Heat shock preconditioning on mitochondria during warm ischemia in rat livers

BACKGROUND: The aim of this study was to investigate the effects of stress tolerance from heat shock preconditioning on changes in mitochondrial functions during ischemia-reperfusion injury of the liver. MATERIALS AND METHODS: Rats were divided into a heat shock group (group HS) and a control group (group C). In group HS, rats received heat shock pretreatment 48 h prior to ischemia-reperfusion. Heat shock pretreatment was performed in a water bath at 42 degrees C for 15 min under general anesthesia. In group C, the same treatment was done with the water bath at 37 degrees C instead of at 42 degrees C. A 30-min warm ischemia by cramping the hepatoduodinal ligament (Pringle's maneuver) followed by a 60-min reperfusion was administered to all rats. Changes in membrane potential of hepatic mitochondria (MPM); mitochondrial respiratory function before ischemia (n = 5), after ischemia (n = 10), and after reperfusion (n = 10); and ATP recovery after reperfusion were compared between the groups. RESULTS: After a 30-min ischemia, MPM in group C decreased significantly and did not recover even after reperfusion. On the other hand, MPM in group HS was maintained even after a 30-min ischemia and 60 min into reperfusion as well. The respiratory control ratio (RCR) of the mitochondria in group C decreased to as low as 5.06 +/- 0.72 after a 30-min ischemia, but in group HS, RCR was maintained near a normal level. The ATP level recovered significantly earlier in group HS than in group C after reperfusion. CONCLUSIONS: Heat shock preconditioning of the liver protected mitochondria from loss of membrane integrity during ischemia and contributed to their ability to produce energy-rich phosphates during reperfusion.     

The portosystemic shunt protects liver against ischemic reperfusion injury.

BACKGROUND: The goal of this study was to characterize the importance of splanchnic viscera in liver ischemic reperfusion injury and to enhance the tolerance of liver to warm ischemia injury with portosystemic shunt. METHODS: The hepatic blood flow of male Sprague Dawley rats was subjected to 45, 60, 120, and 150 min liver warm ischemia with or without portosystemic shunt (splenic-caval shunt). The production of tumor necrosis factor a (TNFa), nuclear factor-kappaB activation, inducible NO synthase (iNOS) expression, and apoptosis were examined. RESULTS: A total of 67% of rats with 45 min liver warm ischemia (n=6) and 100% of rats with 60 min liver warm ischemia (n=6) died within 1 day. However, all rats with 120 min (n=8) liver warm ischemia in splenic-caval shunt group survived for over 1 day, 6/8 for over 3 days, and 5/8 for over 5 days without significant histological changes of the liver. Serum tumor necrosis factor levels in liver warm ischemic rats were increased, This increase was significantly reversed after portosystemic shunt. After challenge with lipopolysaccharide (1 mg/kg, p.v.), naive rats survived for over 5 days (n=4) with the peak value of rat tumor necrosis factor (240 pg/ml) at 90 min. In contrast, all rats died within one day (n=5) with the peak value of rat tumor necrosis factor a (465 pg/ml) at 45 min after administration of lipopolysaccharide in the rats with liver warm ischemia plus splenic-caval shunt. iNOS expression and nuclear factor-kappaB activation were very strongly increased in the hepatocytes after liver warm ischemia with portosystemic shunt, compared with liver ischemia without portosytemic shunt. CONCLUSIONS: We conclude that the splanchnic viscera can contribute to liver ischemic reperfusion injury. Portosystemic shunt enhances the tolerance of liver to warm ischemia through the protective role of iNOS and nuclear factor-kappaB (NF-kappaB).     

Gadolinium chloride-induced improvement of postischemic hepatic perfusion after warm ischemia is associated with reduced hepatic endothelin secretion

Selective Kupffer cell blockade by gadolinium chloride (GdCl₃) pretreatment of liver donors previously proved to be effective in reducing ischemia/reperfusion injury in rat liver transplants. Physiological mechanisms of this effect have not been specified so far. Vasoactive peptides are involved in liver blood flow regulation. We tested the hypothesis, that hepatic hemodynamic effects of GdCl₃ pretreatment are mediated by intrahepatic endothelin‐1 (ET) secretion in a standardized porcine model of warm liver ischemia and reperfusion. Standardized warm hepatic ischemia (45 min) was induced after laparotomy in intubation narcoses (ITN) by Pringle‐maneuver in pigs (n = 12). Animals were either pretreated with GdCl₃ (20 mg/kg i.v.) or sodium chloride 0.9% (control group) in a randomized manner 24 h before investigation. Relaparotomy was performed at day 7. Before, during ischemia and until 6 h after liver reperfusion, transhepatic blood flow (portal venous + hepatic artery flow) was defined by ultrasonic flow probes and hepatic parenchymous microcirculation evaluated by implanted thermodiffusion electrodes. ET plasma concentrations were analyzed (commercial RIA) at all time points in the hepatic veins after selective canulation. GdCl₃ pretreatment of animals markedly improved hepatic macro‐ and microperfusion before and particularly after warm ischemia. Mean ET plasma concentrations in the hepatic vein were significantly lower before, 6 h and 7 days after ischemia, compared with controls. Kupffer cell destruction by GdCl₃ pretreatment improves hepatic micro‐ and macroperfusion after warm ischemia, thus indicating reduced ischemia/reperfusion injury. Documented reduction of postischemic liver blood flow impairment after GdCl₃ pretreatment could be mediated by a decreased hepatic ET secretion, as hemodynamic effects were associated with significantly reduced ET plasma levels in hepatic veins.     

Induction of Heat Shock Response: Effect on the Rat Liver with Carbon Tetrachloride-induced Fibrosis from Ischemia-reperfusion Injury

n = 56) received no pretreatment except anesthesia, and the heat shock group (group HS, n = 56) were exposed to heat shock (42°C) for 15 minutes. After a 48-hour recovery all rats were subjected to 30 minutes of warm ischemia. Western blotting analysis was employed for heat shock protein (HSP) 72 detection. The adenine nucleotide levels in liver tissue and the liver enzyme levels in serum were measured before and after ischemic intervention (seven animals were used at each of six time point measurements in both groups). HSP72 was induced in group HS at greater intensity than in group C. The survival rate on postoperative day 7 in group C (3/14) was significantly poorer than that in group HS (14/14) ( p < 0.01). The higher survival rate in group HS was accompanied by more rapid recovery of the adenosine triphosphate level and lower serum levels of liver enzymes after reperfusion ( p < 0.01 vs. group C). Heat shock preconditioning induces HSP72 in the rat liver with fibrosis and provides significantly increased tolerance of warm-ischemia reperfusion injury.     

Effects of N-acetylcysteine in hepatic ischemia-reperfusion injury during hemorrhagic shock

This article seeks to standardize an experimental model of liver ischemia-reperfusion in rats following hemorrhagic shock modulated by N-acetylcysteine (NAC). Twenty-seven adult Wistar rats were randomized into three groups: the HS-IR-Garm underwent hemorrhagic shock with selective hepatic ischemia followed by reperfusion; the HSIR + NAC-G, the same procedure plus NAC; and the control group, only venous catheterization. Blood was withdrawn for 10 minutes until MABP reached 35 mm Hg, which was maintained for 1 hour. The blood was then reinjected as required to maintain MABP at that level. Ringer's lactate solution was infused in a volume equivalent to three times the shed blood, over a period of 15 minutes. Half of the shed blood was reinfused over 5 minutes. HSIR + NAC-G received 150 mg/kg of NAC, during treatment of the shock, and again 10 minutes before reperfusion and continued for 30 minutes. Finally, both groups were subjected to 40 minutes of warm selective hepatic ischemia and reperfusion for 1 hour. Data were analyzed by nonparametric tests (P < or =.05). Liver enzyme levels were higher in HS-IR-G (DHL = 6094 +/- 1688, AST = 746 +/- 175, and ALT = 457 +/- 90) than in HSIR + NAC-G group (DHL = 2920 +/- 284, AST = 419 +/- 113, and ALT = 253 +/- 26). The values in the control group were lower than both experimental groups (DHL = 965 +/- 173, AST = 163 +/- 42, and ALT = 82 +/- 28). Our data showed that liver ischemia-reperfusion injury following hemorrhagic shock produces important hepatic damage and that NAC reduces injury in this rat model.     

Granulocyte colony-stimulating factor (G-CSF) production in hemorrhagic shock requires both the ischemic and resuscitation phase

Granulocyte colony-stimulating factor (G-CSF) is the cytokine that is critical for polymorphonuclear neutrophilic granulocyte (PMN) production as well as being a potent agonist of PMN activation. We have recently reported that in the lung and the liver of rats resuscitated after hemorrhagic shock (HS) G-CSF mRNA expression is induced. It is not known if both phases of HS, the ischemic and the reperfusion phase, are required for G-CSF mRNA induction. The present study was designed to test the hypothesis that the upregulation of G-CSF mRNA expression is the consequence of HS followed by resuscitation and that ischennia alone is insufficient to induce G-CSF mRNA expression in the affected organs. Male Sprague-Dawley rats were subjected to resuscitated and unresuscitated shock protocols of varying severity. Control animals were subjected to anesthesia and all surgical preparations except for hemorrhage. Lungs and livers were isolated and their RNA extracted. Using semiquantitative reverse trans criptase-polymerase chain reaction (RT-PCR), we demonstrated that G-CSF mRNA was induced in the lung and liver of shock animals above the level observed in control animals. Upregulation of G-CSF mRNA relative to controls occurred only in animals undergoing resuscitated HS and not in ones subjected to unresuscitated HS. These results indicate that G-CSF production specific for the hemorrhage component of shock is dependent on resuscitation. As a consequence, the production of this cytokine may be decreased through modifications in the resuscitation protocols.     

梗阻性黄疸SD大鼠肝热缺血再灌注损伤模型的建立

目的构建阻塞性黄疸合并肝热缺血再灌注损伤的SD大鼠模型。 方法选择SD大鼠40只随机分为4组：假手术组（Sham组）、梗阻7天组（7 d组）、梗阻14天组（14 d组）及梗阻21天组（21 d组）,每组10只。通过双重结扎并切断胆总管建立SD大鼠阻塞性黄疸模型,探索最佳梗阻时间。梗阻7 d后另择SD大鼠62只,再随机分为4组：未缺血组（0 min组,10只）、缺血15 min组（15 min组,12只）、缺血30 min组（30 min组,16只）、缺血45 min组（45 min组,24只）,分别行肝门部血管阻断0、15、30、45 min后再灌注,建立后续肝热缺血再灌注损伤模型,观察生化指标、生存率及病理学改变。 结果梗阻7 d时适合下一步建模。建立阻塞性黄疸模型后,随着肝门部血管阻断时间的延长,肝功能进行性下降,大鼠死亡率逐渐升高,各组间的差异具有统计学意义（P<0.05）;随阻断时间的延长,肝脏损害的病理学表现更为严重。其中肝门部血管阻断30 min时24 h死亡率50%,再灌注2 h后病理学上出现严重的肝细胞变性、坏死改变。 结论对于梗阻性黄疸的SD大鼠,在梗阻7 d后行肝门部血管阻断30 min再恢复血流,可有效建立梗阻性黄疸大鼠的肝缺血再灌注损伤模型。     

Dynamic changes of post-ischemic hepatic microcirculation improved by a pre-treatment of phosphodiesterase-3 inhibitor, milrinone

BACKGROUND: Phosphodiesterase-3 inhibition has been shown to attenuate hepatic warm ischemia-reperfusion injury. The aim of this study was to investigate the effect of milrinone, phosphodiesterase-3 inhibitor, on post-ischemic microcirculation of rat livers by intravital microscopy. MATERIALS AND METHODS: Male Wistar rats were randomly assigned to three groups; group A, milrinone pre-treatment; group B, ischemic pre-conditioning; and group C, no pre-treatment. All animals underwent a 60-min warm ischemia of the left lateral liver lobe. Microvascular perfusion and leukocyte-endothelial interaction were observed by intravital videomicroscopy. Hepatocellular viability and cellular damage were quantified by adenosine triphosphate tissue concentration as well as alanine aminotransferase and lactate dehydrogenase blood levels, respectively. RESULTS: In groups A and B, cyclic AMP hepatic tissue concentration was elevated significantly. After reperfusion, microvascular perfusion in hepatic sinusoids was significantly better maintained, and the number of adherent leukocytes was reduced in sinusoids and in post-sinusoidal venules in these rats. Serum transaminase blood levels were suppressed significantly in these groups compared with controls. CONCLUSION: The demonstrated improvement of hepatic microcirculation is certainly derived from milrinone induced cell protection in ischemia reperfusion of the liver. This effect is outlined by improved energy status and reduced liver enzyme liberation and mimics the effect of ischemic pre-conditioning.     

银杏叶提取物对无心跳供肝热缺血损伤保护作用的实验研究

目的　探讨传统中药银杏叶提取物对肝脏热缺血损伤的保护作用。方法　建立猪肝脏在体完全缺血90min的模型。实验分为3组,对照组11头动物,实验组（银杏组）10头动物,前列腺素E1对照组（PGE1组）9头动物。PGE1组和银杏组按分组要求分别于缺血前30min给予PGE1和银杏叶提取物;观测肝组织中自由基、肝脏能量代谢、肝功能及肝组织病理改变等。结果　PGE1组和银杏组上述指标都优于对照组,银杏叶提取物比PGE1具有更强的抗自由基作用,而在其它方面与PGE1相类似。结论　银杏叶提取物是比PGE1更好的热缺血保护剂,能显著减轻供肝的热缺血损伤。     

The role of HMGB-1 on the development of necrosis during hepatic ischemia and hepatic ischemia/reperfusion injury in mice

BACKGROUND: High-mobility group 1 (HMGB-1) is a late mediator of endotoxin lethality in mice. The release of HMGB-1 is delayed compared to other proinflammatory cytokines that mediate shock and tissue injury. The purpose of this study was to investigate the role of HMGB-1 levels in response to hepatic ischemia, hepatic I/R injury, and the relationship between changes in HMGB-1 and other cytokines. MATERIALS AND METHODS: Three murine models were employed: our robust model of segmental hepatic warm ischemia (SHWI), a model of partial hepatic ischemia/reperfusion injury (PHIRI), and a model of total hepatic ischemia/reperfusion injury (THIRI). Over a 48-h period following ischemic insult and reperfusion using these models, serum HMGB-1 concentrations, concentrations of HMGB-1 in ischemic and nonischemic lobes, and serum concentrations of TNF-alpha and IL-6 levels were determined in mice. An anti-HMGB-1 antibody treatment was used in SHWI and THIRI to evaluate what aspects of response to ischemia and reperfusion were potentially mediated by HMGB-1. RESULTS: Hepatic HMGB-1 tissue concentrations exhibited biphasic changes in SHWI mice, which were increased in the ischemic lobes relative to nonischemic lobes at 12 h but decreased relative to nonischemic lobes at 24 h after ischemic insult. These results suggested that HMGB-1 was released into the systemic circulation by necrotic cells over the first 12 h but this process may be complete by 24 h postischemia. By 6 to 12 h after SHWI, serum TNF-alpha began to increase significantly and continued to increase for 18 h, followed by a sudden decline. Similarly, serum IL-6 increased over 1-3 h after SHWI and then decreased over the next 6 h. Treatment with an anti-HMGB-1 antibody significantly prolonged survival time in SHWI and THIRI. CONCLUSIONS: HMGB-1 plays a significant role in the response to hepatic ischemia and hepatic ischemia/reperfusion injury. The present study demonstrated a time-dependent production of HMGB-1 following hepatic warm ischemia in mice. The inherent HMGB-1 in ischemic areas was exhausted and HMGB-1 may be released by necrotic cells. HMGB-1 activation is involved in immediate proinflammatory stress response to I/R and anti-HMGB-1 antibody treatment remarkably improved survival. We demonstrated that systemic HMGB-1 accumulation was measured at an earlier phase of the hepatic ischemia and ischemia/reperfusion injury model than LPS-induced endotoxemia.     

A pilot study on early versus delayed hypertonic saline dextran resuscitation in a porcine model of near-lethal liver injury: early hemodynamic response and short-term survival

BACKGROUND: We studied the effects of early versus delayed fluid resuscitation on hemodynamic response and short-term survival in a porcine model of severe hepatic injury associated with hemorrhagic shock. MATERIALS AND METHODS: Eighteen anesthetized swine were randomized after standardized liver injury into two groups: early resuscitation (ER, n = 9) and delayed resuscitation (DR, n = 9). The ER and DR groups were resuscitated with hypertonic saline dextran (HSD) 20 min and 40 min after the injury, respectively. Mean arterial pressure (MAP), cardiac output (CO), and arterial blood gases were measured in addition to vascular blood flow rates in the aorta, hepatic artery and portal vein. The duration of follow-up was 100 min. RESULTS: MAP decreased from 112 +/- 4 to 23 +/- 2 mmHg (P < 0.05) during 20 min after the injury. Bolus infusion of HSD significantly elevated MAP, CO, and flow rates in the aorta, portal vein and common hepatic artery in both groups. Portal vein flow remained relatively high during the shock. Intra-abdominal bleeding (ER, 701 +/- 42 mL; DR 757 +/- 78 mL) and the mortality rate (ER 44%; DR 33%) did not differ between the groups 100 min after injury (P > 0.05). Aortic flow, portal vein flow, common hepatic artery flow, MAP, CO, PaO(2), PaCO(2), base deficit, pH, hemoglobin measurements, and the volume of blood shed into the intraperitoneal cavity did not affect survival in the Cox regression analysis. CONCLUSIONS: Early versus delayed fluid infusion with HSD resulted in a comparable hemodynamic response and survival 100 min after injury. No rebleeding was observed.     

The effect of hypothermia on liver adenosine triphosphate (ATP) recovery following combined shock and ischemia.

During both hemorrhagic shock and ischemia, adenosine triphosphate (ATP) concentrations fall in liver tissue. Incomplete recovery of ATP correlates with cell death and subsequent organ dysfunction. Changes in liver ATP levels were evaluated in paired groups of rats subjected to combined hemorrhagic shock and ischemia. A second set of paired animals was studied over time with shock alone. One animal in each pair was maintained at 28 degrees C and the other at 37 degrees C. Ischemia was produced by occluding inflow to the left half of the liver, and tissue was obtained from this area in all animals studied. Adenosine triphosphate levels fell in warm and cold animals subjected to both shock and 60 minutes of ischemia but recovered more completely during reperfusion in the cold animals. Shock alone caused a steady fall in ATP levels in the warm, but not the cold rats. These biochemical changes may indicate a beneficial effect of moderate hypothermia in the management of severe liver hemorrhage requiring temporary occlusion of blood flow.     

Therapeutic effect of cisapride on gastric injury following hemorrhagic shock resuscitation in rats

Whenshockandtraumaoccur, stomachisoneofthetargetorganswhichcaneasilybeharmed,1acutegastricmucosalesionisalatentandfatalthreattothoseclinicalcriticallyillpatients.Aresearchshowsthattreatmentofgastricmotilityishelpfultoreducedeathrateofcriticallyillpatients…     

N-acetylcysteine in pig liver transplantation from non-heart-beating donors.

Lipid peroxidation due to oxygen free radicals (OFR) seems to play a major role in loss of liver graft viability after warm ischemia, preservation, and transplantation. N-acetylcysteine (NAC) is an antioxidant that has a direct effect on OFR, and is also a glutathione precursor, another antioxidant. This study was designed to evaluate the efficacy of NAC in preventing ischemia-reperfusion damage of liver grafts harvested from non-heart-beating donors. Liver transplantation was performed on pigs divided into five groups: group 1 (control group; n=5) received livers from heart-beating donors; livers were subjected to 30 min of warm ischemia in groups 2 (n=3, no NAC) and group 3 (n=3; NAC treatment); warm ischemia time lasted 60 min in groups 4 (n=4; no NAC) and 5 (n=5; NAC treatment). Studied parameters included graft survival for more than 3 days, aspartate aminotransferase plasma levels, liver histology, and hepatic total glutathione concentrations. Graft survival was 100% in groups 1, 2, and 3, 0% in group 4, and 20% in group 5. NAC treatment did not influence initial mean aspartate aminotransferase release which was greater in warm ischemic livers than in controls. NAC treatment had no effect on liver hepatic total glutathione after reperfusion of animals receiving warm ischemic grants. Finally, no effect on liver histology was observed with NAC treatment. Our study suggests that in liver transplantation from non-heart-beating donors, NAC has no effect in both graft viability and lipid peroxidation. The role of OFR in primary dysfunction of transplanted warm ischemic livers remains controversial.     

缺血预处理对大鼠小体积供肝的保护作用及机制

目的探讨缺血预处理（IPC）对大鼠小体积供肝的保护作用及其机制。方法120只SD大鼠随机分为3组（每组20对）：无热缺血组（NWI）、缺血再灌注组（WI）和缺血预处理组（IPC）。用双袖套法建立大鼠小体积肝移植模型。各组10只受体大鼠于术前1d、术后1、2、3、5d取血，用自动生化分析仪检测AST和ALT。NWI组于供肝灌注前及植入后0．5、1、2、3h，WI组于热缺血前及植入后0．5、1、2、3h，IPC组于IPC前、IPC后及植入后0．5、1、2、3h取肝组织，用硝酸还原法检测其NO浓度。结果IPC可降低大鼠小体积肝移植术后血清AST和ALT浓度，提高再灌注早期肝脏组织NO的浓度，降低再灌注晚期肝脏组织NO的浓度（P〈0．05）。结论NO在大鼠肝脏的缺血再灌注损伤中可能具有双重作用。IPC对大鼠小体积供肝的缺血再灌注损伤有保护作用。其机制可能是通过促进供肝再灌注后早期NO合成，改善肝脏微循环，同时抑制供肝再灌注后晚期NO合成，减轻过量NO的损伤作用，从而保护移植肝脏功能。     

Attenuation of ischemic injury by N-acetylcysteine preconditioning of the liver

BACKGROUND: Numerous previous studies have established the hepatoprotective properties of N-acetylcysteine (NAC). The present study was designed to investigate the effects of NAC on a warm hepatic ischemia-reperfusion rat model with a focus on the role of cAMP. MATERIALS AND METHODS: Fifty-six male Wistar rats were allocated randomly into the control group (n = 28) or the study group (group NAC, n = 28). Group NAC animals received an intravenous bolus dose of 0.3 mg/g NAC, whereas control animals were given an equal volume of normal saline. Subsequently, 60-min partial liver ischemia was induced by occlusion of blood inflow to the left and middle liver lobes. Aspartate aminotransferase, alanine aminotransferase, and alpha-glutathione S-transferase levels, platelet aggregation, and ischemic tissue cyclic adenosine 5-monophosphate (cAMP) levels were examined at 30, 60, and 120 min after reperfusion. Parts of the ischemic liver were sampled at the same time-points. Measurements were obtained from seven animals at each time point. RESULTS: The administration of NAC resulted in lower levels of aspartate aminotransferase, alanine aminotransferase, and alpha-glutathione S-transferase, decreased platelet aggregation, and increased levels of ischemic tissue cAMP at all time points after reperfusion. Histologically, fewer necrotic changes were observed in the NAC group at 60 and 120 min after reperfusion. All differences were statistically significant (P < 0.05). CONCLUSIONS: In the present study, NAC seems to attenuate hepatic ischemia-reperfusion damage, as demonstrated by liver function tests and liver histology. The effects of NAC appear to be mediated by the decrease in platelet aggregation and increase in the levels of cAMP observed in ischemic liver tissue.     

甘氨酸和丙酮酸对于局部缺血再灌注后的全身性保护作用

目的 肠系膜上动脉缺血/再灌注可引起小肠局部损伤,甚至休克和心肺功能障碍。丙酮酸和甘氨酸已被证实对缺血再灌注损伤的局部组织器官有保护作用。本文研究其对小肠缺血再灌注之后全身血流动力学以及心肺功能等的影响。方法 采用雄性SD大鼠,麻醉后建立血流动力学监测,建立肠系膜上动脉缺血90 min、再灌注120 min的模型。24只大鼠随机分为4组：丙酮酸组（再灌注前给予丙酮酸50 mg/kg,n=6）;甘氨酸组（再灌注前给予甘氨酸20 mg/kg,n=6）;林格组（再灌注前给予林格氏液1 mL,n=6）;假手术对照组（n=6）。术中记录平均动脉压、心脏指数、肺动脉压等,并估计循环血管阻力。采集动脉血进行血气分析和心肌标志物检测。观察结束后处死大鼠,取小肠、心脏、肺脏、肝脏进行组织学观察。结果 丙酮酸和甘氨酸均能有效稳定血流动力学参数,维持较好的心功能。其中甘氨酸组复苏所需晶体体积显著少于对照组。丙酮酸、甘氨酸对代谢性酸中毒的抑制作用明显优于林格氏液（P<0.01）。甘氨酸组的小肠、肺、心、肝病理评分和中性粒细胞浸润明显低于林格组（P<0.01）,但仍高于假手术组（P<0.01）。丙酮酸组、甘氨酸组CKMB、肌钙蛋白I水平低于林格组,但仍高于假手术组（P<0.01）。结论 丙酮酸和甘氨酸能在严重的局部缺血再灌注之后稳定全身循环状态,改善休克的复苏效果,既可减轻局部组织器官的缺血再灌注损伤,又可保护心肺等器官的功能。     

Study of the Changes of Serum Hyaluronic Acid During Porcine Liver Transplantation: Influence of Warm Ischemia

Abstract: Twelve porcine liver transplantations were performed to investigate whether serum hyaluronic acid (HA) serves as a marker of warm ischemic injury. Group 1 was a control without warm ischemia (n = 7), and pigs in Group 2 were sacrificed by intracardiac KC1 injection 60 min before harvesting (n = 5). All pigs survived more than 4 days in Group 1. In Group 2, all died within 2 days due to graft failure. Arterial and hepatic venous glutamic-oxaloacetic transaminase (GOT) in Group 2 were higher after revascularization. However, there were no differences between the 2 groups in arterial and hepatic venous HA levels. HA clearance by the graft also showed no differences between the groups. Although GOT reflected the degree of warm ischemia, HA and its hepatic clearance were not influenced by warm ischemic damage. In conclusion, HA was not thought to serve as a marker of liver injury when the graft suffered from warm ischemia.     

Oxothiazolidine Carboxylate Provides Protection against Hepatocellular Injury Seen after Porta <Emphasis Type="Bold">Hepatis Occlusion (Pringle Maneuver) under Hypovolemic Conditions</Emphasis>

Abstract The sensitivity of liver to warm ischemia has always been a concern for surgeons. To monitor the ischemia and/or reperfusion injury after the Pringle maneuver (occlusion of porta hepatis) in livers subjected to hemorrhage, blood pressure, blood pH, base deficit (BE), serum alanine aminotransferase (ALT), serum and liver malondialdehyde (MDA), and liver glutathione (GSH) levels were measured. MDA is a by-product of oxidant induced lipid peroxidation, and GSH is an endogenous antioxidant. The effect of lactated Ringer’s (LR) resuscitation with or without the addition of 2-oxothiazolidine-4-carboxylate (OTC), a cysteine prodrug (enhancing glutathione production) on liver injury, if any, were investigated. Rats in the sham group (n = 8) and five other groups (n = 8) underwent femoral artery and vein catheterization and laparotomy. The hemorrhage group was bled 30% of their blood volume and the ischemia group underwent occlusion of the porta hepatis 30 minutes. The hemorrhage-ischemia (HI), LR, and OTC groups underwent both hemorrhage and occlusion. The LR and OTC groups, 30 minutes after hemorrhage, received either LR resuscitation (equivalent to three times the shed blood) or LR resuscitation plus IV OTC (100 mg/kg before clamping and 100 mg/kg after de-clamping). Porta hepatis occlusion in the presence of hypovolemia (HI group) caused an increase in serum ALT, plasma MDA, liver MDA, and base deficit and a decrease in blood pH levels. LR resuscitation lowered only MDA (plasma and liver) and base deficit but did not reduce ALT and increase blood pH. Although liver GSH did not change, OTC kept all parameters at control levels. OTC prevents the deleterious effects of total hepatic inflow occlusion under hypovolemic conditions, but this does not occur through enhancement liver glutathione production. OTC may protect the liver by accelerating hepatic glutathione turnover, but further studies are needed to explain its mechanism of action.     

Prediction of graft viability from non-heart-beating donor pigs using hepatic microdialysate hypoxanthine levels

BACKGROUND: Non-heart-beating donors (NHBDs) are not yet acceptable in orthotopic liver transplantation (OLTX) because of the high frequency of primary graft nonfunction. In this study, we aimed to develop a new predictive method of graft viability in OLTX from NHBDs. MATERIALS AND METHODS: (1) Pigs were subjected to 15 min of hepatic ischemia and reperfusion (I/R). (2) Porcine OLTX was performed using grafts obtained from NHBDs subjected to in situ warm ischemia (0, 30, and 60 min). During both operations, hepatic hypoxanthine levels were measured by a microdialysis method. RESULTS: In the I/R model, hypoxanthine accumulated during ischemia and decreased after reperfusion, whereas marked xanthine and uric acid production were observed after reperfusion. In the NHBDs model, all of the 0-min group, 6 of 13 pigs in the 30-min group, and 1 of 6 pigs in the 60-min group survived more than 7 days. Significant increases of hypoxanthine levels were seen dependent on warm ischemic time. In the 30-min group, hypoxanthine levels were significantly higher in the pigs that died than in those that survived, and correlated with aspartate aminotransferase, lactate dehydrogenase, and adenosine triphosphate levels of recipients. Histological examination revealed that graft injury was severe in the pigs with higher hypoxanthine levels. CONCLUSIONS: It is suggested that hepatic microdialysate hypoxanthine levels during warm ischemia in NHBDs were correlated with graft viability in the recipient. By using of this technique, prediction of the graft viability may be possible during donor operation.