochondrial Mn-SOD, thus protecting against free radical production and mitochondrial dysfunction.     

Rapamycin Attenuates Liver Graft Injury in Cirrhotic Recipient—The Significance of Down-Regulation of Rho-ROCK-VEGF Pathway

To investigate whether rapamycin could attenuate hepatic I/R injury in a cirrhotic rat liver transplantation model, we applied a rat orthotopic liver transplantation model using 100% or 50% of liver grafts and cirrhotic recipients. Rapamycin was given (0.2 mg/kg, i.v.) at 30 min before graft harvesting in the donor and 24 h before operation, 30 min before total hepatectomy and immediately after reperfusion in the recipient. Rapamycin significantly improved small-for-size graft survival from 8.3% (1/12) to 66.7% (8/12) (p = 0.027). It also increased 7-day survival rates of whole grafts (58.3%[7/12] vs. 83.3%[10/12], p = 0.371). Activation of hepatic stellate cells was mainly found in small-for-size grafts during the first 7 days after liver transplantation. Rapamycin suppressed expression of smooth muscle actin, which is a marker of hepatic stellate cell activation, especially in small-for-size grafts. Intragraft protein expression and mRNA levels of vascular endothelial growth factor (VEGF) were down-regulated by rapamycin at 48 h both in whole and small-for-size grafts. Consistently, mRNA levels and protein expression of Rho and ROCK I were decreased by rapamycin during the 48 h after liver transplantation. In conclusion, rapamycin attenuated graft injury in a cirrhotic rat liver transplantation model by suppression of hepatic stellate cell activation, related to down-regulation of Rho-ROCK-VEGF pathway.     

NIM811, a Mitochondrial Permeability Transition Inhibitor, Prevents Mitochondrial Depolarization in Small-for-Size Rat Liver Grafts

ATP decreases markedly in small-for-size liver grafts. This study tested if the mitochondrial permeability transition (MPT) underlies dysfunction of small-for-size livers. Half-size livers were implanted into recipients of about twice the donor weight, resulting in quarter-size liver grafts. NIM811 (5 microM), a nonimmunosuppressive MPT inhibitor was added to the storage solutions. Mitochondrial polarization and cell death were assessed by confocal microscopy of rhodamine 123 (Rh123) and propidium iodide (PI), respectively. After quarter-size transplantation, alanine aminotransferase (ALT), serum bilirubin and necrosis all increased. NIM811 blocked these increases by >70%. After 38 h, BrdU labeling, a marker of cell proliferation and graft weight increase were 3% and 5%, respectively, which NIM811 increased to 30% and 42%. NIM811 also increased survival of quarter-size grafts. In sham-operated livers, hepatocytes exhibited punctate Rh123 fluorescence. By contrast, in quarter-size grafts at 18 h after implantation, mitochondria of most hepatocytes did not take up Rh123, indicating mitochondrial depolarization. Nearly all hepatocytes not taking up Rh123 continued to exclude PI at 18 h, indicating that depolarization preceded cell death. NIM811 and free radical-scavenging polyphenols strongly attenuated mitochondrial depolarization. In conclusion, mitochondria depolarized after quarter-size liver transplantation. NIM811 decreased injury and stimulated regeneration, probably by inhibiting free radical-dependent MPT onset.     

Triptolide Attenuates Acute Small-for-Size Liver Graft Injury in Rats by Inhibition of Toll-like Receptor 4

IntroductionThe mechanism underlying small-for-size graft failure after reperfusion is still unknown. Toll-like receptor 4 (TLR4) has attracted a great deal of attention in inflammation and allograft rejection in recent years. Medicinally, triptolide has anti-inflammatory, immunosuppressive, and antineoplastic activities. In the present study, we studied the effect of triptolide on TLR4 expression in small-for-size grafts.Materials and MethodsThe potential inhibitory effect of triptolide on TLR4 messenger ribonucleic acid and protein in a mouse model of small-for-size liver graft injury was assessed. We also assessed the expression of tumor necrosis factor α and interleukin-6 in this model.ResultsThe expression of hepatic TLR4 messenger ribonucleic acid and protein and downstream mediators, such as tumor necrosis factor α and interleukin-6, were reduced in the triptolide pretreatment groups (50 and 100 μg) in small-for-size liver grafts. In these same triptolide pretreatment groups, edema and necrosis were reduced and the levels of alanine aminotransferase and aspartate aminotransferase were significantly decreased in these small-for-size liver grafts.ConclusionsThis study showed that triptolide might inhibit TLR4 in vivo and that pretreatment with triptolide could inhibit TLR4 activation and reduce small-for-size liver graft injury.     

Attenuation of acute phase shear stress by somatostatin improves small-for-size liver graft survival.

The major concern of living donor liver transplantation is small-for-size graft injury at the early phase after transplantation. Novel therapeutic strategies should be developed. To investigate the protective effect of somatostatin related to hemodynamic stress on small-for-size liver graft injury, we applied a treatment regimen of low-dose somatostatin in a rat orthotopic liver transplantation model using small-for-size grafts (median, 38.7%; range, 35-42%). Somatostatin was given at 5 minutes before total hepatectomy and immediately after reperfusion in the recipient (20 microg/kg). Graft survival, portal hemodynamics, intragraft gene expression and hepatic ultrastructural changes were compared between the rats with or without somatostatin treatment. Seven-day graft survival rates in the somatostatin treatment group were significantly improved compared to the control group (66.7% vs. 16.7%, P = 0.036). In the treatment group, portal pressure and hepatic surface blood flow were significantly decreased within the first 30 minutes after reperfusion, whereas in the control group, transient portal hypertension and excessive hepatic blood flow were observed. Intragraft expression (both messenger RNA and protein) of endothelin-1 was significantly downregulated accompanied with upregulation of heme oxygenase-1 and A20. Better preservation of liver function was found in the treatment group. Hepatic ultrastructure, especially the integrity of sinusoids, was well protected in the treatment group. In conclusion, low-dose somatostatin rescues small-for-size grafts from acute phase injury in liver transplantation by attenuation of acute-phase shear stress that resulted from transient portal hypertension.     

Impaired hepatic regeneration by ischemic preconditioning in a rat model of small-for-size liver transplantation

OBJECTIVE: Graft size is one of the major risk factors in adult-to-adult living donor liver transplantation and rapid regeneration is an essential post-operative requirement. Ischemic preconditioning (IPC) has been shown to be an effective strategy in the reduction of hepatic ischemia-reperfusion injury and stimulation of liver regeneration. This study was designed to evaluate the effects of IPC on liver regeneration in small-for-size liver grafts. METHODS: We employed a rat orthotopic liver transplantation model using small-for-size (30%) grafts, in the presence or absence (control) of IPC (10 min of ischemia followed by 15 min of reperfusion). Survival rate, graft injury, hepatocellular proliferation, cell cycle progression, Stat3 activation, as well as TNF-alpha and IL-6 expression were assessed. RESULTS: IPC significantly enhanced the extent of graft injury and hindered hepatic regeneration in small-for-size liver grafts. The 7-day survival rate was also reduced by IPC, but failed to reach statistical significance. IPC did not affect TNF-alpha levels, but significantly decreased the elevation of IL-6 after reperfusion. These findings were correlated with down-regulation of cyclin E and cyclin D1, and decreased numbers of PCNA-positive nuclei in IPC grafts. These results were inconsistent with Stat3 activation, as P-Stat3 exhibited a stronger and prolonged pattern of expression in the IPC group, compared to controls. CONCLUSIONS: Ischemic preconditioning may impair liver regeneration in small-for-size liver grafts by decreasing IL-6 and blunting cell cycle progression, through a mechanism at least partially independent of Stat3.     

Inhibition of Matrix Metalloproteinase‐9 Attenuates Acute Small‐for‐Size Liver Graft Injury in Rats

Ischemia/reperfusion (I/R) and portal hypertension have been implicated in small‐for‐size liver graft dysfunction. Matrix metalloproteinases‐2 and ‐9 (MMP‐2/9) are critically proposed to involve in hepatic I/R injury and activated by hemodynamic force. We hypothesized that MMP‐2/9 overexpression played a crucial role in acute graft injury following small‐for‐size liver transplantation (LT). Rats were randomly assigned into four groups: 75% partial hepatectomy (PH); 100% LT; 25% LT and 25% LT treated with CTT peptide (MMP‐2/9 inhibitor). ELISA, real‐time PCR, gelatin zymography and immunohistochemistry were used to determine the expression pattern of MMP‐2/9 in liver tissue. MMP‐9 expression was significantly increased 6 h after reperfusion and reached a peak 12 h in the 25% LT group, whereas MMP‐2 was expressed in all groups invariably. Compared with the 25% LT group, rats from CTT‐treated group exhibited markedly decreased alanine aminotransferase and total bilirubin values, downregulated proinflammatory cytokines, attenuated malondialdehyde (MDA) and myeloperoxidase (MPO) activities, and improved liver histology. Likewise, MMP‐9 inhibition significantly reduced number of TUNEL‐positive cells and caspase‐3 activity, along with decreased protein levels of Fas and Fas‐L. Specifically, rat survival was also improved in the CTT‐treated group. These results support critical function of MMP‐9 involved in acute small‐for‐size livergraft injury.     

依达拉奉减轻大鼠小体积肝移植物缺血再灌注损伤

目的 探讨依达拉奉减轻大鼠小体积肝移植物缺血再灌注损伤的作用及其可能机制.方法 采用成年雄性SD大鼠作为肝移植的供、受者,随机将受者分为依达拉奉组和对照组,每组8只.依达拉奉组受者移植前30 min经阴茎背静脉注射依达拉奉3 mg/kg,对照组受者仅给予等量生理盐水.采用改良的二袖套法建立大鼠40%(供肝重量与受者全肝重量比)小体积供肝肝移植模型.术后6 h时,处死两组受者,使用全自动生化分析仪检测血清天冬氨酸转氨酶(AST)和丙氨酸转氨酶(ALT)水平,采用酶联免疫吸附试验(ELISA)法检测移植肝组织中肿瘤坏死因子α(TNF-α)含量,使用相应的检测试剂盒检测移植肝组织中MDA含量以及SOD和MPO的活性.同时,取移植肝组织进行病理学检测,观察肝组织病理损伤情况.结果 术后6h,依达拉奉组受者血清AST和ALT水平分别为(825.50±72.87)U/L和(687.40±72.21)U/L,对照组分别为(1188.03±124.04)U/L和(988.66±91.07)U/L,依达拉奉组明显低于对照组,两组间比较,差异均有统计学意义(P<0.01).与对照组比较,依达拉奉组受者移植肝组织中MDA和TNF-α含量明显下降,MPO活性也明显下降,而SOD活性则明显增加,两组间比较,差异均有统计学意义(P<0.01).移植肝组织病理学检查发现,对照组肝细胞发生明显的空泡样变性伴局部坏死灶,肝小叶结构破坏,门脉周围水肿、充血,炎症细胞浸润明显;依达拉奉组肝损伤明显减轻,小叶结构保存完整,肝细胞变性、坏死轻微,炎症细胞浸润明显减少.结论 依达拉奉能够明显减轻大鼠小体积肝移植物缺血再灌注损伤,其机制可能与增强抗氧化能力、抑制脂质过氧化以及减轻炎症反应密切相关.     

FK 409 ameliorates small-for-size liver graft injury by attenuation of portal hypertension and down-regulation of Egr-1 pathway

OBJECTIVE: To investigate whether low-dose nitric oxide donor FK 409 could attenuate small-for-size graft injury in liver transplantation using small-for-size grafts. SUMMARY BACKGROUND DATA: The major concern of live donor liver transplantation is small-for-size graft injury at the early phase after transplantation. Novel therapeutic strategies should be investigated. METHODS: We employed a rat orthotopic liver transplantation model using small-for-size (40%) graft. FK 409 was given at 30 minutes before graft harvesting (2 mg/kg) to the donor and immediately after reperfusion (1 mg/kg) to the recipient (FK group). Graft survival, intragraft genes expression, portal hemodynamics, and hepatic ultrastructural changes were compared between the 2 groups. RESULTS: Seven-day graft survival rates in the FK group were significantly improved compared with those of rats not receiving FK 409 (control group; 80% versus 28.6%, P = 0.018). In the FK group, portal pressure was significantly decreased within the first 60 minutes after reperfusion whereas in the control group, transient portal hypertension was observed. Intragraft expression (both mRNA and protein) of early growth response-1, endothelin-1, endothelin-1 receptor A, tumor necrosis factor-alpha, macrophage-inflammatory protein-2, and inducible nitric oxide synthase was significantly down-regulated accompanied with up-regulation of heme oxygenase-1, A20, interferon-gamma-inducible protein-10, and interleukin-10 during the first 24 hours after reperfusion. Hepatic ultrastructure, especially the integrity of sinusoids was well protected in the FK group. CONCLUSIONS: Low-dose FK 409 rescues small-for-size grafts in liver transplantation by attenuation of portal hypertension and amelioration of acute phase inflammatory response by down-regulation of Egr-1, together with prior induction of heat shock proteins.