Hepatic ischemic preconditioning increases portal vein flow in experimental liver ischemia reperfusion injury

BACKGROUND: Ischemic preconditioning(IPC) has been shown to decrease liver injury and to increase hepatic microvascular perfusion after liver ischemia reperfusion. This study aimed to evaluate the effects of IPC on hemodynamics of the portal venous system. METHODS: Thirty-two rats were randomized into two groups: IPC group and control group. The rats of the IPC group underwent IPC by 10 minutes of liver ischemia followed by 10 minutes of reperfusion before liver ischemia, and the rats of the control group were subjected to 60 minutes of partial liver ischemia. Non-ischemic lobes were resected immediately after reperfusion. The animals were studied at 4 hours and 12 hours after reperfusion. Mean arterial pressure, heart rate, portal vein flow and pressure were analyzed. Blood was collected for the determination of the levels of aspartate aminotransferase, alanine aminotransferase, calcium, lactate, pH, bicarbonate, and base excess. RESULTS: IPC increased the mean portal vein flow at 4 hours and 12 hours after reperfusion. IPC recovered 78% of the meanportal vein flow at 12 hours after reperfusion. IPC decreased the levels of aspartate aminotransferase, alanine aminotransferase and lactate, and increased the levels of ionized calcium, bicarbonate and base excess at 12 hours after reperfusion. CONCLUSIONS: This study demonstrated that IPC increases portal vein flow and enhances hepatoprotective effects in liver ischemia reperfusion. The better recovery of portal vein flow after IPC may be correlated with the lower levels of transaminases and with the better metabolic profile.

Conventional, but not remote ischemic preconditioning, reduces iNOS transcription in liver ischemia/reperfusion

AIM:To study the effects of preconditioning on inducible nitric oxide synthase(iNOS)and interleukin 1(IL-1)receptor transcription in rat liver ischemia/reperfusion injury(IRI).METHODS:Seventy-two male rats were randomized into 3 groups:the one-hour segmental ischemia(IRI,n=24)group,the ischemic preconditioning(IPC,n=24)group or the remote ischemic preconditioning(RIPC,n=24)group.The IPC and R-IPC were performed as 10 min of ischemia and 10 min of reperfusion.The iNOS and the IL-1 receptor mRNA in the liver tissue was analyzed with real time PCR.The total Nitrite and Nitrate(NOx)in continuously sampled microdialysate(MD)from the liver was analyzed.In addition,the NOx levels in the serum were analyzed.RESULTS:After 4 h of reperfusion,the iNOS mRNA was significantly higher in the R-IPC(ΔCt:3.44±0.57)group than in the IPC(ΔCt:5.86±0.82)group(P=0.025).The IL-1 receptor transcription activity was reduced in the IPC group(ΔCt:1.88±0.53 to 4.81±0.21),but not in the R-IPC group,during reperfusion(P=0.027).In the MD,a significant drop in the NOx levels was noted in the R-IPC group(12.3±2.2 to 4.7±1.2μmol/L)at the end of ischemia compared with the levels in early ischemia(P=0.008).A similar trend was observed in the IPC group(11.8±2.1 to 6.4±1.5μmol/L),although this difference was not statistically significant.The levels of NOx rose quickly during reperfusion in both groups.CONCLUSION:IPC,but not R-IPC,reduces iNOS and IL-1 receptor transcription during early reperfusion,indicating a lower inflammatory reaction.NOx is consumed in the ischemic liver lobe.

Molecular mechanisms of liver ischemia reperfusion injury:Insights from transgenic knockout models

Ischemia reperfusion injury is a major obstacle in liver resection and liver transplantation surgery.Understanding the mechanisms of liver ischemia reperfusion injury(IRI) and developing strategies to counteract this injury will therefore reduce acute complications in hepatic resection and transplantation,as well as expanding the potential pool of usable donor grafts.The initial liver injury is initiated by reactive oxygen species which cause direct cellular injury and also activate a cascade of molecular mediators leading to microvascular changes,increased apoptosis and acute inflammatory changes with increased hepatocyte necrosis.Some adaptive pathways are activated during reperfusion that reduce the reperfusion injury.IRI involves a complex interplay between neutrophils,natural killer T-cells cells,CD4+ T cell subtypes,cytokines,nitric oxide synthases,haem oxygenase-1,survival kinases such as the signal transducer and activator of transcription,Phosphatidylinositol 3-kinases/Akt and nuclear factor κβ pathways.Transgenic animals,particularly genetic knockout models,have become a powerful tool at elucidating mechanisms of liver ischaemia reperfusion injury and are complementary to pharmacological studies.Targeted disruption of the protein at the genetic level is more specific and maintained than pharmacological inhibitors or stimulants of the same protein.This article reviews the evidence from knockout models of liver IRI about the cellular and molecular mechanisms underlying liver IRI.

N-acetylcysteine attenuates reactive-oxygen-speciesmediated endoplasmic reticulum stress during liver ischemia-reperfusion injury

AIM:To investigate the effects of N-acetylcysteine(NAC) on endoplasmic reticulum(ER) stress and tissue injury during liver ischemia reperfusion injury(IRI).METHODS:Mice were injected with NAC(300 mg/kg) intraperitoneally 2 h before ischemia.Real-time polymerase chain reaction and western blotting determined ER stress molecules(GRP78,ATF4 and CHOP).To analyze the role of NAC in reactive oxygen species(ROS)-mediated ER stress and apoptosis,lactate dehydrogenase(LDH) was examined in cultured hepatocytes treated by H2O2 or thapsigargin(TG).RESULTS:NAC treatment significantly reduced the level of ROS and attenuated ROS-induced liver injury after IRI,based on glutathione,malondialdehyde,serum alanine aminotransferase levels,and histopathology.ROS-mediated ER stress was significantly inhibited in NAC-treated mice.In addition,NAC treatment significantly reduced caspase-3 activity and apoptosis after reperfusion,which correlated with the protein expression of Bcl-2 and Bcl-xl.Similarly,NAC treatment significantly inhibited LDH release from hepatocytes treated by H2O2 or TG.CONCLUSION:This study provides new evidence for the protective effects of NAC treatment on hepatocytes during IRI.Through inhibition of ROS-mediated ER stress,NAC may be critical to inhibit the ER-stressrelated apoptosis pathway.

Melatonin abates liver ischemia/reperfusion injury by improving the balance between nitric oxide and endothelin

BACKGROUND: Melatonin exerts complex physiological and pharmacological effects on multiple systems and organs. We hypothesized that melatonin might abate ischemia/ reperfusion (I/R) injury in the liver by inhibiting excessive oxidative stress and keeping nitric oxide (NO) from being scavenged by free radicals. The aim of the present study was to investigate whether melatonin protects the liver from I/R injury and, if so, by what underlying mechanism. METHODS: Under anesthesia, Wistar rats were intraperi- toneally injected with 20 mg/kg melatonin (dissolved in physiological saline containing 4% ethanol, Mel group), 4% alcohol (Alc group), or physiological saline (NS group). The artery, portal vein and bile duct of the left lobe of the liver were clamped for 60 minutes and then released. At different time points after I/R, the rats were sacrificed and blood samples were collected to measure the levels of serum alanine aminotransferase (ALT), lactic dehydrogenase (LDH), and NO. Hepatic tissue samples were collected for measuring endothelin expression by immunohistochemical staining and for routine morphological and histological examination. RESULTS: The levels of both ALT and LDH in the Mel group were significantly reduced for up to 24 hours after I/R compared with the Alc and NS groups (P<0.05). The levels of NO in the Mel group were significantly elevated for up to 12 hours after I/R relative to the NS group (P<0.05). The NO levels were also elevated at 0.5 and 6 hours after I/R in the Alc group (P<0.05). The immunohistochemical staining of hepatic tissue showedthat endothelin-positive cells were significantly fewer in the Mel group than in the Alc and NS groups at 6 hours after I/R (P<0.01). The necrosis of hepatocytes and the destruction of hepatic cords in the Alc and NS groups were greatly improved in Mel-treated rats, which is in concert with our functional data. CONCLUSIONS: Pretreatment with melatonin increased NO bioavailability and decreased endothelin expression, and consequently played a protective role in preserving both liver function and structure during ischemia and reperfusion injury.

Expression of macrophage inflammatory protein-1αin Kupffer cells following liver ischemia or reperfusion injury in rats

瞄准：探索巨噬细胞的表示在在老鼠跟随肝 ischemia/reperfusion 损害 IRI 的 Kupffer 房间(KC ) 的煽动性的 protein-1alpha (MIP-1alpha ) 。方法：四十只男 SD 老鼠随机被划分成五个组。在老鼠肝的部分温暖的 ischemia/reperfusion 损害的一个模型被建立。KC 在灌注以后被孤立并且孵化一个小时，六个小时， 12 h，和 24 h。肿瘤坏死因素高山哈(TNF-alpha ) 并且在上层清液的 interleukin-1beta (IL-1beta ) 被 ELISA 测量。在 KC 的 MIP-1alpha 被细胞化学的免疫和 RT-PCR 检测。结果：没有或很少 MIP-1alpha 蛋白质和 mRNA 在控制组的 KC 被表示。它在 IRI 组的表达式在灌注以后有重要增加(P 【 0.05 ) ，它与控制组相反。结论：在 KC 后面的肝 ischemia/reperfusion 损害的 MIP-1alpha 基因的活跃行为被假定是为肝的 ischemia/reperfusion 损害的主要原因之一。

Oleanolic acid attenuates liver ischemia reper-fusion injury by HO-1/Sesn2 signaling pathway

BACKGROUND: Ischemia reperfusion injury (IRI) is unavoid-able in liver transplantation and hepatectomy. The present study aimed to explore the possible mechanism and the effect of oleanolic acid (OA) in hepatic IRI. METHODS: Mice were randomly divided into 6 groups based on different treatment. IRI model: The hepatic artery, portal vein, and bile duct to the left and median liver lobes (70% of the liver) were occluded with an atraumatic bulldog clamp for 90 minutes and then the clamp was removed for reperfusion. The mice were sacriifced 6 hours after reperfusion, and blood and liver tissues were collected. Liver injury was evaluated by biochemical and histopathologic examinations. The expressions of Sesn2, PI3K, Akt and heme oxygenase-1 (HO-1) were mea-sured with quantitative real-time RT-PCR and Western blotting. RESULTS: The serum aminotransferases level and scores of he-patic histology were increased after reperfusion. The increase was attenuated by pretreatment with OA (P<0.01). Compared with the IR group, OA pretreatment signiifcantly up-regulated the expression of Sesn2, PI3K, Akt and HO-1 in IR livers (P<0.05). Administration of zinc protoporphyrin (ZnPP), an inhibitor of HO-1, diminished the OA effect on HO-1 and Sesn2 expressions (P<0.05) and the protective effect of OA on IRI. CONCLUSIONS: Our results demonstrate that OA can attenu-ate hepatic IRI. The protective mechanism may be related to the OA-induced HO-1/Sesn2 signaling pathway.

Remote ischemic preconditioning protects liver ischemia-reperfusion injury by regulating eNOS-NO pathway and liver microRNA expressions in fatty liver rats

BACKGROUND: Ischemic preconditioning (IPC) is a strategy to reduce ischemia-reperfusion (I/R) injury. The protective effect of remote ischemic preconditioning (RIPC) on liver I/R injury is not clear. This study aimed to investigate the roles of RIPC in liver I/R in fatty liver rats and the involvement of endothelial nitric oxide synthase-nitric oxide (eNOS-NO) pathway and microRNA expressions in this process. METHODS: A total of 32 fatty rats were randomly divided into the sham group, I/R group, RIPC group and RIPC+I/R group. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and nitric oxide (NO) were measured. Hematoxylin-eosin staining was used to observe histological changes of liver tissues, TUNEL to detect hepatocyte apoptosis, and immunohistochemistry assay to detect heat shock protein 70 (HSP70) expression. Western blotting was used to detect liver inducible NOS (iNOS) and eNOS protein levels and realtime quantitative polymerase chain reaction to detect miR-34a, miR-122 and miR-27b expressions. RESULTS: Compared with the sham and RIPC groups, serum ALT, AST and iNOS in liver tissue were significantly higher in other two groups, while serum NO and eNOS in liver tissue were lower, and varying degrees of edema, degeneration and inflammatory cell infiltration were found. Cell apoptosis number was slightly lower in the RIPC+I/R group than that in I/R group. Compared with the sham group, HSP70 expressions were significantly increased in other three groups (all P<0.05). Compared with the sham and RIPC groups, elevated miR-34a expressions were found in I/R and RIPC+I/R groups (P<0.05). MiR-122 and miR-27b were found significantly decreased in I/R and RIPC+I/R groups compared with the sham and RIPC groups (all P<0.05). CONCLUSION: RIPC can reduce fatty liver I/R injury by affecting the eNOS-NO pathway and liver microRNA expressions.

Identification of differentially expressed genes after partial rat liver ischemia/reperfusion by suppression subtractive hybridization

AIM: To identify potential diagnostic target genes in early reperfusion periods following warm liver ischemia before irreversible liver damage occurs.METHODS: We used two strategies (SSH suppression subtractive hybridization and hybridization of cDNA arrays)to determine early changes in gene expression profiles in a rat model of partial WI/R, comparing postischemic and adjacent nonischemic liver lobes. Differential gene expression was verified (WT/R; 1 h/2 h) and analyzed in more detail after warm ischemia (1 h) in a reperfusion time kinetics (0, 1, 2 and 6 h) and compared to untreated livers by Northern blot hybridizations. Protein expression was examined on Western blots and by immunohistochemistry for four differentially expressed target genes (Hsp70,Hsp27, Gadd45a and IL-1rl).RESULTS: Thirty-two individual WI/R target genes showing altered RNA levels after confirmation by Northern blot analyzes were identified. Among them, six functionally uncharacteristic expressed sequences and 26 known genes (12 induced in postischemic liver lobes, 14 with higher transcriptional expression in adjacent nonischemic liver lobes). Functional categories of the verified marker genes indicate on the one hand cellular stress and tissue damage but otherwise activation of protective cellular reactions (AP-1 transcription factors, apoptosis related genes, heat shock genes). In order to assign the transcriptional status to the biological relevant protein level we demonstrated that Hsp70, Hsp27, Gadd45a and IL-1rI were clearly up-regulated comparing postischemic and untreated rat livers, suggesting their involvement in the WI/R context.CONCLUSION: This study unveils a WI/R response gene set that will help to explore molecular pathways involved in the tissue damage after WI/R. In addition, these genes especially Hsp70and Gadd45a might represent promising new candidates indicating WI/R liver damage.

Role of NF-kappaB in Liver Ischemia Reperfusion Injury of Rats

To determine the role of NF-kappaB in ischemia reperfusion (I/R) injury of the rat liver, rats underwent partial hepatic ischemia and reperfusion. The left and median lobes of the liver were subjected to ischemia for 90 min followed by reperfusion for defined times. NF-kappaB activity was analyzed by electrophoretic mobility shift assay (EMSA). Semiquantitative reverse-transcriptase polymerase chain reaction was used to analyze TNF-α and ICAM-1 mRNA levels. Results showed during liver I/R injury, NF-kappaB activation was induced in a time dependent manner. NF-kappaB was activated within 1h and 2h after the initiation of reperfusion and decreased after 4 h. Messenger RNA expression of TNF-α and ICAM-1 were increased after the reperfusion of 2 h. It was concluded that during hepatic I/R injury, NF-kappaB was activated and could bind to special sequence in the promoters of budget genes, which can up-regulate the expression of TNF-α and ICAM-1 mRNA to result in ischemia reperfusion injury of the rat liver.

Resveratrol attenuates oxidative stress and histological alterations induced by liver ischemia/reperfusion in rats

AIM:To investigate the effects of resveratrol on liver ischemia/reperfusion (I/R) injury in rats. METHODS: A total of 40 male Sprague-Dawley rats weighing 240-290 g were randomized into four groups of ten: (1) controls: data from unmanipulated animals; (2) sham group: rats subjected to the surgical procedure, except for liver I/R, and given saline; (3) I/R group: rats underwent liver ischemia for 45 min followed by reperfusion for 45 min; (4) I-R/Resveratrol group: rats pretreat- ed with resveratrol (10 μmol/L,iv). Liver tissues wweerre obtained to determine antioxidant enzyme levels and for biochemical and histological evaluation. RESULTS: Plasma aminotransferase activities were higher in the I/R group than in the I-R/Resveratrol group. Malondialdehyde levels and the hepatic injury score decreased, while superoxide dismutase, catalase ,and glutathione peroxidase levels increased in group 4 compared to group 3. In group 4, histopathological changes were significantly attenuated in resveratrol-treated livers. CONCLUSION: These results suggest that resveratrol has protective effects against hepatic I/R injury, and is a potential therapeutic drug for ischemia reperfusion-related liver injury.

Beneficial effects of adenosine triphosphate-sensitive K^+ channel opener on liver ischemia/reperfusion injury

AIM:To investigate the effect of diazoxide administration on liver ischemia/reperfusion injury.METHODS:Wistar male rats underwent partial liver ischemia performed by clamping the pedicle from the medium and left anterior lateral segments for 1 h under mechanical ventilation.They were divided into 3 groups:Control Group,rats submitted to liver manipulation,Saline Group,rats received saline,and Diazoxide Group,rats received intravenous injection diazoxide(3.5 mg/kg) 15 min before liver reperfusion.4 h and 24 h after reperfusion,blood was collected for determination of aspartate transaminase(AST),alanine transaminase(ALT),tumor necrosis factor(TNF-α),interleukin-6(IL-6),interleukin-10(IL-10),nitrite/nitrate,creatinine and tumor growth factor-β1(TGF-β1).Liver tissues were assembled for mitochondrial oxidation and phosphorylation,malondialdehyde(MDA) content,and histologic analysis.Pulmonary vascular permeability and myeloperoxidase(MPO) were also determined.RESULTS:Four hours after reperfusion the diazoxide group presented with significant reduction of AST(2009 ± 257 U/L vs 3523 ± 424 U/L,P = 0.005); ALT(1794 ± 295 U/L vs 3316 ± 413 U/L,P = 0.005); TNF-α(17 ± 9 pg/mL vs 152 ± 43 pg/mL,P = 0.013; IL-6(62 ± 18 pg/mL vs 281 ± 92 pg/mL); IL-10(40 ± 9 pg/mL vs 78 ± 10 pg/mL P = 0.03),and nitrite/nitrate(3.8 ± 0.9 μmol/L vs 10.2 ± 2.4 μmol/L,P = 0.025) when compared to the saline group.A significant reduction in liver mitochondrial dysfunction was observed in the diazoxide group compared to the saline group(P < 0.05).No differences in liver MDA content,serum creatinine,pulmonary vascular permeability and MPO activity were observed between groups.Twenty four hours after reperfusion the diazoxide group showed a reduction of AST(495 ± 78 U/L vs 978 ± 192 U/L,P = 0.032); ALT(335 ± 59 U/L vs 742 ± 182 U/L,P = 0.048),and TGF-β1(11 ± 1 ng/mL vs 17 ± 0.5 ng/mL,P = 0.004) serum levels when compared to the saline group.The control group did not present alterations when compared to the diazoxide and saline groups.CONCLUSION:Diazoxide maintains liver mitochondrial function,increases liver tolerance to ischemia/reperfusion injury,and reduces the systemic inflammatory response.These effects require further evaluation for using in a clinical setting.

Interaction of L-Arginine-methyl ester and Sonic hedgehog in liver ischemia-reperfusion injury in the rats

AIM: To investigate the role of Sonic hedgehog (Shh) on the course of liver ischemia and reperfusion (I/R) in rats, and the interaction between treatment with nitric oxide donor L-Arginine-methyl ester (L-Arg) and up-regulation of Shh expression. METHODS: A total of 30 male Sprague-Dawley rats weighing 220-240 g were used in this study. Sham-control group (G1, n = 10): a sham operation was performed (except for liver I/R). I/R-untreated group (G2, n = 10): rats underwent liver ischemia for 1 h followed by reperfusion for 45 min. I/R-L-Arg group (G3, n = 10): after performing the same surgical procedure as in group 2, animals were treated with L-Arg. Liver tissues were taken for determination of malondialdehyde (MDA) levels, and biochemical and histological evaluations were made. RESULTS: Plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and γ-glutamyltranspeptidase (GGT) activities were higher in group 2 than in group 3. MDA values and the hepatic injury score decreased in the L-Arg treated group compared to the I/R-untreated group. In group 2, the hepatocytes were swollen with marked vacuolization. Group 3 rats showed well-preserved liver parenchyma, with hepatocytes extending from the central vein. The morphology of the hepatocytes and the sinusoidal structures was normal, without any signs of congestion. Mild Shh positive immunostaining was detected in group 2 animals. The expression of immunoreactive cells was increased markedly in liver tissue from I/R-L-Arg rats.CONCLUSION: Our findings suggest that Shh molecules are critical factors in the pathophysiology of inflammatory liver injury induced by I/R. In addition, NO plays an important role in the immunohistochemical expression of these molecules.

STUDY ON INTERCELLULAR ADHESIONMOLECULE-1 AND P-SELECTIN IN LIVER ISCHEMIA AND REPERFUSION INJURY

Objective To investigate the role of intercellular adhesion molecule-1 (ICAM-1) andP- selectin in hepatic ischemia/reperfusion injury. Methods The relationship between P- selectin as well asICAM- 1 and liver ischemia/reperfusion was studied, using a 60 minutes ischemia - reperfusion rat liver model.The animals were divided into three groups including: the sham group, the ischemic control group receiving onlythe normal saline and the treated group receiving anti-P-selection monoclonal antibody (Mab) at a dose of2mg/kg 15 minutes before reperfusion. The following indexes were analyzed: liver injury tests, liver histotogy,serum enzymes level (AST, ALT), and the levels of ICAM-1 and P-selectin in the blood of rats. ResultsSerum enzymes levels were significantly increased during sixty minutes of left lobar ischemia and reperfusion(saline control), and the increment was significantly inhibited with P- selectin Mab. Liver pathology observed bylight microscopy was greatly ameliorated by Mab. Furthermore, the elevated levels of ICAM- 1 and P- selectinwere found in the blood of ischemia/ reperfusion rats. Concluhon ICAM- 1 and P- selectin contribute tohepatic ischemia / reperfusion injury,and the P - selectin Mab can protect the liver against the injury.

Treatment with dimethyl fumarate ameliorates liver ischemia/reperfusion injury

AIM To investigate the hypothesis that treatment with dimethyl fumarate(D MF) mayame liorate liver ischemia/reperfusion injury(I/RI).METHODS Rats were divided into 3 groups: sham, control(CTL), and DMF. DMF(25 mg/kg, twice/d) was orally administered for 2 d before the procedure. The CTL and DMF rats were subjected to ischemia for 1 h and reperfusion for 2 h. The serum alanine aminotransferase(ALT) and malondialdehyde(MDA) levels, adenosine triphosphate(ATP), NO × metabolites, anti-oxidant enzyme expression level, antiinflammatory effect, and anti-apoptotic effect were determined.RESULTS Histological tissue damage was significantly reduced in the DMF group(Suzuki scores: sham: 0 ± 0; CTL: 9.3± 0.5; DMF: 2.5 ± 1.2; sham vs CTL, P < 0.0001; CTL vs DMF, P < 0.0001). This effect was associated with significantly lower serum ALT(DMF 5026 ± 2305 U/L vs CTL 10592 ± 1152 U/L, P = 0.04) and MDA(DMF 18.2 ± 1.4 μmol/L vs CTL 26.0 ± 1.0 μmol/L, P = 0.0009). DMF effectively improved the ATP content(DMF 20.3 ± 0.4 nmol/mg vs CTL 18.3 ± 0.6 nmol/mg, P = 0.02), myeloperoxidase activity(DMF 7.8 ± 0.4 m U/m L vs CTL 6.0 ± 0.5 m U/m L, P = 0.01) and level of endothelial nitric oxide synthase expression(DMF 0.38 ± 0.05-fold vs 0.17 ± 0.06-fold, P = 0.02). The higher expression levels of anti-oxidant enzymes(catalase and glutamatecysteine ligase modifier subunit and lower levels of key inflammatory mediators(nuclear factor-kappa B and cyclooxygenase-2 were confirmed in the DMF group.CONCLUSION DMF improved the liver function and the anti-oxidant and inflammation status following I/RI. Treatment with DMF could be a promising strategy in patients with liver I/RI.

Effects of isoflurane on ICAM-1 expression and neutrophils infiltration in rats with liver ischemia and reperfusion injury

Objective: To establish a rat model of warm partial hepatic ischemia-reperfusion (IR), and investigate the protective and anti-inflammatory effects of isoflurane on warm hepatic ischemia-reperfusion injury (IRI) in rats. Methods: Thirty-two female Sprague-Dawley rats were divided equally into 4 groups (n=8): PB-Sham group in which the rats were anesthetized by intraperitoneal injection of pentobarbital sodium (1.0%, 40 mg/kg, PB) and received a sham operation without occlusion of liver blood flow; PB-IR group whose rats underwent partial hepatic IR after anesthesia; Iso-Sham group in which inhalation of 1.0 MAC isoflurane and sham operation was performed; Iso-IR group in which 1.0 MAC isoflurane was inhaled for 4 h and IR was performed. Rat model of warm partial hepatic IR was established by clamping the hepatic arteries and hilar vessels distributing to the left and median lobes to induce partial hepatic ischemia (70%) for 60 min followed by reperfusion for 3 h. The rats were killed 3 h after declamping, and specimens of liver tissue and blood were obtained. The serum ALT and AST were detected as liver damage markers. Viability of myeloperoxidase (MPO) in liver was measured. The protein level of ICAM-1 in the liver was detected by immunohistochemistry and Western blotting. Results: Rats treated with 1.0 MAC isoflurane during warm partial (70%) hepatic ischemia 60 min and 3 h reperfusion had significantly lower serum ALT and AST compared with rats anesthetized with pentobarbital sodium subjected to hepatic IRI. The expression of ICAM-1 in hepatic tissue was significantly increased by hepatic IRI after pentobarbital sodium anesthesia. Isoflurane significantly inhibited protein expression of ICAM-1 in hepatic IR injury compared with pentobarbital sodium anesthesia. Viability of liver MPO was significantly increased by hepatic IRI after pentobarbital sodium anesthesia; Isoflurane can significantly inhibit MPO alteration in rat liver ischemia-reperfusion injury compared with rats anesthetized with pentobarbital sodium. Conclusion: Isoflurane anesthesia can attenuate liver IR injury in rats that maybe by inhibiting ICAM-1 expression and reducing the infiltration of neutrophils.

Ankaflavin ameliorates steatotic liver ischemiareperfusion injury in mice

BACKGROUND： It is well-known that steatotic liver is more susceptible to ischemia-reperfusion （I/R） injury during liver transplantation, liver resection and other liver surgeries. The increasing incidence of non-alcoholic fatty liver disease （NAFLD） decreases the availability of liver donors. Although steatotic liver is now accepted as a source of liver for trans- plantation, NAFLD exacerbates the liver injury after liver surgery. The present study was to investigate the protective role of ankaflavin in steatotic liver I/R injury.

Polyethylene glycols: An effective strategy for limiting liver ischemia reperfusion injury

Liver ischemia-reperfusion injury(IRI) is an inherent feature of liver surgery and liver transplantation in which damage to a hypoxic organ(ischemia) is exacerbated following the return of oxygen delivery(reperfusion). IRI is a major cause of primary nonfunction after transplantation and may lead to graft rejection, regardless of immunological considerations. The immediate response involves the disruption of cellular mitochondrial oxidative phosphorylation and the accumulation of metabolic intermediates during the ischemic period, and oxidative stress during blood flow restoration. Moreover, a complex cascade of inflammatory mediators is generated during reperfusion, contributing to the extension of the damage and finally to organ failure. A variety of pharmacological interventions(antioxidants, anticytokines, etc.) have been proposed to alleviate graft injury but their usefulness is limited by the local and specific action of the drugs and by their potential undesirable toxic effects. Polyethylene glycols(PEGs), which are non-toxic water-soluble compounds approved by the FDA, have been widely used as a vehicle or a base in food, cosmetics and pharmaceuticals, and also as adjuvants for ameliorating drug pharmacokinetics. Some PEGs are also currently used as additives in organ preservation solutions prior to transplantation in order to limit the damage associated with cold ischemia reperfusion. More recently, the administration of PEGs of different molecular weights by intravenous injection has emerged as a new therapeutic tool to protect liver grafts from IRI. In this review, we summarize the current knowledge concerning the use of PEGs as a useful target for limiting liver IRI.

Proanthocyanidin Alleviates Liver Ischemia/Reperfusion Injury by Suppressing Autophagy and Apoptosis via the

Background and Aims:Hepatic ischemia-reperfusion injury(IRI)is a common pathophysiological phenomenon in clinical practice,which usually occurs in liver transplantation,liver resection,severe trauma,and hemorrhagic shock.Proanthocyanidin(PC),exerted from various plants with antioxidant,antitumor,and antiaging activity,were administrated in our study to investigate the underlying mechanism of its protective function on IRI.Methods:Two doses of PC(50 mg/kg,100 mg/kg)were given to BALB/c mice by intragastric administration for 7 days before partial(70%)warm IR surgery.Serum and liver tissues were collected 2,8,and 24 h after reperfusion for relevant experiments.Results:The results of transaminase and hematoxylin and eosin staining indicated that PC pretreatment significantly alleviated IRI in mice.Serum total superoxide dismutase increased and malondialde-hyde decreased in PC pretreatment groups.Enzyme-linked immunosorbent assays,western blotting,quantitative real-time polymerase chain reaction,and immunohistochemistry showed that inflammation,apoptosis,and autophagy in PC preprocessing groups were significantly inhibited and were dose-dependent.The protein,mRNA expression,and immunohistochemical staining results of peroxisome proliferator-activated receptor alpha(PPARa)and peroxisome proliferator-activated receptor gamma coactivator 1-alpha(PGC1a)in the PC pretreatment groups were significantly upregulated compared with the IR group in a dose-dependent manner.Conclusions:PC pretreatment suppressed inflammation,apoptosis,and autophagy via the PPAR-α signaling pathway to protect against IRI of the liver in mice.