Ischemia-reperfusion Injury Of Rat Liver Research Articles

Dimethyloxalylglycine pretreatment of living donor alleviates both donor and graft liver ischemia-reperfusion injury in rats.

Background: Under the circumstance of the increasing waiting list for liver transplantation, living donor liver transplantation (LDLT) can alleviate the shortage of liver donors to some extent. However, how to reduce both donor and graft ischemia-reperfusion injury (IRI) is still an unsolved problem in LDLT. Hypoxia-induced transcription factor 1 (HIF1) activation is considered an important mechanism of cellular adaptation to hypoxia, and early activation of HIF1 may be a new way to alleviate liver IRI. Therefore, we aimed to investigate the impact of the HIF1 stabilizer dimethyloxalylglycine (DMOG) on IRI and the survival rate of donors and recipients of rat LDLT. Methods: Seventy percent partial liver resection and 30% partial liver transplantation were used to simulate donor and recipient of clinical LDLT. Rats were treated with DMOG (40mg/kg) or with an equivalent amount of saline. The expression of HIF1 and downstream targets was analyzed after 2h of reperfusion. Liver function and histopathology, apoptosis and oxidative stress levels were detected 6h after reperfusion. At the same time, the 7-day survival rate of rats was calculated. Results: DMOG pretreatment significantly reduced IR-induced injury in the donor and recipient, which was manifested by reducing liver function damage and promoting tissue recovery. Meanwhile, compared with the untreated group, the oxidative stress level and the cell apoptosis rate were decreased in the group pretreated with DMOG. In addition, the transcription and expression of HIF1 target genes in the DMOG group were significantly enhanced. Remarkably, DMOG also increased the survival rate of the recipient. Conclusion: This study provides the first evidence that DMOG pretreatment of donors significantly alleviates liver IRI in both donors and recipients and increases the survival rate of recipients in LDLT. Therefore, DMOG may be a promising strategy for improving LDLT in the future.

Pre-treatment with pregabalin reduces liver ischemia-reperfusion injury in rats: tissue protection with an analgesic.

Ischemia-reperfusion injury is thought to be the most important factor affecting the success of liver surgery. Pregabalin has been studied to prevent ischemic reperfusion injury in many organs. The aim of this study was to investigate the role of pregabalin in preventing liver ischemic injury. 40 male Wistar-Albino rats, 6-8 weeks old, were divided into 5 groups. Four groups other than the sham group were subjected to hepatic ischemia for 1 hour, followed by 2 hours of reperfusion. Effects of 30 mg/and 60 mg/kg pregabalin were evaluated by aspartate aminotransferase (AST), alanine aminotransferase (ALT), tumor necrosis factor α (TNF-α), nuclear factor-kappa B (NF-кB), interleukin (IL)-6 levels, measured in blood samples collected before and after ischemia. Apoptosis was measured by caspase-3, and tissue samples were evaluated for ischemia by histopathologic examination. The 60 mg pregabalin group was significantly superior (p=0.024) to the N-acetylcysteine group and the 30 mg pregabalin group for AST levels (p=0.612 and p=0.807, respectively). The difference between before and after ischemia-reperfusion blood TNF-α levels was higher in the 60 mg pregabalin group, but not significantly different from the 30 mg pregabalin and N-acetylcysteine groups (p>0.05). Tissue TNF-α levels showed that 60 mg and 30 mg pregabalin treatment was more effective than no-treatment (p=0.011, p=0.033, respectively), but not superior to N-acetylcysteine (p>0.05). It has been found that ischemia-reperfusion causes damage to the liver, and this damage may be irreversible if no treatment is given. Our study group, pregabalin molecule was found to be significantly effective in preventing ischemia-reperfusion injury and may have a therapeutic advantage over N-acetylcysteine.

Combination of Cold Storage in a Heavy Water-Containing Solution and Post-Reperfusion Hydrogen Gas Treatment Reduces Ischemia-Reperfusion Injury in Rat Livers

We previously reported the efficacy of cold storage (CS) using a heavy water-containing solution (Dsol) and post-reperfusion hydrogen gas treatment separately. This study aimed to clarify the combined effects of these treatments. Rat livers were subjected to 48-hour CS and a subsequent 90-minute reperfusion in an isolated perfused rat liver system. The experimental groups were the immediately reperfused control group (CT), the CS with University of Wisconsin solution (UW) group, the CS with Dsol group, the CS with UW and post-reperfusion H2 treatment group (UW-H2), and the CS with Dsol and post-reperfusion H2 group (Dsol-H2). We first compared the Dsol-H2, UW, and CT groups to evaluate this alternative method to conventional CS. The protective potential of the Dsol-H2 group was superior to that of the UW group, as evidenced by lower portal venous resistance and lactate dehydrogenase leakage, a higher oxygen consumption rate, and increased bile production. Multiple comparison tests among the UW, Dsol, UW-H2, and Dsol-H2 groups revealed that both treatments, during CS and after reperfusion, conferred a similar extent of protection and showed additive effects in combination therapy. Furthermore, the variance in all treatment groups appeared smaller than that in the no-treatment or no-stress groups, with excellent reproducibility. In conclusion, combination therapy with Dsol during CS and hydrogen gas after reperfusion additively protects against graft injury.

Effect of the Non-steroidal Anti-inflammatory Drug Diclofenac on Ischemia-Reperfusion Injury in Rat Liver: A Nitric Oxide-Dependent Mechanism.

Ischemia/reperfusion injury (IRI) is an inevitable complication of liver surgery and transplantation. The purpose of this study was to examine the beneficial effects of diclofenac on hepatic IRI and the mechanism behind it. Wistar rats' livers were subjected to warm ischemia for 60min followed by 24h of reperfusion. Diclofenac was administered intravenously 15min before ischemia at 10, 20, and 40mg/kg body weight. To determine the mechanism of diclofenac protection, the NOS inhibitor L-Nitro-arginine methyl ester (L-NAME) was administered intravenously 10min after diclofenac injection (40mg/kg). Liver injury was evaluated by aminotransferases (ALT and AST) activities and histopathological analysis. Oxidative stress parameters (SOD, GPX, MPO, GSH, MDA, and PSH) were also determined. Then, eNOS gene transcription and p-eNOS and iNOS protein expressions were evaluated. The transcription factors PPAR-γ and NF-κB in addition to the regulatory protein IκBα were also investigated. Finally, the gene expression levels of inflammatory (COX-2, IL-6, IL-1β, IL-18, TNF-α, HMGB-1, and TLR-4) and apoptosis (Bcl-2 and Bax) markers were measured. Diclofenac, at the optimal dose of 40mg/kg, decreased liver injury and maintained histological integrity. It also reduced oxidative stress, inflammation, and apoptosis. Its mechanism of action essentially depended on eNOS activation rather than COX-2 inhibition, since pre-treatment with L-NAME abolished all the protective effects of diclofenac. To our knowledge, this is the first study demonstrating that diclofenac protects rat liver against warm IRI through the induction of NO-dependent pathway. Diclofenac reduced oxidative balance, attenuated the activation of the subsequent pro-inflammatory response and decreased cellular and tissue damage. Therefore, diclofenac could be a promising molecule for the prevention of liver IRI.

Effects of cerium oxide (CeO2) on liver tissue in liver ischemia-reperfusion injury in rats undergoing desflurane anesthesia

IntroductionDuring liver surgery and transplantation, periods of partial or total vascular occlusion are inevitable and result in ischemia-reperfusion injury (IRI). Nanomedicine uses the latest technology, which has emerged with interdisciplinary effects, such as biomedical sciences, physics, and engineering, to protect and improve human health. Interdisciplinary research has brought along the introduction of antioxidant nanoparticles as potential therapeutics. The goal of this study was to investigate the effects of cerium oxide (CeO2) administration and desflurane anesthesia on liver tissue in liver IR injury.Material and methodsThirty rats were randomly divided into five groups: control (C), ischemia-reperfusion (IR), IR-desflurane (IRD), cerium oxide-ischemia reperfusion (CeO2-IR), and cerium oxide-ischemia reperfusion-desflurane (CeO2-IRD). In the IR, IRD, and CeO2-IRD groups, hepatic ischemia was induced after the porta hepatis was clamped for 120 min, followed by 120 min of reperfusion. Intraperitoneal 0.5 mg/kg CeO2 was administered to the CeO2 groups 30 min before ischemia. Desflurane (6%) was administered to the IRD and CeO2-IRD groups during IR. All groups were sacrificed under anesthesia. Liver tissue samples were examined under a light microscope by staining with hematoxylin-eosin (H&E). Malondialdehyde (MDA) levels, catalase (CAT), glutathione-s-transferase (GST), and arylesterase (ARE) enzyme activities were measured in the tissue samples.ResultsThe IR group had considerably more hydropic degeneration, sinusoidal dilatation, and parenchymal mononuclear cell infiltration than the IRD, CeO2-IR, and CeO2-IRD groups. Catalase and GST enzyme activity were significantly higher in the CeO2-IR group than in the IR group. The MDA levels were found to be significantly lower in the IRD, CeO2-IR, and CeO2-IRD groups than in the IR group.ConclusionIntraperitoneal CeO2 with desflurane reduced oxidative stress and corrected liver damage.

Pre-Ischemic Hypothermic Oxygenated Perfusion Alleviates Protective Molecular Markers of Ischemia-Reperfusion Injury in Rat Liver

To expand the pool of organs, hypothermic oxygenated perfusion (HOPE), one of the most promising perfusion protocols, is currently performed after cold storage (CS) at transplant centers (HOPE-END). We investigated a new timing for HOPE, hypothesizing that performing HOPE before CS (HOPE-PRE) could boost mitochondrial protection allowing the graft to better cope with the accumulation of oxidative stress during CS. We analyzed liver injuries at 3 different levels. Histologic analysis demonstrated that, compared to classical CS (CTRL), the HOPE-PRE group showed significantly less ischemic necrosis compared to CTRL vs HOPE-END. From a biochemical standpoint, transaminases were lower after 2 hours of reperfusion in the CTRL vs HOPE-PRE group, which marked decreased liver injury. qPCR analysis on 37 genes involved in ischemia-reperfusion injury revealed protection in HOPE-PRE and HOPE-END compared to CTRL mediated through similar pathways. However, the CTRL vs HOPE-PRE group demonstrated an increased transcriptional level for protective genes compared to the CTRL vs HOPE-END group. This study provides insights on novel biomarkers that could be used in the clinic to better characterize graft quality improving transplantation outcomes.

Effects of Mirtazapine on Liver Ischemia-Reperfusion Injury in Rats

Effects of Mirtazapine on Liver Ischemia-Reperfusion Injury in Rats

MiR-29a-3p in Exosomes from Heme Oxygenase-1 Modified Bone Marrow Mesenchymal Stem Cells Alleviates Steatotic Liver Ischemia-Reperfusion Injury in Rats by Suppressing Ferroptosis via Iron Responsive Element Binding Protein 2

Hepatic ischemia-reperfusion injury (IRI) is an inevitable result of liver surgery. Steatotic livers are extremely sensitive to IRI and have worse tolerance. Ferroptosis is considered to be one of the main factors of organ IRI. This study is aimed at exploring the role of ferroptosis in the effect of heme oxygenase-1-modified bone marrow mesenchymal stem cells (HO-1/BMMSCs) on steatotic liver IRI and its mechanism. An IRI model of a steatotic liver and a hypoxia reoxygenation (HR) model of steatotic hepatocytes (SHPs) were established. Rat BMMSCs were extracted and transfected with the Ho1 gene to establish HO-1/BMMSCs, and their exosomes were extracted by ultracentrifugation. Ireb2 was knocked down to verify its role in ferroptosis and cell injury in SHP-HR. Public database screening combined with quantitative real-time reverse transcription PCR identified microRNAs (miRNAs) targeting Ireb2 in HO-1/BMMSCs exosomes. miR-29a-3p mimic and inhibitor were used for functional verification experiments. Liver function, histopathology, terminal deoxynulceotidyl transferase nick-end-labeling staining, cell viability, mitochondrial membrane potential, and cell death were measured to evaluate liver tissue and hepatocyte injury. Ferroptosis was assessed by detecting the levels of IREB2, Fe2+, malondialdehyde, glutathione, lipid reactive oxygen species, glutathione peroxidase 4, prostaglandin-endoperoxide synthase 2 mRNA, and mitochondrial morphology. The results revealed that HO-1/BMMSCs improved liver tissue and hepatocyte injury and suppressed ferroptosis in vivo and in vitro. The expression of IREB2 was increased in steatotic liver IRI and SHP-HR. Knocking down Ireb2 reduced the level of Fe2+ and inhibited ferroptosis. HO-1/BMMSC exosomes reduced the expression of IREB2 and inhibited ferroptosis and cell damage. Furthermore, we confirmed high levels of miR-29a-3p in HO-1/BMMSCs exosomes. Overexpression of miR-29a-3p downregulated the expression of Ireb2 and inhibited ferroptosis. Downregulation of miR-29a-3p blocked the protective effect of HO-1/BMMSC exosomes on SHP-HR cell injury. In conclusion, ferroptosis plays an important role in HO-1/BMMSC-mediated alleviation of steatotic liver IRI. HO-1/BMMSCs could suppress ferroptosis by targeting Ireb2 via the exosomal transfer of miR-29a-3p.

Effects of Propofol and Vitexin on Apoptosis in Rat Liver Ischemia Reperfusion Injury

Effects of Propofol and Vitexin on Apoptosis in Rat Liver Ischemia Reperfusion Injury

The protective effect of boric acid on cholestatic rat liver ischemia reperfusion injury.

Background/aim To evaluate the potential protective effects of boric acid (BA) in experimental cholestatic liver ischemia reperfusion (IR) injury model.Materials and methods The study included 24 female rats which were divided into 3 groups each containing 8 rats. The control group (Group 1) only received laparotomy. In the IR group (Group 2) biliary tract ligation was applied and 1 week later 45 min ischemia and 1 h reperfusion with relaparotomy without any treatment was implemented. In the treatment BA+IR group (Group 3). 1 week after the biliary ligation intraperitoneal administration of 200 mg/kg BA was given 10 min before the ischemia for 45 min and reperfusion for 1 h with relaparotomy. Liver tissue and blood samples were taken for histopathological and biochemical examination. Ischemia modified albumin (IMA), SCUBE1, total antioxidant status (TAS), and total oxidant status (TOS) levels were also examined.Results Compared to control, groups IR and BA+IR had higher serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), total, and direct bilirubin levels. Albumin value was high in the control group and low in the other groups. In terms of IMA levels there was no significant difference between groups (p > 0.05). When SCUBE-1 levels were examined groups IR and BA+IR were significantly higher than the group 1. TAS was highest in the group BA+IR whereas TOS was highest in the group IR and lower in the group BA+IR. In histopathological analysis, loss of intercellular border loss in hepatocytes, diffuse nuclear pycnosis and mild to moderate neutrophilic cell infiltration were observed in the IR group. Statistically significant dissociation, hemorrhage and severe neutrophilic cell infiltration were seen in hepatocytes of rats with IR (p < 0.05). Conclusion BA has promising results in the treatment of experimental IR injury of the cholestatic liver because of its antioxidant effects. It may be used in clinical practice after more extensive studies about the effects of BA on IR injury of the cholestatic liver.

The Effects of Esmolol on Erythrocyte Deformability in Rat Liver Ischemia-Reperfusion Injury

The Effects of Esmolol on Erythrocyte Deformability in Rat Liver Ischemia-Reperfusion Injury

Effects of Carvedilol on liver ischemia-reperfusion injury in rats.

The aim of this study was to analyze the potential protective effect of Carvedilol against liver ischemia-reperfusion (I/R) injury in rats. A total of 40 Wistar albino rats were randomly divided into four groups (n=10 each). Group I (Sham/Control group) underwent only laparotomy, Group II (Carvedilol group) was administered carvedilol and then underwent laparotomy, Group III (I/R group) underwent laparotomy and hepatic ischemia/reperfusion, and Group IV (I/R + Carvedilol group) was administered carvedilol and then underwent laparotomy and hepatic ischemia/reperfusion. Blood samples were collected for malondialdehyde, glutathione (GSH), and myeloperoxidase (MPO) analysis. Liver sections were obtained for histopathological analysis and stained with hematoxy-lin-eosin. Tumor necrosis factor-α (TNF-α) and Caspase-3 primary antibodies were used for the immunohistochemical analysis. Serum GSH levels increased in the I/R + Carvedilol group. MPO activity was increased significantly in the IR group. In I/R + Carvedilol group, serum MPO levels were similar to the control group. Histopathological findings showed reduced dilatation and congestion in vena centralis, regenerative changes in hepatocyte cells with the protected nucleus structure in the I/R + Carvedilol group. Hepatocyte nuclei with increased pycnosis and apoptosis and the dilated vena centralis were observed in I/R group. In the control group, TNF-α showed a positive reaction in macrophage cells around vena centralis. An increase in TNF-α expression was observed in hepatocyte cells of I/R group. Positive expression of caspase-3 in hepatocyte cells and a small number of endothelial and Kupffer cells were seen in I/R group. However, negative caspase-3 expression was seen in hepatocyte, endothelial, and Kupffer cells in I/R + Carvedilol group. Carvedilol may prevent initiation of oxidative stress process, inflammation induction and apoptotic progression.

Hepatoprotective properties of p-coumaric acid in a rat model of ischemia-reperfusion.

The liver as a highly metabolic organ, has a crucial role in human body. Its function is often impressed by changes of the blood flow, hypovolemic shock, transplantation, etc. Maintaining liver function is a major challenge and there are many approaches to potentiate this organ against different stresses. Antioxidants protect organs against oxidative stress. P-coumaric acid (PC) as an oxidant has many beneficial effects. Therefore, PC was used as a pretreatment to test its potential against oxidative stress induced by liver Ischemia-reperfusion injury in rats. In order to test the potential hepatoprotective effect of PC against IR injury, five groups of rats were used: Normal (NC; intact group); Sham; p-coumaric acid (PC); IR-CO, and PC-IR. PC, Sham, NC, PC-IR and IR-CO groups that received vehicle or p-coumaric acid at a dose of 100 mg/kg for 7 consecutive days as pretreatment before IR induction. Animals in PC-IR, and IR-CO groups underwent hepatic IR injury. Liver levels of antioxidants were determined and functional liver tests were done. Hematoxylin and eosin staining was done to determine the structural changes of the liver. Gene expression of caspase-3 was also assessed. Hepatic IR injury disrupted liver function by increasing the levels of AST, and ALT, and decreasing GSH, SOD and catalase. PC significantly decreased liver inflammation, reverted liver functional enzymes and antioxidants levels to normal, reduced the gene expression of caspase-3 in PC-IR rats compared to the IR-CO group. These findings revealed that PC through improving liver´s antioxidants, liver functional tests and down-regulating apoptotic gene protein, caspase-3, protects the liver against injury induced by IR.

Protective effect and mechanism of alpha-lipoic acid on partial hepatic ischemia-reperfusion injury in adult male rats.

In order to reduce tissue damage caused by ischemia-reperfusion injury, this study aims to investigate the protective effect and mechanism of ?-lipoic acid on hepatic ischemia-reperfusion injury in rats. The bloodstream of rats was blocked in the left middle and left lateral liver lobes of the liver. Forty rats were randomly divided into two groups: treatment group and injury group. Rats were injected with either 25 mg/1 ml of alpha-lipoic acid (treatment group) or 1 ml of saline (injury group) into the caudal vein 15 min before hepatic ischemia-reperfusion. Rat serum alanine aminotransferase (GPT), glutathione (GSH) and superoxide dismutase (SOD) levels were examined at various time points (1, 3, 6 and 12 h) in both groups. Changes in nuclear factor kappa B P65 (NF-kappaB P65) expression in ischemia-reperfusion liver at various time points after reperfusion (1, 3, 6 and 12 h) were evaluated through immunohistochemistry assay. Changes in macrophage inflammatory protein-2 (MIP-2) mRNA and inducible nitric oxide synthase (iNOS) mRNA expression in ischemic reperfused rat livers were detected by RT-PCR. Serum GPT level was significantly higher in the injury group than in the treatment group (P<0.01). NF-kappaB P65, MIP-2 mRNA and iNOS mRNA expression in ischemic reperfused rat livers were significantly higher in the injury group than in the treatment group (P<0.01). Serum GSH and SOD levels were higher in the treatment group than in the injury group (P<0.01). Alpha-lipoic acid significantly reduced ischemia-reperfusion injury in rat livers. This may be associated to the direct scavenging of oxygen-free radicals, increased GSH production, and the activation of downstream media due to decreased NF-kappaB and GSH consumption.

TAK242 suppresses the TLR4 signaling pathway and ameliorates DCD liver IRI in rats.

Ischemia-reperfusion injury (IRI) is a notable cause of tissue damage during surgical procedures and a major risk factor in graft dysfunction in liver transplantation. Livers obtained from donors after circulatory death (DCD) are prone to IRI and toll-like receptor 4 (TLR4) serves a prominent role in the inflammatory response associated with DCD liver IRI. The present study was designed to investigate whether TAK242, a specific TLR4 inhibitor, improves hepatic IRI following a DCD graft and to investigate its underlying protective mechanisms. Male Sprague-Dawley rats were randomized into 4 groups: Control, TAK242, DCD and DCD+TAK242 groups. Rats were pretreated with TAK242 or its vehicle for 30 min, then the livers were harvested without warm ischemia (control group and TAK242 group) or with warm ischemia in situ for 30 min. The livers were stored in cold University of Wisconsin solution for 24 h and subsequently perfused for 60 min with an isolated perfused rat liver system. Rat liver injury was evaluated thereafter. When compared with the DCD group, DCD livers with TAK242 pretreatment displayed significantly improved hepatic tissue injury and less tissue necrosis (P<0.05). Compared with DCD livers, mechanistic experiments revealed that TAK242 pretreatment alleviated mitochondrial dysfunction, reduced reactive oxygen species and malondialdehyde levels and inhibited apoptosis. Additionally, TAK242 significantly inhibited the IRI-associated inflammatory response, indicated by the decreased expression of TLR4, interleukin (IL)-1β, IL-6 and cyclooxygenase 2 at the mRNA and protein levels (P<0.05). TAK242 ameliorates DCD liver IRI via suppressing the TLR4 signaling pathway in rats. The results of the present study have revealed that TAK242 pretreatment harbors a potential benefit for liver transplantation.

Effect of berberine on fatty liver ischemia-reperfusion injury in rats: the relationship with endoplasmic reticulum stress in liver tissues

Objective To evaluate the effect of berberine on fatty liver ischemia-reperfusion(I/R) injury and the relationship with endoplasmic reticulum stress in liver tissues. Methods Thirty-two male Wistar rats, aged 4 weeks, weighing 100-150 g, were divided into 4 groups(n=8 each) using a random number table method: control group(group C), fatty liver group(group FL), I/R group and berberine group(group BBR ). Rats were fed a normal fat diet for 12 weeks, normal saline 3.5 ml was given intragastrically for 4 weeks starting from 9th week, and rats only underwent simple laparotomy in group C. Rats were fed a high-fat diet(45% energy originating from fat) for 12 weeks, and the other treatments were similar to those previously described in group C. Rats were fed a high-fat diet(45% energy originating from fat) for 12 weeks, normal saline 3.5 ml was given intragastrically for 4 weeks starting from 9th week, and then the model of liver I/R injury was established in group I/R. Rats were fed a high-fat diet(45% energy originating from fat) for 12 weeks, berberine solution(300 mg/kg) 3.5 ml was given intragastrically for 4 weeks starting from 9th week, and then the model of liver I/R injury was established in group BBR. Hepatic ischemia was induced by clamping the portal vein, hepatic artery, right gastric vein, and supra- and inferior-hepatic vena cava to perform cold perfusion with 4 ℃ lactated Ringer′s solution lasting for 30 min, followed by reperfusion. The serum triglyceride(TG) concentrations were determined after 4, 8 and 12 weeks of diet. Blood samples were collected at 6 h of reperfusion for measurement of serum aspartate transminase(AST )and alanine transaminase(ALT)concentrations. Livers were removed after blood sampling at 6 h of reperfusion and liver tissues were obtained and stained with oil red O and haematoxylin and eosin for examination of pathological changes and for determination of the expression of Bip, CCAAT/enhancer-binding protein homologous protein(CHOP), protein kinase RNA-like endoplasmic reticulum kinase(PERK) and phosphorylated PERK(p-PERK)(by Western blot). p-PERK/PERK ratio was calculated. Results Compared with group C, the serum TG, ALT and AST concentrations were significantly increased, the expression of Bip and CHOP was up-regulated, p-PERK/PERK ratio was increased(P<0.05), lipid deposition was increased, and liver steatosis was found in group FL. Compared with group FL, the serum AST and ALT concentrations were significantly increased, the expression of Bip and CHOP was up-regulated, p-PERK/PERK ratio was increased(P<0.05), and the pathological changes of liver tissues were accentuated in group I/R. Compared with group I/R, the serum TG, ALT and AST concentrations were significantly decreased, the expression of Bip and CHOP was down-regulated, p-PERK/PERK ratio was decreased(P<0.05), lipid deposition was reduced, and the pathological changes of liver tissues were significantly attenuated in group BBR. Conclusion Berberine can ameliorate fatty liver I/R injury, and the mechanism may be related to inhibiting endoplasmic reticulum stress in liver tissues of rats. Key words: Berberine; Fatty liver; Reperfusion injury; Endoplasmic reticulum; Stress

Influence of intravenous injected sodium hydrosulfide on fatty liver ischemia-reperfusion injury in rats

Objective To investigate whether intravenous injected sodium hydrosulfide (NaHS) could alleviate the fatty liver ischemia-reperfusion injury in rats and the mechanism. Methods 30 healthy male Sprague-Dawley (SD) rats were fed with high fat diet for 4 weeks then divided into five groups randomly, sham operation group (S group), ischemia-reperfusion group (IR group) and different doses of sodium hydrosulfide groups (NaHS 1-3 groups). In S group hepatic portal was only exposed but not ligated. In IR group the left and middle lobes of hepatic portal vein and hepatic artery were clamped for 1 h and then reperfused. NaHS 1-3 groups received intravenous of NaHS 14, 28, 56 μmol/kg 5 min before reperfusion. Blood samples were collected for measuring the level of alanine transaminase (ALT) in serum at 6 h after reperfusion. Liver tissue samples were collected for measurement the content of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) and pathologic examination. Results The level of ALT in serum of S group, IR group and NaHS 1-3 group were(64±8), (1 393±69), (852±53), (823±42), (807±57) U/L respectively; The content of MDA in liver tissue of S group, IR group and NaHS 1-3 group were (2.15±0.24), (7.97±0.42), (5.26±0.34), (4.95±0.42), (4.77±0.40) nmol/mg prot respectively; the activity of SOD in liver tissue were (421±20), (201±32), (517±27), (601±23), (607±30) U/mg prot respectively. Compared with S group, the level of ALT in serum and MDA content in liver tissue were increased in IR group (t=44.194, P=0.000; t=42.068, P=0.000), and the activity of SOD in liver tissue was decreased in IR group (t=-14.658, P=0.000). Compared with IR group, the level of ALT in serum were decreased in NaHS 1-3 group (t=-11.563, P=0.000; t=-36.415, P=0.000; t=-13.372, P=0.000), and the content MDA in liver tissue were decreased in NaHS 1-3 group (t=-10.375, P=0.000; t=-17.532, P=0.000; t=-12.402, P=0.000), the activity of SOD in liver tissue was increased in NaHS 1-3 group (t=24.087, P=0.000; t=30.451, P=0.000; t=42.542, P=0.000). The pathological damage degree was lighter in NaHS 1-3 group (Suzuki’s score 2.50, 2.33, 2.17) than IR group (Suzuki’s score 3.67) (t=3.873, P=0.012; t=6.325, P=0.001; t=11.608, P=0.000). Conclusion Intravenous injected sodium hydrosulfide can reduce fatty liver ischemia-reperfusion injury in rats through the inhibition of lipid peroxidation. Key words: Sodium hydrosulfide; Liver ischemia; Reperfusion injury; Fatty liver; Lipid peroxidation

Neutrophil extracellular traps in acrolein promoted hepatic ischemia reperfusion injury: Therapeutic potential of NOX2 and p38MAPK inhibitors.

Neutrophil is a significant contributor to ischemia reperfusion (IR) induced liver tissue damage. However, the exact role of neutrophils in IR induced innate immune activation and liver damage is not quite clear. Our study sheds light on the role of chronic oxidative stress end products in worsening the IR inflammatory process by neutrophil recruitment and activation following liver surgery. We employed specific inhibitors for molecular targets-NOX2 (NADPH oxidase 2) and P38 MAPK (Mitogen activated protein kinase) signal to counteract neutrophil activation and neutrophil extracellular trap (NET) release induced liver damage in IR injury. We found that acrolein initiated neutrophil chemotaxis and induced NET release both in vitro and in vivo. Acrolein exposure caused NET induced nuclear and mitochondrial damage in HepG2 cells as well as aggravated the IR injury in rat liver. Pretreatment with F-apocynin and naringin, efficiently suppressed acrolein induced NET release in vitro. Notably, it suppressed the expression of inflammatory cytokines, P38MAPK-ERK activation, and apoptotic signals in rat liver exposed to acrolein and subjected to IR. Moreover, this combination effectively attenuated acrolein induced NET release and hepatic IR injury. In the current study we have shown that the acrolein accumulation in liver due to chronic stress, is responsible for neutrophil recruitment and its activation leading to NET induced liver damage during surgery. Our study shows that therapeutic targeting of NOX2 and P38MAPK signaling in patients with chronic hepatic disorders would improve post operative hepatic function and survival.

Effect of hydrogen sulfide on fatty liver ischemia-reperfusion injury in rats

Objective To investigate the role of hydrogen sulfide in fatty liver ischemia-reperfusion injury in rats. Methods Eighteen healthy male Sprague-Dawley (SD) rats were fed on high fat diet for 4 weeks, and then divided into three groups according to the method of random number table, sham operation group (S group), ischemia-reperfusion group (IR group) and sodium hydrosulfide group (NaHS group). In S group hepatic portal was only exposed but not ligated. In IR group hepatic portal vein and hepatic artery of the left and middle lobes were clamped for 1 h and then reperfused. NaHS group received intravenous injection of NaHS (28 μmol/kg) 5 min before reperfusion. Blood samples were collected for measuring the level of alanine transaminase (ALT) and tumor necrosis factor-α (TNF-α) in serum at 6 h after reperfusion. Liver tissue samples were collected for pathologic examination. Results The serum ALT levels in S group, IR group and NaHS group were (64±8), (1 393±69) and (823±42) U/L, and the serum TNF-α levels in S group, IR group and NaHS group were (55.62±7.24), (288.97±41.42) and (203.65±37.36) ng/L respectively. As compared with S group, the serum levels of ALT and TNF-α were significantly increased in IR group (t=44.194, P=0.000; t=20.586, P=0.000). As compared with IR group, the serum levels of ALT and TNF-α were significantly decreased in NaHS group (t=-36.415, P=0.000; t=-4.556, P=0.006). The pathological damage degree was milder in NaHS group (Suzuki’s score 2.33) than in IR group (Suzuki’s score 3.67; t=6.325, P=0.001). Conclusion Hydrogen sulfide can reduce fatty liver ischemia-reperfusion injury in rats through the inhibition of TNF-α expression. Key words: Hydrogen sulfide; Liver ischemia; Reperfusion injury; Fatty liver; Tumor necrosis factor-α

Postconditioning attenuates bile duct cell damage by apoptosis from liver ischemia-reperfusion injury in rats

Objective To study the protective effect of postconditioning on bile duct cell damage in the form of apoptosis during liver ischemia-reperfusion (IR) injury by observing the expression of B cell lymphoma/leukemia-2 (bcl-2) and B cell lymphoma/leukemia-2 associated X protein (bax) on bile ducts. Methods Thirty healthy male SD rats were randomly divided into three groups: sham-operation (SO) group, IR group and ischemic postconditioning (IPO) group. IPO was achieved by 6 brief reperfused/ischemia cycles before the persistent reperfusion procedure. The samples of blood and hepatic tissue of all groups were taken after experiment. The activity of γ-glutamyl transpeptidase (GT) in serum was determined. The expression of bcl-2 and bax on bile ducts was detected by immunohistochemistry. The apoptosis index on bile ducts was observed by TdT-mediated dUTP nick end labeling (TUNEL) methods. Results The activity of γ-GT was lower in IPO group [(26.30±3.32) U/L] than that in IR group [(34.64±3.28) U/L] with the difference being statistically significant (P=0.001). As compared with the IR group, the expression of bcl-2 on bile ducts was up-regulated [(77.94±5.25)% vs. (42.67±3.73)%], and that of bax down-regulated [(70.10±4.27)% vs. (90.17±2.12)%] in IPO group, with the difference being statistically significant (P=0.000). As compared with IR group, the apoptosis index in IPO group was decreased [(58.90±2.75)% vs. (79.31±1.12)%, P=0.000], and the pathologically morphologic damages of the bile duct cells were attenuated. Conclusion In the process of liver IR, the postconditioning can promote the expression of bcl-2 and inhibit the expression of bax on bile duct, which may withstand the happening of the bile duct cell apoptosis, thus attenuating the bile duct damage caused by liver IR injury. Key words: Reperfusion injury; Postconditioning; Bile duct; Apoptosis; B cell lymphoma/leukemia-2; B cell lymphoma/leukemia-2 associated X protein