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Thioesters of coenzyme A (CoA) carrying different acyl chains (acyl-CoAs) are central intermediates of many metabolic pathways and donor molecules for protein lysine acylation. Acyl-CoA species largely differ in terms of cellular concentrations and physico-chemical properties, rendering their analysis challenging. Here, we compare several approaches to quantify cellular acyl-CoA concentrations in normal and ischemic rat liver, using HPLC and LC-MS/MS for multi-acyl-CoA analysis, as well as NMR, fluorimetric and spectrophotometric techniques for the quantification of acetyl-CoAs. In particular, we describe a simple LC-MS/MS protocol that is suitable for the relative quantification of short and medium-chain acyl-CoA species. We show that ischemia induces specific changes in the short-chain acyl-CoA relative concentrations, while mild ischemia (1–2 min), although reducing succinyl-CoA, has little effects on acetyl-CoA, and even increases some acyl-CoA species upstream of the tricarboxylic acid cycle. In contrast, advanced ischemia (5–6 min) also reduces acetyl-CoA levels. Our approach provides the keys to accessing the acyl-CoA metabolome for a more in-depth analysis of metabolism, protein acylation and epigenetics. [ABSTRACT FROM AUTHOR]

Teaching Point: Synthetic cannabinoids are drugs whose use has increased significantly in recent years and whose toxicological effects cannot be ignored. Chronic inflammatory processes such as vasculitis that may be caused by these substances pose serious health problems at all ages.

Thioesters of coenzyme A (CoA) carrying different acyl chains (acyl-CoAs) are central intermediates of many metabolic pathways and donor molecules for protein lysine acylation. Acyl-CoA species largely differ in terms of cellular concentrations and physico-chemical properties, rendering their analysis challenging. Here, we compare several approaches to quantify cellular acyl-CoA concentrations in normal and ischemic rat liver, using HPLC and LC-MS/MS for multi-acyl-CoA analysis, as well as NMR, fluorimetric and spectrophotometric techniques for the quantification of acetyl-CoAs. In particular, we describe a simple LC-MS/MS protocol that is suitable for the relative quantification of short and medium-chain acyl-CoA species. We show that ischemia induces specific changes in the short-chain acyl-CoA relative concentrations, while mild ischemia (1–2 min), although reducing succinyl-CoA, has little effects on acetyl-CoA, and even increases some acyl-CoA species upstream of the tricarboxylic acid cycle. In contrast, advanced ischemia (5–6 min) also reduces acetyl-CoA levels. Our approach provides the keys to accessing the acyl-CoA metabolome for a more in-depth analysis of metabolism, protein acylation and epigenetics.

Aims: To discuss treatment strategies for non-traumatic, non-iatrogenic hepatic artery aneurysms (HAAs) in the presence of an arteriobiliary fistula, illustrated by a case and followed by a comprehensive review of the literature. Methods: Following the PRISMA guidelines, 24 eligible HAA cases presenting with haemobilia were identified. Characteristics of patients, aneurysms, treatment strategies and their outcomes were collected. Results: A 69 year old patient with no previous hepatobiliary intervention or trauma, presented with jaundice and haemobilia caused by a HAA. Initial treatment by endovascular stenting was chosen to prevent ischaemic liver complications. Unfortunately, this strategy failed because of stent migration due to ongoing infection leading to a type 1A endoleak. The patient had to be converted to open surgery with ligation of the HAA. The patient recovered uneventfully and no complications occurred during the following 12 months. Comprehensive literature review: Of the 24 cases, nine had a true HAA and 15 were pseudo/mycotic aneurysms, mainly caused by endocarditis or cholecystitis. The majority were located in the right hepatic artery. In 20 cases, an endovascular first approach was chosen with embolisation, none with covered stents. Three of these cases had to be converted to open surgery because of rebleeding. In all open (primary or secondary) cases, ligation of the HAA was performed. One patient in these series died. No liver ischaemia or abscesses were reported, although one patient developed an ischaemic gallbladder. Conclusions: Patients who present with a HAA and haemobilia may be treated safely by embolisation or open ligation. Using a covered stent graft in these patients can cause problems due to ongoing infection and should be monitored closely by imaging. Publication bias and lack of long term follow up imply cautious interpretation of these findings.

Global organ shortage has led to the acceptance of steatotic livers for transplantation, taking the risk of graft dysfunction associated with the higher sensitivity of steatotic livers to ischemia and reperfusion injury (IRI). Data about circular RNAs (circRNAs) in steatotic livers following IRI are practically nonexistent. In our study, a high‐fat diet‐fed mouse model of hepatic steatosis was generated, and RNA sequencing was performed both on IRI and on sham liver tissues of these mice to screen for circRNAs with significant differential expression. To further validate our bioinformatics data, one upregulated circRNA and four downregulated circRNAs were examined. The circularity of these circRNAs was demonstrated using RNaseR digestion and Sanger sequencing. The expression of four stable circRNAs undigested by RNaseR was further validated by quantitative PCR. In summary, this study unearths several circRNAs as novel and potentially effective targets involved in the more severe damage of steatotic livers following IRI. [ABSTRACT FROM AUTHOR]

Teaching Point : Synthetic cannabinoids are drugs whose use has increased significantly in recent years and whose toxicological effects cannot be ignored. Chronic inflammatory processes such as vasculitis that may be caused by these substances pose serious health problems at all ages., Competing Interests: The authors have no competing interests to declare., (Copyright: © 2024 The Author(s).)

Although aggravated liver injury has been reported in aged livers post‐ischemia and reperfusion (IR), the underlying mechanism of innate immune activation of aged macrophages is not well understood. Here, we investigated whether and how Stimulator of interferon genes (STING) signaling regulated macrophage proinflammatory activation and liver IR injury. Mice were subjected to hepatic IR in vivo. Macrophages isolated from IR‐stressed livers and bone marrow‐derived macrophages (BMDMs) from young and aged mice were used for in vitro studies. Enhanced nucleotide‐binding domain and leucine‐rich repeat containing protein 3 (NLRP3) activation was found in both livers and macrophages of aged mice post‐IR. NLRP3 knockdown in macrophages inhibited intrahepatic inflammation and liver injury in both young and aged mice. Interestingly, enhanced activation of the STING/ TANK‐binding kinase 1 (TBK1) signaling pathway was observed in aged macrophages post‐IR and mitochondria DNA (mtDNA) stimulation. STING suppression blocked over‐activation of NLRP3 signaling and excessive secretion of proinflammatory cytokines/chemokines in the mtDNA‐stimulated BMDMs from aged mice. More importantly, STING knockdown in macrophages abrogated the detrimental role of aging in aggravating liver IR injury and intrahepatic inflammation. Finally, peripheral blood from the recipients undergoing liver transplantation was collected and analyzed. The results showed that the elderly recipients had much higher levels of TNF‐α, IL‐6, IL‐1β, and IL‐18 post‐transplantation, indicating increased NLRP3 activation in lR‐stressed livers of elderly recipients. In summary, our study demonstrated that the STING‐NLRP3 axis was critical for the proinflammatory response of aged macrophages and would be a novel therapeutic target to reduce IR injury in elderly patients. [ABSTRACT FROM AUTHOR]

Aim: Platelet count seems to assess liver function and predict liver regeneration, but factors associated with liver regeneration remain unclear. This study analyzed the relationship between platelet recovery and postresection liver regeneration. Methods: Data from 343 candidates from 1245 consecutive patients with liver resection of more than Couinaud's segments were analyzed. Patients were divided into a low‐platelet‐recovery rate (LPRR) group (lowest 25%) or a control group on the basis of the platelet recovery rate on postoperative day (POD)7. Data were matched before analysis to adjust for operation scale. Trends in liver functional recovery were assessed, and liver volume recovery and remnant ischemic area was calculated using computed tomography volumetry. Factors predicting liver regeneration were analyzed. Results: In 78 matched‐pair patients, the all‐complications rate (42.3% vs. 26.9%, P = 0.002) and infectious complications rate (21.8% vs. 9.0%, P = 0.027) were significantly higher in the LPRR group than in controls. Trends in liver functional recovery did not differ significantly, whereas significant differences remained for platelet recovery. Parenchyma volume recovery was delayed in the LPRR group from POD7 (84.5% vs. 78.1, P < 0.01) to POD30 (92.5% vs. 85.6, P < 0.01). Platelet recovery rate on POD7 correlated negatively with ischemic liver volume as evaluated on POD2 by computed tomography (r = 0.691). Postoperative ischemic volume on POD2 (5.41 [1.98–11.21], P < 0.001), infectious complications (3.48 [1.44–7.37], P < 0.001), and multiple resection (1.67 [1.10–4.11], P = 0.011) predicted delayed platelet recovery rate on multivariate analysis. Conclusion: Platelet recovery correlated with liver volume recovery and occurrence of complications. Large ischemic area might negatively impact regeneration after liver resection. [ABSTRACT FROM AUTHOR]

Introduction: We glad to introduce several variants of pharmacological correction of ischemic hepatic injury by imidazoline I2 receptor agonistС7070. Materials and methods: The experiment was carried out on 70 rats of both sexes, divided into 7 groups (n = 10): an intact group; Pseudo-operated animals (autopsy of the abdominal wall without ligation of the liver vessels); Ischemia / reperfusion group without drug correction; Animals undergoing ischemia / liver reperfusion + Metformin (50 mg / kg); Animals undergoing ischemia / liver reperfusion + Moxonidine (1 μg / kg); Animals undergoing ischemia / liver reperfusion + C7070 (1 mg / kg). For the evaluation, the coefficients calculated from the level of hepatic transaminases (ALT, AST), as well as morphometric ratios of the area of necrosis and deep ischemia of the liver, were used for the evaluation according to the histological examination. Results and discussion: The indicated agonists of peripheral imidazoline I2receptors (C7070) significantly reducesischemically-reperfusion injury of the liver, in comparison with the preparations of moxonidine and metformine. Indirect sign of imidazoline activating mechanism of C7070 is decreasing of the hepatoprotective effect of C7070 by the preliminary administration of imidazoline receptor blocker BU-224. The coefficients for ALT / AST for C7070, moxonidine and metformin were 72.8 / 62.13, respectively; 44.99 / 34.20 and 36.88 / 21.02. The coefficients of the morphological hepatoprotective activity of the preparations were: С7070 – 82.61, moxonidine – 72.33, metformin – 38.96. Conclusions: The imidazoline receptor agonists significantly and significantly reduce the functional and morphological manifestations of liver ischemia / reperfusion.

Background: Liver ischemia and reperfusion injury (IRI) is a major problem associated with liver surgery. This study is aimed to compare the preventive effect of an antioxidative nutrient-rich enteral diet (Ao diet) with an ordinal enteral diet (control diet) against liver IRI.Methods: The Ao diet was an ordinary diet comprising polyphenols (catechin and proanthocyanidin) and enhanced levels of vitamins C and E. Male C57BL/6 mice were fed the Ao or control diet for 7 days before ischemic insult for 60 minutes, followed by reperfusion for 6 hours. The levels of inflammatory cytokines, chemokines, and antioxidant enzymes and oxidative stress were evaluated.Results: After 7 days of pretreatment with the Ao diet, the serum levels of vitamins C and E in mice were markedly elevated. The levels of serum aspartate aminotransferase and alanine aminotransferase, as well as the scores of liver necrosis caused by ischemia and reperfusion, were significantly lower in the Ao diet group than in the control diet group. The gene expression levels of inflammatory cytokines and chemokines, such as interleukin-6 and CXCL1, were significantly lower in the Ao diet group. In the liver, the levels of antioxidant enzymes superoxide dismutase 1 (SOD1) and SOD2 were significantly higher and the malondialdehyde levels were significantly lower in the Ao diet group. Cell adhesion molecule expression was significantly lower, and neutrophil and macrophage infiltration was less in the Ao diet group.Conclusions: Antioxidative nutrient supplementation to an ordinary enteral diet may mitigate liver IRI by causing an antioxidant effect and suppressing inflammation. [ABSTRACT FROM AUTHOR]

Background/Objectives Celiac axis stenosis (CAS) represents an uncommon and typically innocuous condition. However, when a pancreatic resection is required, a high risk for upper abdominal organs ischemia is observed. In presence of collaterals, such a risk is minimized if their preservation is realized. The aim of the present study is to systematically review the literature with the intent to address the routine management of collateral arteries in the case of CAS patients requiring pancreatoduodenectomy. Methods A systematic search was done in accordance with the PRISMA guidelines, using “celiac axis stenosis” AND “pancreatoduodenectomy” as MeSH terms. Seventy-four articles were initially screened: eventually, 30 articles were identified (n = 87). Results The main cause of CAS was median arcuate ligament (MAL) (n = 31; 35.6%), followed by atherosclerosis (n = 20; 23.0%). CAS was occasionally discovered during the Whipple procedure in 15 (17.2%) cases. Typically, MAL was divided during surgery (n = 24/31; 77.4%). In the great majority of cases (n = 83; 95.4%), vascular abnormalities involved the pancreatoduodenal arteries (i.e., dilatation, arcade, channels, aneurysms). Collateral arteries were typically preserved, being divided or reconstructed in only 14 (16.1%) cases, respectively. Severe ischemic complications were reported in six (6.9%) patients, 20.0% of whom were reported in patients with preoperatively unknown CAS (p-value 0.06). Conclusions A correct pre-operative evaluation of anatomical conditions as well as a correct surgical planning represent the paramount targets in CAS patients with arterial collaterals. Vascular flow must be always safeguarded preserving/reconstructing the collaterals or resolving the CAS, with the final intent to avoid dreadful intra- and post-operative complications. [ABSTRACT FROM AUTHOR]

Purpose: Although nitric oxide (NO) is considered one of the initial signals that promote postsurgery liver regeneration, NO’s exact role in the liver regeneration mechanism is still not clear. Therefore, developing a practical gas sensor and testing it in a clinical setting through basic research will lay the groundwork for advanced clinical research on the action mechanism of NO. Methods: A thin nano wire NO sensor was made by wrapping a pair of parlyene-coated gold wires around a needle. The NO blood concentration determined by measuring the potential difference across the oscilloscope using electrical conductivity. In order to measure changes in NO level before and after the surgery, the NO sensor was inserted in the hepatic portal vein and a 75 percent partial hepatectomy was performed. The NO blood concentration was measured regularly with both the NO kit and the sensor. Results: One significant challenge was separation of the wire upon insertion into the hepatic portal vein. Despite separation, the constant measurements of the wire-type sensor were similar to those measured by the NO measurement kit. Conclusion: The development of a needle-type sensor allowed for easier insertion. In the future, using difference in electric potential, as used in the NO sensor, may be a more effective method of measuring blood ion concentration.

Summary Background Operative injury to the hepatic artery is a serious complication of pancreaticoduodenectomy and guidelines to manage this complication are lacking. Methods A systematic search performed in PubMed database identified eleven studies overall including 20 patients having sustained injury to the hepatic artery during pancreaticoduodenectomy ( n = 18) or total pancreatectomy ( n = 2). One further unpublished personal observation following pancreaticoduodenectomy was also included. Results Sixteen of 21 patients (76%) experienced serious complications including liver necrosis/abscess ( n = 14), acute liver failure ( n = 3), and biliary anastomotic dehiscence ( n = 6). Eleven patients (52%) were reoperated and 5 patients died (24%). Arterial injury was recognized and repaired immediately in five patients, four recovering uneventfully and one dying from acute liver failure (20%). In contrast delayed or conservative treatment in 16 patients was associated with serious early morbidity in 15 patients (94%), leading to death in 4 patients and late biliary complications in four others. Conclusions Accidental interruption of arterial flow to the liver during pancreaticoduodenectomy often results in serious short and long-term consequences. Immediate restoration of arterial flow is indicated whenever technically feasible and may prevent early life-threatening complications as well as late biliary stenosis. [ABSTRACT FROM AUTHOR]

Acute kidney injury (AKI) is a major complication of hepatic surgeries. The primary cilium protrudes to the lumen of kidney tubules and plays an important role in renal functions. Disruption of primary cilia homeostasis is highly associated with human diseases including AKI. Here, we investigated whether transient hepatic ischemia induces length change and deciliation of kidney primary cilia, and if so, whether reactive oxygen species (ROS)/oxidative stress regulates those. HIR induced damages to the liver and kidney with increases in ROS/oxidative stress. HIR shortened the cilia of kidney epithelial cells and caused them to shed into the urine. This shortening and shedding of cilia was prevented by Mn(III) tetrakis(1-methyl-4-pyridyl) porphyrin (MnTMPyP, an antioxidant). The urine of patient undergone liver resection contained ciliary proteins. These findings indicate that HIR induces shortening and deciliation of kidney primary cilia into the urine via ROS/oxidative stress, suggesting that primary cilia is associated with HIR-induced AKI and that the presence of ciliary proteins in the urine could be a potential indication of kidney injury. [ABSTRACT FROM AUTHOR]

Introduction: We glad to introduce several variants of pharmacological correction of ischemic hepatic injury by imidazoline I2 receptor agonist C7070. Materials and methods: The experiment was carried out on 70 rats of both sexes, divided into 7 groups (n = 10): an intact group; Pseudo-operated animals (autopsy of the abdominal wall without ligation of the liver vessels); Ischemia/reperfusion group without drug correction; Animals undergoing ischemia/liver reperfusion + Metformin (50 mg/kg); Animals undergoing ischemia/liver reperfusion + Moxonidine (1 μg/kg); Animals undergoing ischemia/liver reperfusion + C7070 (1 mg/kg). For the evaluation, the coefficients calculated from the level of hepatic transaminases (ALT, AST), as well as morphometric ratios of the area of necrosis and deep ischemia of the liver, were used for the evaluation according to the histological examination. Results and discussion: The indicated agonists of peripheral imidazoline I2receptors (C7070) significantly reduces is chemically-reperfusion injury of the liver, in comparison with the preparations of moxonidine and metformine. Indirect sign of imidazoline activating mechanism of C7070 is decreasing of the hepatoprotective effect of C7070 by the preliminary administration of imidazoline receptor blocker BU-224. The coefficients for ALT/AST for C7070, moxonidine and metformin were 72.8/62.13, respectively; 44.99/34.20 and 36.88/21.02. The coefficients of the morphological hepatoprotective activity of the preparations were: C7070 -- 82.61, moxonidine -- 72.33, metformin -- 38.96. Conclusions: The imidazoline receptor agonists significantly and significantly reduce the functional and morphological manifestations of liver ischemia/reperfusion. [ABSTRACT FROM AUTHOR]

PURPOSE: To analyze the effects of hyperbaric oxygen therapy on liver function in rats previously subjected to ischemia and reperfusion. METHODS: A randomly distribution of 23 Wistar rats was conducted into three groups: SHAM, animals subjected to surgical stress without restricting blood flow by clamping the hepatic pedicle, IR, rats underwent hepatic vascular occlusion intermittently for two complete cycles of 15 minutes of ischemia followed by 5 min of reperfusion, IR / HBO, rats underwent hepatic pedicle clamping and thereafter exposed to hyperbaric oxygen pressure of 2 absolute atmospheres for 60 minutes. We evaluated liver function through mitochondrial function, determined by the stages 3 and 4 of respiration, respiratory control ratio (RCR) and mitochondrial permeability transition (Swelling). Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were also quantified . We analyzed the results using the Mann-Whitney test and were considered significant all results with p OBJETIVO: Analisar os efeitos da oxigenoterapia hiperbárica sobre a função hepática de ratos previamente submetidos à isquemia e reperfusão. MÉTODOS: Realizou-se a distribuição aleatória de 23 ratos Wistar em três grupos: SHAM, animais submetidos ao estresse cirúrgico sem restrição de fluxo sanguíneo por clampeamento do pedículo hepático; IR ratos submetidos a oclusão vascular hepática de maneira intermitente em dois ciclos completos de 15 minutos de isquemia, seguidos por 5 min de reperfusão; IR/HBO, ratos submetidos ao clampeamento do pedículo hepático e ,ulteriormente , expostos a oxigenoterapia hiperbárica a pressão de 2 atmosferas absolutas durante 60 minutos. Avaliou-se a função hepática através da função mitocondrial, determinada pelos estados 3 e 4 da respiração mitocondrial, razão de controle respiratório(RCR) e transição de permeabilidade mitocondrial (Swelling) .Quantificou-se também alanina aminotransferase e aspartato aminotransferase séricas. Analisou-se os resultados pelo teste de Mann-Whitney e foram considerados significativos os valores de p < 0,05. RESULTADOS:Houve diferença significativa nos valores do estado 3 no grupo SHAM vs IR; estado 4 nos grupos SHAM vs IR, SHAM vsIR/HBO; Razão de Controle Respiratório(RCR) no grupo IR vs IR/HBO; alanina aminotransferase nos grupos SHAM vs IR, SHAM vs IR/HBO, IR vs IR/HBO; aspartato aminotransferase nos grupos SHAM vs IR , SHAM vs IR/HBO. CONCLUSÃO: A análise dos parâmetros mitocondriais como um todo permitiu concluir que a oxigenoterapia hiperbárica atuou como agente protetor da função mitocondrial, minimizando os efeitos deletérios da lesão de isquemia e reperfusão do parênquima hepático.

Purpose/Aim:Hepatic ischemia/reperfusion (I/R) describes the paradox of additional tissue injury caused by reperfusion. The aim of this survey was to investigate the mRNA expression of genes exerting their inflammatory and regenerative reaction in a porcine model of I/R and extended hepatectomy. Material and methods:Twelve pigs were used, weighing 30–35 kg in average, which were allocated in two groups: the I/R group with eight pigs and the sham-operated (control) one with four pigs. The I/R group underwent portacaval anastomosis and Pringle maneuver followed by extended hepatectomy. The hepatoduodenal ligament was occluded for 150 min and the liver remnant was reperfused for 24 hours. Blood samples were steadily received throughout the surgical procedure, where hepatic biopsies were taken for pathological evaluation. Animals were sacrificed in 24 hours after the onset of reperfusion. Results:Between the two groups, statistically significant differences were noticed in serum values of AST, ALT, ALP, and total bilirubin in the early and late phase of reperfusion. The mRNA expression of iNOS, IL-1b, and TGF-a did not increase significantly in the I/R group. Conversely, the mRNA modification of IL-6, STAT-3, and E-selectin demonstrated significantly increased expression in I/R animals. Conclusions:In the present survey, a new I/R swine model was proposed and specific parameters were analyzed, revealing differences between the study groups. [ABSTRACT FROM PUBLISHER]

Background: Hepatic perfusion failure represents an important risk factor for severe complications and death after pancreatic resections. Arterial reconstruction could be required during pancreatic surgery because of tumor infiltration, benign strictures, or as a consequence of accidental arterial injury during dissection. All these situations can be faced with a certain frequency in high-volume pancreatic centers, where surgeons must be aware of the different alternatives to deal with these intricate scenarios. Purpose: We herein describe the preoperative surgical planning as well as different surgical strategies for the restoration of arterial perfusion of the liver in pancreatic resections. Conclusion: A thorough preoperative evaluation is essential for planning pancreatic surgery and preparing the surgeon and patient for potentially high complex procedures. The various therapeutic alternatives presented in this technical report might represent a good solution for selected patients with no other potentially curative option than surgery. [ABSTRACT FROM AUTHOR]

PURPOSE: Hepatic ischemia and reperfusion can cause several problems in hepatic surgery. The aim of this study was to determine pyruvate kinase activation and lipid peroxidation after hepatic ischemia. METHODS: Twenty-four Wistar rats were submitted to 90 minutes of selective liver ischemia and 15 minutes of reperfusion. Twelve animals were submitted to selective liver ischemia and reperfusion (Group A) and the other 12 were submitted to sham operation (Group B). After 15 minutes of reperfusion, the following parameters were measured: mean arterial pressure (MAP), alanine aminotransferase (ALT), glycemia (GLY), hepatic glycogen (GH), pyruvate kinase (PK) activation, hepatic glutathione (GSH) and malondialdehyde (MDA). Analysis of the results were made by the Student t-test and has been considered significant difference for pOBJETIVO: A isquemia e reperfusão hepática podem causar graves repercussões hepatocelulares em cirurgias hepáticas. O objetivo deste estudo foi determinar o comportamento da piruvato EM PORTUGUÊS quinase e a lipoperoxidação após isquemia hepática. MÉTODOS: Foram utilizados vinte e quatro ratos Wistar machos divididos em dois grupos. Doze animais foram submetidos a 90 minutos de isquemia hepática seletiva e reperfusão hepática de por 15 minutos (pressão arterial média (PAM), alanina aminotransferase (ALT), glicemia (GLI), gicogênio hepático (GH), ativação da piruvato quinase (PQ), glutationa hepática (GSH) e malondialdeído (MDA). Os resultados foram analisados utilizando o teste t de Student sendo as diferenças consideradas significativas para p

Background & Aims Fasting and calorie restriction are associated with a prolonged life span and an increased resistance to stress. The protective effects of fasting have been exploited for the mitigation of ischemic organ injury, yet the underlying mechanisms remain incompletely understood. Here, we investigated whether fasting protects liver against ischemia reperfusion (IR) through energy-preserving or anti-inflammatory mechanisms. Methods Fasted C57BL6 mice were subjected to partial hepatic IR. Injury was assessed by liver enzymes and histology. Raw264-7 macrophage-like cells were investigated in vitro. Sirt1 and HMGB1 were inhibited using Ex527 and neutralizing antibodies, respectively. Results Fasting for one, but not two or three days, protected from hepatic IR injury. None of the investigated energy parameters correlated with the protective effects. Instead, inflammatory responses were dampened in one-day-fasted mice and in starved macrophages. Fasting alone led to a reduction in circulating HMGB1 associated with cytoplasmic HMGB1 translocation, aggregate formation, and autophagy. Inhibition of autophagy re-elevated circulating HMGB1 and abolished protection in fasted mice, as did supplementation with HMGB1. In vitro, Sirt1 inhibition prevented HMGB1 translocation, leading to elevated HMGB1 in the supernatant. In vivo, Sirt1 inhibition abrogated the fasting-induced protection, but had no effect in the presence of neutralizing HMGB1 antibody. Conclusions Fasting for one day protects from hepatic IR injury via Sirt1-dependent downregulation of circulating HMGB1. The reduction in serum HMGB1 appears to be mediated by its engagement in the autophagic response. These findings integrate Sirt1, HMGB1, and autophagy into a common framework that underlies the anti-inflammatory properties of short-term fasting. [ABSTRACT FROM AUTHOR]

Pentoxifylline is a methylxanthine compound which was first filed in 1973 and registered in 1974 in the United States by Sanofi-Aventis Deustchland Gmbh for the treatment of intermittent claudication for chronic occlusive arterial disease. This methylxanthine was later discovered to be a phosphodiesterase inhibitor. Furthermore, its hemorheological properties and its function as an inhibitor of inflammatory cytokines, like TNF-α, allowed researchers to study its effects in organ ischemia and reperfusion and transplantation. Although this drug has demonstrated beneficial effects, the mechanisms by which Pentoxifylline exerts a protective effect are not fully understood. This paper focuses on reviewing the literature to define the effect of Pentoxifylline when used in liver ischemia and reperfusion injury. Our research shows different animal models in which Pentoxifylline has been used as well as different doses and time of administration, as the ideal dose and timing have not yet been ascertained in liver ischemia and reperfusion. In conclusion, Pentoxifylline has shown positive effects in liver ischemia and reperfusion injury, and the main mechanism seems to be associated with the inhibition of TNF-α. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: A number of hepatic ischemia/hypoxia–reperfusion models have been described. This study characterised the functional and structural changes induced by the most commonly used in vivo and in situ models for hypoxia/ischemia-reperfusion in the rat liver. Methods: A range of no-flow, slow-flow and lobar ischemia and reperfusion models were established in the rat liver. Changes following reperfusion were monitored using physiological, biochemical, histological and pharmacological assessments, including bile production, oxygen consumption, lignocaine extraction, enzyme release, and disposition of exogenous markers. Results: Short periods of hepatic ischemia/hypoxia–reperfusion led to minimal changes in liver function whereas long periods of ischemia–reperfusion led to substantial liver injury. The most severe injury was found with the slow flow, reflow model. The formation of cell vacuoles, blebs and focal hepatitis were the most important liver morphological changes observed as a consequence of ischemia/hypoxia. The major liver histological findings after reperfusion were dispersed apoptosis and local necrosis. Hepatic ischemia/hypoxia–reperfusion was also associated with significant changes in the hepatic extracellular and intracellular spaces. Discussion: The morphology and function of the liver associated with a range of hepatic ischemia/hypoxia–reperfusion models varies with the duration of the insult and between models. The choice of model is therefore an important consideration in seeking to resolve any particular hypothesis associated with hepatic ischemia/hypoxia–reperfusion. [Copyright &y& Elsevier]

Background: Ischemic preconditioning (IPC) of the liver decreases liver injury secondary to ischemia and reperfusion. An attractive alternative to IPC is remote ischemic preconditioning (R-IPC), but these two methods have not previously been compared. Material and Methods: Eighty-seven rats were randomized into four groups: sham operated (n = 15), 1 h segmental ischemia (IRI, n = 24), preceeded by IPC (n = 24), or R-IPC (n = 24) (to the left hindleg). IPC and R-IPC were performed with 10 min ischemia and 10 min of reperfusion. Analyses of liver microdialysate (MD), serum transaminase levels, and liver histology were made. Results: Rats treated with IPC and R-IPC had significantly lower AST, 71.5 (19.6) IU/L respective 96.6 (12.4) at 4 h reperfusion than those subjected to IRI alone, 155 (20.9), P = 0.0004 and P = 0.04 respectively. IPC also had lower ALT levels, 41.6 (11.3) IU/L than had IRI 107.4 (15.5), P = 0.003. The MD glycerol was significantly higher during ischemia in the R-IPC [759 (84) μM] and the IRI [732 (67)] groups than in the IPC 514 (70) group, P = 0.022 and P = 0.046 respectively. The MD glucose after ischemia was lower in the IPC group 7.1 (1.2) than in the IRI group 12.7 (1.6), P = 0.005. Preconditioning to the liver caused an direct increase in lactate, glucose and glycerol in the ischemic segment compared with the control segment an effect not seen in the R-IPC and IRI groups. Conclusions: IPC affects glucose metabolism in the rat liver, observed with MD. IPC reduces liver cell injury during ischemic and reperfusion in rats. R-IPC performed over the same length of time as IPC does not have the same effect as the latter on ALT levels and MD glycerol; this may suggest that R-IPC does not offer the same protection as IPC in this setting of rat liver IRI. [Copyright &y& Elsevier]

Introduction: Allopurinol was first introduced, in 1963, as a xanthine oxidase inhibitor when it was investigated for concomitant use with cancer chemotherapy drugs. Today it is used in gout and hyperuricemia. Due to its additive benefit in preventing oxidative damage, attention has shifted towards the use of allopurinol in organ ischemia and reperfusion. Current status: Currently, the mechanism by which allopurinol exerts a protective benefit in ischemia reperfusion related events is not fully understood. There are various theories: it may act by inhibiting the irreversible breakdown of purine substrates, and/or by inhibiting the formation of reactive oxygen species, and/or by protecting against damage to the mitochondrial membrane. Aim: This work focuses on liver ischemia and reperfusion injury in an effort to better understand the mechanisms associated with allopurinol and with this pathological entity. Review of literature: The current research, mainly in animal models, points to allopurinol having a protective benefit, particularly if used pre-ischemically in liver ischemia reperfusion injury. Furthermore, after reviewing allopurinol dosing and administration, it was found that 50 mg/kg is statistically the most effective dose in attenuating liver ischemia reperfusion injury. Owing to the limited number of samples, the time of administration did not show statistical difference, but allopurinol was often beneficial when given around 1 h before ischemia. Conclusion: In conclusion, allopurinol, through its known xanthine oxidase inhibitory effect, as only one of the potential mechanisms, has demonstrated its potential application in protecting the liver during ischemia and reperfusion. [ABSTRACT FROM AUTHOR]

Hepatic artery and portal vein thrombosis are devastating complications of partial liver transplantation. Early detection of inflow complications is important, as re-reconstruction can salvage the graft. Near-infrared spectroscopy or laser Doppler flowmetry can be used to detect tissue oxygenation or microcirculation on the liver surface. The aim of this study was to examine which of these two methods better detects changes in hepatic inflow. Sangen-strain pigs (n = 5) were used. The tips of the near-infrared spectroscopy and laser Doppler flowmetry probes were placed separately on the surface of the right liver. Inflow to the liver was controlled during the following seven conditions: control (not clamped), half- and totally clamped portal vein, half- and totally clamped hepatic artery, and half- and totally clamped portal vein and artery. Tissue blood flow was calculated using laser Doppler flowmetry. Oxyhemoglobin, deoxyhemoglobin, and the tissue oxygenation index were measured and calculated using a near-infrared spectroscopy system. The tissue blood flow and oxygenation index could not be used to differentiate between the half-clamped portal vein, half-clamped hepatic artery, and totally clamped portal vein conditions. The oxyhemoglobin minus deoxyhemoglobin value was significantly decreased after half or total clamping of the portal vein or hepatic artery (p < .001 for each condition). The findings of the present study indicate that near-infrared spectroscopy was more sensitive than Doppler flowmetry for detecting changes in hepatic tissue inflow from the liver surface. [ABSTRACT FROM AUTHOR]

Abstract: Ischemia and reperfusion (I/R)-induced liver injury occurs in several pathophysiological disorders including hemorrhagic shock and burn as well as resectional and transplantation surgery. One of the earliest events associated with reperfusion of ischemic liver is endothelial dysfunction characterized by the decreased production of endothelial cell-derived nitric oxide (NO). This rapid post-ischemic decrease in NO bioavailability appears to be due to decreased synthesis of NO, enhanced inactivation of NO by the overproduction of superoxide or both. This review presents the most current evidence supporting the concept that decreased bioavailability of NO concomitant with enhanced production of reactive oxygen species initiates hepatocellular injury and that endogenous NO or exogenous NO produced from nitrite play important roles in limiting post-ischemic tissue injury. [Copyright &y& Elsevier]

Background: The aim of this study was to provide an improved outline of the patterns and correlates of changes in plasma bilirubin after partial hepatectomy. Methods: A large series of blood measurements and complementary variables were prospectively collected from 85 patients undergoing liver resection, and bilirubin correlations were assessed by regression analysis. Results: Early postoperatively, the best simultaneous correlates of increasing bilirubin were the preoperative value, the duration of surgery, and the number of blood transfusions (r2=0.74, p<0.001). Subsequently, increasing bilirubin became related to the number of resected liver segments, the duration of intraoperative liver ischemia, the use of continuous vs. intermittent ischemia, and the presence of sepsis (r2=0.82, p<0.001); these were also the best simultaneous correlates of peak bilirubin. This pattern was characterized by prominently conjugated hyperbilirubinemia, hypocholesterolemia, and moderately increased alkaline phosphatase, and occurred in the absence of obstructive cholestasis. Conclusions: Major hepatectomy, parenchymal ischemia, and sepsis have similar and synergistic impacts as determinants of prominently conjugated hyperbilirubinemia after liver resection. This is likely related to impaired hepatocellular bilirubin transport and occurs in the absence of obstructive components. Clin Chem Lab Med 2008;46:1598–601. [ABSTRACT FROM AUTHOR]