allopurinol and Peritonitis

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

Activation of the NLRP3 inflammasome by microbial ligands or tissue damage requires intracellular generation of reactive oxygen species (ROS). We present evidence that macrophage secretion of IL1β upon stimulation with ATP, crystals or LPS is mediated by a rapid increase in the activity of xanthine oxidase (XO), the oxidized form of xanthine dehydrogenase, resulting in the formation of uric acid as well as ROS. We show that XO-derived ROS, but not uric acid, is the trigger for IL1β release and that XO blockade results in impaired IL1β and caspase1 secretion. XO is localized to both cytoplasmic and mitochondrial compartments and acts upstream to the PI3K-AKT signalling pathway that results in mitochondrial ROS generation. This pathway represents a mechanism for regulating NLRP3 inflammasome activation that may have therapeutic implications in inflammatory diseases.

Topics: Animals; Autophagy; Blotting, Western; Calcium; Calcium Phosphates; Carrier Proteins; Caspase 1; Gene Knockdown Techniques; In Vitro Techniques; Interleukin-1beta; Lipopolysaccharides; Macrophages; Mice; Mice, Inbred C57BL; Monocytes; NLR Family, Pyrin Domain-Containing 3 Protein; Peritonitis; Phosphorylation; Proto-Oncogene Proteins c-akt; Reactive Oxygen Species; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Uric Acid; Xanthine Dehydrogenase; Xanthine Oxidase

The effects of nitric oxide (NO) from calcium-independent NO synthase (iNOS) on microvascular protein leak in acute lung injury (ALI) are uncertain, possibly because of disparate effects of iNOS-derived NO from different cells. We assessed the contribution of iNOS from inflammatory versus parenchymal cells to pulmonary protein leak in murine cecal ligation and perforation-induced ALI. We studied iNOS+/+, iNOS-/-, and two reciprocally bone marrow-transplanted iNOS chimeric mice groups: + to - (iNOS+/+ donor bone marrow-transplanted into iNOS-/- recipient mice) and - to +. Sepsis-induced ALI was characterized by pulmonary leukocyte infiltration, increased pulmonary iNOS activity, and increased pulmonary microvascular protein leak, as assessed by Evans blue (EB) dye. Despite equal neutrophil infiltration, sepsis-induced EB-protein leak was eliminated in iNOS-/- mice and in - to + iNOS chimeras (parenchymal cell-localized iNOS) but was preserved in + to - chimeric mice (inflammatory cell-localized iNOS). EB-protein leak was also prevented by pretreatment with allopurinol and superoxide dismutase. Microvascular protein leak in sepsis-induced ALI is uniquely dependent on iNOS in inflammatory cells with no obvious contribution of iNOS in pulmonary parenchymal cells. Pulmonary protein leak is also dependent on superoxide, suggesting an effect of peroxynitrite rather than NO itself.

Topics: Allopurinol; Animals; Bone Marrow Transplantation; Capillary Leak Syndrome; Chimera; Coloring Agents; Disease Models, Animal; Evans Blue; Free Radical Scavengers; Lung; Male; Mice; Nitric Oxide; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Peritonitis; Pilot Projects; Polyethylene Glycols; Respiratory Distress Syndrome; Sepsis; Superoxide Dismutase

The role of oxidant release and tissue antioxidant defenses on inflammation-induced organ injury is not clearly defined.. We determined the effect of acute zymosan peritonitis in rats on lung and liver tissue oxidant stress and antioxidant defenses during a 5-day period. Oxidant activity was measured as tissue malondialdehyde and oxidized glutathione (GSSG). Antioxidant activity was measured as tissue-reduced glutathione (GSH) and catalase activity. Rats were maintained hydrated with subcutaneous crystalloid. Animals were killed at 4, 12, and 24 hours and 5 days.. Acute peritonitis was evident at 12 and 24 hours but was resolving at 5 days. Peritoneal fluid cultures were negative after 24 hours. A 50% mortality rate was noted between 20 and 30 hours, with no deaths after 30 hours. We noted a significant increase in lung GSSG and malondialdehyde at 4 hours that persisted for the 5 days, as did histologic evidence of a progressing severe lung inflammation. No increased conversion of lung xanthine dehydrogenase to xanthine oxidase was noted. Lung GSH and catalase activity were maintained at control despite negligible food intake. In contrast, liver GSSG was increased significantly only at the 4-hour period, corresponding with a transient conversion of xanthine dehydrogenase to xanthine oxidase from 10% to 31%. Tissue malondialdehyde did not increase despite the initial oxidant stress. However, tissue GSH and catalase values decreased by more than 50% after 24 hours and remained decreased at 5 days.. We conclude that early lung and liver oxidant stress is initiated by acute peritonitis. Lung oxidant changes persist and lung dysfunction progresses, even though antioxidant activity is maintained and acute peritonitis is resolving. Liver lipid peroxidation did not develop despite oxidant release, probably because of a large antioxidant reserve. However, a severe and sustained decrease in liver antioxidants results, increasing the potential damage from a subsequent oxidant insult.

Topics: Animals; Antioxidants; Body Weight; Catalase; Diuresis; Glutathione; Glutathione Disulfide; Hematocrit; Liver; Lung; Male; Oxidants; Oxygen; Peritonitis; Rats; Rats, Wistar; Time Factors; Xanthine Dehydrogenase; Xanthine Oxidase; Zymosan

We studied the toxicity of free radicals to human mesothelial cells in vitro and to the peritoneal membrane of rats during peritoneal dialysis. Free radicals cause damage to mesothelial cells as measured by release of cytosolic markers such as 86Rb and lactate dehydrogenase. Vitamin E neutralized the toxic effect of free radicals in vitro. Human mesothelial cells exposed over 6 h to a mixture of essential and nonessential amino acids in medium are more vulnerable to the cytotoxic effect of free radicals than control cells exposed to medium alone. Cells exposed previously to glucose or glycerol are less vulnerable than controls. In rats free radicals generated intraperitoneally by a xanthine-xanthine oxidase system induce changes in peritoneal permeability similar to those observed during peritonitis: loss of ultrafiltration, increased glucose absorption from the dialysate and augmented transperitoneal loss of albumin. In addition lipids in the peritoneum became peroxidated. The addition of vitamin E to the peritoneal fluid with xanthine-xanthine oxidase prevents peroxidation of lipids and the subsequent loss of ultrafiltration. Our results show that free radicals may exert a potentially toxic effect on the peritoneal membrane during peritonitis. In such circumstances the addition of free radical scavenger to the dialysis fluid may preserve intact structure and function of peritoneum.

Topics: Animals; Epithelial Cells; Epithelium; Free Radical Scavengers; Free Radicals; Humans; In Vitro Techniques; L-Lactate Dehydrogenase; Peritoneal Dialysis, Continuous Ambulatory; Peritoneum; Peritonitis; Rats; Rats, Wistar; Reactive Oxygen Species; Vitamin E; Xanthine; Xanthine Oxidase; Xanthines

To determine the effect of a severe nonbacterial-dependent peritonitis on the degree and time course of liver oxidant stress and antioxidant activity.. Prospective, randomized, controlled study.. Animal laboratory.. Thirty-eight male Sprague-Dawley rats were injected with zymosan 0.75 mg/g body weight, mixed in mineral oil, and fluid resuscitated.. None.. Oxygen consumption (VO2), base deficit, and blood gases were determined. Liver tissue oxidized and reduced glutathione, malondialdehyde catalase, xanthine oxidase, and xanthine dehydrogenase were measured and data were compared with both a pair-fed and an ad libitum fed group over a 24-hr period. We noted a 30% mortality rate with animals dying between 20 and 24 hrs. Peak decrease in VO2 occurred at 12 hrs, corresponding with a metabolic acidosis. Marked liver oxidant stress was seen at 4 hrs with oxidized glutathione increased from a control value of 0.2 +/- 0.1 to 1.1 +/- 0.2 mg/g of tissue, while reduced glutathione decreased from a control value of 1.8 +/- 0.1 to 0.3 +/- 0.1 mg/g. By 24 hrs, oxidized glutathione activity was no longer increased, but reduced glutathione concentrations were still markedly decreased. Tissue catalase was also significantly decreased at the 24-hr period. Liver malondialdehyde was increased at 24 hrs when the peak decrease in antioxidants was evident. Liver xanthine oxidase activity increased significantly from 15 +/- 3 to 45 +/- 8 mumol uric acid/min/g by 4 hrs and remained increased, with the initial increase predating evidence of impaired perfusion. Pair-fed animals demonstrated no changes in oxidant or antioxidant activity.. We conclude that a marked increase in liver oxidant stress and decrease in antioxidant activity occurs in the first several hours after the onset of nonbacterial peritonitis. An early increase in liver xanthine oxidase activity may be a source of the oxidants. Decreased liver antioxidant activity persists well after the oxidant stress resolves.

Topics: Acidosis, Lactic; Animals; Antioxidants; Blood Gas Analysis; Disease Models, Animal; Glutathione; Inflammation; Liver; Male; Malondialdehyde; Oxidants; Oxygen Consumption; Peritonitis; Random Allocation; Rats; Rats, Sprague-Dawley; Time Factors; Xanthine Dehydrogenase; Xanthine Oxidase; Zymosan

Our purpose was to determine the effect of non-bacteria-dependent systemic inflammation on the degree and time course of lung oxidant activity and antioxidant defenses, comparing these changes with lung, physiologic, and histologic alterations. Adult male rats were given intraperitoneal zymosan (0.7 mg/g body weight) and were fluid resuscitated. Oxidant changes were measured as lung tissue oxidized glutathione (GSSG) and malondialdehyde (MDA) content, antioxidant defenses as tissue reduced glutathione (GSH), and catalase. Animals were killed at 4, 12, and 24 h, and at 5, 10, and 30 days. Lung data were compared with that found in liver. We noted a 45% mortality in the first 18 to 36 h with all remaining animals surviving. In the first 24 h, we noted a doubling of lung MDA and an 80% conversion of tissue GSH to GSSG compared with less than 5% in control animals, indicating a severe oxidant stress. These findings corresponded with marked increase in lung neutrophils. Arterial pressure (PaO2) was significantly decreased from a control of 95 +/- 4 mm Hg to 80 +/- 5 mm Hg and 75 +/- 4 mm Hg at Days 5 and 10, respectively, but returned toward control by 30 days. Lung GSSG and MDA remained significantly increased for the 30-day period, whereas amounts of the antioxidants, catalase, and GSH returned to control after 24 h. The ongoing oxidant stress corresponded with marked mononuclear cell infiltration and interstitial thickening, which persisted over the 30-day period even after peritonitis had completely resolved.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Blood Gas Analysis; Catalase; Disease Models, Animal; Evaluation Studies as Topic; Glutathione; Glutathione Disulfide; Inflammation; Lipid Peroxidation; Male; Malondialdehyde; Oxygen Consumption; Peritonitis; Rats; Rats, Sprague-Dawley; Respiratory Distress Syndrome; Time Factors; Xanthine Dehydrogenase; Xanthine Oxidase; Zymosan

This work uses cecal perforation on the rat as a model of intra-abdominal sepsis. Under these conditions, various antibiotics were tested alone or in association with free radical scavengers, such as allopurinol and catalase. It can be concluded that the scavengers were not effective alone, but when combined with antibiotics they rendered good results in the majority of the groups when given postsepsis. Further studies are needed to determine the real role of agents like the free radical scavengers in infectious situations such as the one discussed here.

Topics: Allopurinol; Animals; Anti-Bacterial Agents; Bacterial Infections; Catalase; Cecal Diseases; Drug Therapy, Combination; Female; Intestinal Perforation; Leukocyte Count; Peritonitis; Rats