Graft Ischemia-reperfusion Injury Research Articles

Polyethylene glycol rinse solution: an effective way to prevent ischemia-reperfusion injury.

To test whether a new rinse solution containing polyethylene glycol 35 (PEG-35) could prevent ischemia-reperfusion injury (IRI) in liver grafts. Sprague-Dawley rat livers were stored in University of Wisconsin preservation solution and then washed with different rinse solutions (Ringer's lactate solution and a new rinse solution enriched with PEG-35 at either 1 or 5 g/L) before ex vivo perfusion with Krebs-Heinseleit buffer solution. We assessed the following: liver injury (transaminase levels), mitochondrial damage (glutamate dehydrogenase activity), liver function (bile output and vascular resistance), oxidative stress (malondialdehyde), nitric oxide, liver autophagy (Beclin-1 and LCB3) and cytoskeleton integrity (filament and globular actin fraction); as well as levels of metalloproteinases (MMP2 and MMP9), adenosine monophosphate-activated protein kinase (AMPK), heat shock protein 70 (HSP70) and heme oxygenase 1 (HO-1). When we used the PEG-35 rinse solution, reduced hepatic injury and improved liver function were noted after reperfusion. The PEG-35 rinse solution prevented oxidative stress, mitochondrial damage, and liver autophagy. Further, it increased the expression of cytoprotective heat shock proteins such as HO-1 and HSP70, activated AMPK, and contributed to the restoration of cytoskeleton integrity after IRI. Using the rinse solution containing PEG-35 was effective for decreasing liver graft vulnerability to IRI.

Challenges in machine perfusion preservation for liver grafts from donation after circulatory death

Donation after circulatory death (DCD) is a promising solution to the critical shortage of donor graft tissue. Maintaining organ viability after donation until transplantation is essential for optimal graft function and survival. To date, static cold storage is the most widely used form of preservation in clinical practice. However, ischemic damage present in DCD grafts jeopardizes organ viability during cold storage, and whether static cold storage is the most effective method to prevent deterioration of organ quality in the increasing numbers of organs from DCD is unknown. Here we describe the historical background of DCD liver grafts and a new preservation method for experimental and clinical transplantation. To prevent ischemia-reperfusion injury in DCD liver grafts, a hypothermic machine perfusion (HMP) technique has recently been developed and may be superior to static cold preservation. We present evidence supporting the need for improving liver perfusion performance and discuss how doing so will benefit liver transplantation recipients.

Protective effects of N-acetylcysteine on myocardial ischemia-reperfusion injury in the rat heart transplantation

Objective To explore the protective effect of N-acetylcysteine (NAC) on graft ischemia-reperfusion injury (IRI) in the rat heart transplantation.Methods 100 healthv male Lewis rats and 20 healthy male BN rats were randomly divided into four groups.In control group,2 ml normal saline was infused via the inferior vena cave 30 min before donor harvest or implantation.In donor preconditioning group,NAC (300 mg/kg body weight,iv.) was infused via the inferior vena cave 30 min before donor harvest,and the recipient was not processed.In recipient preconditioning group,NAC (300 mg/kg body weight,iv.) was infused via the inferior vena cava 30 min before recipient implantation,and the donor was not processed; Grafts underwent cold storage in 4℃ conventional histidine-tryptophan-ketoglutarate(HTK)solution for 18 h prior to heterotopic transplantation (Lewis→Lewis).Another 20 male Lewis rats for recipients,and 20 male BN rats for donors were used for survival analysis.Graft function was monitored by daily palpation.Blood was drawn at 6 and 24 h post-reperfusion for analysis of creatine kinase isoenzvme MB (CK-MB),Troponin T (TnT),lactic acid dehydrogenase (LIDH) as markers of graft injury.Graft superoxide dismutase (SOD),and lipid hydroperoxide (LPO) activity were detected at 24 h after reperfusion.Tissue samples were taken 24 h after reperfusion for histological and ultrastructural changes.Inducible nitric oxide svnthase (iNOS) and endothelial nitric oxide syuthase (eNOS) protein expression was detected by using immunohistochemistrv.The expression of iNOS and eNOS mRNA was detected using by real-time quantitative polymerase chain reaction (Real-time PCR).Results Suaival rate of rats in the NAC pretreatment groups was significantly higher than in control group.The serum levels of CK-MB,TnT,LIDH at 6/24 h after reperfusion were reduced significantly in donor preconditioning group or recipient preconditioning group as compared with control group [for CK-MB,(10 681.11 ± 2052.01)/(12 903.29 ± 1789.46)/(31093.11 ± 6822.67) U/L at 6 h,and (1797.89 ± 383.96)/(3408.0 ± 1028.48)/(2230.40 ±450.03) U/Lat24h; forTnT,(45.76±7.46)/(17.90±2.87)/(49.51 ±6.41) μg/L at 6 h,and(11.08±1.53)/(7.06 ±0.71)/(20.28 ±2.90) μg/L at 24 h; for LDH,(4019.00 ±678.03)/(4235.17 ±585.88)/(8197.00 ±807.20) U/L at 6 h,and (1005.67 ± 164.71)/(774.00 ± 113.13)/(1619.50 ± 289.11) U/L at 24 h],respectively.LPO activity at 24 h after reperfusion was lower (9.48 ± 1.05)/(7.82 ± 1.56) vs.(10.90 ±2.28) μmol/L,and SOD activity was significautly higher in pretreatment groups (4.71 ± 1.09)/(4.57 ± 1.09) vs.(2.38 ±0.39) U/ml than in control group (P ＜0.05).Histological examinations (HE staining and electron microscopy) also proved that the injury in pretreatment group was alleviated as compared with control group.Immunohistochemical analysis and Real-time PCR revealed the decreases of iNOS (1.50 ± 0.22)/(1.63 ± 0.26) vs.(3.00 ± 0.15) and (0.95 ± 0.41) / (0.43 ± 0.17) vs.(1.00 ± 0.41),and the increase of eNOS (3.60 ± 0.16) / (3.40 ± 0.26) vs.(2.00 ± 0.21) and (3.06 ± 1.47)/(1.48 ± 0.53) vs.(1.00 ± 0.65) in pretreatment group as compared with control group.Conclusion NAC reduces IRI after heart transplantation and improves the outcome of the transplanted heart after prolonged cold preservation,which is most likely through anti-oxidation and enhancing the oxidase activity to reduce myocardial cell injury,thereby reducing mvocardial IRI. Key words: N-acetylcysteine; Heart transplation; Ischemia reperfusion injury

Protein Globule Formation in the Liver Graft during Cold Preservation for Liver Transplantation: Its Clinical and Pathological Significance

In liver transplantation, liver graft ischemia-reperfusion injury occurs mainly due to cold preservation and warm reperfusion. In this research, we study the affection of plasma protein of the donor on liver graft during cold preservation and warm reperfusion. In this study, 34 liver transplantations were performed from 2007 to 2010, and the clinical data were collected retrospectively from the Dongfang Hospital database. 34 specimens were harvested from 34 liver grafts when graft trimming as Group A and 34 specimens harvested from the same 34 liver grafts during liver transplantation surgery but before abdominal closure as B group. All liver tissue specimens were fixed with 40 g/L neutral formalin, embedded in paraffin. Light microscopy, transmission electron microscopy, Periodic Acid-Schiff (PAS) stain and immunohistochemical stain of IgG, IgM, IgA, C3d, C4d, Fib, C1q, and CD61 were used. In this study, we found that eosinophilic bodies emerged in liver lobes during liver transplantation which had not been reported previously in the literature. 1) Protein globules were found exclusively in liver graft specimens. The globules were round or oval with sharp edges, measured approximately 1.59 to 9.41 μm in diameter, and were scattered in the liver sinusoids or space of Disse or hepatocyte cytoplasm, were stained with IgG, IgM, IgA, Fib, C3d by immunohistochemical staining; 2) There was no statistical significant difference of protein globules number between A group and B group (P > 0.05); 3) IRI score of B group was not correlated with protein globules number (P > 0.05). Protein globules contain plasma composition, and may form during cold preservation.

Supplemental hydrogen sulphide protects transplant kidney function and prolongs recipient survival after prolonged cold ischaemia–reperfusion injury by mitigating renal graft apoptosis and inflammation

What's known on the subject? and What does the study add? Hydrogen sulphide (H(2) S) has recently been classified as a member of the family of small gaseous molecules called gasotransmitters and has been found to have many important physiological functions. Several recent studies have elucidated the protective effects of H(2) S in many models of tissue ischaemia-reperfusion injury (IRI), including hepatic, myocardial, pulmonary, cerebral and renal IRI. It has previously been shown that H(2) S has a number of properties that may contribute to its protection against IRI, including vasodilatory, anti-apoptotic, anti-inflammatory and anti-oxidant effects, although the specific actions appear to vary between tissues. The few studies investigating the effects of H(2) S against renal IRI have only involved clamping of the renal pedicle to induce warm IRI. This study investigated the protective effects of H(2) S in the context of renal transplantation (RTx), which generally involves a more severe period of prolonged cold IRI. A previous study investigated the actions of H(2) S in RTx, but it was performed ex vivo and did not involve actual transplantation of donor kidneys. To our knowledge, this is the first study using a clinically relevant model of RTx to show that treatment of donor kidneys with H(2) S during preservation is protective against prolonged cold IRI. These findings suggest that H(2) S has potential utility in improving clinical organ preservation techniques and increasing the overall success of organ transplantation. • To characterize the effects of hydrogen sulphide (H(2) S), an endogenously produced molecule recently described to have protective effects against warm ischaemic tissue injury, in mitigating transplantation-associated prolonged cold ischaemia-reperfusion injury (IRI) in a clinically applicable in vivo model of renal transplantation (RTx). • After undergoing bilateral native nephrectomy, Lewis rats underwent RTx with kidneys that were flushed with either cold (4 °C) standard University of Wisconsin preservation solution (UW) or cold UW + 150 µM NaHS (H(2) S) solution and stored for 24 h at 4 °C in the same solution. • Recipient rats were monitored for a 14-day time course using metabolic cages to assess various characteristics of renal graft function. • Renal grafts were removed at time of death or after the rats were killed for histological, immunohistochemical and quantitative PCR analysis. • H(2) S-treated rats exhibited immediate and significant (P < 0.05) decreases in serum creatinine levels, increased urine output and increased survival compared with UW-treated rats. • H(2) S-treated grafts showed significantly reduced glomerular and tubular necrosis and apoptosis, diminished graft neutrophil and macrophage infiltrates and a trend towards improved inflammatory and anti-apoptotic cytokine profiles. • Our results provide the first evidence that supplemental H(2) S can mitigate renal graft IRI incurred during transplantation and prolonged cold storage, improving early graft function and recipient survival in a clinically applicable model of RTx.

Procurement Regimens to Reduce Ischemia Reperfusion Injury of Vascular Grafts

Background: Ischemia reperfusion injury is an important nonimmunological factor contributing to the development of chronic rejection. The aim of this study was to compare different cell culture media in terms of vascular lesion formation after ischemia reperfusion injury. Methods: BALB/c aortic grafts were incubated in different cell media (endothelial cell growth, ECG, RPMI-1640 and Waymouth/Ham’s F12) for various time spans (5, 6.5 and 8.5 h) at 37°C and implanted into syngeneic BALB/c recipients. On day 30 after implantation, histology, immunofluorescence and morphometric measurements were performed. Results: A total of 36 transplants were performed for this study with an overall survival rate of 72.2%. The most frequent complication was thrombosis of the aortic graft (n = 9) and there was one late death due to other courses. All the recipients with vascular grafts incubated in the ECG medium survived and showed no signs of intimal proliferation independent of the time of ischemia. Aortic grafts incubated in the RPMI medium resulted in a reduced recipient survival rate of 66.7% and grafts incubated in the Waymouth medium showed only a 50% survival by day 30. Analysis of the vascular morphology revealed moderate amounts of intimal proliferation within two aortic grafts in this group. CD31 staining revealed superior endothelial cell integrity after incubation with the ECG medium. Conclusions: Data from the current study suggest that under optimized conditions vascular grafts can be safely kept in tissue culture up to 8.5 h without significant ischemic damage. Differences in vascular integrity and animal survival depended mostly on the respective tissue culture medium used for the storage of the vessel.

The Role of CD14 and Toll-Like Receptor 4 of Kupffer Cells in Hepatic Ischemia-Reperfusion Injury in Rats

ObjectiveThe objective of this study was to study the role of CD14 and Toll-like receptor 4 (TLR4) in Kupffer cells (KCs) on ischemia reperfusion injury (IRI) in rat liver grafts. MethodsIsolated KCs were obtained from control, IRI, and IRI plus anti-CD14 antibody groups. We measured messenger RNA (mRNA) and protein expression of the lipopolysaccharide receptor CD14 and TLR4, nuclear factor kappa B (NF-κβ) activity, and TNF-α levels. ResultsmRNA and protein expressions of CD14 and TLR4 were significantly higher in the IRI than in the control group, as were protein expressions of CD14 and TLR4 by flow cytometry and by Western blots. NF-κβ activity and tumor necrosis factor-α level in the IRI group were significantly higher than in the control group (3.17 ± 0.21 and 0.28 ± 0.03 vs 654.2 ± 3.6 pg/mL and 147.4 ± 1.1 pg/mL; t value = 4.11 and 4.29 for each; P < .01). Compared with the IRI group they were greatly decreased after anti-CD14 antibody treatment: 2.14 ± 0.17 vs 3.17 ± 0.21, 298.7 ± 1.8 pg/mL vs 654.2 ± 3.6 pg/mL (t value = 2.52 and 2.92 for each; P < .05). They were still significantly higher than the control group (t values of 3.01 and 3.27 for each; P < .01). ConclusionIRI up-regulated CD14 and TLR4 gene expression in KCs, and subsequently activated NF-κβ to produce cytokines.

Protective Role of Shenfu on Ischemia-Reperfusion Injury of Rat Liver Grafts

AimsWe sought to investigate the protective role of Shenfu (SF),a traditional Chinese formulation comprising Radix Ginseng and Radix Aconitum Carmichaeli on ischemia-reperfusion injury in rat liver grafts. MethodsNinety-six male Sprague Dawley rats were used as donors (n = 48) and recipients (n = 48) of orthotopic liver transplantation. They were randomly divided into a control group with donor livers injected with saline through the portal vein immediately after recovery versus the SF group, with livers injected with SF. Each group was further divided into 3 subgroups equally to obtain bood and hepatic tissues samples at 2, 4, and 6 hours reperfusion. ResultsAt each phase, the SF group, showed significantly higher bile production (P < .05) with lower serum levels of alanine aminotransferase and tumor necrosis factor-α, and nuclear factor-κB expression in the hepatic tissues. (P < .05). SF group hepatic tissues showed less injury compared with controls. ConclusionSF injection seemed to protect hepatocytes from injury during the early reperfusion phase and to improve subsequent rat liver graft function.

328 Retention of IL-10+ Neutrophils May Be Essential To Limit Lung Graft Ischemia-Reperfusion Injury

328 Retention of IL-10+ Neutrophils May Be Essential To Limit Lung Graft Ischemia-Reperfusion Injury

Remote ischemic preconditioning promotes early liver cell proliferation in a rat model of small-for-size liver transplantation

BackgroundThe size of the liver donor graft is a major concern in living donor liver transplantation. Rapid regeneration is essential for the survival of these grafts. The purpose of this study was to investigate the effect of remote ischemic preconditioning (RIPC) on liver regeneration in a rat small-for-size liver transplantation model. MethodsWe established rat models of small-for-size liver transplantation (30%) in the presence or absence (control) of remote ischemic preconditioning. We observed liver mass regeneration, serum alanine aminotransferase, hepatic pathologic alterations, flow cytometry, and Ki-67 antigen immunohistochemistry. In addition, using Western blotting and reverse-transcriptase–polymerase chain reaction, we assessed the activation of cell cycle progression as well as tumor necrosis factor-α and interleukin-6 expression. ResultsCompared with the control group, serum alanine aminotransferase activity was significantly lower and histopathology changes were significantly attenuated in the RIPC group. Remote ischemic preconditioning induced a high level of interleukin-6 mRNA in small grafts, but suppressed the expression of tumor necrosis factor-α. The proliferation index, indicated by the S-phase and G2/M-phase ratio [(S+G2/M)/(G0/G1+S+G2/M)], was significantly increased in the RIPC group at 24 h (58.25% ± 0.506% versus 53.405% ± 1.25%; P = .007). Meanwhile, cell cycle progression and regeneration (Ki-67) were initiated early in liver grafts treated with RIPC. ConclusionsThese results suggest that RIPC can protect liver cells against ischemia reperfusion injury in the small grafts and enhance liver regeneration. Interleukin-6 may be a critical mediator in the stimulatory effect on liver cell regeneration, which may make RIPC valuable as a hepatoprotective modality.

Liver Transplantation for Hepatocellular Carcinoma: Five Steps to Prevent Recurrence

Liver transplantation is the best treatment of patients with unresectable early hepatocellular carcinoma, allowing disease-free survival rates of 60-80% at 5 years. Despite these good results, some 10% of recipients experience a posttransplant HCC recurrence, which leads to death in almost all patients. Recurrence is either due to the growth of occult metastases or to the engraftment of circulating tumor cells. It can be hypothesized that strategies to decrease the engraftment of circulating tumor cells could decrease the risk of recurrence and, in addition, extend access to transplantation to patients with more advanced HCC. These potential strategies can be schematized into five steps, including (1) selecting recipients with low baseline levels of circulating HCC cells, by adding biological markers (such as alpha fetoprotein or molecular signatures) to the accepted combination of morphological criteria; (2) decreasing the perioperative release of HCC cells, with careful perioperative handling of the tumors; (3) preventing the engraftment of circulating HCC cells by decreasing liver graft ischemia-reperfusion injury, which has been shown to promote cancer cell engraftment and growth; (4) using anticancer drugs, including mammalian target of rapamycin inhibitors and (5) tuning immunity toward HCC clearance.

Protection against lung graft injury from brain-dead donors with carbon monoxide, biliverdin, or both

The process of brain death can induce acute lung injury in donors and aggravate ischemia-reperfusion injury in grafts. Carbon monoxide (CO) and biliverdin (BV) have been shown to attenuate ischemia-reperfusion injury. We therefore examined if the administration of both CO and BV provide enhanced cytoprotection against lung graft injury from brain-dead (BD) rat donors. Brain death was induced in all donors, after which they were observed for 1.5 hours and then underwent lung transplantation. The recipients were ventilated with 40% oxygen (control group), ventilated with 250 ppm CO in 40% oxygen (CO group), treated with BV (35 mg/kg) intraperitoneally (BV group), or treated with CO and BV conjointly (COBV group) before transplantation (n = 8 each group). The recipients were sacrificed 2 hours after lung transplantation by exsanguination. Serum levels of interleukin (IL)-8 and tumor necrosis factor (TNF)-α were measured by enzyme-linked immunosorbent assay. CO and/or BV treatment attenuated partial pressure of arterial oxygen (Pao(2))/fraction of inspired oxygen (Fio(2)) aggravation in the recipients after reperfusion, reduced the wet weight/dry weight ratio, decreased the lung injury score, inhibited the activity of myeloperoxidase in grafts, and decreased serum levels of IL-8 and TNF-α compared with the control group (p < 0.05). The COBV group had significantly decreased malonaldehyde levels and increased superoxide dismutase levels in lung grafts compared with the CO group (p < 0.05). The static pressure-volume curve of the lungs was ameliorated in the CO group, BV group, and COBV group compared with the control group (p < 0.05). CO and BV exert protective effects through anti-inflammatory and anti-oxidant mechanisms, and dual treatment provided enhanced cytoprotection against lung graft injury from BD rat donors.

Perfusion Using Oxygenated Buffer Containing Prostaglandin E 1 before Cold Preservation Prevents Warm Ischemia-Reperfusion Injury in Liver Grafts from Non-Heart-Beating Donors

We have previously reported that perfusion using warm oxygenated buffer before cold preservation (preperfusion) improved the viability of liver grafts from non-heart-beating donors. We demonstrated that adenosine triphosphate content was restored and apoptosis was reduced. The objective of the present study was to evaluate mitochondrial functions after this preperfusion and the effects of addition of prostaglandin E 1 (PGE 1) to the preperfusion buffer. Preperfusion improved portal flow, bile production, and mitochondrial function, and reduced alanine aminotransferase levels in the perfusate. Addition of PGE 1 significantly increased bile production and suppressed alanine aminotransferase and tumor necrosis factor-α levels. PGE 1 minimized mitochondrial membrane damage and ischemic injury after liver graft reperfusion. Release of mitochondrial cytochrome c was suppressed by addition of PGE 1. In conclusion, perfusion using oxygenated buffer containing PGE 1 before cold preservation significantly prevented cellular damage, protected mitochondrial function, and suppressed the release of mitochondrial cytochrome c in livers undergoing warm ischemia-reperfusion injury. This method shows promise for reducing cellular damage in non-heart-beating donor liver grafts.

Orthotopic Hind-Limb Transplantation in Rats

Composite tissue allotransplantation (CTA) now represents a valid therapeutic option after the loss of a hand, forearm or digits and has become a novel therapeutic entity in reconstructive surgery. However, long term high-dose multi-drug immunosuppressive therapy is required to ensure graft survival, bearing the risk of serious side effects which halters broader application. Further progression in this field may depend on better understanding of basic immunology and ischemia reperfusion injury in composite tissue grafts. To date, orthotopic hind limb transplantation in rats has been the preferred rodent model for reconstructive transplantation (RT), however, it is an extremely demanding procedure that requires extraordinary microsurgical skills for reattachment of vasculature, bones, muscles and nerves. We have introduced the vascular cuff anastomosis technique to this model, providing a rapid and reliable approach to rat hind limb transplantation. This technique simplifies and shortens the surgical procedure and enables surgeons with basic microsurgical experience to successfully perform the operation with high survival and low complication rates. The technique seems to be well suited for immunological as well as ischemia reperfusion injury (IRI) studies.

Protective effects of MnTBAP and ischemia preconditioning on small-for-size graft ischemia-reper fusion injury in liver transplantation rats

Objective To study the protective effect and the possible mechanism of MnTBAP and ischemia preconditioning on small-for-size graft ischemia-reperfusion injury in liver transplantation rats.Methods Male Sprague-Dawley rats were divided into 4 groups(n = 24 in each group)of liver transplantation models with graft volume/standard liver volume(GV/SLV)≤45%:untreated group(A),MnTBAP-treated group(B),ischemia preconditioning group(C),and MnTBAP treatment + ischemia preconditioning group(D).The expression of NF-κB and its inhibitor I-κB,TNF-α,the level of malondialdehyde(MDA),and alanine aminotransferase(ALT)level were detected at 3rd,6th,12th,and 24th h after reperfusion.The morphological changes of hepatic tissues were observed under a light microscope at different time points.Results Compared with group A,the expression of NF-κB and the levels of MDA and ALT in the grafts were significantly reduced(P＜0.01)in groups B and D,but the expression of I-κB was increased(P ＜0.05).In group C,the expression of NF-κB and the level of MDA were significantly decreased too at the 6th,12th,and 24th h after reperfusion as compared with group B(P ＜0.05),meanwhile the level of serum ALT was obviously lower in groups B,C and D than that in group A(P＜0.01).Conelusion Both MnTBAP and ischemia preconditioning could decrease the activities of NF-κB and the release of inflammatory mediators to protect the graft against ischemia/reperfusion injury via different mechanisms.But the two methods co-employed against the injury show no more effects than anyone of the two methods. Key words: Liver transplantation; Ischemia precondition; Repeffusion injury; MnTBAP

Effects of ischemic postconditioning on reperfusion injury in rat liver grafts after orthotopic liver transplantation

The effects of ischemic postconditioning (IPostC) on ischemia reperfusion (IR) injury of liver grafts was examined in rats after orthotopic liver transplantation (OLT). Male Wistar rats were used as donors and recipients to establish a liver transplantation model. The animals were randomly divided into four groups: sham-operated (SO, n = 6), IR (n = 6), IPostC1 (n = 6) and IPostC2 (n = 6). IPostC was achieved by several intermittent interruptions of blood flow in the early phase of reperfusion. Several parameters of hepatic damage, oxidative stress, neutrophil infiltration and the expression of TNF-alpha and MIP-2 were detected as well as microscopic examination. Nitric oxide release and liver NO synthases (endothelial NO synthase and inducible NO synthase) expression were also measured. We observed that a significant reduction in alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase values in two IPostC groups when compared with IR group. The increases in hepatic malondialdehyde, and decreases in superoxide dismutase and reduced glutathione levels after orthotopic liver transplantation were significantly inhibited by IPostC. IR induced increase in hepatic myeloperoxidase content, TNF-alpha and MIP-2 expression were also lowered by IPostC. The increases in NO content and NOS protein expression were much more prominent in IPostC treated groups. Animals treated with IPostC presented minimal hemorrhage and reduced signs of liver injury. There was no significant difference between two IPostC treated groups. IPostC provided significant protection against IR injury to liver grafts. The protective effect of IPostC is closely related to the NO production following the increase in endothelial and inducible NO synthases expression and the suppression of tumor necrosis factor-alpha and macrophage inflammatory protein-2 overproduction.

Protective effect of MnTBAP on small for size graft ischemia-reperfusion injury in liver transplantation rats

Objective To study the protective effect of MnTBAP on small for size graft ischemia-reperfusion injury in liver transplantation rats. Methods The models of liver transplantation with graft vol-ume/standard liver volume (GV/SLV) ≤30% were created by two-cuff method in SD rats. The rats were randomly divided into sham operation group, untreated group, and model group treated by MnTBAP. The expression of TNF-α mRNA and the levels of myeloperoxiase ( MPO ), malondialdehyde (MDA) were measured as well as alanine aminotransferase (ALT) levels at 3rd ,6th, 12th, and 24th h after reperfusion determined. Results Compared with the sham operation group, the expression of TNF-α mRNA, and the levels of MDA,MPO and ALT in the grafts were significantly higher (P < 0.01 ) in untreated group. In model group treated by MnTBAP,the expression of TNF-α mRNA and the levels of MDA, MPO and ALT were significantly lower than in untreated group ( P < 0.05 or P < 0.01 ). Conclusion Protective effect of MnTBAP on liver graft ischemia-reperfusion injury in rats was remarkable by reducing the TNF-α mRNA expression and inhibiting the activity of ROS,thus lessening the level of MDA. Key words: Liver transplantation; MnTBAP; Ischemia; Reperfusion injury

A Free Radical Scavenger, Edaravone, Prevents Ischemia-Reperfusion Injury in Liver Grafts From Non–Heart-Beating Donors

Background Due to the increase in liver transplantation, the donor shortage has become a serious problem, requiring marginal, non–heart-beating donors (NHBDs). The aims of this study were to evaluate the cytoprotective effect of edaravone, a free radical scavenger, on warm ischemia-reperfusion (I/R) injury of liver grafts from NHBDs. Methods Rat livers were harvested from heart-beating donors (HB group) or from NHBDs undergoing cardiac arrest for 30 minutes led by thoracotomy (NHB group), and reperfused for 60 minutes with Krebs-Henseleit bicarbonate buffer after cold preservation for 6 hours. In another group (ED group), warm ischemic livers from NHBDs were reperfused with buffer containing edaravone (1 mg/L) after cold preservation. Results In the ED group, portal flow volume, bile production, and energy charge were significantly ameliorated. Lipid peroxidation, elevation of hepatic enzymes, and release of tumor necrosis factor-alpha and interleukin-1 beta were significantly alleviated, compared with the NHB group. Conclusions These results suggested that edaravone has suppressive effects on warm I/R injury in liver grafts from NHBDs.

Increased Serum Phospholipase A 2 Activity After Non-Heart-Beating Donor Liver Transplantation and Association With Ischemia-Reperfusion Injury

Secretory phospholipase A(2) (sPLA(2)) degrades cell membrane phospholipids and plays an important role in the synthesis of pro-inflammatory lipid mediators (arachidonic acid and cytokines) during inflammatory events such as ischemia-reperfusion injury after liver transplantation (LTx). A role for sPLA(2) in LTx from non-heart-beating donors (NHBD) has never been demonstrated. Furthermore data on the natural sPLA(2) inhibition capacity are scarce. Using our previously validated pig model of NHBD-LTx, we evaluated changes in sPLA(2) enzyme activity in serum early after reperfusion of livers exposed to warm ischemia. Porcine livers were exposed to incremental periods of warm ischemia, procured, and transplanted after 4 h of cold storage. In serum samples, collected prior to and after reperfusion, sPLA(2) enzyme activity, tumor necrosis factor-alpha, and interleukin-6 levels were determined. After reperfusion, sPLA(2) activity increased and peaked significantly at 60 min in recipients with primary nonfunction (PNF). Tumor necrosis factor-alpha and interleukin-6 peaked later (at 180 min) in these PNF recipients. We observed a strong natural inhibition of sPLA(2) activity in serum at baseline; this inhibition was substantial reduced 1 h after reperfusion in both PNF and non-PNF recipients. In the non-PNF recipients, however, this natural PLA(2) inhibition was restored within 24 h after reperfusion. This study suggests that an increased sPLA(2) activity and a reduced inhibition may play an important role in the pathogenesis of ischemia-reperfusion injury of NHBD liver grafts.

439: Bcl-3 Negatively Regulates Ischemia Reperfusion Injury in Mouse Orthotopic Vascularized Lung Grafts

Paradoxically, NF-kB gene transcription is required for both the initiation as well as the attenuation of inflammatory responses. Unlike the case for NF-kB dependent pro-inflammatory responses, the mechanisms that inhibit NF-kB dependent gene expression are less defined following reperfusion signals. Bcl-3, an IkB family member, has been recently shown to negatively regulate NF-kB dependent inflammatory genes in response to toll-like receptor (TLR) stimulation. As TLRs are known to play a role in solid organ graft injury we asked if Bcl-3 controls ischemia-reperfusion (I/R) injury in lung grafts.