Remote renal injury following partial hepatic ischemia/reperfusion injury in rats

Renoprotective effects of zinc sulfate against transient liver ischemia/reperfusion injury in rats

Objectives

Liver ischemia/reperfusion damage frequently occurs in setting of hepatic resection and liver transplantation. It leads to disturbance in remote organs such as heart, lung and kidneys. This study explored the consequences of hepatic ischemia/reperfusion on the oxidative stress parameters, biochemical factors, and histopathological alterations in the kidney's rats, as well as evaluated the role of zinc sulfate on above-mentioned parameters.

Materials and methods

Twenty-eight male Wistar rats were accidently assigned into four groups (n = 7). They were Sham, ischemia/reperfusion, zinc sulfate pretreatment, and zinc sulfate pretreatment + ischemia/reperfusion groups. Sham group: obtained normal saline (2 ml/day, seven consecutive days), intraperitoneally, zinc sulfate pretreatment group: obtained zinc sulfate (5 mg/kg, seven consecutive days, intraperitoneally). Ischemia/reperfusion group: obtained normal saline as mentioned previous, then rats experienced the partial ischemia (%70) for 45 min followed by 60 min reperfusion. Zinc sulfate pretreatment group: obtained zinc sulfate as mentioned previous, then rats experience the partial ischemia/reperfusion as presented earlier. At the end of investigation, blood was withdrawn, liver and renal tissues were removed. Then, biochemical and oxidative stress parameters, and histological changes were evaluated in the mentioned tissues.

Results

The findings of this experiment indicated that zinc sulfate markedly reduced the serum levels of liver and kidney function tests in relative to ischemia/reperfusion group. Also, antioxidant enzymes activity, ferric reducing antioxidant power, and nitric oxide significantly increased, while malondialdehyde level declined in the renal tissue of zinc sulfate + ischemia/reperfusion group compared to ischemia/reperfusion rats. Furthermore, zinc sulfate alleviated the liver and kidneys histopathological alterations following ischemia/reperfusion.

Conclusion

Zinc sulfate ameliorated liver and kidney function, and improved oxidant-antioxidant balance in favor of antioxidants. It is suggested that zinc sulfate may be beneficial effects on hepato-renal injury after ischemia/reperfusion.

Luteolin Pretreatment Attenuates Hepatic Ischemia-Reperfusion Injury in Mice by Inhibiting Inflammation, Autophagy, and Apoptosis via the ERK/PPARα Pathway

Hepatic ischemia-reperfusion (IR) injury is a clinically significant process that frequently occurs in liver transplantation, partial hepatectomy, and hemorrhagic shock. The aim of this study was to explore the effectiveness of luteolin in hepatic IR injury and the underlying mechanism. BALB/c mice were randomly divided into six groups, including normal controls (NC), luteolin (50 mg/kg), sham procedure, IR+25 mg/kg luteolin, and IR+50 mg/kg luteolin group. Serum and tissue samples were collected at 6 and 24 h after reperfusion to assay liver enzymes, inflammatory factors, expression of proteins associated with apoptosis and autophagy, and factors associated with the extracellular signal-regulated kinase/peroxisome proliferator-activated receptor alpha (ERK/PPARα) pathway. Luteolin preconditioning decreased hepatocyte injury caused by ischemia-reperfusion, downregulated inflammatory factors, and inhibited apoptosis and autophagy. Luteolin also inhibited ERK phosphorylation and activated PPARα.

Pro-inflammatory cytokines/chemokines, TNF-α, IL-6 and MCP-1, as biomarkers for the nephro- and pneumoprotective effect of silibinin after hepatic ischemia/reperfusion: confirmation by immunihistochemistry and qRT-PCR

The present study investigated the potential nephro- and pneumoprotective effect of silibinin (Si) after hepatic ischemia-reperfusion (I/R) injury, by measuring pro-inflammatory factors. Sixty-three rats were randomly assigned into three groups, as follows: (a) the sham group (n=7 rats), subjected to opening and closing the abdomen; (b) the control group (n = 28 rats), subjected to 45-min hepatic ischemia followed by reperfusion; and (c) the silibinin group (n=28), subjected to 45-min hepatic ischemia followed by intravenous administration of lyophilized SLB-HP-β-CD before reperfusion. Control and silibinin groups were further subdivided into time-point groups, according to the duration of reperfusion. TNF-α, IL-6 and MCP-1 expressions were determined immunihistochemically and by qrT-PCR at each time-point. Kidney TNF-α expression was significantly lower at 180 and 240 min, while lung TNF-α expression was significantly lower at 240 min. Comparison between the control and Si group at the same time-points, showed very strong evidence of difference at 240 min, with the levels of IL-6 shifting towards lower values in the Si group. Finally, we found a high MCP-1 expression after 120 min. We conclude that hepatic I/R injury remotely increases proinflammatory mediators in the kidney and lung, whereas silibinin shows a time-dependent nephro- and pneumoprotective effect.

Silibinin-hydroxypropyl-β-cyclodextrin (SLB-HP-β-CD) complex prevents apoptosis in liver and kidney after hepatic ischemia-reperfusion injury

BACKGROUND

We investigated the protective effect of silibinin on rat liver and kidney after hepatic inschemia/reperfusion (I/R) injury.

METHODS AND MATERIALS

Sixty three male Wistar-type rats (median age 13 weeks; average weight 314 g) were subjected to I/R injury of the liver. They were randomly divided into three groups: Sham (n = 7), Control (C, n = 28) and Silibinin (Si, n = 28). The last group received intravenously silibinin. The C and Si groups were each subdivided in four subgroups according to euthanasia times (i.e., 60, 120, 180, 240 min). We assessed expression of caspase-3 and TUNEL assay, and biochemical and histological parameters.

RESULTS

At 240 min, expression of caspase-3 and TUNEL assay were statistically significantly lower in the Si compared to the C group for both liver and kidney. SGOT and SGPT were also statistically significantly lower in the Si than in the C group at all time points. Histological parameters of the liver were also improved in the Si group.

CONCLUSION

Silibinin was found to exhibit a protective effect on liver and kidney after hepatic I/R injury. The present results are encouraging for further studies and future clinical application.

Protective effects of levo-tetrahydropalmatine on hepatic ischemia/reperfusion injury are mediated by inhibition of the ERK/NF-κB pathway

BACKGROUND

Hepatic ischemia/reperfusion (IR) injury is a common medical phenomenon that occurs during a number of clinical conditions, such as liver transplantation, severe injuries, and shock. In our study, we determined the protective functions of levo-tetrahydropalmatine (L-THP) on hepatic IR injury in mice by inhibiting the ERK/NF-κB signaling pathway.

METHOD

BALB/c mice were randomly divided into six groups as follows: normal control (NC); sham; L-THP (40 mg/kg); IR; L-THP (20 mg/kg) + IR; and L-THP (40 mg/kg) + IR. Liver tissues and sera were collected at three time points after reperfusion (2, 8, and 24 h). The liver enzyme, inflammatory factor, and other protein levels in the serum and liver tissues were detected.

RESULTS

L-THP pretreatment alleviated hepatocyte injury caused by IR and reduced the production of proinflammatory cytokines, such as IL-6 and TNF-α. Furthermore, L-THP could inhibit the ERK/NF-κB signaling pathway to attenuate hepatocyte apoptosis and autophagy. And the protective effect of L-THP is positively correlated with its dose.

CONCLUSION

L-THP protects the liver from IR injury by inhibiting the release of inflammatory factors and alleviating liver cell apoptosis and autophagy. The protective functions of L-THP may be partly based on the downregulation of the ERK/NF-κB pathway.

Irisin alleviates liver ischemia-reperfusion injury by inhibiting excessive mitochondrial fission, promoting mitochondrial biogenesis and decreasing oxidative stress

Current management of liver ischemia-reperfusion (I/R) injury is mainly based on supportive care and no specific treatment is available. Irisin, a recently identified hormone, plays pivotal roles in energy expenditure and oxidative metabolism; however, it remains unknown whether irisin has any protective effects on hepatic I/R injury. In this study, we found that serum and liver irisin levels were markedly decreased at 24 h after hepatic I/R. Treatment with exogenous irisin improved liver function, reduced liver necrosis and cell apoptosis, and relieved inflammatory response after hepatic I/R. Meanwhile, exogenous irisin markedly inhibited mitochondrial fission related protein dynamin related protein 1 (drp-1) and fission 1 (Fis-1) expression in hepatic I/R. Additionally, treatment with exogenous irisin increased mitochondrial content and increased mitochondrial biogenesis related peroxisome proliferative activated receptor-γ (PPARγ) co-activator 1α (PGC-1α) and mitochondrial transcription factor (TFAM) expression. Furthermore, irisin decreased oxidative stress by upregulating uncoupling proteins (UCP) 2 expression in hepatic I/R. The results reveal that treatment with exogenous irisin alleviated hepatic I/R injury by restraining mitochondrial fission, promoting mitochondrial biogenesis and relieving oxidative stress. Irisin treatment appears to be a novel and promising therapeutic approach for hepatic I/R injury.

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Irisin protects hepatocytes against ischemia/reperfusion (I/R)-induced injury.

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Irisin inhibits excessive mitochondrial fission after hepatic I/R.

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Irisin promotes mitochondrial biogenesis after hepatic I/R.

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Irisin reduces oxidative stress after hepatic I/R.

Silibinin Improves TNF-α and M30 Expression and Histological Parameters in Rat Kidneys After Hepatic Ischemia/Reperfusion

BACKGROUND

Remote kidney damage is a sequel of hepatic ischemia-reperfusion (I/R) injury. Silibinin is the main ingredient of the milk thistle plant seed extract with known antioxidant and hepatoprotective activity. Our study investigates the nephroprotective potential of intravenously administered silibinin, as a lyophilized SLB-hydoxypropyl-beta-cyclodextrin product, in hepatic I/R injury.

MATERIAL AND METHODS

63 Wistar rats were divided into three groups: Sham (virtual intervention); Control (45 min ischemia and reperfusion); and Silibinin (200 μL intravenous silibinin administration after 45 min of ischemia). Kidney tissues were collected to determine TNF-α, M30 and histopathological changes at predetermined time intervals.

RESULTS

Comparing Sham vs. Control groups, proved that hepatic I/R injury increased renal TNF-α and M30 expression. Deterioration was observed in hyperemia/filtration of renal parenchyma and tubules, cortical filtration, tubular necrosis and edema (tissue swelling index). Intravenous silibinin administration and comparison of the Control vs. Silibinin groups showed a statistically significant decrease in TNF-α levels at 240 min following I/R (p < 0.0001), and in M30 at 180 min (p = 0.03) and 240 min (p < 0.0001). Renal parameters have significantly decreased in: hyperemia/filtration of renal parenchyma at 120 min (p = 0.003), 180 min (p = 0.0001) and 240 min (p = 0.0002); hyperemia/filtration of renal tubules at 120 min (p = 0.02), 180 min (p = 0.0001) and 240 min (p = 0.0005); cortical filtration (240 min - p = 0.005); tubular necrosis (240 min - p = 0.021); and edema (240 min - p = 0.001).

CONCLUSION

Our study confirms that hepatic I/R injury causes remote renal damage while the intravenous administration of silibinin leads to statistically significant nephroprotective action.

Effects of hepatic ischemia-reperfusion injury on the blood-brain barrier permeability to [14C] and [13C]sucrose

Hepatic encephalopathy that is associated with severe liver failure may compromise the blood-brain barrier (BBB) integrity. However, the effects of less severe liver diseases, in the absence of overt encephalopathy, on the BBB are not well understood. The goal of the current study was to investigate the effects of hepatic ischemia-reperfusion (IR) injury on the BBB tight junction permeability to small, hydrophilic molecules using the widely used [¹⁴C]sucrose and recently-proposed alternative [¹³C]sucrose as markers. Rats were subjected to 20 min of hepatic ischemia or sham surgery, followed by 8 h of reperfusion before administration of a single bolus dose of [¹⁴C] or [¹³C]sucrose and collection of serial (0-30 min) blood and plasma and terminal brain samples. The concentrations of [¹⁴C] and [¹³C]sucrose in the samples were determined by measurement of total radioactivity (nonspecific) and LC-MS/MS (specific), respectively. IR injury significantly increased the blood, plasma, and brain concentrations of both [¹⁴C] and [¹³C]sucrose. However, when the brain concentrations were corrected for their respective area under the blood concentration-time curve, only [¹⁴C]sucrose showed significantly higher (30%) BBB permeability values in the IR animals. Because [¹³C]sucrose is a more specific BBB permeability marker, these data indicate that our animal model of hepatic IR injury does not affect the BBB tight junction permeability to small, hydrophilic molecules. Methodological differences among studies of the effects of liver diseases on the BBB permeability may confound the conclusions of such studies.

Impact of graft preservation solutions for liver transplantation on early cytokine release and postoperative organ dysfunctions. A pilot study

INTRODUCTION

During liver transplantation, graft ischemia-reperfusion injury leads to a systemic inflammatory response producing postoperative organ dysfunctions. The aim of this observational and prospective study was to compare the impact of Solution de conservation des organes et tissus (SCOT) 15 and University of Wisconsin (UW) preservation solutions on early cytokine release, postreperfusion syndrome and postoperative organ dysfunctions.

METHODS

Thirty-seven liver transplantations were included: 21 in UW Group and 16 in SCOT 15 group. Five cytokines were measured in systemic blood after anesthetic induction, 30minutes after unclamping portal vein and on postoperative day 1.

RESULTS

Following unclamping portal vein, cytokines were released in systemic circulation. Systemic cytokine concentrations were higher in UW than in SCOT 15 group: Interleukin-10, Interleukine-6. In SCOT 15 group, significant reduction of postreperfusion syndrome incidence and acute kidney injury were observed. Alanine and aspartate aminotransferase peak concentrations were higher in SCOT 15 group than in UW group. However, from postoperative day 1 to day 10, aminotransferase returned to normal values and did not differ between groups.

CONCLUSIONS

Compared to UW, SCOT 15 decreases systemic cytokine release resulting from graft ischemia-reperfusion injury and reduces incidence of postreperfusion syndrome and postoperative renal failure.

Protective effects of ginsenoside Rg1 on intestinal ischemia/reperfusion injury-induced oxidative stress and apoptosis via activation of the Wnt/β-catenin pathway

Ginsenoside Rg1 (Rg1) is one of the major bioactive ingredients in Panax ginseng, and it attenuates inflammation and apoptosis. The aims of our study were to explore the potential of Rg1 for the treatment of intestinal I/R injury and to determine whether the protective effects of Rg1 were exerted through the Wnt/β-catenin signaling pathway. In this study, Rg1 treatment ameliorated inflammatory factors, ROS and apoptosis that were induced by intestinal I/R injury. Cell viability was increased and cell apoptosis was decreased with Rg1 pretreatment following hypoxia/reoxygenation (H/R) in the in vitro study. Rg1 activated the Wnt/β-catenin signaling pathway in both the in vivo and in vitro models, and in the in vitro study, the activation was blocked by DKK1. Our study provides evidence that pretreatment with Rg1 significantly reduces ROS and apoptosis induced by intestinal I/R injury via activation of the Wnt/β-catenin pathway. Taken together, our results suggest that Rg1 could exert its therapeutic effects on intestinal I/R injury through the Wnt/β-catenin signaling pathway and provide a novel treatment modality for intestinal I/R injury.

Effects of hydrogen sulfide on cognitive dysfunction and NR2B in rats

BACKGROUND

Hepatic ischemia/reperfusion (hepatic I/R) has been found to induce cognitive dysfunction. The NR2B subunit of N-methyl-D-aspartate (NMDA) receptors is a major factor in memory and learning processes, and hydrogen sulfide (H2S) may modulate this NMDA receptor. Therefore, in this study, sodium hydrosulfide (NaHS, a donor of H2S) was administered in an animal model of hepatic I/R to investigate the effects of H2S on cognitive impairment and expression of NR2B.

MATERIALS AND METHODS

NaHS (5 mg/kg) or normal saline was administered intraperitoneally once a day for 11 consecutive days, during which a rat model of 70% hepatic I/R was established on the fourth day. Cognitive function was evaluated using a Morris water maze, mRNA and protein levels of the NR2B subunit were detected in the hippocampus by RT-PCR and Western blotting. All these tests were performed on postoperative days 1, 3, 5, and 7.

RESULTS

Cognitive dysfunction was detected in the hepatic I/R group, and this dysfunction was associated with a decrease in the mRNA and protein levels of the NR2B subunit of the NMDA receptors in the hippocampus. In contrast, treatment with NaHS significantly ameliorated the impairment of cognitive function caused by hepatic I/R, and an increase in mRNA and protein levels of the NR2B subunit was detected in the corresponding hippocampus tissues.

CONCLUSIONS

The present data suggest that H2S exerts a protective effect on hepatic I/R-induced cognitive impairment, and this effect may be associated with the NR2B subunit of the NMDA receptors. H2S may represent a novel therapeutic agent for the treatment of postoperative cognitive dysfunction after liver surgery.

Antioxidant, Antiapoptotic and Inflammatory Effects of Interleukin-18 Binding Protein on Kidney Damage Induced by Hepatic Ischemia Reperfusion

OBJECTIVE

Acute kidney injury (AKI) is a serious condition that can be induced by liver transplantation, major hepatic resection or prolonged portal vein occlusion. The AKI can increase the frequency of postoperative complications. In the current study, we aimed to investigate whether interleukin-18 binding protein (IL-18BP) pretreatment has a protective effect against possible kidney injury-mediated liver ischemia-reperfusion (IR) achieved by Pringle maneuver in an experimental rat model.

MATERIALS AND METHODS

A total of 21 Wistar albino rats were included in this study. Animals were equally and randomly separated into 3 groups as follows: Sham (n = 7), IR group (n = 7) and IR + IL-18BP group (n = 7). Serum aspartate transaminase, alanine aminotransaminase and lactate dehydrogenase enzyme activities and serum urea and creatinine levels were determined. Tumor necrosis factor-α, IL-6, IL-1β, interferon gamma, total oxidant status, total antioxidant status and oxidative stress index were measured in kidney tissue homogenate samples. Histopathological examination and immunohistochemical Caspase-3 staining were applied to examine the general morphologic structure and apoptosis.

RESULTS

Renal total oxidant status; oxidative stress index; IL-18 levels; serum aspartate transaminase, alanine aminotransaminase and lactate dehydrogenase activities and creatinine levels were significantly lower in IR + IL-18BP group, when compared with the IR group. Beside this, total antioxidant status levels were remarkably higher in IR + IL-18BP group, when compared with the IR group. The caspase-3 expression degree in IR group was remarkably higher than other groups.

CONCLUSIONS

It has been demonstrated that IL-18BP pretreatment may have inflammatory, antioxidant and antiapoptotic effects against AKI induced by hepatic IR.

Nebivolol Ameliorates Hepatic Ischemia/Reperfusion Injury on Liver But Not on Distant Organs

INTRODUCTION

Hepatic ischemia/reperfusion injury may occur after large tumor resection and liver transplantation procedures. Nitric oxide was shown to have protective effects on ischemia/reperfusion injury. Nebivolol is a compound that has been reported to improve nitric oxide release. We evaluated the effects of nebivolol in a rat liver ischemia/reperfusion model.

METHODS

A total of 40 rats were randomly divided into four groups (n = 10 each). Group I underwent only laparotomy, Group II was administered nebivolol and then underwent laparotomy, Group III underwent laparotomy and hepatic ischemia/reperfusion, and Group IV was administered nebivolol and then underwent laparotomy and hepatic ischemia/reperfusion. Serum AST, ALT, urea, and creatinine levels, and TAS and TOS levels of liver, lung, and kidney tissues were determined. Histopathological determination was also performed.

RESULTS

Nebivolol significantly reduced liver function tests in group IV, but it did not improve renal functions. Oxidative stress and abnormal histopathological findings were found to be reduced in liver tissue in group IV. Although the oxidative stress was increased after hepatic ischemia/reperfusion, nebivolol could not reduce the oxidative stress in kidney tissue. There were no significant differences between group III and group IV in terms of the histopathological changes in kidney tissue. There were no significant differences in lung tissue between the groups.

CONCLUSIONS

The results of this study suggest that nebivolol has protective effects on liver but not on distant organs in a hepatic ischemia/reperfusion injury model. These experimental findings indicate that nebivolol may be useful in the treatment of hepatic ischemia/reperfusion injury.

Lung matrix metalloproteinase activation following partial hepatic ischemia/reperfusion injury in rats

Purpose. Warm hepatic ischemia-reperfusion (I/R) injury can lead to multiorgan dysfunction. The aim of the present study was to investigate whether acute liver I/R does affect the function and/or structure of remote organs such as lung, kidney, and heart via modulation of extracellular matrix remodelling. Methods. Male Sprague-Dawley rats were subjected to 30 min partial hepatic ischemia by clamping the hepatic artery and the portal vein. After a 60 min reperfusion, liver, lung, kidney, and heart biopsies and blood samples were collected. Serum hepatic enzymes, creatinine, urea, Troponin I and TNF-alpha, and tissue matrix metalloproteinases (MMP-2, MMP-9), myeloperoxidase (MPO), malondialdehyde (MDA), and morphology were monitored. Results. Serum levels of hepatic enzymes and TNF-alpha were concomitantly increased during hepatic I/R. An increase in hepatic MMP-2 and MMP-9 activities was substantiated by tissue morphology alterations. Notably, acute hepatic I/R affect the lung inasmuch as MMP-9 activity and MPO levels were increased. No difference in MMPs and MPO was observed in kidney and heart. Conclusions. Although the underlying mechanism needs further investigation, this is the first study in which the MMP activation in a distant organ is reported; this event is probably TNF-alpha-mediated and the lung appears as the first remote organ to be involved in hepatic I/R injury.

Alpha-tocopherol ameliorates oxidative renal insult associated with spinal cord reperfusion injury

Ischemic-reperfusion procedures targeting a specific organ often results in remote multiple organ injuries mediated possibly by heightened oxidative stress levels. As the kidney is one of the most vulnerable organs for ischemic oxidative stress, the aim of the present study was to confirm the occurrence of renal complication secondary to spinal cord ischemic-reperfusion injury (SC-IRI) induced by aortic clamping. The study also investigated the possible prophylactic effect of long-term administration of α-tocopherol (α-TOL) against high level of renal oxidative stress and inflammatory processes induced by SC-IRI. In this study, a total of 60 male Sprague-Dawley rats were randomly divided into five equal groups: C group underwent no surgery; CE group received α-TOL 600 mg/kg intramuscular twice weekly for 6 weeks; S group were subjected to laparotomy without clamping of the aorta; SE group were handled as S group and treated with α-TOL as group CE; SC-IRI group were subjected to laparotomy with clamping of the aorta just above the bifurcation of the aorta for 45 min, then the clamp was released for 48 h for reperfusion. SC-IRIE group was subjected to IRI as in group SC-IRI and was injected with α-TOL in the same dose and route as α-TOL-treated control group. SC-IRI resulted in increases in serum creatinine, blood urea nitrogen, plasma nitrite/nitrate level, serum tumor necrosis factor alpha, renal tissue homogenate level for malondialdehyde, superoxide dismutase and prostaglandin E2. Long-term prophylactic treatment with α-TOL resulted in amelioration of the renal functional disturbances and all measured parameters of oxidative stress and inflammation. Ischemic reperfusion injury of the spinal cord induced some remote renal functional disturbances although some of the observed changes may have resulted from decreased renal blood flow due to the hypotension induced during the procedure. Prophylactic long-term α-TOL administration guards against the renal function disturbances an effect that can be attributed, at least partially, to improvement of the renal pro-oxidant/antioxidant balance and inhibition of the inflammatory processes.

Ischemia/Reperfusion injury in liver surgery and transplantation: pathophysiology

Liver ischemia/reperfusion (IR) injury is caused by a heavily toothed network of interactions of cells of the immune system, cytokine production, and reduced microcirculatory blood flow in the liver. These complex networks are further elaborated by multiple intracellular pathways activated by cytokines, chemokines, and danger-associated molecular patterns. Furthermore, intracellular ionic disturbances and especially mitochondrial disorders play an important role leading to apoptosis and necrosis of hepatocytes in IR injury. Overall, enhanced production of reactive oxygen species, found very early in IR injury, plays an important role in liver tissue damage at several points within these complex networks. Many contributors to IR injury are only incompletely understood so far. This paper tempts to give an overview of the different mechanisms involved in the formation of IR injury. Only by further elucidation of these complex mechanisms IR injury can be understood and possible therapeutic strategies can be improved or be developed.

Pretreatment with pentoxifylline and N-acetylcysteine in liver ischemia reperfusion-induced renal injury

BACKGROUND AND AIMS

Acute hepatic injury causes systematic inflammatory responses which may finally lead to functional disturbances in remote organs. In this study, the effects of an inhibitor of inflammatory cytokines (pentoxifylline, PTX) and a well-known antioxidant, N-acetylcysteine (NAC), were evaluated on renal damage and oxidative stress following liver ischemia reperfusion (IR).

METHOD

Five groups of six male rats were used. Group 1 was sham operated. In group 2, 90 min liver partial ischemia was induced by a clamp around both hepatic artery and portal vein and then followed by 4 h of reperfusion. In groups 3 and 4, PTX or NAC was injected intraperitoneally before the ischemia, while in group 5 both drugs were co-administered. The levels of alanine amino-transferase (ALT), aspartate amino-transferase (AST), blood urea nitrogen (BUN), and creatinine in serum as well as malonyldialdehyde (MDA) and glutathione (GSH) levels and morphological changes in renal tissues were assessed.

RESULTS

Significant increase in the serum levels of ALT and AST in IR group is indicative of liver functional damages. Elevated BUN and renal tissue MDA, decreased GSH levels, and morphological damages in IR group demonstrate a significant kidney injury and oxidative stress comparing to sham group. Administration of PTX alone and PTX + NAC prevented the IR-induced increase in renal MDA levels. Administration of both drugs and their co-administration prevented the reduction in renal GSH levels and morphological changes.

CONCLUSION

Pretreatment with PTX and NAC before liver IR may be useful to ameliorate renal oxidative damage by preservation of cellular GSH concentration and a reduction in MDA levels.

Sphingosine-1-phosphate reduces hepatic ischaemia/reperfusion-induced acute kidney injury through attenuation of endothelial injury in mice

AIM

Hepatic ischaemia/reperfusion injury (IRI) frequently complicates acute kidney injury (AKI) during the perioperative period. This study was to determine whether hepatic IRI causes AKI and the effect of the sphingosine-1-phosphate (S1P) on AKI.

METHODS

S1P and vehicle were given to mice before ischaemia and mice were subjected to hepatic IRI. Plasma creatinine (PCr), alanine transaminase (ALT), urinary neutrophil gelatinase-associated lipocalin (NGAL) and renal histological changes were determined. As a marker of endothelial injury, vascular permeability was measured. The effect of VPC 23019, a S1P(1) receptor antagonist, was also assessed.

RESULTS

Hepatic IRI resulted in liver injury (increased ALT) and systemic inflammation. Kidneys showed elevated inflammatory cytokines, leucocyte infiltration, increased vascular permeability, tubular cell apoptosis and increased urinary NGAL, although PCr did not increase. Pretreatment with S1P resulted in an attenuation of systemic inflammation and kidney injury without any effect on plasma ALT or peripheral lymphocytes. The protective effect of S1P was partially reversed by VPC 23019, suggesting the important contribution of the S1P/S1P(1) pathway to protect against hepatic IRI-induced AKI.

CONCLUSION

The study data demonstrate the important contribution of systemic inflammation and endothelial injury to AKI following hepatic IRI. Modulation of the S1P/S1P(1) receptor pathway might have some therapeutic potential in hepatic IRI-induced kidney injury.

Effects of partial liver ischemia followed by global liver reperfusion on the remote tissue expression of nitric oxide synthase: lungs and kidneys

Hepatic ischemia followed by reperfusion (IR) results in mild to severe remote organ injury. Oxidative stress and nitric oxide (NO) seem to be involved in the IR injury. Our aim was to investigate the effects of liver I/R on hepatic function and lipid peroxidation, leukocyte infiltration and NO synthase (NOS) immunostaining in the lung and the kidney. We randomized 24 male Wistar rats into 3 groups: 1) control; 2) 60 minutes of partial (70%) liver I and 2 hours of global liver R; and 3) 60 minutes of partial (70%) liver I and 6 hours of global liver R. Groups 2 and 3 showed significant increases in plasma alanine and aspartate aminotransferase levels and in tissue malondialdehyde and myeloperoxidase contents. In the kidney, positive endothelial NOS (eNOS) staining was significantly decreased in group 3 compared with group 1. However, staining for inducible NOS (iNOS) and neuronal NOS (nNOS) did not differ among the groups. In the lung, the staining for eNOS and iNOS did not show significant differences among the groups; no positive nNOS staining was observed in any group. These results suggested that partial liver I followed by global liver R induced liver, kidney, and lung injuries characterized by neutrophil sequestration and increased oxidative stress. In addition, we supposed that the reduced NO formation via eNOS may be implicated in the moderate impairment of renal function, observed by others at 24 hours after liver I/R.

Hydrogen sulphide attenuates renal and cardiac injury after total hepatic ischemia and reperfusion

BACKGROUND

There are few studies that focus on the important organs injuries induced by total hepatic ischemia and reperfusion (THIR), which is a key to save the lives of hepatic surgery patients. We evaluated changes in the hydrogen sulphide production system and injuries to the heart and kidney. The aim of this study was to assess whether sodium hydrosulphide (NaHS) has protective effects against THIR injury.

MATERIALS AND METHODS

Under anaesthesia of the Wistar rats, the hepatic artery, the portal vein, and the inferior vena cava above and below the liver were clamped with nontraumatic arterial clamps. Hepatic reperfusion was achieved by removing the clamps.

RESULTS

Hydrogen sulphide production system was down-regulated after THIR, which caused severe damage to the heart and kidney, apart from the liver. In treated animals, CK-MB and LDH were lower by 26.9% and 14.2% (P < 0.05), respectively. The kidney showed similar change. Hematoxylin and eosin staining demonstrated fewer injuries in NaHS treated animals. The results indicated that the damage was abolished by exogenous NaHS.

CONCLUSIONS

The observed protection of exogenous NaHS is associated with reduced myocardial and renal inflammation and oxidative potential after THIR. The current results suggest that hydrogen sulphide is protective during the evolution of THIR and that either direct hydrogen sulphide administration or the modulation of endogenous production may be of clinical importance.

Liver ischemia/reperfusion injury: processes in inflammatory networks--a review

Liver ischemia/reperfusion (IR) injury is typified by an inflammatory response. Understanding the cellular and molecular events underpinning this inflammation is fundamental to developing therapeutic strategies. Great strides have been made in this respect recently. Liver IR involves a complex web of interactions between the various cellular and humoral contributors to the inflammatory response. Kupffer cells, CD4+ lymphocytes, neutrophils, and hepatocytes are central cellular players. Various cytokines, chemokines, and complement proteins form the communication system between the cellular components. The contribution of the danger-associated molecular patterns and pattern recognition receptors to the pathophysiology of liver IR injury are slowly being elucidated. Our knowledge on the role of mitochondria in generating reactive oxygen and nitrogen species, in contributing to ionic disturbances, and in initiating the mitochondrial permeability transition with subsequent cellular death in liver IR injury is continuously being expanded. Here, we discuss recent findings pertaining to the aforementioned factors of liver IR, and we highlight areas with gaps in our knowledge, necessitating further research.

The role of the polyol pathway in acute kidney injury caused by hindlimb ischaemia in mice

The polyol pathway, a collateral glycolytic process, previously considered to be active in high glucose milieu, has recently been proposed to play a crucial role in ischaemia/reperfusion tissue injury. In this study, we explored the role of the polyol pathway in acute kidney injury (AKI), a life-threatening condition, caused by hindlimb ischaemia, and determined if inhibition of the polyol pathway by aldose reductase (AR) inhibitor is beneficial for this serious disorder. Mice 8 weeks of age rendered hindlimb ischaemic for 3 h by the clipping of major supporting arteries revealed marked muscle necrosis with accumulation of sorbitol and fructose in ischaemic muscles. Serum concentrations of blood urea nitrogen (BUN), creatinine phosphokinase (CPK), creatinine, tumour necrosis factor (TNF)-alpha as well as interleukin (IL)-6 were all elevated in these mice. Treatment with AR inhibitor (ARI) effectively suppressed muscle necrosis and accompanying inflammatory reactions and prevented renal failure. Similar to ARI-treated mice, AR-deficient mice were protected from severe ischaemic limb injury and renal failure, showing only modest muscle necrosis and significant suppression of serum markers of renal failure and inflammation. Thus, these findings suggest that the polyol pathway is implicated in AKI caused by ischaemic limb injury and that AR may be a potential therapeutic target for this condition.

Selective intrarenal human A1 adenosine receptor overexpression reduces acute liver and kidney injury after hepatic ischemia reperfusion in mice

Acute kidney injury (AKI) is frequent after liver ischemia reperfusion (IR) can potentiate liver injury and is often complicated by subsequent multiorgan dysfunction syndrome. AKI because of liver IR is characterized by early renal endothelial cell apoptosis and impaired vascular integrity with subsequent neutrophil infiltration, proximal tubule necrosis/inflammation, and filamentous (F) actin disintegration. We tested whether selective renal overexpression of human A(1) adenosine receptors (huA(1)AR) protects against both liver and kidney injury sustained after liver IR. Mice were subjected to liver IR or to sham surgery 48 h after unilateral intrarenal injection of lentivirus encoding enhanced green fluorescent protein (EGFP) or EGFP-huA(1)AR. Intrarenal lentiviral gene delivery caused a robust transgene expression in the injected kidney without significant expression in the contralateral kidney or in the liver. Mice injected with EGFP-huA(1)AR lentivirus were protected against hepatic IR-induced liver and kidney injury with reduced necrosis, inflammation, and apoptosis, and better preserved F-actin and vascular permeability compared with mice injected with EGFP lentivirus. Importantly, we show that removing the EGFP-huA(1)AR lentivirus-injected kidney before hepatic ischemia abolished both renal and hepatic protection after liver IR showing that the overexpression of huA(1)AR in the injected kidney has a crucial role in protecting the kidney and liver after liver IR. Therefore, our findings show that protecting the kidney reduces liver IR injury and selective overexpression of cytoprotective A(1)ARs in the kidney leads to protection of both liver and kidney after hepatic IR.

Human activated protein C attenuates both hepatic and renal injury caused by hepatic ischemia and reperfusion injury in mice

Hepatic ischemia and reperfusion (IR) injury is a major clinical problem often leading to acute kidney injury characterized by early endothelial cell apoptosis, subsequent neutrophil infiltration, proximal tubule necrosis/inflammation, impaired vascular permeability, and disintegration of the proximal tubule filamentous actin cytoskeleton. Activated protein C is a major physiological anticoagulant with anti-inflammatory and anti-apoptotic activities in endothelial cells. Here we tested if activated protein C would attenuate hepatic and renal injury caused by hepatic ischemia and reperfusion. Both liver and kidney injury were significantly reduced when activated protein C was given immediately before and 2 h after liver reperfusion, in that there was reduced renal endothelial and hepatocyte apoptosis, as well as reduced hepatic and renal tubular necrosis. Further, the administration of activated protein C also reduced the expression of several pro-inflammatory genes, liver and kidney filamentous-actin degradation, and neutrophil infiltration, and resulted in better preservation of vascular permeability of both the liver and kidney than is normally seen after liver ischemia and reperfusion. These protective effects of activated protein C were due to protease-activated receptor-1 modulation since administration of a selective receptor antagonist dose-dependently inhibited its ameliorative effects in both organs after liver ischemia and reperfusion. Our results suggest the powerful multi-organ protective effects of activated protein C may improve outcome in those patients at significant risk of developing acute kidney injury following liver ischemia and reperfusion during transplantation.

Acute kidney injury after hepatic ischemia and reperfusion injury in mice

Hepatic ischemia reperfusion (IR) is the leading cause of acute liver failure (ALF) during the perioperative period and patients with ALF frequently develop acute kidney injury (AKI). There is no effective therapy for AKI associated with ALF because pathomechanisms are incompletely characterized, in part due to the lack of an animal model. In this study, we characterize a novel murine model of AKI following hepatic IR. Mice subjected to approximately 70% liver IR not only developed acute liver dysfunction, but also developed severe AKI 24 h after liver injury. Mice subjected to liver IR developed histological changes of acute tubular injury including focal proximal tubular cell necrosis involving the S3 segment, cortical tubular ectasia, focal tubular simplification and granular bile/heme cast formation. In addition, there was focal interstitial edema and hyperplasia of the juxtaglomerular apparatus. Inflammatory changes in the kidney after hepatic IR included neutrophil infiltration of the interstitium and upregulation of several proinflammatory mRNAs (tumor necrosis factor-alpha, keratinocyte-derived cytokine, monocyte chemotactic protein-1, macrophage inflammatory protein-2, intercellular adhesion molecule-1). In addition, marked renal endothelial cell apoptosis was detected involving peritubular interstitial capillaries, accompanied by increased renal vascular permeability. Finally, there was severe disruption of renal proximal tubule epithelial filamentous-actin. Our results show that AKI rapidly and reproducibly develops in mice after hepatic IR and is characterized by renal tubular necrosis, inflammatory changes and interstitial capillary endothelial apoptosis. Our murine model of AKI after liver injury closely mimics human AKI associated with ALF and may be useful in delineating the mechanisms and potential therapies for this common clinical condition.