allopurinol and Necrosis

Allopurinol hypersensitivity syndrome (AHS) is a severe reaction which is potentially lethal. Exanthematous rash, fever, eosinophilia, and other severe reactions such as toxic epidermal necrolysis, acute vasculitis, and severe hepatic and renal dysfunctions are manifestations of this syndrome. The authors report a case of lethal massive hepatic necrosis due to allopurinol in a patient with the asymptomatic hyperuricemia. They also describe the risk factors most frequently associated with the development of AHS and the strategy for its prevention and consequent reduction of the mortality associated with this syndrome.

Topics: Aged; Aged, 80 and over; Allopurinol; Drug Hypersensitivity; Fatal Outcome; Gout; Gout Suppressants; Humans; Liver; Male; Necrosis

There is a growing body of evidence for the role of free radicals in mediating myocardial tissue injury during myocardial ischemia and in particular during the phase of myocardial reoxygenation. Associated with myocardial ischemia and reperfusion is the generation of oxygen-derived free radicals from a variety of sources that include the mitochondrial electron transport chain; the biosynthesis of prostaglandins; the enzyme xanthine oxidase; and circulating elements in the blood, with the polymorphonuclear neutrophil assuming a primary focus of attention. Experimental studies have shown that free radical scavengers (e.g., N-[2-mercaptopropionyl]glycine) and enzymes that scavenge or degrade reactive species of oxygen (superoxide dismutase or catalase) can reduce the mass of myocardial tissue that undergoes irreversible injury. Additionally allopurinol, which inhibits the enzyme xanthine oxidase, reduces ultimate infarct size, putatively by reducing the xanthine oxidase generation of superoxide anion. Neutrophils that enter the ischemically injured myocardium under the influence of chemotactic attraction and activation of the complement system generate and release highly reactive and cytotoxic oxygen derivatives that are destructive to the vascular endothelium and to the cardiac myocytes. Studies have documented that neutrophil depletion or suppression of neutrophil function (ibuprofen, nafazatrom, BW 755C, or more recently with prostacyclin or iloprost) results in a significant salvage of myocardial tissue that is subjected to a period of regional ischemia followed by reperfusion. Our current understanding of the events associated with myocardial ischemia suggests that within the ischemic myocardial region or area at risk, there is a population of cells that are reversibly injured and that reperfusion within a specified period (less than 3 hours) of time is capable of restoring the majority of the jeopardized cells to a normal status, but that the act of reperfusion itself will lead to the sudden demise of a fraction of the cells because of the cytotoxic effects of reactive species of oxygen derived from one or more of the sources indicated above. The efforts to minimize the amount of tissue that undergoes cell death as a result of myocardial ischemia demand that early reperfusion be established. However, the reintroduction of molecular oxygen and the circulating elements of the blood will be associated with an "explosive" and self-limited destruction of so

Topics: Antioxidants; Ascorbic Acid; Cell Adhesion; Coronary Disease; Free Radicals; Glycoproteins; Humans; Lysosomes; Myocardial Infarction; Myocardium; Necrosis; Neutrophils; Oxygen; Superoxide Dismutase; Xanthine Oxidase

Topics: Acrylamides; Animals; Calcium; Cnidarian Venoms; Coronary Disease; Doxorubicin; Egtazic Acid; Electron Spin Resonance Spectroscopy; Free Radicals; Guinea Pigs; Heart; Hypoxia; Isoproterenol; Myocardium; Necrosis; Rabbits; Rats; Xanthine Oxidase

Free radicals produced by the hypoxanthine-xanthine oxidase reaction in ischemia/reperfusion experiments have been proposed as contributing to myocardial cell necrosis in acute myocardial infarction. In this study, the hypothesis was tested that a commonly observed late phase of necrosis, infarct extension, could be prevented by allopurinol, an inhibitor of xanthine oxidase.. Allopurinol, a xanthine oxidase inhibitor, was used with placebo in a double-blind randomized therapy study in 140 patients with ischemic heart disease admitted to the authors' hospital. Eighty-four had acute myocardial infarction and the remaining 56 had unstable angina. Of the 84 patients with infarction, 39 received allopurinol treatment. If xanthine oxidase production of cytotoxic free radical plays a major role in the pathogenesis of infarct extension, blockade of the reaction with allopurinol should decrease the occurrence of extension.. Nineteen infarct extensions were observed; five (11%) in the placebo group and 14 (36%) in the allopurinol.. The increased incidence of extension (P less than 0.007) in the treatment group does not support the hypothesis that xanthine oxidase contributes to infarct extension, which is consistent with recent reports that xanthine oxidase is not a significant component of the human myocardium. These findings indicate that allopurinol may actually be contraindicated in patients with ischemic heart disease.

Topics: Adult; Aged; Allopurinol; Angina, Unstable; Creatine Kinase; Double-Blind Method; Female; Free Radicals; Humans; Isoenzymes; Male; Middle Aged; Myocardial Infarction; Necrosis; Xanthine Oxidase

Topics: Adenosine; Adult; Allopurinol; Costs and Cost Analysis; Creatinine; Glutathione; Humans; Hypertonic Solutions; Insulin; Kidney Transplantation; Kidney Tubules; Necrosis; Organ Preservation; Organ Preservation Solutions; Prospective Studies; Raffinose; Solutions; United States

Topics: Adenosine; Allopurinol; Cold Temperature; Female; Glutathione; Humans; Hypertonic Solutions; Insulin; Kidney Transplantation; Male; Necrosis; Organ Preservation; Organ Preservation Solutions; Raffinose; Solutions

Topics: Animals; Apoptosis; Calcium; Endoplasmic Reticulum Stress; Gene Expression Regulation; Humans; Hydrogen Peroxide; Lipopolysaccharides; Mice; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Necrosis; Reactive Oxygen Species; Receptor-Interacting Protein Serine-Threonine Kinases; Reperfusion Injury; Xanthine Oxidase

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a rare but potentially fatal adverse drug reaction with variable renal involvement. We report the case of a man who presented with allopurinol-induced DRESS and acute kidney injury (AKI) requiring hemodialysis. Kidney biopsy revealed eosinophilic tubulointerstitial nephritis and necrotizing vasculitis of the intralobular arteries without systemic markers of vasculitis. After cyclophosphamide and glucocorticoids, his symptoms and AKI resolved. To our knowledge, this is the first case of kidney-limited necrotizing vasculitis, questioning whether a biopsy should be routinely performed in patients with DRESS accompanied by severe AKI. It is possible that kidney-limited necrotizing vasculitis is an under-diagnosed manifestation of DRESS syndrome, and in such a setting, early recognition, stopping the offending agent, and use of aggressive immunosuppressive therapy, including cyclophosphamide, may lead to a favorable outcome.
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Topics: Acute Kidney Injury; Allopurinol; Drug Hypersensitivity Syndrome; Humans; Male; Middle Aged; Necrosis; Nephritis, Interstitial; Vasculitis

The purpose of this study is to explore whether normothermic machine perfusion (NMP) preservation is superior to cold preservation during reduced-size liver transplantation (RSLT) in pigs. Twenty-four healthy Ba-Ma mini pigs were used (aged >13 months; weight 25-35 kg; regardless of sex). The animals were randomized into 2 groups. In group A (NMP), donor livers were harvested without warm ischemia time and heartbeats and then were connected to the NMP system to reduce the livers' size under the normothermic condition. In group B (University of Wisconsin [UW] solution), donor livers were harvested without warm ischemia time and heartbeats after being perfused by UW solution and were then preserved in 0°C-4°C UW solution to reduce the livers' size under cold conditions. After that, liver transplantation without venovenous bypass was performed. General RSLT information of the pigs from the 2 groups was recorded; the serological indices were measured; and routine pathological examination of liver tissue was observed. A significant difference was observed in the intraoperative bleeding between the 2 groups (P < 0.05), whereas no significant difference was found in the other indices (all P > 0.05). Significant differences of alanine aminotransferase levels, aspartate aminotransferase levels, and lactate dehydrogenase levels between the 2 groups were observed between postoperative days 3 and 5 (P < 0.05). Significant differences of lactic acid levels between the 2 groups were observed between postoperative days 2 and 5 (P < 0.05). Compared with the cold preservation group, the liver tissues of the NMP preservation group only rarely experienced liver cell necrosis and maintained integrities in the hepatic sinusoid spaces and endothelial cells. In conclusion, NMP preservation is superior to cold preservation during RSLT in pigs. Liver Transplantation 22 968-978 2016 AASLD.

Topics: Adenosine; Alanine Transaminase; Allopurinol; Animals; Aspartate Aminotransferases; Cold Ischemia; Glutathione; Hepatocytes; Humans; Insulin; L-Lactate Dehydrogenase; Liver; Liver Transplantation; Necrosis; Organ Preservation; Organ Preservation Solutions; Perfusion; Postoperative Period; Raffinose; Reperfusion Injury; Swine; Swine, Miniature; Temperature

Necrotic cell death in vivo induces a robust neutrophilic inflammatory response and the resulting inflammation can cause further tissue damage and disease. Dying cells induce this inflammation by releasing pro-inflammatory intracellular components, one of which is uric acid. Cells contain high levels of intracellular uric acid, which is produced when purines are oxidized by the enzyme xanthine oxidase. Here we test whether a non-nucleoside xanthine oxidase inhibitor, Febuxostat (FBX), can reduce intracellular uric acid levels and inhibit cell death-induced inflammation in two different murine tissue injury models; acid-induced acute lung injury and acetaminophen liver injury. Infiltration of inflammatory cells induced by acid injection into lungs or peritoneal administration of acetaminophen was evaluated by quantification with flow cytometry and tissue myeloperoxidase activity in the presence or absence of FBX treatment. Uric acid levels in serum and tissue were measured before giving the stimuli and during inflammation. The impact of FBX treatment on the peritoneal inflammation caused by the microbial stimulus, zymosan, was also analyzed to see whether FBX had a broad anti-inflammatory effect. We found that FBX reduced uric acid levels in acid-injured lung tissue and inhibited acute pulmonary inflammation triggered by lung injury. Similarly, FBX reduced uric acid levels in the liver and inhibited inflammation in response to acetaminophen-induced hepatic injury. In contrast, FBX did not reduce inflammation to zymosan, and therefore is not acting as a general anti-inflammatory agent. These results point to the potential of using agents like FBX to treat cell death-induced inflammation.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Cell Death; Chemical and Drug Induced Liver Injury; Dose-Response Relationship, Drug; Enzyme Inhibitors; Febuxostat; Gastroesophageal Reflux; Gout Suppressants; Liver; Lung; Lung Injury; Male; Mice, Inbred C57BL; Necrosis; Neutrophil Infiltration; Peritoneum; Peritonitis; Thiazoles; Uric Acid; Xanthine Oxidase

To compare the efficacy of different types of solutions (Belzer or Euro-Collins) for the preservation of rat pancreas during cold ischemia.. Thirty Wistar rats were divided into three groups according to the perfusion or storage solution: Group E (perfusion and storage in Euro-Collins solution); Group B (perfusion and storage in Belzer solution) and Group BE (Perfusion in Belzer solution and storage in Euro-Collins solution). After perfusion, the pancreas was excised and stored at 4˚C for 18 hours. Amylase was measured at 6, 12 and 18h, and histological analysis of the pancreas was performed after 18h of cold storage.. Amylase was elevated and comparable in Groups E and BE after 12 and 18 hours of ischemia (p<0.05). In the exocrine pancreas, histological differences in the amount of necrosis (p=0.049), lymphocytic infiltrate (p<0.001) and neutrophilic infiltrate (p=0.004) were observed, with more favorable features present in Group B. In the endocrine pancreas, Group B showed less edema (p<0.001), but other parameters were similar among all groups.. The Euro-Collins solution is inferior to the Belzer solution for the preservation of rat pancreas during cold ischemia.

Topics: Adenosine; Allopurinol; Amylases; Animals; Cold Ischemia; Female; Glutathione; Hypertonic Solutions; Insulin; Models, Animal; Necrosis; Organ Preservation; Organ Preservation Solutions; Pancreas; Raffinose; Rats; Rats, Wistar; Reference Values; Reproducibility of Results; Time Factors

Use of grafts from donors after cardiac death (DCD) would greatly contribute to the expansion of the donor organ pool. However, this requires the development of novel preservation methods to recover the organ from changes due to warm ischemia time (WIT).. Porcine livers were perfused with a newly developed machine perfusion (MP) system. The livers were perfused with modified University of Wisconsin solution (UW) - gluconate. All grafts were procured after acute hemorrhagic shock with the ventilator off. For group 1 (n = 6), grafts were procured after WIT of 60 minutes and preserved by hypothermic MP (HMP) for 3 hours. For group 2 (n = 5), grafts were preserved with 2 hours of simple cold storage (SCS) and HMP for 2 hours. For group 3 (n = 6), grafts were preserved with 2 hours of SCS and rewarming up to 25°C by MP for 2 hours (RMP). The preserved liver grafts were transplanted orthotopically.. The alanine aminotransferase level in perfusate in RMP during perfusion preservation was maintained at less than that of HMP. The levels of aspartate aminotransferase and lactate dehydrogenase in the 2 hours after reperfusion were significantly lower in group 3. Histologically, the necrosis of hepatocytes was less severe in group 3. The survival rate in group 3 was 2/4, but 0/4 in the other group.. RMP is expected to facilitate the recovery of the DCD liver grafts.

Topics: Adenosine; Alanine Transaminase; Allopurinol; Animals; Aspartate Aminotransferases; Biomarkers; Cold Ischemia; Disease Models, Animal; Female; Glutathione; Graft Survival; Heart Arrest; Hepatectomy; Insulin; L-Lactate Dehydrogenase; Liver; Liver Transplantation; Necrosis; Organ Preservation; Organ Preservation Solutions; Perfusion; Raffinose; Reperfusion Injury; Rewarming; Sus scrofa; Time Factors; Tissue and Organ Harvesting; Warm Ischemia

S-Nitrosated human serum albumin (SNO-HSA) is useful in preventing liver ischemia/reperfusion injury, and SNO-HSA should thus be able to prevent cell injury during liver transplantation. However, the potential protective effect of SNO-HSA on a combination of cold and warm ischemia, which is obligatory when performing liver transplantation, has not been examined. Therefore, we evaluated the protective effect of SNO-HSA added to University of Wisconsin (UW) solution during cold or/and warm ischemia in situ and in vitro. First, we observed that apoptotic and necrotic cell death were increased during cold and warm ischemia, respectively. SNO-HSA, which possesses anti-apoptosis activity at low NO concentrations, can inhibit cold ischemia injury both in situ and in vitro. In contrast, SNO-HSA had no significant effect on warm liver ischemia injury which, however, can be reduced by UW solution. We also demonstrated that the cellular uptake of NO from SNO-HSA can occur during cold ischemia resulting in induction of heme oxygenase-1 within 3h of cold ischemia. Our results indicate that treatment with SNO-HSA or UW solution alone is not sufficient to inhibit liver injury during a period of both cold and warm ischemia. However, a combination of SNO-HSA and UW solution can be used to prevent the two types of ischemia. SNO-HSA-added UW solution could be very useful in transplantation, because the previously imposed constraints on preservation time can be removed. This is a great advantage in a situation as the present one with increased utilization of scarce donor organs for more recipients.

Topics: Adenosine; Allopurinol; Analysis of Variance; Animals; Apoptosis; Glutathione; Hep G2 Cells; Humans; Insulin; Liver; Liver Diseases; Liver Transplantation; Male; Necrosis; Nitric Oxide Donors; Nitroso Compounds; Organ Preservation Solutions; Raffinose; Rats; Rats, Wistar; Reperfusion Injury; Serum Albumin; Serum Albumin, Human

Degloving injuries may be a challenge when it comes to deciding the surgical approach to be used. Repositioning of the flap and suturing are faster and more straightforward, but often these procedures often lead to total or partial loss of the avulsed flap. Pharmacological agents with vascular properties that enhance the viability of the reattached flap could be beneficial to patients with degloving injuries. Experimental models with which to test this hypothesis are scarce. An experimental model reproducing a degloving injury of the hind limb of rats was developed in our department, and the effects of pentoxifylline (Ptx) and allopurinol (Alp) were assessed.. In all, 3 groups of rats were studied (25 rats each). A hind limb degloving model was used in all groups, resulting in a reverse flow flap. The flap was then repositioned and sutured. The control (Ct) group received only saline solution, the Ptx group received pentoxifylline (25 mg/kg), and the Alp group received allopurinol (45 mg/kg). The rats were observed for 7 days, after which they were killed, and the flap was removed. The total area of the avulsed flap and the necrotic area were measured.. The median total flap area (cm) was 5.6 for the Ct group, 5.5 for the Ptx group, and 5.8 for the Alp group (P = 0.9465). Thus, the flaps were similar. The median necrotic flap area (cm) was 3.3 for the Ct group, 2.3 for the Ptx group, and 1.9 for the Alp group (P = 0.0001). There was a statistical difference between the Ct and Ptx groups and the Ct and Alp groups (P < 0.05).. The areas of necrosis observed in the degloved flaps of the rats' hind limbs were smaller in the pentoxifylline and allopurinol groups. Although allopurinol seems to be more efficient, the difference was not significant.

Topics: Allopurinol; Animals; Antioxidants; Cell Survival; Graft Survival; Hindlimb; Male; Necrosis; Pentoxifylline; Rats; Rats, Wistar; Skin; Soft Tissue Injuries; Surgical Flaps; Vasodilator Agents; Xanthine Oxidase

No consensus exists on the optimal heart preservative solution (HPS) for cardiac allograft preservation. The significance of varying degrees of acute ischemic necrosis (AIN) in early transplant biopsy specimens is unknown. We investigated the effects of HPS on early cardiac histopathology by developing a novel grading system of AIN.. A retrospective review of our institutional database of orthotopic heart transplants (OHT) identified hearts preserved with University of Wisconsin (UW) or Celsior solutions. AIN severity was graded on early post-transplant biopsy specimens. Primary stratification was by HPS. Multivariable models examined mortality, AIN grade, primary graft dysfunction (PGD), and right heart failure (RHF).. From 1996 to 2010, 42 of 174 adult OHTs were preserved with UW and 132 with Celsior, from which 431 biopsy specimens were reviewed. UW and Celsior had similar 30-day (p = 0.79) and 1-year mortality (p = 0.92). Celsior was associated with significantly more AIN on the first (p = 0.02) and second (p = 0.04) specimens and persisted on multivariable analysis for the first (odds ratio, 2.93; 95% confidence interval, 1.26-6.83; p = 0.01) and second biopsy specimen (2.08; 0.99-4.34; p = 0.05). When stratified by AIN score, 30-day and 1-year mortality were similar (p > 0.05). Adjusted analysis showed increasing AIN score on the first biopsy was strongly associated with an increased incidence of PGD (1.59; 1.02-2.47; p = 0.04) and RHF (2.45; 1.14-5.27; p = 0.02).. Our grading system provides a simple, reproducible method for determining AIN. UW is associated with less AIN than Celsior solution. Early biopsy ischemia is associated with PGD and RHF. AIN may have prognostic significance and its routine evaluation should be considered.

Topics: Adenosine; Adult; Allopurinol; Biopsy; Disaccharides; Electrolytes; Female; Glutamates; Glutathione; Graft Rejection; Heart Failure; Heart Transplantation; Histidine; Humans; Incidence; Insulin; Male; Mannitol; Middle Aged; Multivariate Analysis; Myocardial Reperfusion Injury; Myocardium; Necrosis; Organ Preservation; Organ Preservation Solutions; Primary Graft Dysfunction; Raffinose; Retrospective Studies; Survival Rate; Transplantation, Homologous

Topics: Acute Kidney Injury; Allopurinol; Chemical and Drug Induced Liver Injury; Delayed Diagnosis; Drug Hypersensitivity; Female; Gout Suppressants; Humans; Middle Aged; Necrosis; Time Factors

The aims of this study were to compare extracellular and intracellular-type University of Wisconsin (UW) solutions for liver grafts and to assess oxygenation in this perfusion system.. The organ preservation system consisted of 3 circulating systems for the portal vein, hepatic artery, and maintenance of the perfusion solution. The portal vein or hepatic artery system had a roller pump, a flow meter, and a pressure sensor. In this study, we perfused livers with UW or extracellular type UW-gluconate at 4°C-6°C for 4 hours. The flow rates at the entrance were 0.5 mL/min/g liver in the portal vein and 0.2 mL/min/liver in the hepatic artery. Orthotopic liver transplantation was performed in pigs: group 1-a, grafts procured after acute hemorrhagic shock were preserved by a solution without O(2); group 1-b, grafts were preserved with O(2); group 2-a, grafts were perfused using intracellular type solution (UW); and group 2-b, grafts were perfused using extracellular-type solution (UW-gluconate).. Effluent aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) levels in group 1-b were lower than those in group 1-a. Survival rates in group 2-a and group 2-b were 1/4 and 3/3, respectively. Effluent AST and LDH levels in the perfusate of group 2-b were lower than group 2-a. Histological study revealed necrosis of hepatocytes and sinusoidal congestion in group 2-a.. A beneficial effect of extracellular-type solution with oxygenation in a novel continuous machine preservation system yielded well-preserved liver graft function.

Topics: Adenosine; Allopurinol; Animals; Aspartate Aminotransferases; Cold Temperature; Equipment Design; Gluconates; Glutathione; Hepatic Artery; Insulin; L-Lactate Dehydrogenase; Liver; Liver Transplantation; Necrosis; Organ Preservation; Organ Preservation Solutions; Oxygen; Perfusion; Portal Vein; Raffinose; Sus scrofa; Time Factors

Neurons can undergo a diverse range of death responses under oxidative stress, encompassing apoptosis (caspase-dependent, programmed cell death) to various forms of caspase-independent death, including necrosis. We recently showed that primary murine cortical neurons exposed acutely to hydrogen peroxide undergo caspase-independent death, both autophagic cell death and programmed necrosis. To determine how oxidative stress induced by superoxide affects the route to cellular demise, we exposed primary cortical neurons to extended superoxide insult (provided by exogenous xanthine and xanthine oxidase in the presence of catalase). Under these conditions, over 24h, the nitroblue tetrazolium-reducing activity (indicative of superoxide) rose significantly during the first 4 to 8h and then declined to background levels. As with hydrogen peroxide, this superoxide insult failed to activate downstream caspases (-3, -7, and -9). Substantial depolarization of mitochondria occurred after 1h, and nuclear morphology changes characteristic of oxidative stress became maximal after 2h. However, death indicated by plasma membrane permeabilization (cellular uptake of propidium iodide) approached maximal levels only after 4h, at which time substantial redistribution to the cytosol of death-associated mitochondrial intermembrane space proteins, notably endonuclease G, had occurred. Applying established criteria for autophagic death (knockdown of Atg7) or programmed necrosis (knockdown of endonuclease G), cells treated with the relevant siRNA showed significant blockade of each type of cell death, 4h after onset of the superoxide flux. Yet at later times, siRNA-mediated knockdown failed to prevent death, monitored by cellular uptake of propidium iodide. We conclude that superoxide initially invokes a diverse programmed caspase-independent death response, involving transient manifestation in parallel of autophagic death and programmed necrosis. Ultimately most neurons become overwhelmed by the consequences of severe oxidative stress and die. This study reveals the multiple phases of neuronal cell death modalities under extended oxidative stress.

Topics: Animals; Apoptosis; Autophagy; Autophagy-Related Protein 7; Caspase 3; Caspase 7; Caspase 9; Catalase; Cells, Cultured; Endodeoxyribonucleases; Mice; Mice, Inbred C57BL; Microtubule-Associated Proteins; Necrosis; Neurons; Oxidative Stress; RNA Interference; RNA, Small Interfering; Superoxides; Xanthine; Xanthine Oxidase

The differences and efficacy of standard preservation solutions in kidney transplantation, University of Wisconsin (UW) and histidine-tryptophan-ketoglutarate (HTK), remain a topic of debate in recent clinical studies. P-selectins represent glycoproteins expressed on endothelial cells and platelets responsible for the earliest events in ischemia/reperfusion injury in kidney transplantation. This study aimed to compare the levels of P-selectin expression between cold preserved kidney tissues in UW and HTK solutions. Thirty kidneys were procured from male Lewis rats and stored in cold (4°C) solutions for periods of 4, 12, 16, 20, and 24h. Group 1 (n=15) kidneys were stored in UW solutions, and group 2 (n=15) kidneys were submerged in HTK solutions. At the end of each time point, the kidneys underwent preparation and levels of P-selectin expression in the tissues were measured using Immunoblot analyses and adjusted volumetric quantification of Western blot signals. For all periods of cold preservation, P-selectin expression was significantly down-regulated in kidney tissues stored in UW compared with HTK solutions (P<0.001). In summary, UW demonstrated a significant benefit over HTK solution in down-regulating P-selectin expression in cold preserved kidney grafts.

Topics: Adenosine; Allopurinol; Animals; Cryopreservation; Down-Regulation; Glucose; Glutathione; Insulin; Ischemia; Kidney; Male; Mannitol; Models, Animal; Necrosis; Organ Preservation Solutions; P-Selectin; Potassium Chloride; Procaine; Raffinose; Rats; Rats, Inbred Lew

The improvement of the ischaemic tolerance of myocutaneous flaps is of clinical importance and hence the subject of numerous investigations.. In an attempt to increase the ischaemic tolerance, 20 myocutaneous flaps (rectus abdominis muscle) in pigs were elevated and perfused with various, established solutions prior to the onset of ischaemia. The flaps were elevated, utilizing the superior epigastric vessels as the pedicle. Ten flaps were flushed with the University of Wisconsin solution, five with the Euro-Collins solution and the last five with a Ringer-Lactate solution, prior to the 6h long, normothermic ischaemia. On the day of operation, the first, third, fifth, seventh and tenth postoperative day clinical examinations and thermography were performed as well as biopsies. Additionally, on the tenth postoperative day, the rate of necrosis was determined morphometrically as the average of three measurements.. Ten days after surgery, the flaps pretreated with the University of Wisconsin solution displayed a vital surface area of 89%, the Euro-Collins solution 23% and the Ringer-Lactate solution 14%. Histologically, muscle tissue proved to be more susceptible to ischaemia than skin.. Regarding the rectus abdominis flap in a pig model, the University of Wisconsin solution proved superior in the prevention of ischaemic injury compared with the Euro-Collins solution and Ringer Lactate. In accordance with the literature, muscle tissue proved to be more susceptible to ischaemia than skin in our study.

Topics: Adenosine; Allopurinol; Animals; Biopsy; Disease Susceptibility; Epigastric Arteries; Glutathione; Graft Survival; Hypertonic Solutions; Insulin; Ischemia; Ischemic Preconditioning; Isotonic Solutions; Models, Animal; Necrosis; Organ Preservation Solutions; Raffinose; Rectus Abdominis; Reperfusion; Ringer's Lactate; Skin Transplantation; Surgical Flaps; Swine; Thermography; Time Factors; Tissue Preservation; Transplantation Conditioning; Warm Ischemia

To determine if blockade of P-selectin in the isolated blood-perfused cold ex vivo rat liver model protects the liver from ischemia-reperfusion injury.. The effect of P-selectin blockade was assessed by employing an isolated blood-perfused cold ex vivo rat liver with or without P-selectin antibody treatment before and after 6 h of cold storage in University of Wisconsin solution.. In our isolated blood-perfused rat liver model, pre-treatment with P-selectin antibody failed to protect the liver from ischemia-reperfusion injury, as judged by the elevated aspartate aminotransferase activity. In addition, P-selectin antibody treatment did not significantly reduced hepatic polymorphonuclear leukocyte accumulation after 120 min of perfusion. Histological evaluation of liver sections obtained at 120 min of perfusion showed significant oncotic necrosis in liver sections of both ischemic control and P-selectin antibody-treated groups. However, total bile production after 120 min of perfusion was significantly greater in P-selectin antibody-treated livers, compared to control livers. No significant difference in P-selectin and ICAM-1 mRNAs and proteins, GSH, GSSG, and nuclear NF-kappaB was found between control and P-selectin antibody-treated livers.. In conclusion, we have shown that blockade of P-selectin alone failed to reduced polymorphonuclear leukocyte accumulation in the liver and protect hepatocytes from ischemia-reperfusion injury in the isolated blood-perfused cold-ex vivo rat liver model.

Topics: Adenosine; Allopurinol; Animals; Antibodies; Aspartate Aminotransferases; Bile; Cold Ischemia; Glutathione; Glutathione Disulfide; In Vitro Techniques; Insulin; Intercellular Adhesion Molecule-1; Liver; Male; Necrosis; Neutrophils; NF-kappa B; Organ Preservation Solutions; P-Selectin; Perfusion; Raffinose; Rats; Rats, Sprague-Dawley; Reperfusion Injury; RNA, Messenger; Time Factors

The study was designed to investigate the role of molybdenum iron-sulfur flavin hydroxylases in the pathogenesis of liver injuries induced by structurally and mechanistically diverse hepatotoxicants. While carbon tetrachloride (CCl4), thioacetamide (TAA) and chloroform (CHCl3) inflict liver damage by producing free radicals, acetaminophen (AAP) and bromobenzene (BB) exert their effects by severe glutathione depletion. Appropriate doses of these compounds were administered to induce liver injury in rats. The activities of the Mo-Fe-S flavin hydroxylases were measured and correlated with the biochemical markers of hepatic injury. The activity levels of the anti-oxidative enzymes and glutathione redox cycling enzymes were also determined. The treatment of rats with the hepatotoxins that inflict liver injury by generating free radicals (CCl4, TAA, CHCl3) had elevated activity levels of hepatic Mo-Fe-S flavin hydroxylases (p<0.05). Specific inhibition of these hydroxylases by their common inhibitor, sodium tungstate, suppresses biochemical and oxidative stress markers of hepatic tissue damage. On the contrary, Mo-Fe-S flavin hydroxylases did not show any change in animals receiving AAP and BB. Correspondingly, sodium tungstate could not attenuate damage in AAP and BB treated groups of rats. The study concludes that Mo-Fe-S hydroxylases contribute to the hepatic injury inflicted by free radical generating agents and does not play any role in hepatic injury produced by glutathione depleting agents. The study has implication in understanding human liver diseases caused by a variety of agents, and to investigate the efficacy of the inhibitors of Mo-Fe-S flavin hydroxylases as potential therapeutic agents.

Topics: Aldehyde Oxidase; Animals; Antioxidants; Chemical and Drug Induced Liver Injury; Coenzymes; Cytosol; Female; Flavin Mononucleotide; Liver; Metalloproteins; Molybdenum Cofactors; Necrosis; Oxidative Stress; Pteridines; Rats; Rats, Wistar; Xanthine Oxidase

Topics: Aged; Allopurinol; Epidermis; Fatal Outcome; Gout Suppressants; Humans; Kidney Failure, Chronic; Male; Necrosis; Stevens-Johnson Syndrome; Uric Acid

The hepatic lesion produced as a result of oxidative stress is of wide occurrence. In the present study, the effect of tungsten on liver necrosis and fulminant hepatic failure (FHF) has been studied in rats treated with various compounds known to produce oxidative stress. Supplementation of animals with sodium tungstate for 7 weeks before the induction of liver injury by chemicals including thioacetamide (TAA), carbon tetrachloride (CCl(4)), or chloroform (CHCl(3)) could protect progression of hepatic injury. Various biochemical changes associated with liver damage and oxidative stress were measured. Hepatic malondialdehyde content, endogenous tripeptide, and reduced glutathione were measured as oxidative stress markers. The activity of xanthine oxidase, which generates reactive oxygen species (ROS) as a by-product, was also determined and found to be perturbed. Tungsten supplementation to rats caused a significant decrease in lipid peroxidation and lowered the levels of the biochemical markers of hepatic lesions produced by TAA, CCl(4) (CCl(4)), or CHCl(3). Tungsten could also cause an increase in the survival rate in rats receiving lethal doses of TAA, CCl(4), or CHCl(3). The protective effect of tungsten, however, is suggested to be limited to the conditions where the hepatic lesion is reported to be due to the generation of ROS. The progression of liver injury produced by the compounds causing oxidative stress without initiating the generation of free radicals such as bromobenzene (BB), or acetaminophen (AAP), could not be inhibited by tungsten. The possible mechanism explaining the role of oxyanionic form of tungsten in free radical-induced hepatic lesions is discussed.

Topics: Acetaminophen; Alkaline Phosphatase; Allopurinol; Animals; Bromobenzenes; Carbon Tetrachloride Poisoning; Chloroform; Dimethyl Sulfoxide; Female; Lethal Dose 50; Liver; Liver Failure; Necrosis; Oxidative Stress; Rats; Rats, Wistar; Thioacetamide; Transaminases; Tungsten Compounds

To study effects of pharmacologic concentrations of azathioprine and 6-mercaptopurine (6-MP) on rat hepatocytes.. Hepatocytes cultured on matrigel were incubated with azathioprine or 6-MP; effects of putative protective agents were studied. Viability (LDH leakage), reduced (GSH) and oxidized glutathione (GSSG), mitochondrial (mt) GSH, ATP and ultrastructural changes were determined.. Azathioprine and 6-MP (0.5-5 micromol/l) reduced viability 5-34% at day 1 and 42-92% by day 4. Allopurinol (20 microM) (xanthine oxidase inhibitor) and 2 mM Trolox (vitamin E analog) together provided near complete protection. During culture with azathioprine, GSSG increased before cell death and there was a disproportionate reduction of mtGSH and ATP, together with ultrastructural abnormalities in mitochondria. All changes were prevented by allopurinol and trolox. Discontinuation of 1 micromol/l azathioprine restored ATP levels and arrested cell injury, while culture in glucose-enriched media augmented ATP levels and ameliorated cell death.. Clinically relevant concentrations of azathioprine and 6-MP are toxic to rat hepatocyte cultures by a mechanism that involves oxidative stress, mitochondrial injury and ATP depletion. This can lead to irreversible de-energization and cell death by oncosis (necrosis).

Topics: Adenosine Triphosphate; Allopurinol; Animals; Antioxidants; Azathioprine; Cell Differentiation; Cell Survival; Cells, Cultured; Chromans; Enzyme Inhibitors; Glutathione; Glutathione Disulfide; Hepatocytes; Male; Mercaptopurine; Microscopy, Electron; Mitochondria, Liver; Necrosis; Oxidative Stress; Rats; Rats, Wistar; Time Factors; Xanthine Oxidase

Osmotic diuretics are used successfully to alleviate acute tubular necrosis (ATN) produced by chemotherapeutic agents and aminoglycoside antibiotics. The beneficial action of these agents likely involves rapid elimination of the nephrotoxic agents from the kidney by promoting diuresis. Adenosine A1 receptor (A1AR) subtype present on renal proximal tubular epithelial and cortical collecting duct cells mediates the antidiuretic and cytoprotective actions of adenosine. These receptors are induced by activation of nuclear factor (NF)-kappaB, a transcription factor reported to mediate hyperosmotic stress-induced cytoprotection in renal medullary cells. In this study, we tested the hypothesis that induction of the A1AR in renal proximal tubular cells by NF-kappaB contributes to the cytoprotection afforded by osmotic diuretics. Exposure of porcine renal proximal tubular epithelial (LLC-PK1) cells to mannitol or NaCl produced a significant increase in A1AR. This increase was preceded by adenosine release and NF-kappaB activation. Expression of an IkappaB-alpha mutant, which acts as a superrepressor of NF-kappaB, abrogated the increase in A1AR. Cells exposed to mannitol demonstrated increased reactive oxygen species (ROS) generation, which was attenuated by inhibiting xanthine oxidase with allopurinol. Allopurinol attenuated both the increase in A1AR expression and NF-kappaB activation produced by osmotic diuretics, indicating a role of adenosine metabolites in these processes. Treatment of LLC-PK1 cells with cisplatin (8 microm) resulted in apoptosis, which was attenuated by mannitol but exacerbated by selective A1AR blockade. Administration of mannitol to mice increases A1AR expression and activation of NF-kappaB in renal cortical sections. Taken together, these data provide novel mechanisms of nephroprotection by osmotic diuretics, involving both activation and induction of the A1AR, the latter mediated through activation of a xanthine oxidase pathway leading to ROS generation and promoting activation of NF-kappaB.

Topics: Allopurinol; Animals; Annexin A5; Apoptosis; Blotting, Northern; Cell Line; Cell Nucleus; Cisplatin; Coloring Agents; Diuretics; Dose-Response Relationship, Drug; Epithelial Cells; Immunohistochemistry; Kidney; Kidney Cortex; Kidney Tubules; Kidney Tubules, Collecting; Luciferases; Male; Mannitol; Mice; Mice, Inbred C57BL; Microscopy, Fluorescence; Necrosis; NF-kappa B; Polymerase Chain Reaction; Protein Binding; Reactive Oxygen Species; Receptor, Adenosine A1; RNA; Sodium Chloride; Swine; Transcription, Genetic; Up-Regulation; Xanthine Oxidase

Peroxisome proliferator-activated receptor gamma (PPAR-gamma) is a nuclear hormone receptor super family that has recently been implicated in atherosclerosis, inflammation, cancer, infertility, and demyelination. Oxidative stress, neutrophil infiltration, proinflammatory cytokines, and the exhibition of luminal acid play a role in the pathogenesis of gastric injury induced by ischemia-reperfusion. Rosiglitazone, a specific PPAR-gamma ligand, has been shown to have antiinflammatory activity, but its effects on experimental ischemia-reperfusion gastric injury remain unknown. We have investigated the effects of the rosiglitazone on gastric injury caused by ischemia following reperfusion in rats. Tumour necrosis factor-alpha (TNF-alpha) levels and changes in enzymatic activities of myeloperoxidase, as a marker of neutrophils infiltration, xanthine oxidase, superoxide dismutase, and glutathione peroxidase, were determined. Histological analysis of the lesions was also carried out. Pretreatment with 1 or 4 mg/kg of rosiglitazone ameliorated the gastric damage induced by clamping the celiac artery for 30 min followed by 60 min of reperfusion. It significantly (P<0.05) reduced the index of neutrophil infiltration and the levels of the cytokine. Rosiglitazone did not revert the reduced glutathione peroxidase activity but enhanced significantly (P<0.01) the decreased xanthine oxidase and superoxide dismutase activities in gastric mucosa of ischemic rats. In conclusion, rosiglitazone reduces the damage in ischemia-reperfusion gastric injury and alleviates the inflammatory response and the oxidative events.

Topics: Animals; Cyclooxygenase 1; Cyclooxygenase 2; Gastric Mucosa; Glutathione Peroxidase; Immunohistochemistry; Male; Membrane Proteins; Necrosis; Neutrophils; Oxidative Stress; Peroxidase; PPAR gamma; Prostaglandin-Endoperoxide Synthases; Rats; Rats, Wistar; Reactive Oxygen Species; Reperfusion Injury; Rosiglitazone; Stomach; Superoxide Dismutase; Thiazolidinediones; Tumor Necrosis Factor-alpha; Up-Regulation; Xanthine Oxidase

Acute tumor lysis syndrome (ATLS), which occurs spontaneously, without cytotoxic therapy, is a rare condition. Spontaneous TLS (STLS) has been seen most commonly in lymphoma and leukemia. We report a series of 3 cases of STLS in patients with solid tumors who were hospitalized in our department during a 9-month period and suggest that STLS is probably more frequent than previously thought.

Topics: Adrenal Gland Neoplasms; Aged; Aged, 80 and over; Allopurinol; Bone Neoplasms; Colonic Neoplasms; Female; Fluid Therapy; Humans; Hydrogen-Ion Concentration; Liver Neoplasms; Male; Necrosis; Pheochromocytoma; Tomography, X-Ray Computed; Tumor Lysis Syndrome; Urine

Donor cells can be preserved in University of Wisconsin (UW), histidine-tryptophan-ketoglutarate (HTK), or Celsior solution. However, differences in efficacy and mode of action in preventing hypothermia-induced cell injury have not been unequivocally clarified. Therefore, we investigated and compared necrotic and apoptotic cell death of freshly isolated primary porcine hepatocytes after hypothermic preservation in UW, HTK, and Celsior solutions and subsequent normothermic culturing. Hepatocytes were isolated from porcine livers, divided in fractions, and hypothermically (4 degrees C) stored in phosphate-buffered saline (PBS), UW, HTK, or Celsior solution. Cell necrosis and apoptosis were assessed after 24- and 48-h hypothermic storage and after 24-h normothermic culturing following the hypothermic preservation periods. Necrosis was assessed by trypan blue exclusion, lactate dehydrogenase (LDH) release, and mitochondrial 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) reduction. Apoptosis was assessed by the induction of histone-associated DNA fragments and cellular caspase-3 activity. Trypan blue exclusion, LDH release, and MTT reduction of hypothermically preserved hepatocytes showed a decrease in cell viability of more than 50% during the first 24 h of hypothermic preservation. Cell viability was further decreased after 48-h preservation. DNA fragmentation was slightly enhanced in hepatocytes after preservation in all solutions, but caspase-3 activity was not significantly increased in these cells. Normothermic culturing of hypothermically preserved cells further decreased cell viability as assessed by LDH release and MTT reduction. Normothermic culturing of hypothermically preserved hepatocytes induced DNA fragmentation, but caspase-3 activity was not hanced in these cells. Trypan blue exclusion, LDH leakage, and MTT reduction demonstrated the highest cell viability after storage in Celsior, and DNA fragmentation was the lowest in cells that had been stored in PBS and UW solutions. None of the preservation solutions tested in this study was capable of adequately preventing cell death of isolated porcine hepatocytes after 24-h hypothermic preservation and subsequent 24-h normothermic culturing. Culturing of isolated and hypothermically preserved hepatocytes induces DNA fragmentation, but does not lead to caspase-3 activation. With respect to necrosis and DNA fragmentation of hypothermically preserved cells, UW and Celsior were superio

Topics: Adenosine; Allopurinol; Animals; Apoptosis; Caspase 3; Caspases; Cell Count; Cell Culture Techniques; Cell Division; Cell Survival; Cells, Cultured; Cryopreservation; Cryoprotective Agents; Disaccharides; DNA Fragmentation; Electrolytes; Female; Glucose; Glutamates; Glutathione; Hepatocytes; Histidine; Hypothermia, Induced; Insulin; L-Lactate Dehydrogenase; Liver Diseases; Male; Mannitol; Models, Biological; Necrosis; Organ Preservation Solutions; Potassium Chloride; Procaine; Raffinose; Tetrazolium Salts; Thiazoles; Tissue Transplantation

Acute renal failure commonly follows reduced renal perfusion or ischemia. Reperfusion is essential for recovery but can itself cause functional and structural injury to the kidney. The separate contributions of ischemia and of reperfusion were examined in the isolated perfused rat kidney. Three groups were studied: brief (5 min) ischemia, 20 min ischemia, and repetitive brief ischemia (4 periods of 5 min) with repetitive intervening reperfusion of 5 min. A control group had no intervention, the three ischemia groups were given a baseline perfusion of 30 min before intervention and all groups were perfused for a total of 80 min. In addition, the effects of exogenous *NO from sodium nitroprusside and xanthine oxidase inhibition by allopurinol were assessed in the repetitive brief ischemia-reperfusion model. Brief ischemia produced minimal morphological injury with near normal functional recovery. Repetitive brief ischemia-reperfusion caused less functional and morphological injury than an equivalent single period of ischemia (20 min) suggesting that intermittent reperfusion is less injurious than ischemia alone over the time course of study. Pretreatment with allopurinol improved renal function after repetitive brief ischemia-reperfusion compared with the allopurinol-untreated repetitive brief ischemia-reperfusion group. Similarly, sodium nitroprusside reduced renal vascular resistance but did not improve the glomerular filtration rate or sodium reabsorption in the repetitive brief ischemia-reperfusion model. Thus, these studies show that the duration of uninterrupted ischemia is more critical than reperfusion in determining the extent of renal ischemia-reperfusion injury and that allopurinol, in particular, counteracts the oxidative stress of reperfusion.

Topics: Allopurinol; Animals; Disease Models, Animal; Free Radical Scavengers; Glomerular Filtration Rate; Kidney Diseases; Kidney Medulla; Kidney Tubules, Proximal; Male; Natriuresis; Necrosis; Nitroprusside; Rats; Rats, Sprague-Dawley; Reperfusion; Reperfusion Injury; Severity of Illness Index; Vascular Resistance; Vasodilator Agents

Extensive and severe hepatic centrilobular hemorrhagic necrosis is a common finding in hepatic vein obstruction and Budd-Chiari syndrome. Some drugs, including allopurinol, can also cause this histopathologic appearance but to our knowledge in this setting the lesions are not so massive. Here we report a case of a 41-year-old female who developed fever, pruritic skin rash, jaundice, eosinophilia, abnormal liver function tests, and acute renal failure 3 weeks after the beginning of allopurinol treatment, complicated with severe hepatocyte necrosis around most terminal hepatic venules suggesting Budd-Chiari syndrome.

Topics: Acute Kidney Injury; Adult; Allopurinol; Antihypertensive Agents; Chemical and Drug Induced Liver Injury; Female; Hemorrhage; Humans; Hypertension; Liver Diseases; Necrosis

Oxidative stress is a relevant event in the pathogenesis of acute pancreatitis. Investigations in vivo are limited because of the complexity of the organism and the short half-life of free radicals. The isolated perfused rat pancreas could be useful for investigations in the early phase of acute pancreatitis especially under conditions of oxidative stress.. External perfusions of the pancreatic glands of Wistar rats were carried out using a modified Krebs-Ringer buffer including an additive of the detergents Triton X-100 and a perfusion including hydrogen peroxide (0.0012%) or tert-butylhydroperoxide (0.0042%) or xanthine oxidase (0.1 U/ml). Changes in amylase, lipase, LDH in the portal outflow fluid and for histological alterations were analyzed.. Damage to pancreatic parenchyma using Triton X-100 was indicated by increased levels of pancreatic enzymes in the perfusion medium. During perfusion with hydrogen peroxide or tert-butylhydroperoxide we found no changes in pancreatic enzymes in the portal outflow. In contrast, perfusion with xanthine oxidase induced a significant elevation in lipase and amylase in the effusion fluid after 30 min. We found a significant increase in edema in the hydrogen peroxide and in the xanthine oxidase group. Focal necroses of the pancreatic parenchyma were detected in all groups of oxidative stress.. The isolated perfused rat pancreas is a valuable experimental model for investigating the early phase of pathophysiology in acute pancreatitis, for instance, the effect of oxidative stress as an early event in acute pancreatitis. Using hydrogen peroxide tert-butylhydroperoxide or xanthine oxidase, only xanthine oxidase was able to induce a typical elevation in the pancreas enzymes in the effusion fluid.

Topics: Acute Disease; Amylases; Animals; Biopsy; Detergents; Disease Models, Animal; Hydrogen Peroxide; In Vitro Techniques; L-Lactate Dehydrogenase; Lipase; Lipid Peroxidation; Male; Malondialdehyde; Necrosis; Octoxynol; Organ Size; Oxidative Stress; Pancreatitis; Perfusion; Rats; Rats, Wistar; tert-Butylhydroperoxide; Xanthine Oxidase

The benefit of Celsior in liver graft preservation is controversial. In the isolated perfused rat liver model, we compared the effects of Celsior, University of Wisconsin (UW), and histidine-tryptophan-ketoglutarate (HTK) preservation solutions on liver cell death.. Rat livers were stored at 4 degrees C for 0, 8, 16, or 24 hr in either Celsior, UW, or HTK and reperfused for 90 min (37 degrees C). Bile secretion and perfusate levels of liver enzymes and histone-associated DNA fragments were measured. Apoptosis and oncotic necrosis were analyzed in biopsies by DNA gel electrophoresis, hematoxylin and eosin histology, and enzyme histochemistry for lactate dehydrogenase (LDH) and 5'-nucleotidase (5'-NT).. Perfusate flow rate through the liver during perfusion did not significantly differ among preservation solutions. Bile secretion was best preserved in UW livers after 16-hr (versus HTK livers) and 24-hr storage (versus HTK and Celsior livers). Enzyme leakage from UW livers was lower compared with HTK livers after 8-hr storage (serum glutamic oxaloacetic transaminase [SGOT], LDH) and with Celsior and HTK livers after 16-hr (SGOT, LDH) and 24-hr storage (SGOT, serum glutamic pyruvic transaminase, LDH, purine nucleoside phosphorylase). In situ LDH and 5'-NT activities were best preserved in UW livers (up to 24 hr), whereas enzyme activities declined remarkably in HTK livers (after 8 hr) and Celsior livers (after 16 hr of cold storage). Although perfusate DNA fragment levels were repeatedly lowest from Celsior livers, apoptotic DNA laddering and the number of fragmented nuclei in hematoxylin and eosin sections was not different among livers after 8, 16, or 24 hr of storage.. Celsior and UW are equally effective in preventing rat liver cell death after 0-16 hr of cold preservation as compared with the less effective HTK solution. After 24-hr cold storage, rat livers were best preserved in UW. Furthermore, there was no significant difference in mode of cell death (apoptosis or oncotic necrosis) after storage in any of the three solutions.

Topics: Adenosine; Alanine Transaminase; Allopurinol; Animals; Apoptosis; Aspartate Aminotransferases; Bile; Cold Temperature; Disaccharides; DNA Fragmentation; Electrolytes; Glucose; Glutamates; Glutathione; Histidine; Insulin; L-Lactate Dehydrogenase; Liver; Male; Mannitol; Necrosis; Organ Preservation; Organ Preservation Solutions; Potassium Chloride; Procaine; Raffinose; Rats; Rats, Wistar

Reperfusion injury can occur when blood flow is restored after a transient period of ischaemia. The resulting cascade of reactive oxygen species damages tissue. This mechanism may contribute to the tissue damage produced by 5-aminolaevulinic acid-induced photodynamic therapy, if this treatment temporarily depletes oxygen in an area that is subsequently reoxygenated. This was investigated in the normal colon of female Wistar rats. All animals received 200 mg kg(-1) 5-aminolaevulinic acid intravenously 2 h prior to 25 J (100 mW) of 628 nm light, which was delivered continuously or fractionated (5 J/150 second dark interval/20 J). Animals were recovered following surgery, killed 3 days later and the photodynamic therapy lesion measured macroscopically. The effects of reperfusion injury were removed from the experiments either through the administration of free radical scavengers (superoxide dismutase (10 mg kg(-1)) and catalase (7.5 mg kg(-1)) in combination) or allopurinol (an inhibitor of xanthine oxidase (50 mg kg(-1))). Prior administration of the free radical scavengers and allopurinol abolished the macroscopic damage produced by 5-aminolaevulinic acid photodynamic therapy in this model, regardless of the light regime employed. As the specific inhibitor of xanthine oxidase (allopurinol) protected against photodynamic therapy damage, it is concluded that reperfusion injury is involved in the mechanism of photodynamic therapy in the rat colon.

Topics: Allopurinol; Aminolevulinic Acid; Animals; Catalase; Colon; Female; Necrosis; Photochemotherapy; Rats; Rats, Wistar; Reperfusion Injury

We investigated the chronological profile of graft damage and recovery after liver cold ischemia-reperfusion (I/R) injury, with particular attention to the role of apoptosis on hepatocyte and sinusoidal endothelial cell (SEC) damage. Male Lewis rats underwent rearterialized orthotopic liver transplantation using grafts subjected to a short (University of Wisconsin [UW] solution for 1 hour [UW1h]) and prolonged period (UW16h) of cold preservation. Experiments were performed immediately after preservation and 4 hours, 24 hours, 3 days, and 7 days after reperfusion. At each time, graft function, incidence of apoptotic cells, expression of the epitope recognized by a monoclonal antibody specific to rat SECs (SE-1), and incidence of proliferating cells were estimated. In the UW16h group, the proportion of apoptotic SECs was markedly elevated at 4 hours. The incidence of hepatocyte apoptosis was very low, although massive hepatocyte necrosis was evident at 24 hours. The incidence of proliferating hepatocytes and SECs peaked at 3 days, then returned to normal by 7 days. SE-1 expression was reduced immediately after preservation, followed by a marked reduction at 4 and 24 hours after reperfusion, and expression returned to normal by 7 days. Although SEC apoptosis was induced in the early phase of cold I/R injury, hepatocyte damage developed without the occurrence of apoptosis. Regeneration of both hepatocytes and SECs after cold I/R injury peaked at 3 days and was complete by 7 days, whereas functional recovery of these cell populations was complete 3 days after reperfusion.

Topics: Adenosine; Allopurinol; Animals; Apoptosis; Bile; Caspase 3; Caspases; Cell Division; Glutathione; Graft Survival; Hepatocytes; Immunohistochemistry; Insulin; Ki-67 Antigen; Kinetics; Liver; Liver Function Tests; Liver Transplantation; Necrosis; Organ Preservation; Organ Preservation Solutions; Raffinose; Rats; Rats, Inbred Lew; Time Factors; Transplantation, Isogeneic

Xanthine oxidase (XO) generates reactive oxygen metabolites (ROM) as a by-product while catalyzing their reaction. The present study implicates these ROM in the pathogenesis of liver necrosis produced in rats by the intraperitoneal administration of thioacetamide (TAA; 400 mg/kg b.wt.). After 16 h of TAA administration, the activity of rat liver XO increased significantly compared to that of the control group. At the same time, the level of serum marker enzymes of liver necrosis (aminotransferases and alkaline phosphatase) and tissue malondialdehyde content also increased in TAA treated rats. Tissue malondialdehyde concentration is an indicator of lipid peroxidation and acts as a useful marker of oxidative damage. Pretreatment of rats with XO inhibitor (4-hydroxypyrazolo[3,4-d]pyrimidine; allopurinol (AP)) followed by TAA could lower the hepatotoxin-mediated rise in malondialdehyde level as well as the level of marker enzymes associated with liver necrosis. The survival rate also increased in rats given AP followed by the lethal dose of TAA. In either case, the effect of AP was dose-dependent. Results presented in the paper indicate that increased production of XO-derived ROM contributes to liver necrosis, which can be protected by AP.

Topics: Alkaline Phosphatase; Allopurinol; Animals; Dose-Response Relationship, Drug; Enzyme Inhibitors; Female; Glutathione; Lipid Peroxidation; Liver; Malondialdehyde; Necrosis; Oxidative Stress; Rats; Rats, Wistar; Reactive Oxygen Species; Thioacetamide; Transaminases; Xanthine Oxidase

A recent clinical study demonstrated that in renal allografts preserved in the cold apoptosis occurred soon after reperfusion. The mode of cell death during cold storage is generally considered necrotic. Whether apoptosis occurs as a part of cold storage is uncertain. The objective was to determine in human renal tubular cells whether apoptosis is specific for rewarming or it also occurs during cold storage and whether it could be modified.. Cold storage (4 degrees C) of primary human renal proximal tubular epithelial (RPTE) in University of Wisconsin (UW) solution up to 48 hr caused a time-dependent increase in cell death measured by lactic dehydrogenase (LDH) release and vital dye exclusion methods. Transmission electron microscopy (TEM) demonstrated that cell death in the cold was necrotic, involving considerable mitochondrial disruption, and was not apoptotic. The TUNEL assay that provides a specific, quantitative measure for apoptosis showed no increase in TUNEL-positivity during flow cytometry of cells stored in cold: 37 degrees C, 0.23+/-0.14%; 24 hr cold, 0.23+/-0.1%; 48 hr cold, 1.79+/-0.58%. Annexin-V staining, a sensitive method for detecting early apoptosis, similarly showed no increase in positively stained cells during cold storage. Addition of antioxidants 2-methyl aminochroman and deferoxamine to UW solution inhibited necrotic cell death and preserved mitochondrial structure. In contrast to cold storage alone, rewarming (37 degrees C for 24 hr) of cold stored cells, however, resulted in significant apoptosis (TUNEL positive: 48 hr cold: 2+/-0.6%, 48 hr cold and 24 hr rewarming: 54+/-17%), which was confirmed by the TEM based on typical apoptotic features. Addition of 2-MAC and DFO significantly inhibited rewarming-induced apoptotic cell death (plus 2-MAC: 3+/-1%, plus DFO: 3+/-2%).. Our study in human tubular cells provides evidence that cold storage per se does not result in apoptosis, but is primarily necrotic. However, rewarming is associated with significant apoptosis in the presence of ongoing necrosis, speculatively due to the activation of the apoptotic enzymic process of sublethally injured cells. Inclusion of antioxidants in the storage solution confers protection against both cold storage and rewarming-induced necrosis and apoptosis.

Topics: Adenosine; Allopurinol; Annexin A5; Apoptosis; Cells, Cultured; Cold Temperature; Epithelial Cells; Glutathione; Hot Temperature; Humans; In Situ Nick-End Labeling; In Vitro Techniques; Insulin; Kidney Tubules, Proximal; L-Lactate Dehydrogenase; Microscopy, Electron; Necrosis; Organ Preservation Solutions; Raffinose; Reperfusion Injury; Tissue Preservation; Trypan Blue

Free radicals may produce cytotoxicity to pancreatic islets under pathophysiological conditions. The aim of our in vitro investigations was to compare functional and morphological changes in pancreatic beta-cells induced by reactive oxygen species (ROS) generated by alloxan or xanthine oxidase/hypoxanthine (XO/HX), respectively. We demonstrate that short-term exposure to alloxan or to XO/HX leads to a temporarily elevated insulin release from isolated pancreatic islets. On application of alloxan, this effect is caused by beta-cell necrosis and can be prevented by administration of melatonin, while in contrast, XO/HX did not lead to long-term morphological changes in the majority of the cells. Among the cells destroyed by alloxan, only necrosis could be detected, while in contrast, some apoptotic cells were identified by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) reaction and electron microscopic examinations of cells treated with XO/HX. Melatonin was able to prevent the changes caused by alloxan, but failed to influence the alterations caused by XO/HX. Using electron spin resonance and lipid peroxidation assay, respectively, it was confirmed that melatonin effectively detoxifies hydroxyl radicals. Therefore, we believe that hydroxyl radicals are the toxic principle of alloxan, but not of XO/HX toxicity.

Topics: Alloxan; Animals; Electron Spin Resonance Spectroscopy; Female; Free Radical Scavengers; Free Radicals; Hydroxyl Radical; Hypoxanthine; In Situ Nick-End Labeling; Insulin; Insulin Secretion; Islets of Langerhans; Lipid Peroxidation; Male; Melatonin; Necrosis; Rats; Rats, Wistar; Reactive Oxygen Species; Xanthine Oxidase

Cisplatin (CDDP) is an effective chemotherapeutic agent used against various human malignancies. However, it induces nephrotoxicity, a severe side effect in which oxygen free radicals have been implicated to play an important role. The effect of allopurinol (Allp) given in a dose of 50 mg/kg subcutaneously (s.c.) for five days was examined on induced nephrotoxicity by a single dose of 5 mg/kg CDDP intraperitoneally (i.p.) in male wistar rats. Serum creatinine and blood urea nitrogen (BUN) concentrations were found significantly higher in the group given both Allp and CDDP than in the group given CDDP alone, p < 0.001, and histopathological examination showed more excessive degree of proximal tubular necrosis in the kidneys of animals given CDDP plus Allp than in those treated with CDDP alone. Increased renal lipid peroxidation, p < 0.001 associated with these pathological alterations suggested that oxidative stress may be involved in the potentiation of CDDP-induced nephrotoxicity by Allp.

Topics: Allopurinol; Animals; Antimetabolites; Antineoplastic Agents; Cisplatin; Drug Interactions; Injections, Subcutaneous; Kidney; Lipid Peroxidation; Male; Necrosis; Oxidative Stress; Rats; Rats, Wistar

Xanthine oxidase (XO) is an important source of reactive oxygen species in the small intestine.. To examine the interaction of platelet activating factor (PAF), XO, and neutrophils in mediating intestinal injury in rats.. Two doses of PAF were used to induce either reversible hypotension, or irreversible shock with intestinal necrosis. The activities of XO, and its precursor xanthine dehydrogenase (XD), in both the whole intestinal tissue and epithelial cells, were measured. XO was localised by histochemical staining.. PAF dose dependently induced an increase in XO activity, predominantly in the ileal epithelium, without altering the total activity of XD+XO. Most of the XD to XO conversion was via proteolysis. PAF induced XO activation and intestinal injury were prevented by prior neutrophil depletion. PAF induced XO activation is probably not due to reperfusion, as XO activation preceded the recovery of mesenteric flow. Allopurinol pretreatment substantially inhibited intestinal neutrophil sequestration induced by high dose (but not low dose) PAF.. PAF rapidly activates intestinal XO through proteolytic XD-XO conversion, predominantly in the ileal epithelium. This effect is mediated by neutrophils. XO activation promotes PAF induced polymorphonuclear leucocyte sequestration in the intestine.

Topics: Allopurinol; Animals; Dose-Response Relationship, Drug; Enzyme Inhibitors; Epithelium; Ileum; Male; Necrosis; Platelet Activating Factor; Rats; Rats, Sprague-Dawley; Xanthine Dehydrogenase; Xanthine Oxidase

In situ manipulation by touching, retracting, and moving liver lobes gently during harvest dramatically reduces survival after transplantation (P. Schemmer, R. Schoonhoven, J. A. Swenberg, H. Bunzendahl, and R. G. Thurman. Transplantation 65: 1015-1020, 1998). The development of harvest-dependent graft injury upon reperfusion can be prevented with GdCl3, a rare earth metal and Kupffer cell toxicant, but it cannot be used in clinical liver transplantation because of its potential toxicity. Thus the effect of glycine, which prevents activation of Kupffer cells, was assessed here. Minimal dissection of the liver for 12 min plus 13 min without manipulation had no effect on survival (100%). However, gentle manipulation decreased survival to 46% in the control group. Furthermore, serum transaminases and liver necrosis were elevated 4- to 12-fold 8 h after transplantation. After organ harvest, the rate of entry and exit of fluorescein dextran, a dye confined to the vascular space, was decreased about twofold, indicating disturbances in the hepatic microcirculation. Pimonidazole binding, which detects hypoxia, increased about twofold after organ manipulation, and Kupffer cells isolated from manipulated livers produced threefold more tumor necrosis factor-alpha after lipopolysaccharide than controls. Glycine given intravenously to the donor increased the serum glycine concentration about sevenfold and largely prevented the effect of gentle organ manipulation on all parameters studied. These data indicate for the first time that pretreatment of donors with intravenous glycine minimizes reperfusion injury due to organ manipulation during harvest and after liver transplantation.

Topics: Adenosine; Allopurinol; Animals; Female; Gadolinium; Glutathione; Glycine; Graft Survival; Hepatectomy; Infusions, Intravenous; Insulin; Kupffer Cells; Liver; Liver Transplantation; Microcirculation; Necrosis; Nitrites; Organ Preservation; Organ Preservation Solutions; Raffinose; Rats; Rats, Inbred Lew; Reperfusion Injury; Tumor Necrosis Factor-alpha; Valine

Topics: Adenosine; Allopurinol; Animals; Disaccharides; Electrolytes; Glutamates; Glutathione; Graft Survival; Heart Arrest; Histidine; Insulin; Liver; Liver Transplantation; Mannitol; Necrosis; Organ Preservation; Organ Preservation Solutions; Raffinose; Swine; Tissue Donors; Transplantation, Homologous

Topics: Acetylcysteine; Allopurinol; Animals; Glutathione; Intestine, Small; Ischemia; Lung; Malondialdehyde; Myocardium; Necrosis; Rats; Rats, Wistar; Reperfusion; Reperfusion Injury

Reactive oxygen species (ROS) and caspases have been implicated as potential mediators of cell death. However, their mechanistic relationship remains to be elucidated. Here we investigated the roles of caspases in apoptosis and necrosis induced by ROS, generated by the mixture of xanthine and xanthine oxidase (X/XO). A low concentration of XO (0.025 U/ml) induced DNA fragmentation with little cellular membrane damage 3 h after treatment, suggesting the induction of apoptosis. The same treatment induced membrane blebbing, a morphological change typical of apoptosis, 15 min after treatment. A high concentration of XO (0.1 U/ml) damaged cell membranes with little concomitance of DNA fragmention, suggesting the induction of necrosis. ROS also activated caspase 3-like proteases and caspase 3 itself together with the release of cytochrome c which might be the cause of caspase activation. Apoptosis induced by low concentrations of XO and necrosis induced by high concentrations of XO was inhibited by z-DEVD-CH2F, an irreversible inhibitor of caspase 3. However, rapid induction of membrane blebbing was not inhibited by z-DEVD-CH2F. These results suggest that both apoptosis and necrosis could be induced by ROS through the activation of caspase 3-like protease; however, caspase 3 activation is not needed for ROS-induced membrane blebbing.

Topics: Apoptosis; Caspase 3; Caspases; Cell Membrane; Cytochrome c Group; DNA Fragmentation; Endopeptidases; Enzyme Activation; Enzyme Inhibitors; Humans; Leukemia, Myeloid; Necrosis; Neoplasm Proteins; Oxidative Stress; Protease Inhibitors; Reactive Oxygen Species; Tumor Cells, Cultured; Xanthine; Xanthine Oxidase

Flupirtine (KATADOLON), known as a nonopiate centrally acting analgesic drug, was tested as to its potential to prevent apoptosis of human endothelial cells induced by reactive oxygen species (ROS). It was found that Flupirtine displayed no effect on viability and cell proliferation of human umbilical vein endothelial cells (HUVEC) up to a concentration of 10 microg/mL. Apoptosis, induced by ROS and generated by hypoxanthine/xanthine oxidase (EC 1.1.3.22) (HX/XOD) or t-butyl hydroperoxide, was reduced after preincubation with Flupirtine for 3 hr by 35% and 41%, respectively. The maximal cytoprotective effect against apoptosis was observed at a drug concentration of 1 to 3 microg/mL. Flow cytometric studies revealed that Flupirtine was able to decrease the number of necrotic cells as well as of apoptotic cells. Neither the simultaneous administration of Flupirtine with the apoptosis-inducing agent nor the preincubation of HUVEC with Flupirtine influenced the increase in the intracellular Ca2+ concentration [Ca2+]i caused by the production of ROS.

Topics: Aminopyridines; Calcium; Cell Death; Cells, Cultured; DNA Fragmentation; Dose-Response Relationship, Drug; Endothelium, Vascular; Humans; Necrosis; Reactive Oxygen Species; Umbilical Veins; Xanthine; Xanthine Oxidase

Progressive tissue necrosis is a unique reaction to spinal cord trauma in which the site of injury is gradually transformed into a large, cavity-filled lesion. The earliest histopathological changes after injury include a widely disseminated extravasation of erythrocytes and neutrophils. To test whether such an inflammatory reaction might initiate progressive necrosis, we examined the effects of the following anti-inflammatory treatments: allopurinol (Ap) to inhibit injury-induced xanthine oxidase, indomethacin (I) or naproxen to inhibit constitutive and inducible cyclooxygenase, aminoguanidine (Ag) to inhibit inducible nitric oxide synthase, pregnenolone (P) as a precursor steroid, and a bacterial lipopolysaccharide (L) to stimulate secretory activities of glial cells and macrophages. The spinal cord of adult rats was crushed at T8 with jeweler's forceps and, after 3 or 21 days of treatment, the cords were studied quantitatively by light microscopical image analysis. Ag, Ag+I, or Ap significantly reduced the size of the primary lesion at 3 days postoperatively, while P+L+I did so only after 21 days of treatment. A secondary lesion developed in the dorsal column and gradually extended for many millimeters rostral and caudal from the primary lesion. The size of the dorsal column lesion was diminished by 3-day treatment with Ap and by 21-day treatment with Ap or P+L+I, but Ag or Ag+I had no effect. We conclude that (a) progressive necrosis is initiated and maintained by inflammatory mechanisms and (b) for this reason, treatment with specific anti-inflammatory agents selectively attenuates various components of the necrotizing process.

Topics: Allopurinol; Animals; Anti-Inflammatory Agents; Disease Models, Animal; Female; Naproxen; Necrosis; Rats; Rats, Sprague-Dawley; Spinal Cord Injuries

Topics: Animals; Cats; Colic; Horse Diseases; Horses; Intestinal Diseases; Intestinal Mucosa; Intestine, Small; Laparotomy; Necrosis; Peroxidase; Rats; Reperfusion Injury; Swine; Xanthine Dehydrogenase; Xanthine Oxidase

Oxygen-derived free radicals are known to injure the endothelium of aorta in diverse disorders. In this study we compared the cytoprotective effects of three flavonoids against oxyradical damage to porcine aortic endothelial cells in vitro. Cultured porcine aortic endothelial cells were exposed to oxyradicals generated by xanthine oxidase--hypoxanthine (XO-HP). The cytoprotective activities of morin, quercetin, and catechin on these systems were compared using established morphologic criteria. The results in the XO-HP system showed that morin at 0.125, 0.25, and 0.5 mM delayed cell necrosis to 27.4 +/- 1.3, 46.8 +/- 1.8, and longer than 70 min, respectively, compared with 12.0 +/- 1.3 min in the control group. These degrees of protection were significantly stronger than those provided by quercetin and catechin at corresponding concentrations (p < 0.01). Morin and quercetin were moderate inhibitors of xanthine oxidase on the basis of the oxygen consumption rate, whereas catechin at the same concentrations had little inhibitory effect. The data from uric acid formation and cytochrome c reduction were consistent with the oxygen consumption measurement for the three flavonoids.

Topics: Animals; Antioxidants; Aorta; Catechin; Cells, Cultured; Endothelium, Vascular; Flavonoids; Necrosis; Quercetin; Reactive Oxygen Species; Swine; Xanthine Oxidase

We investigated the role of adhesion molecules in the early phase of reperfusion following cold ischemia. Livers of male Lewis rats were preserved for 0 h (group A) or 24 h in University of Wisconsin (UW) solution without additives (group B) or in UW solution with anti-ICAM-1 antibody (group C) or anti-E-selectin-1, SLe(x) and SLe(a) antibodies (group D). The livers were then reperfused with diluted rat whole blood (DWB; groups A and B). DWB containing anti-ICAM-1 and LFA-1 antibodies (group C) or DWB containing anti-L-selectin, SLe(x) and SLe(a) antibodies (group D). The reperfusion was performed at 37 degrees C for 1 h at 5 cm H2O of perfusion pressure. During reperfusion, hepatic microcirculation was assessed by monitoring portal and peripheral tissue blood flow. Bile production was significantly reduced in group B livers compared with those in group A. Anti-ICAM-1 and LFA-1 antibodies failed to improve hepatic microcirculation, whereas anti-LECAM-1, SLe(x) and SLe(a) antibodies significantly improved the microcirculation. Bile production in group C and D livers was comparable to that in group B livers. Preservation for 24 h significantly increased the release of TNF-alpha from 0.207 to 43.7 pg/g per hour during reperfusion. Monoclonal antibodies to the adhesion molecules did not suppress the release of TNF-alpha in groups C and D. Histological examination demonstrated a lack of leukocyte infiltration or thrombus in hetapic microvessels. The extent of hepatocyte necrosis did not differ among groups B, C, and D. We conclude that the microcirculatory disturbance in the early phase of reperfusion occurs as a result of the tethering of leukocytes through the interaction of the selectin family and their ligands, and that the ICAM-1-LFA-1 pathway is not involved in this step. The lack of improvement in bile production with antibodies to the selectin family and their ligands strongly suggests that other mechanisms participate in the deterioration of hepatic function.

Topics: Adenosine; Allopurinol; Animals; Antibodies, Monoclonal; Antibody Specificity; Bile; CA-19-9 Antigen; Cell Adhesion; Cold Temperature; E-Selectin; Glutathione; Insulin; Intercellular Adhesion Molecule-1; Ischemia; L-Lactate Dehydrogenase; L-Selectin; Leukocytes; Liver; Lymphocyte Function-Associated Antigen-1; Male; Microcirculation; Necrosis; Oligosaccharides; Organ Preservation; Organ Preservation Solutions; Raffinose; Rats; Rats, Inbred Lew; Reperfusion; Reperfusion Injury; Sialyl Lewis X Antigen; Tumor Necrosis Factor-alpha

Post-ischemic hepatic injury is characterized by zonal heterogeneity of injury (central lobular necrosis), sinusoidal neutrophil accumulation, and injury generated by reactive oxygen metabolites. We evaluated the role of the heterogeneous distribution of hepatic xanthine oxidase in the generation of neutrophil accumulation and consequent hepatocellular injury in rats subjected to shock [controlled hemorrhagic hypotension (mean arterial pressure = 37.5 + or - 2.5 mmHg for 120 min)], with or without subsequent resuscitation and hemodynamic stabilization, compared with sham-operated rats. Shock/resuscitation produced striking neutrophil accumulation (assayed by esterase histochemistry) in the pericentral sinusoids, associated with centrolobular necrosis. This paralleled the pericentral distribution of xanthine oxidase (determined by histochemical assay of frozen sections) and its release from the liver into the circulation at resuscitation. Pretreatment with allopurinol inhibited hepatic xanthine oxidase activity, neutrophil accumulation, and pericentral hepatocyte necrosis in shock/resuscitation in rats. These findings suggest that reactive oxygen metabolites generated by heterogeneously distributed xanthine oxidase may contribute to the heterogeneity of hepatocellular injury in "ischemic hepatitis."

Topics: Animals; Cell Movement; Liver; Male; Necrosis; Neutrophil Activation; Neutrophils; Rats; Rats, Sprague-Dawley; Shock; Xanthine Oxidase

Topics: Adenine Nucleotides; Allopurinol; Animals; Body Water; Catalase; Energy Metabolism; Femoral Artery; Hindlimb; Mannitol; Muscle, Skeletal; Necrosis; Neutrophils; Peroxidase; Rabbits; Reperfusion; Reperfusion Injury; Superoxide Dismutase

Morin hydrate is a bioactive pigment found in yellow Brazil wood. Recently, we reported that morin hydrate prolongs the survival of three types of cells from the human circulatory system against oxyradicals generated in vitro. The protection excels that given by equimolar concentrations of ascorbate, mannitol, and Trolox. Here, we demonstrate that, in vivo, morin hydrate at 5 mumol/kg actually reduced by > 50% the tissue necrosis in post-ischemic and reperfused rabbit hearts. Mechanistically, morin hydrate not only scavenges oxyradicals, but also moderately inhibits xanthine oxidase, a free-radical generating enzyme from the ischemic endothelium. Among other possibilities, morin hydrate appears to chelate some metal ions (e.g. Fe2+) in oxyradical formation, although this needs to be examined further. Nuclear magnetic resonance (at 500 mHz) and electron-impact mass spectrometry also supported a molecular formula of C15H10O7 for morin hydrate. Only by X-ray crystallography was it clearly revealed that there are two water molecules attached by intermolecular hydrogen bonds to a morin molecule. Also, the three rings of morin hydrate approach coplanarity. This conformation favours a delocalization of electrons after oxyradical reduction, making morin an effective antioxidant. Thus, we have documented some of the molecular properties and myocardial salvage effects of morin hydrate.

Topics: Animals; Antioxidants; Coronary Disease; Crystallography, X-Ray; Flavonoids; Heart; Magnetic Resonance Spectroscopy; Mass Spectrometry; Myocardial Reperfusion; Myocardium; Necrosis; Rabbits; Xanthine Oxidase

The small intestine (SI) is highly sensitive to oxygen free radical-induced injury. The most common preservation solution, University of Wisconsin (UW) solution, does not adequately prevent free radical-induced injury. Lazaroids, and U74389G in particular, are a new class of compound that are potent inhibitors of superoxide-mediated lipid peroxidation. We studied the added influence of U74389G to 18-hr cold preservation of rat SI in UW solution. Three groups of rats were studied. In group 1, SI was excised and reperfused immediately. In group 2, SI was stored in UW solution at 4 degrees C for 18 hr. In group 3, U74389G was given to the SI graft before storage and again before reperfusion. Blood reperfusion of the grafts was achieved via connection to the superior mesenteric artery and portal vein of support rats. Functional recovery was assessed using a maltose tolerance test. Weight changes were calculated and histologic studies done. After 30 and 60 min of reperfusion, maltose uptake in group 3 was significantly better than that of the group 2, and returned to control levels. Significantly more tissue swelling was noted in group 3 over control, but the magnitude was less than that of group 2. Less transmural necrosis and villous blunting were noted in group 3 versus group 2; the appearance of the mucosa in group 3 approached that of group 1. We conclude that the use of U74389G treatment in addition to cold storage in UW solution improves recovery of graft function and minimizes morphologic damage to the small intestinal mucosa.

Topics: Adenosine; Allopurinol; Animals; Blood Glucose; Cryopreservation; Glutathione; Hemodynamics; Insulin; Intestinal Mucosa; Intestine, Small; Necrosis; Organ Preservation; Organ Preservation Solutions; Pregnatrienes; Raffinose; Rats; Rats, Inbred Lew

Topics: Adenosine; Allopurinol; Animals; Epithelium; Exudates and Transudates; Glutathione; Graft Survival; Insulin; Intestinal Mucosa; Jejunum; Necrosis; Organ Preservation; Organ Preservation Solutions; Predictive Value of Tests; Raffinose; Rats; Rats, Inbred Lew; Reperfusion; Transplantation, Isogeneic

Collagen is lysed early during ischemia-reperfusion, but whether this is due to ischemia or reperfusion injury is not known. The effect of oxygen free radicals and free radical scavengers on left ventricular hemodynamics, myocardial morphology and collagen content were studied in an isolated, Langendorff-perfused rat heart model of regional ischemia-reperfusion.. All hearts received left anterior descending coronary artery ischemia for 20 mins. Group 1 had ischemia only; group 2 had ischemia followed by reperfusion with oxygenated Krebs-Henseleit buffer for 20 mins; group 3 had oxygen free radicals generated by hypoxanthine and xanthine oxidase during reperfusion; group 4 had free radical scavengers with superoxide dismutase plus catalase; group 5 had both oxygen free radicals and free radical scavengers during reperfusion.. Left ventricular developed pressure decreased significantly in group 3 during ischemia followed by reperfusion (58 +/- 3.1 mmHg versus 42 +/- 2.4 mmHg, P = 0.004), but did not change significantly in any of the other groups. Necrosis score on pathology was highest in group 3; this score also was higher than that in group 5 with free radical scavengers added (3.0 +/- 0.3 versus 2.0 +/- 0.4, P = 0.07) and higher than that of group 2 with reperfusion with buffer only (3.0 +/- 0.3 versus 1.4 +/- 0.5, P < 0.05). Collagen content decreased significantly compared with control in group 3 only with ischemia followed by reperfusion with the addition of oxygen free radicals (18.4 +/- 1.5 versus 11.9 +/- 1.7 g/mg protein, P < 0.05). The addition of free radical scavengers in group 5 mainly attenuated the collagen loss. Scanning electron microscopy revealed profound structural changes of the extracellular collagen matrix in numerous regions of 'stunning' independent of tissue necrosis.. We conclude that: first, oxygen free radicals trigger significant collagen damage and left ventricular dysfunction during reperfusion; second, these changes extend beyond the ischemic damage alone; and third, free radical scavengers can effectively limit oxygen free radical-induced collagen loss and left ventricular dysfunction.

Topics: Animals; Catalase; Collagen; Drug Evaluation, Preclinical; Extracellular Matrix; Free Radical Scavengers; Free Radicals; Heart; Hemodynamics; Hypoxanthine; Hypoxanthines; In Vitro Techniques; Male; Microscopy, Electron, Scanning; Myocardial Reperfusion Injury; Necrosis; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Severity of Illness Index; Superoxide Dismutase; Xanthine Oxidase

Frozen section examination was performed on 385 donor livers before transplantation. Exclusion criteria were applied to the donor livers examined to exclude potentially dysfunctional livers. The exclusion criteria included the following: severe macrovesicular steatosis, ischemic necrosis, prominent chronic portal inflammation, prominent periductular fibrosis, granulomatous inflammation, bridging fibrosis, and malignancy. Twenty-seven of the 385 donor livers examined were excluded before transplantation. The following histologic features were present in the excluded livers: severe steatosis (22), ischemic necrosis (2), portal inflammation (1), and periductular fibrosis (2). Steatosis was present in 51 of the 385 (13.25%) organs examined, including 22 of the donor organs excluded before transplantation. Twenty-nine livers with mild to moderate steatosis were implanted into size and blood type-matched recipients. Indicators of allograft function (prothrombin time and bilirubin) and damage (aspartate aminotransferase and alanine aminotransferase) were measured daily for the first 10 days after transplant. There was no statistically significant difference between the group of nonfat livers and donor livers containing mild steatosis. Statistically significant higher posttransplant serum alanine aminotransferase and prothrombin time levels were present in the patients with livers implanted with mild versus moderate steatosis. The 1-year survival rate for patients receiving fatty versus nonfatty donor livers was not statistically different (Kaplan-Meier, P = 0.592). No significant differences were found in the clinical and laboratory characteristics of donors whose organs were implanted compared with the clinical and laboratory characteristics of donors whose organs were excluded. The primary nonfunction rate after applying the exclusion criteria was 1.4%, which is a significant decrease compared with our primary nonfunction rate of 8.5% before using frozen section examination. Frozen section examination is useful in excluding donor organs which may become dysfunctional after transplantation.

Topics: Adenosine; Adult; Allopurinol; Azo Compounds; Child; Fatty Liver; Female; Fibrosis; Frozen Sections; Glutathione; Hepatitis; Humans; Hypertonic Solutions; Insulin; Ischemia; Liver; Liver Transplantation; Male; Necrosis; Organ Preservation; Organ Preservation Solutions; Raffinose; Staining and Labeling; Survival Rate; Tissue Donors

Oxidative stress induced by reactive oxygen species is one aspect of the deleterious mechanisms involved in myocardial post-ischemic reperfusion injury. The antioxidant properties of the new molecule S12340 (8-[3-(3,5-diterbutyl-4-hydroxyphenyl-thio)propyl]-1-oxa-2- oxo-3,8-diazaspiro[4.5]decane) were evaluated using three successive in vitro approaches mimicking the cardiac cell damages induced by reactive oxygen species released into the reperfused myocardium. (i) The effects of S12340 on lipid peroxidation were evaluated using an original cell-free model of non-enzymatic peroxidation of 1.32 mM arachidonic acid induced by reactive oxygen species generated photochemically. S12340 (13.2 microM) inhibited by 29% the rate of oxidative fragmentation of monohydroperoxidized arachidonic acid into aldehydic products. (ii) S12340 (10 microM) inhibited by 96% and 58% the oxidative necrosis of cultured rat cardiomyocytes induced by xanthine oxidase (20 mU/ml) and monohydroperoxidized arachidonic acid (30 microM), respectively. (iii) Superfusion of guinea-pig papillary muscle with monohydroperoxidized arachidonic acid (20 microM) resulted in marked alterations of their electrophysiological and mechanical activities. These modifications, maximal 15-17 min after the addition of lipid hydroperoxide, were completely abolished by S12340 (30 microM).

Topics: Animals; Antioxidants; Arachidonic Acids; Cells, Cultured; Guinea Pigs; Hypoxanthines; Lipid Peroxidation; Male; Myocardial Reperfusion Injury; Necrosis; Papillary Muscles; Probucol; Rats; Rats, Wistar; Spiro Compounds; Xanthine Oxidase

To determine whether released oxidants in endotoxemia contribute to the development of hepatocellular necrosis, we examined the effects of antioxidants and antioxidant enzymes on endotoxin hepatotoxicity in rats. In rats given endotoxin, focal and random hepatocellular coagulative necrotic areas with infiltration of polymorphonuclear leukocytes and mononuclear cells and an elevation of serum transaminase activities were found. The extent of hepatocellular necrosis and the level of serum transaminase activities were not significantly decreased by treatment with superoxide dismutase, catalase, alpha-tocopherol or allopurinol. These experimental data indicate that even if endotoxin is related to a release of oxidants, the oxidants do not appear to play an important role in the development of hepatocellular necrosis.

Topics: Allopurinol; Animals; Antioxidants; Catalase; Endotoxins; Liver; Male; Necrosis; Rats; Rats, Wistar; Superoxide Dismutase; Vitamin E

The effectiveness of the University of Wisconsin solution and the Collins' M solution for preservation of rat hearts was compared by examining histologic appearance, tissue water content, and mitochondrial respiratory functions after prolonged hypothermic storage and subsequent heterotopic transplantation. Survival of transplanted hearts after 5 days of reperfusion was markedly lowered by storage in Collins' M solution for 15 hours. Hearts stored in University of Wisconsin solution for 10 hours showed no increase in myocardial necrosis after 5 days of reperfusion, whereas hearts stored in University of Wisconsin solution for 15 hours and Collins' M solution for 10 and 15 hours showed a significant increase in tissue necrosis. University of Wisconsin solution reduced tissue swelling during hypothermic storage, whereas Collins' M solution did not cause such reduction. The yield of mitochondrial protein after reperfusion was significantly decreased by storage in either solution, especially after 15 hours in Collins' M solution. Mitochondrial oxidative phosphorylation was significantly inhibited by storage, especially by storage in Collins' M solution and subsequent reperfusion. These results indicate that myocardial injury, after prolonged ischemia and reperfusion, results in a decrease in functionally and structurally intact mitochondria that is dependent on preservation conditions. University of Wisconsin solution protects isolated hearts against ischemia and reperfusion injury possibly by preventing cellular and mitochondrial deterioration.

Topics: Adenosine; Allopurinol; Animals; Body Water; Cardioplegic Solutions; Cold Temperature; Glutathione; Graft Survival; Heart Transplantation; Hypertonic Solutions; Insulin; Male; Mitochondria, Heart; Myocardial Ischemia; Myocardium; Necrosis; Organ Preservation; Organ Preservation Solutions; Oxidative Phosphorylation; Raffinose; Rats; Rats, Inbred Lew

We investigated whether xanthine oxidase (XO) is a major source of oxygen-derived free radicals (oxy-radicals) in the pig and human skeletal muscles. It was observed that xanthine dehydrogenase and XO activities in nonischemic pig latissimus dorsi (LD) and gracilis muscles and human LD and rectus abdominis (RA) muscles were < 0.5 mU/g wet wt. The pig LD muscle hypoxanthine content increased significantly from 0.33 +/- 0.02 to 2.33 +/- 0.44 mumol/g dry wt after 5 h of warm ischemia, but the muscle uric acid content remained unchanged up to 2 h of reperfusion. Similarly, the hypoxanthine content in the human LD and RA muscles increased from 0.33 +/- 0.03 to 0.84 +/- 0.23 mumol/g dry wt after 2.0-3.5 h of warm ischemia, and the muscle uric acid content remained unchanged at the end of 15-90 min of reperfusion. Furthermore, 5 days of allopurinol treatment (25 mg/kg iv twice daily) starting 2 days before ischemia or 3 days of oxypurinol treatment (25 mg/kg iv twice daily) starting 15 min before reperfusion did not attenuate the extent of skeletal muscle necrosis in pig LD muscles subjected to 5 h of ischemia and 48 h of reperfusion. However, deferoxamine treatment (250 mg/kg iv twice daily) starting before or after ischemia, as described above, significantly reduced the extent of pig LD muscle necrosis. Finally, at 2 and 48 h of reperfusion significantly higher muscle neutrophil contents were seen in ischemic than in nonischemic control pig LD muscles. Neutrophil depletion with mechlorethamine (0.75 mg/kg iv) significantly reduced the extent of necrosis in pig LD muscles. These observations indicate that XO is not a major source of oxy-radicals in ischemia/reperfusion injury in the pig gracilis and LD muscles and human RA and LD muscles.

Topics: Adult; Allopurinol; Animals; Blood Cell Count; Chromatography, High Pressure Liquid; Female; Humans; Hypoxanthines; Male; Mechlorethamine; Muscles; Necrosis; Neutrophils; Orchiectomy; Oxypurinol; Peroxidase; Reactive Oxygen Species; Reperfusion Injury; Swine; Uric Acid; Xanthine Dehydrogenase; Xanthine Oxidase; Xanthines

Activated neutrophil granulocytes are an important source of oxygen free radicals in acute skin grafts. Lipid peroxidation and immigration of PMNs, indicating inflammatory mechanisms, affect each other to a variable extent. The effect of the scavengers allopurinol and alpha-D-tocopherol on both lipid peroxidation and neutrophilic infiltration was investigated. A possible mechanism for the superior effect of allopurinol compared to vitamin E was discussed.

Topics: Allopurinol; Animals; Free Radical Scavengers; Lipid Peroxidation; Male; Necrosis; Neutrophils; Peroxidase; Rats; Rats, Wistar; Skin Transplantation; Vitamin E

The role of platelet-activating factor as a potential mediator of hepatic inflammatory injury associated with liver ischemia/reperfusion was investigated using a partial no-flow model in rats in vivo. Platelet-activating factor levels of livers from sham-operated rats and from animals experiencing hepatic reperfusion for less than 6 hr were very low. They were observed to increase significantly after 12 hr of reperfusion and reached peak levels after a 24-hr reperfusion period, a time when maximal hepatic injury and inflammation occurred. Treatment of experimental rats with WEB2170, a platelet-activating factor receptor antagonist, attenuated the hepatic injury and inflammation, as evidenced by decreases in plasma ALT and in hepatocyte necrosis and neutrophil infiltration. Both inactivation of Kupffer cells with gadolinium chloride and inhibition of the formation of reactive oxygen species with allopurinol reduced platelet-activating factor production in the liver, whereas induction of neutropenia had no effect, suggesting that interaction of Kupffer cells with oxygen-derived free radicals may be a plausible mechanism for hepatic platelet-activating factor accumulation. It is concluded that platelet-activating factor contributes to the inflammatory consequences of ischemia/reperfusion underlying late-phase hepatic injury.

Topics: Alanine Transaminase; Allopurinol; Animals; Azepines; Gadolinium; Hepatitis; Ischemia; Leukocytes; Liver; Male; Necrosis; Platelet Activating Factor; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Triazoles

When Trolox (a polar analog of vitamin E) is conjugated to p-aminophenyl-beta-D-lactopyranoside, the resulting lactosylphenyl Trolox becomes a markedly more stable and effective hepatoprotector than Trolox. In primary rat hepatocytes exposed to xanthine oxidase-hypoxanthine, lactosylphenyl Trolox prolonged cell survival better than did Trolox, mannitol or ascorbate. In rats that underwent 80-min partial hepatic ischemia, infusion of lactosylphenyl Trolox at 2.9 to 5.7 mumol/kg body wt just before reoxygenation salvaged the organ more extensively than did Trolox. Mechanistically, we showed (a) that lactosylphenyl Trolox does not inhibit xanthine oxidase; (b) that lactosylphenyl Trolox effectively scavenges oxyradicals generated with xanthine oxidase and the peroxyl radicals produced with 2,2'-azo-bis(2-amidinopropane) HCl; (c) that both in hepatocytes and in vivo, lactosylphenyl Trolox is distinctly more cytoprotective than either or both of its precursors; and (d) that lactosylphenyl Trolox is amphipathic (i.e., it has both hydrophilic and hydrophobic properties), which enable it to better access and protect the lipid and aqueous milieus of the cell than the lipophile vitamin E and the moderately polar Trolox. Thus there are strong fundamental reasons for lactosylphenyl Trolox being an effective antioxidant-based hepatoprotector.

Topics: Animals; Antioxidants; Chromans; Drug Stability; Free Radicals; Glycosides; Liver; Male; Necrosis; Oxygen; Rats; Rats, Inbred Strains; Solubility; Xanthine Oxidase

Allopurinol has been reported to improve cell survival in a variety of conditions, including the ischemia-reperfusion injury occurring in skin flaps. It has been suggested that the beneficial effect of allopurinol on rat skin flaps is through blockage of xanthine oxidase-generated oxygen-derived free radicals. We have previously reported on the lack of xanthine oxidase activity in the skin of humans and pigs as compared with that of rats. This current study attempts to improve skin and myocutaneous flap survival in pigs in two separate experiments using allopurinol. In the first experiment, a suspension of 50 mg/kg (N = 12) allopurinol resulted in no significant difference in the survival of control and treated flaps. Because of the negative results in the first experiment, a second experiment was designed making several changes. The length of the global ischemic insult was reduced from 8 to 6 hours, and allopurinol was administered as a solution of 300 mg/kg (N = 14). This higher dose is expected to produce complete inhibition of xanthine oxidase in this animal model. These changes resulted in three operative deaths, no improvement in skin-flap survival, and a decrease in myocutaneous flap survival. Allopurinol's therapeutic effectiveness and its mechanism of action in an ischemia-reperfusion injury model lacking xanthine oxidase activity are discussed.

Topics: Allopurinol; Animals; Female; Graft Survival; Necrosis; Random Allocation; Reperfusion Injury; Surgical Flaps; Swine; Xanthine Oxidase

The role of Sucralfate in prevention of acute gastric injuries and its comparison with free radicals blockers as Allopurinol, Soybean Trypsin Inhibitor and Superoxide Dismutase was studied in the ischemia-reperfusion model by total occlusion of the celiac axis in Wistar rats. In control rats, the gross gastric mucosal necrotic area was of 80%; in contrast, the antioxidant drugs resulted in a necrotic area of 7%-15% and Sucralfate resulted in a necrotic area of only a 4%. It was concluded that Sucralfate, as antioxidant-cytoprotective drug, by enhancing the gastric defensive barrier was more important than the secondary aggression induced by free radicals.

Topics: Allopurinol; Animals; Female; Gastric Mucosa; Necrosis; Random Allocation; Rats; Rats, Inbred Strains; Reperfusion Injury; Sucralfate; Superoxide Dismutase; Trypsin Inhibitor, Kunitz Soybean

Frostbite is characterized by acute tissue injury induced by freezing and thawing. Initial complete ischemia is followed by reperfusion and later, tissue necrosis. These vascular events support the hypothesis that free radical-mediated reperfusion injury at thawing might contribute to tissue necrosis after frostbite in a manner similar to that seen after normothermic ischemia. To test this hypothesis, rabbit ears were frozen at -21 degrees C for 30, 60, 90, or 120 s and rewarmed at room temperature (22 degrees C). Rabbits were treated "blindly" with saline alone, highly purified, pharmaceutical grade superoxide dismutase (SOD), allopurinol, or deferoxamine. The area of ear necrosis was determined 3 weeks after frostbite by "blinded" morphometry. The administration of SOD at the time of thawing significantly improved viability in ears frozen for 60 and 90 s, but not in those frozen for 30 or 120 s. Deferoxamine also improved viability in ears frozen for 60 s. Allopurinol did not significantly affect ear survival. Electron micrographs showed the appearance of severe endothelial cell injury beginning during freezing and extending through early reperfusion. Later, neutrophil adhesion, erythrocyte aggregation, and microvascular stasis were seen. These findings suggest that free radical-mediated reperfusion injury has a role in frostbite, and quantitate the proportion of the injury that is due to this mechanism.

Topics: Allopurinol; Animals; Deferoxamine; Disease Models, Animal; Ear; Free Radicals; Freezing; Frostbite; Male; Necrosis; Rabbits; Reperfusion Injury; Superoxide Dismutase

Topics: Allopurinol; Animals; Aspartate Aminotransferases; Coenzymes; Dose-Response Relationship, Drug; Free Radicals; Glutathione; Liver; Necrosis; Oxygen; Rats; Rats, Inbred Lew; Reperfusion Injury; Superoxide Dismutase; Temperature; Ubiquinone

We previously showed that combined treatment with allopurinol plus verapamil had a salutary effect on tissue necrosis during 24-h permanent coronary occlusion. The present study was undertaken to determine whether cardioprotection with allopurinol plus verapamil as compared with either allopurinol or verapamil treatment alone could be sustained in dog hearts during 48-h permanent coronary occlusion. In 46 dogs, coronary occlusion was induced using a closed-chest embolization procedure. Four groups were studied: (a) untreated controls, (b) dogs receiving allopurinol, (c) dogs receiving verapamil, and (d) dogs receiving allopurinol plus verapamil. Tissue necrosis was evaluated using triphenyltetrazolium staining and was related to two major baseline predictors of infarct size: anatomic risk zone size and coronary collateral flow. In untreated controls, the ratio of infarct to risk zone was inversely related to coronary collateral flow; analysis of covariance (ANCOVA) indicated that treatment with allopurinol or verapamil alone and combined allopurinol plus verapamil shifted this relationship downward. In conclusion, combined treatment with allopurinol plus verapamil did not afford additional limitation of tissue necrosis as compared with either allopurinol or verapamil treatment alone; however, considerable and statistically significant limitation of tissue necrosis was observed even during 48-h permanent coronary occlusion without reperfusion.

Topics: Allopurinol; Animals; Calcium; Coronary Circulation; Dogs; Free Radicals; Hemodynamics; Male; Myocardial Infarction; Myocardium; Necrosis; Oxygen Consumption; Verapamil

Isoproterenol produces myocardial necrosis in rats. To investigate the possible role of oxygen free radicals generated by xanthine oxidase and neutrophils, we examined the effects of the xanthine oxidase inhibitors, 6-mercaptopurine (6MP) and 6-thioguanine (6TG) combined and allopurinol, or of irradiation (to induce leukopenia) on isoproterenol-induced myocardial necrosis (ISOMN). The incidence and severity of ISOMN was significantly reduced by 6MP + 6TG but not by the specific inhibitor of xanthine oxidase, allopurinol, indicating that the protective effects of 6MP + 6TG may be due to its free radical scavenging activity rather than its xanthine oxidase inhibitory activity. Irradiation provided complete protection against ISOMN in all rats. Marked leukopenia or other radiation-induced protective factors could play a role in the mechanism of the protection.

Topics: Allopurinol; Animals; Heart Diseases; Isoproterenol; Leukocytes; Leukopenia; Male; Mercaptopurine; Myocardium; Necrosis; Radiation Injuries, Experimental; Rats; Rats, Inbred Strains; Thioguanine

Topics: Adenocarcinoma; Aged; Allopurinol; Arteritis; Coformycin; Drug Hypersensitivity; Humans; Lung Neoplasms; Male; Necrosis; Pentostatin; Ribonucleosides

Oxygen-free radicals have been implicated as mediators of ischemic damage in a number of tissues, including heart, kidney, small intestine, and skin. Superoxide dismutase, a free radical scavenger, and allopurinol, an inhibitor of xanthine oxidase (a catalyst in the formation of superoxide) have been shown separately to decrease ischemic damage to tissue. Sixty-two male Sprague-Dawley rats (220 to 280 g) were divided into five groups: control, superoxide dismutase only, allopurinol only, high-dose combined allopurinol and superoxide dismutase, and low-dose combined allopurinol and superoxide dismutase. An 18-cm2 ventral island skin flap, based on a single inferior epigastric vessel, was raised and replaced. Blood flow was assessed with a perfusion fluorometer immediately after the flap was replaced, and on postoperative days 1 and 3. Gross necrosis was assessed on postoperative day 7. Gross necrosis was reliably reduced in all groups as compared with the control; however, necrosis in any one experimental group was not significantly different from any other experimental group. Necrosis (expressed as a percentage of the area of the random [distal] half of the flap) was as follows for each group: control, 74%; superoxide dismutase, 43%; allopurinol, 43%; high-dose combined, 48%; low-dose combined, 33%. Blood flow, as represented by the dermofluorescence index, was not changed by any of the treatments. Blood flow was also related to the eventual survival or necrosis for any one portion of tissue. All experimental groups survived with significantly less blood flow than the control.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Allopurinol; Animals; Male; Necrosis; Rats; Rats, Inbred Strains; Regional Blood Flow; Reperfusion Injury; Skin; Superoxide Dismutase; Surgical Flaps

Topics: Aged; Allopurinol; Chemical and Drug Induced Liver Injury; Gout; Humans; Liver Diseases; Male; Necrosis

Topics: Free Radicals; Humans; Inflammation; Necrosis; Superoxide Dismutase; Superoxides; Xanthine Oxidase

Cardioprotection by allopurinol during ischemia is thought to be due to inhibition of xanthine oxidase-derived reactive oxygen intermediates. Previous studies have reported that long pretreatment with allopurinol limits tissue necrosis during acute myocardial ischemia. This study investigated whether a prolonged pretreatment with allopurinol was necessary for cardioprotection. Tissue necrosis was measured in a closed chest canine model of permanent coronary occlusion when the drug was administered post coronary occlusion. In 20 dogs the coronary artery was occluded by an embolus injected into the left coronary artery. Three groups were studied: untreated controls (saline given intravenously post occlusion); allopurinol 1 min post occlusion (25 mg/kg given intravenously, 1 min post occlusion); and allopurinol 30 mins post occlusion (25 mg/kg given intravenously 30 mins post occlusion). Dogs in both drug treatment groups also received allopurinol (25 mg/kg intravenously) every 8 h post coronary occlusion. After 24 h of permanent coronary occlusion tissue necrosis was evaluated using triphenyl tetrazolium chloride staining and was related to major baseline predictors of infarct size, including anatomic risk zone and coronary collateral flow. In control dogs, infarct to risk zone ratio was inversely related to subepicardial collateral flow; analysis of covariance indicated that allopurinol administered post coronary occlusion did not shift this relationship. Treatment with allopurinol within the first minutes after coronary occlusion was ineffective in limiting tissue necrosis in this model of permanent coronary occlusion, therefore, long pretreatment with allopurinol is necessary for cardioprotection.

Topics: Allopurinol; Animals; Constriction; Coronary Vessels; Disease Models, Animal; Dogs; Male; Myocardial Infarction; Myocardium; Necrosis; Premedication; Time Factors

Topics: Allopurinol; Animals; Female; Free Radicals; Gastric Mucosa; Ischemia; Necrosis; Platelet Activating Factor; Rats; Rats, Inbred Strains; Reference Values; Reperfusion Injury; Stomach; Superoxide Dismutase

Skin-flap ischemia has been associated with the presence of free radicals. In this study, two enzyme systems involved in free-radical metabolism were used to compare a distal skin flap to a skin graft. Forty-two rats were divided into several test groups. A 10 X 3 cm dorsal rat flap was used, and tissue biopsies for xanthine oxidase and malonyldialdehyde (MDA) were obtained 2.5, 5.5, and 8.5 cm from the base of the flap at the hours given. In group I (control), the flap was outlined but not elevated, and biopsies were obtained. In group II, the flap was elevated, and biopsies were obtained at 6 hours. In group III, the flap was elevated, the distal 4 X 3 cm was amputated and replaced as a full-thickness skin graft, and biopsies were obtained at 6 hours. In group IV, the flap was elevated, and biopsies were obtained at 12 hours. In group V, the flap was treated as in group III, and biopsies were obtained at 12 hours. In group VI, the flap was elevated, and biopsies were obtained at 24 hours. In group VII, the flap was treated as in group III, and biopsies were obtained at 24 hours.. Xanthine oxidase was significantly higher in all distal biopsies compared to proximal biopsies. Xanthine oxidase also increased with time. Malonyldialdehyde increased over time as well as with distance from the flap base. Distal flap biopsies at 24 hours had greatly increased levels of malonyldialdehyde compared to skin grafts (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Analysis of Variance; Animals; Free Radicals; Ischemia; Malondialdehyde; Necrosis; Rats; Rats, Inbred Strains; Skin; Surgical Flaps; Xanthine Oxidase

The role of oxygen-derived free radicals in the pathogenesis of acute pancreatitis was studied by evaluating the effects of catalase, allopurinol, and dimethylsulfoxide on diet-induced acute hemorrhagic pancreatic necrosis in mice. The mortality rate and degree of hyperamylasemia associated with this model of pancreatitis were reduced by catalase but a similar result followed the administration of heat-denatured catalase, suggesting that the apparent protective effect of catalase was not the result of reductions in free radical levels. Neither allopurinol nor dimethylsulfoxide reduced mortality or degree of hyperamylasemia. The increased pancreatic content of amylase and the necrosis that characterize this model of pancreatitis were not altered by any of the agents tested. In contrast, both allopurinol and dimethylsulfoxide reduced peripancreatic edema formation, suggesting that edema, but not the other features that characterize this model of pancreatitis, may result from generation of oxygen-derived free radicals.

Topics: Acute Disease; Allopurinol; Amylases; Animals; Catalase; Choline Deficiency; Diet; Dimethyl Sulfoxide; Edema; Ethionine; Female; Free Radicals; Hemorrhage; Mice; Necrosis; Oxygen; Pancreatitis

Topics: Allopurinol; Animals; Catalase; Creatine Kinase; Dogs; Free Radicals; Heart; Hypertonic Solutions; L-Lactate Dehydrogenase; Lactates; Lung; Myocardium; Necrosis; Organ Preservation

Topics: Animals; Dermatologic Surgical Procedures; Free Radicals; Graft Survival; Hematoma; Ischemia; Male; Malondialdehyde; Necrosis; Rats; Rats, Inbred F344; Skin; Surgical Flaps; Xanthine Oxidase

This study presents further evidence of free radical involvement in skin flap necrosis in a dorsal rat flap model. Rats receiving deferoxamine, a free radical scavenger and iron chelator had significantly less necrosis (p less than 0.001) than saline treated rats. In a separate experiment, tissue determinations for malonyldialdehyde (MDA) were consistent with the survival results in showing a significant decrease in MDA in all biopsy sites (p less than 0.05 or less), indicative of reduced lipoperoxidation in the deferoxamine treated rats.

Topics: Animals; Deferoxamine; Free Radicals; Graft Survival; Male; Malondialdehyde; Necrosis; Rats; Rats, Inbred Strains; Skin; Surgical Flaps; Xanthine Oxidase

We have investigated the possible protective effect of superoxide dismutase and allopurinol in a rat model of mild and severe hepatic necrosis produced by Corynebacterium parvum with or without endotoxin. Histology showed a sinusoidal mononuclear cell infiltrate with multiple granulomata but variable degrees of hepatic necrosis. In the severe hepatic injury model there was a reduction in mortality, associated with a decrease in histologic and biochemical evidence of hepatic necrosis, after treatment with superoxide dismutase. This protective effect was not demonstrated with partially heat-inactivated superoxide dismutase. In the mild hepatic injury model similar trends in reduction of serum levels of hepatic enzymes were observed after treatment with both superoxide dismutase and allopurinol. These results indicate that oxygen-derived free radicals may play an important role in the pathogenesis of hepatic injury in the rat.

Topics: Alanine Transaminase; Allopurinol; Animals; Disease Models, Animal; Endotoxins; Free Radicals; Hepatitis; Isocitrate Dehydrogenase; Liver; Liver Diseases; Necrosis; Propionibacterium acnes; Rats; Rats, Inbred Strains; Superoxide Dismutase; Superoxides; Xanthine Oxidase

Experiments were performed to determine if xanthine oxidase is a source of free radicals during myocardial ischemia. Open chest dogs were subjected to 1 h of total occlusion of the left anterior descending coronary artery followed by 4 h of reperfusion. Directly after coronary artery occlusion, Ce141 microspheres were injected into the left atrium to mark the ischemic bed. At the end of reperfusion, the hearts were removed and sectioned. Autoradiography determined the ischemic myocardium at risk, and the necrotic zone was determined by triphenyl-tetrazolium staining. Animals were divided into three groups: control, allopurinol (24-h oral pretreatment 400 mg, then 50 mg/kg IV bolus on occlusion); and superoxide dismutase starting with occlusion (15 000 U/kg). The size of the infarct as a percentage of the tissue at risk was: 23.1 +/- 4.1 for the control; 8.7 +/- 1.2 for the allopurinol group; and 5.4 +/- 1.2 for the superoxide dismutase group. The infarcts in the allopurinol and superoxide dismutase groups were significantly smaller than those in the control groups. In a second series of experiments we determined the xanthine oxidase/xanthine dehydrogenase content of dog myocardium. The left anterior descending branch was ligated for 30 min and then biopsies were removed from both the normal and the ischemic regions. Total enzyme content did not differ between the two regions averaging 0.259 U/g protein for the ischemic tissue and 0.225 U/g protein for the normal region. Only 9.8% of the enzyme was in the oxidase form in the normal region while 32.8% was in the oxidase form in the ischemic zone.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Allopurinol; Animals; Coronary Circulation; Coronary Disease; Dogs; Female; Free Radicals; Male; Myocardium; Necrosis; Superoxide Dismutase; Xanthine Oxidase

Allopurinol hepatotoxicity occurred in two patients. Data from the literature suggest that allopurinol can occasionally cause liver injury, particularly in persons receiving diuretic drugs or with compromised renal function. Clinical and laboratory findings are consistent with hepatocellular injury mediated by a hypersensitivity reaction. Most patients recover when the drug is withdrawn; the possible benefits of corticosteroid treatment remain to be established.

Topics: Adrenal Cortex Hormones; Aged; Allopurinol; Chemical and Drug Induced Liver Injury; Drug Hypersensitivity; Humans; Liver Diseases; Male; Necrosis

Allopurinol, acting as a metabolic depressant, significantly increases flap survival in high doses, but not at doses that might be acceptable clinically. Prednisolone is highly effective in improving flap survival when the afferent blood supply is provided by small arteries such as are found in the panniculus carnosus of rabbits and in axial pattern flaps. I feel that the study should encourage plastic surgeons to experiment with drugs that sustain metabolism during ischemic periods, as a means of improving flap survival. In situations in which ischemia can be anticipated, its effects may be minimized by using such drugs before the insult.

Topics: Allopurinol; Animals; Graft Survival; Ischemia; Necrosis; Prednisolone; Rabbits; Skin; Surgical Flaps

Rats were anesthetized and their lift kidneys were made ischemic for 1 h by clamping of the aorta just above the left renal artery. Mannitol (2.5 g/kg), Dextran 70 (0.6 g/kg), methylprednisolone (50 and 100 mg/kg), and allopurinol (100 mg/kg body weight) were administered before, during, or after the ischemia period in order to test the effect of each of these drugs upon this model of renal injury. At 24 h after the release of the aortic clamp the left kidneys of the drug treated animals wwere perfusion fixed and processed for light and electron microscopy. Dextran administration to animals with ischemic kidneys gave rise to a pronounced vacuolization ("osmotic nephrosis"), in the entire proximal tubule and especially in the pars recta. This was in contrast to dextran administration to rats with nonischemic kidenys, which showed no or very mild "osmotic nephrosis." This demonstrates that ischemia makes rat kidneys more susceptible to the development of "osmotic nephrosis." In controls (no drug treatment) one hour of renal ischemia gave partial necrosis of pars recta of the proximal tubule, while the pars convoluta tubule survived. Mannitol treatment significantly reduced the amount of necrosis of the pars recta, whereas dextran, methylprednisolone, and allopurinol had no or a negative effect on the survival of the cells of the pars recta segment. It is suggested that mannitol protects against the development of necrosis by increasing medullary blood flow in combination with a counteractive influence on the cellular swelling, which is known to occur in ischemia.

Topics: Allopurinol; Animals; Dextrans; Ischemia; Kidney Tubules, Proximal; Male; Mannitol; Methylprednisolone; Microscopy, Electron; Necrosis; Rats; Shock

Topics: Allopurinol; Chemical and Drug Induced Liver Injury; Drug Hypersensitivity; Female; Humans; Middle Aged; Necrosis; Pruritus; Uric Acid; Urticaria

Topics: Allopurinol; Chemical and Drug Induced Liver Injury; Drug Interactions; Humans; Necrosis

Topics: Adult; Allopurinol; Bone Diseases; Clofibrate; Diet Therapy; Dietary Carbohydrates; Femur Head Necrosis; Humans; Humerus; Hyperlipidemias; Joint Prosthesis; Knee Joint; Lipoproteins; Male; Necrosis; Prediabetic State; Triglycerides; Uric Acid