3-nitrotyrosine and Multiple-Organ-Failure

Olprinone is a specific phosphodiesterase (PDE)-III inhibitor, which has been found to have anti-inflammatory effects in addition to its main inotropic and peripheral vasodilatory effects. In the present study we investigated the effects of olprinone (0.2mg/kg, i.p.) on the development of zymosan-induced multiple organ failure in mice. Treatment with olprinone attenuated the peritoneal exudation and the migration of polymorphonuclear cells caused by zymosan. Olprinone also attenuated the lung, liver and pancreatic injury, renal dysfunction as well as the increased lung and intestine myeloperoxidase (MPO) activity caused by zymosan. Immunohistochemical analysis for inducible nitric oxide synthase (iNOS), nitrotyrosine, poly(ADP-ribose) (PAR), tumor necrosis factor-α (TNF-α) and interleuchin-1β (IL-1β) revealed positive staining in pancreatic and intestinal tissue obtained from zymosan-injected mice. The degree of staining for nitrotyrosine, iNOS, PAR, TNF-α and IL-1β was markedly reduced in tissue sections obtained from zymosan-injected mice, which had received olprinone. In addition, administration of zymosan caused a severe illness in the mice characterized by significant loss of body weight and a 60% of mortality at the end of observation period (7 days). Treatment with olprinone significantly reduced the development of systemic toxicity, loss in body weight and mortality, caused by zymosan. This study provides evidence that olprinone attenuates the degree of zymosan-induced shock in mice.

Topics: Alanine Transaminase; Alkaline Phosphatase; Amylases; Animals; Apoptosis; Ascitic Fluid; Aspartate Aminotransferases; bcl-2-Associated X Protein; Bicarbonates; Bilirubin; Blood Gas Analysis; Body Weight; Cell Count; Creatinine; Fas Ligand Protein; Hydrogen-Ion Concentration; Imidazoles; Intercellular Adhesion Molecule-1; Interleukin-1beta; Kidney; Lipase; Liver; Lung; Male; Mice; Mice, Inbred Strains; Multiple Organ Failure; Nitrates; Nitrites; P-Selectin; Pancreas; Phosphodiesterase 3 Inhibitors; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerases; Proto-Oncogene Proteins c-bcl-2; Pyridones; Survival Analysis; Tumor Necrosis Factor-alpha; Tyrosine; Zymosan

Glutamine is the most abundant amino acid in the bloodstream. It is important in nucleotide synthesis, is anti-catabolic, has anti-oxidant properties via metabolism to glutathione, may enhance immune responsiveness and possesses immunoregulatory functions. Moreover, it reduces atrophy of intestinal mucosa in animals on total parenteral nutrition and prevents intestinal mucosal injury accompanying small bowel transplantation, chemotherapy and radiation. In the present study, we investigated the effects of glutamine on development of non-septic shock caused by zymosan. Mice received either zymosan (500 mg/kg, administered i.p., as a suspension in saline) or vehicle (saline). Glutamine (1.5 mg/kg i.p.) was administered 1 and 6h after zymosan administration. Organ failure and systemic inflammation in mice were assessed 18 h after administration of zymosan and/or glutamine. Glutamine-treatment reduced the peritoneal exudation and the migration of polymorphonuclear cells caused by zymosan-injection and also attenuated the pancreatic and gut injury. Inflammatory and apoptotic parameters were evaluated to better investigate the effects of the glutamine-administration. So, by immunohistochemical analysis and in vitro assays, we have clearly showed that glutamine reduces: 1) the histological damage in pancreas and gut; 2) the inducible nitric oxide synthase expression; 3) nitrotyrosine and poly (ADP-ribose) formation; 4) TNF-α and IL-1β tissue and plasma levels; 5) FasL localization; and 6) alteration of the balance between Bax and Bcl-2. In addition, at the end of the observation period (7 days), zymosan causes severe illness in the mice characterized by a systemic toxicity, significant loss of body weight and mortality. Glutamine-treatment significantly reduced all these parameters.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Body Weight; Cytokines; Enzyme Activation; Fas Ligand Protein; Gene Expression Regulation; Glutamine; Inflammation; Lipid Peroxidation; Male; Mice; Multiple Organ Failure; Neutrophil Infiltration; Nitric Oxide; Peritoneal Cavity; Poly Adenosine Diphosphate Ribose; Poly(ADP-ribose) Polymerases; Protein Transport; Proto-Oncogene Proteins c-bcl-2; Tyrosine; Zymosan

PD98059 (MEK1 Inhibitor) has been shown to act in vivo as a highly selective inhibitor of MEK1 activation and the MAP kinase cascade. In the present study, we have investigated the effects of PD98059, on the development of non-septic shock caused by zymosan in mice. Mice received either intraperitoneally zymosan (500mg/kg, administered i.p. as a suspension in saline) or vehicle (0.25ml/mouse saline). PD98059 (10mg/kg) was administered 1 and 6h after zymosan administration i.p. Organ failure and systemic inflammation in mice was assessed 18h after administration of zymosan and/or PD98059. Treatment of mice with PD98059 attenuated the peritoneal exudation and the migration of polymorphonuclear cells caused by zymosan. PD98059 also attenuated the lung, liver and pancreatic injury and renal dysfunction caused by zymosan as well as the increase of TNF-alpha and IL-1beta plasma levels caused by zymosan. Immunohistochemical analysis for inducible nitric oxide synthase (iNOS), nitrotyrosine, poly(ADP-ribose) (PAR), ICAM-1, P-selectin, Bax, Bcl-2 and FAS-ligand revealed positive staining in pancreatic and intestinal tissue obtained from zymosan-injected mice. The degree of staining for nitrotyrosine, iNOS, PAR, ICAM-1, P-selectin, Bax, Bcl-2 and FAS-ligand were markedly reduced in tissue sections obtained from zymosan-injected mice, which had received PD98059. Moreover treatment of mice with PD98059 (10mg/kg) attenuated the NF-kappaB activation and mitogen-activated protein kinases (MAPK) expression induced by zymosan injection. In addition, administration of zymosan caused a severe illness in the mice characterized by a systemic toxicity, significant loss of body weight and a 60% of mortality at the end of observation period. Treatment with PD98059 significantly reduced the development of systemic toxicity, the loss in body weight and the mortality (20%) caused by zymosan. This study provides evidence that PD98059 attenuates the degree of zymosan-induced non-septic shock in mice.

Topics: Acute Disease; Animals; Apoptosis; bcl-2-Associated X Protein; Cell Adhesion Molecules; Cytokines; Fas Ligand Protein; Flavonoids; I-kappa B Proteins; Inflammation Mediators; Male; Mice; Mitogen-Activated Protein Kinases; Multiple Organ Failure; Neutrophil Infiltration; NF-KappaB Inhibitor alpha; Nitric Oxide; Nitric Oxide Synthase Type II; p38 Mitogen-Activated Protein Kinases; Peritonitis; Phosphorylation; Poly(ADP-ribose) Polymerases; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-bcl-2; Systemic Inflammatory Response Syndrome; Time Factors; Transcription Factor RelA; Tyrosine; Zymosan

The aim of the present study was to assess the relative contributions of peroxynitrite formation following induction of nitric-oxide synthase (iNOS) in the pathophysiology of endotoxin-induced shock in the rat. To this end, we used a selective inhibitor of iNOS, N-(3-(aminomethyl)benzyl)acetamidine (1400W), and a peroxynitrite decomposition catalyst, 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrinato iron III chloride (FeTTPs). Intravenous (i.v.) administration of Escherichia coli lipopolysaccharide (LPS; 4 mg/kg) elicited a time-dependent fall in mean arterial pressure as well as liver, renal, and pancreatic tissue damage. 1400W (3-10 mg/kg i.v.) administered 30 min before LPS delayed the development of hypotension but did not improve survival. On the other hand, FeTTPs administered (10-100 mg/kg i.v.) inhibited in a dose-dependent manner LPS-induced hypotension, tissue injury, and improved mortality rate. In separate experiments, rats were treated with LPS (4 mg/kg) or saline for control, and their aortas were isolated and placed in organ baths 2 h later. Tissues from LPS-treated rats had significant inhibition of contractile activity to phenylephrine as well as a significantly impaired relaxation response to acetylcholine. FeTPPs, when administered (100 mg/kg i.v.) 1 h before LPS, prevented the LPS-induced aortic contractile and endothelial dysfunction. These results demonstrate that nitric oxide-derived peroxynitrite formation plays an important role in this model of endotoxemia. Our results also suggest that use of an iNOS inhibitor in this setting has little beneficial effect in part because, in the presence of a failing eNOS system, some NO is needed to maintain adequate organ function.

Topics: Amidines; Animals; Benzylamines; Endothelium, Vascular; Liver; Male; Metalloporphyrins; Multiple Organ Failure; Nitric Oxide; Nitric Oxide Synthase Type II; Peroxynitrous Acid; Rats; Rats, Sprague-Dawley; Shock, Septic; Tyrosine; Vasoconstriction

The peroxisome proliferator-activated receptor (PPAR) alpha is a member of the nuclear receptor superfamily of ligand-dependent transcription factors related to retinoid, steroid, and thyroid hormone receptors. The aim of the present study is to evaluate the role of PPAR-alpha receptor on the development of multiple-organ dysfunction syndrome (MODS) induced by zymosan. MODS was induced by peritoneal injection of zymosan (dose, 500 mg/kg i.p. as a suspension in saline) in PPAR-alpha wild-type (PPAR-alphaWT) and PPAR-alpha knockout (PPAR-alphaKO) mice, was assessed 18 h after the administration of zymosan, and was monitored for 12 days (for loss of body weight and mortality). A severe inflammatory process, induced by zymosan administration in wild-type mice, coincided with the damage of liver, kidney, pancreas, and small intestine. Myeloperoxidase activity, indicative of neutrophil infiltration, and lipid peroxidation were significantly increased in zymosan-treated wild-type mice. Zymosan in the wild-type mice also induced a significant increase in the plasma levels of nitrite/nitrate. Immunohistochemical examination demonstrated a marked increase in the immunoreactivity to nitrotyrosine and Fas ligand in the intestine of zymosan-treated wild-type mice. In contrast, the degree of (1) peritoneal inflammation and tissue injury, (2) nitrotyrosine formation and Fas ligand expression, and (3) neutrophil infiltration were markedly enhanced in intestinal tissue obtained from zymosan-treated PPAR-alphaKO mice. Zymosan-treated PPAR-alphaKO mice also showed a significantly increased mortality. Taken together, the present study clearly demonstrates that PPAR-alpha pathway modulates the degree of MODS associated with zymosan-induced nonseptic shock.

Topics: Animals; Apoptosis; Fas Ligand Protein; Inflammation; Intestines; Kidney; Lipid Peroxidation; Mice; Mice, Knockout; Multiple Organ Failure; Neutrophil Infiltration; Nitric Oxide; PPAR alpha; Shock; Tumor Necrosis Factor-alpha; Tyrosine; Up-Regulation; Zymosan

This study investigated the effects of hyperbaric oxygen (HBO) therapy on the cardiovascular alteration (e.g. mean arterial pressure, vascular reactivity of thoracic aorta rings changes) caused by zymosan in rats.. Rats.. University research laboratory.. We investigated the effects of HBO therapy (2 ATA at the fourth and eleventh hours after study onset) on the cardiovascular alteration caused by zymosan (500 mg/kg, administered i.p. as a suspension in saline) in rats. Cardiovascular alterations were assessed 18 h after administration of zymosan and/or HBO therapy.. Treatment of rats with HBO therapy attenuated the vasoplegic response to zymosan. In fact, the analysis of arterial pressure curves revealed no signs of vasoplegic shock. The aorta rings of animals treated with zymosan and HBO had a significantly increased contraction to norepinephrine (NE) and endothelin-1 (ET-1) and dilation to acetylcholine (ACh) compared with the zymosan group. The HBO therapy also attenuated the increase of malondialdehyde (MDA) levels caused by zymosan in the aorta. Immunohistochemical analysis for nitrotyrosine and for iNOS revealed positive staining in the aorta from zymosan-treated rats. The degree of staining for nitrotyrosine and iNOS was markedly reduced in tissue sections obtained from zymosan-rats treated with HBO therapy.. This study provides the first evidence that HBO therapy attenuates the degree of zymosan-induced cardiovascular derangement in the rat.

Topics: Analysis of Variance; Animals; Aorta; Endothelium, Vascular; Hyperbaric Oxygenation; Immunohistochemistry; Male; Malondialdehyde; Multiple Organ Failure; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Random Allocation; Rats; Rats, Sprague-Dawley; Tyrosine; Vascular Diseases; Vasodilation; Zymosan

Nuclear factor (NF) kappaB is a transcription factor which plays a pivotal role in the induction of genes involved in physiological processes as well as in the response to injury and inflammation. Dithiocarbamates are anti-oxidants which are potent inhibitors of NF-kappaB. We postulated that pyrrolidine dithiocarbamate (PDTC) would attenuate multiple-organ failure (MOF).. Rats in a university research laboratory.. We investigated the effects of PDTC (10 mg/kg) on the MOF caused by zymosan (500 mg/kg, administered i.p. as a suspension in saline) in mice. MOF in mice was assessed 18 h after administration of zymosan and/or PDTC and monitored for 7 days (for loss of body weight and mortality).. Treatment of mice with PDTC (10 mg/kg i.p., 1 and 6 h after zymosan) attenuated the peritoneal exudation and the migration of polymorphonuclear cells caused by zymosan. PDTC also attenuated the lung, liver and pancreatic injury and renal dysfunction caused by zymosan as well as the increase in myeloperoxidase activity and malondialdehyde levels caused by zymosan in the lung, liver and intestine. Immunohistochemical analysis for inducible nitric oxide synthase, nitrotyrosine and poly(ADP-ribose) revealed positive staining in lung, liver and intestine tissues obtained from zymosan-treated mice. The degree of staining for nitrotyrosine and poly(ADP-ribose) were markedly reduced in tissue sections obtained from zymosan-treated mice which received PDTC. Furthermore, treatment of mice with PDTC significantly reduced the expression of nitric oxide synthase in lung, liver and intestine.. This study provides the first evidence that PDTC attenuates the degree of zymosan-induced MOF in mice.

Topics: Animals; Antioxidants; Blotting, Western; Chemotaxis, Leukocyte; Disease Models, Animal; Drug Evaluation, Preclinical; Immunohistochemistry; Lipid Peroxidation; Male; Malondialdehyde; Mice; Mice, Inbred Strains; Multiple Organ Failure; Neutrophils; NF-kappa B; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Peroxidase; Poly(ADP-ribose) Polymerases; Pyrrolidines; Random Allocation; Thiocarbamates; Time Factors; Tyrosine; Zymosan

Zymosan enhances the formation of reactive oxygen species, which contributes to the pathophysiology of multiple organ failure. We investigated the effects of calpain inhibitor I (5, 10, or 20 mg/kg) on the multiple organ failure caused by zymosan (500 mg/kg, administered intraperitoneally as a suspension in saline) in rats.. University research laboratory.. Male Sprague-Dawley rats.INTERVENTIONS Multiple organ failure in rats was assessed 18 hrs after administration of zymosan and/or calpain inhibitor I and was monitored for 12 days (for loss of body weight and mortality rate).. Treatment of rats with calpain inhibitor I (5, 10, or 20 mg/kg intraperitoneally, 1 and 6 hrs after zymosan) attenuated the peritoneal exudation and the migration of polymorphonuclear cells caused by zymosan in a dose-dependent fashion. Calpain inhibitor I also attenuated the lung, liver, and intestinal injury (histology) as well as the increase in myeloperoxidase activity and malondialdehyde concentrations caused by zymosan in the lung, liver, and intestine. Immunohistochemical analysis for nitrotyrosine and for poly(adenosine-disphosphate-ribose) revealed positive staining in lung, liver, and intestine from zymosan-treated rats. The degree of staining for nitrotyrosine and poly(adenosine-disphosphate-ribose) was reduced markedly in tissue sections obtained from zymosan-treated rats administered calpain inhibitor I (20 mg/kg intraperitoneally). Furthermore, treatment of rats with calpain inhibitor I significantly reduced the expression of inducible nitric oxide synthase and cyclooxygenase-2 in lung, liver, and intestine.. This study provides the first evidence that calpain inhibitor I attenuates the degree of zymosan-induced multiple organ failure in the rat.

Topics: Animals; Calpain; Cell Movement; Cyclooxygenase 2; Dose-Response Relationship, Drug; Glycoproteins; Immunohistochemistry; Intestinal Mucosa; Intestines; Isoenzymes; Liver; Lung; Male; Malondialdehyde; Multiple Organ Failure; Neutrophils; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Peritoneum; Peritonitis; Peroxidase; Peroxynitrous Acid; Poly Adenosine Diphosphate Ribose; Prostaglandin-Endoperoxide Synthases; Rats; Rats, Sprague-Dawley; Tyrosine; Zymosan

An enhanced formation of nitric oxide (NO) by the inducible NO synthase (iNOS) may contribute to the pathophysiology of hemorrhagic shock. This study investigates the effect of a novel, potent and selective inhibitor of iNOS activity (GW274150) on the circulatory failure and the organ injury and dysfunction associated with hemorrhagic shock in the anesthetised rat. Hemorrhage (sufficient to lower mean arterial blood pressure to 45 mmHg for 90 min) and subsequent resuscitation with shed blood resulted (within 4 h after resuscitation) in a delayed fall in blood pressure, renal and liver injury and dysfunction as well as the pancreatic injury. Pre-treatment of rats with GW274150 (5 mg/kg at 30 min prior to the onset of hemorrhage) attenuated the renal dysfunction as well as the liver and pancreatic injury caused by hemorrhage and resuscitation. Interestingly, GW274150 did not reduce the delayed fall in blood pressure associated with hemorrhagic shock. We propose that an enhanced formation of NO from iNOS contributes to the organ injury and dysfunction in hemorrhagic shock, and that highly selective inhibitors of iNOS activity, such as GW274150, may represent a novel therapeutic approach for the therapy of hemorrhagic shock.

Topics: Animals; Blood Pressure; Enzyme Inhibitors; Heart Rate; Liver; Lung; Male; Multiple Organ Failure; Neutrophils; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Rats; Shock, Hemorrhagic; Sulfides; Tyrosine

Brain death induces multiple-organ dysfunction, with undesirable consequences for organ transplantation. However, the mechanisms are not completely clear. In the hearts, lungs, livers, and kidneys of rats, we investigated whether brain death leads to changes in nitric oxide (NO) production or to the formation of nitrotyrosine (the footprint of peroxynitrite, formed from NO and superoxide) or to lipid peroxidation products. To produce a rat model of brain death, we inflated a subdurally placed balloon catheter. We used the Griess reaction to assay plasma nitrite and nitrate. Proteolytic digestion followed by high-performance liquid chromatography (HPLC) with electrochemical detection determined nitrotyrosine formation in the tissues. Tissues were also examined immunohistochemically with anti-nitrotyrosine antibody. We used a thiobarbituric acid method to assay lipid peroxidation. An intense, transient hemodynamic activation occurred at the onset of brain death (heart rate, 496 beats/min; mean arterial pressure (AP), 181 mm Hg; dP/dt(max), 11,500 mm Hg/sec). A constant hypotensive phase (mean AP, 50 mm Hg; dP/dt(max), 2,674 mm Hg/sec) followed. Plasma concentration of nitrite plus nitrate remained unchanged 2 hours after brain death (32.8 +/- 1.5 vs 31.3 +/- 2.2 micromol/liter at zero time). Neither HPLC nor immunohistochemistry detected significant nitrotyrosine formation in the tissues. We detected no increase in lipid peroxidation products.Our results indicate that changes in the generation of reactive nitrogen and active oxygen species do not play an important role in post-brain-death organ dysfunction, at least not at the early stage.

Topics: Animals; Biomarkers; Brain Death; Chromatography, High Pressure Liquid; Heart Transplantation; Hemodynamics; Lipid Peroxidation; Liver; Liver Transplantation; Male; Multiple Organ Failure; Myocardium; Nitrates; Nitric Oxide; Nitrites; Rats; Rats, Wistar; Thiobarbiturates; Tissue Donors; Tyrosine

We investigated the effects of tempol, a membrane-permeable radical scavenger, on the multiple organ failure (MOF) caused by zymosan in the rat. Zymosan (500 mg/kg, suspended in saline solution, ip) enhances formation of reactive oxygen species, which contribute to the pathophysiology of MOF. After zymosan or saline administration, animals were monitored for 12 days.. Treatment of rats with tempol (10, 30, or 100 mg/kg ip, 1 and 6 hrs after zymosan) attenuated the peritoneal exudation and the migration of polymorphonuclear cells caused by zymosan in a dose-dependent fashion. Tempol also attenuated the lung, liver, and intestinal injury (histology) as well as the increase in the concentrations of myeloperoxidase and malondialdehyde caused by zymosan in the lung, liver, and intestine. Immunohistochemical analysis for nitrotyrosine and for poly(adenosine 5'-diphosphate-ribose)synthetase demonstrated a positive staining in lung, liver, and intestine from zymosan-treated rats. The degree of staining for nitrotyrosine and for poly(adenosine 5'-diphosphate-ribose) synthetase was markedly reduced in tissue sections obtained from zymosan-treated rats that had received tempol (100 mg/kg ip). Furthermore, treatment of rats with tempol significantly reduced the following: a) the formation of peroxynitrite, b) the DNA damage, c) the impairment in mitochondrial respiration, and d) the decrease in the cellular concentration of oxidized nicotinamide adenine dinucleotide observed in macrophages harvested from the peritoneal cavity of rats treated with zymosan.. This study provides the first evidence that tempol, a small molecule that permeates biological membranes and scavenges reactive oxygen species, attenuates the degree of MOF associated with zymosan-induced peritonitis in the rat.

Topics: Analysis of Variance; Animals; Cyclic N-Oxides; Free Radical Scavengers; In Vitro Techniques; Intestine, Small; Liver; Lung; Male; Multiple Organ Failure; Poly(ADP-ribose) Polymerases; Random Allocation; Rats; Rats, Sprague-Dawley; Spin Labels; Statistics, Nonparametric; Tyrosine; Zymosan

In the present study, by comparing the responses in wild-type mice (+/+) and mice lacking (-/-) the inducible (or type 2) nitric oxide synthase (iNOS), we investigated the role played by iNOS in the development of non-septic shock. A severe inflammatory response characterized by peritoneal exudation, high peritoneal levels of nitrate/nitrite, and leukocyte infiltration into peritoneal exudate was induced by zymosan administration in iNOS +/+ mice. This inflammatory process coincided with the damage of lung, liver, and small intestine, as assessed by histological examination. Lung, small intestine, and liver myeloperoxidase (MPO) activity, indicative of neutrophil infiltration and lipid peroxidation, were significantly increased in zymosan-treated iNOS +/+ mice. Peritoneal administration of zymosan in the iNOS +/+ mice induced also a significant increase in the plasma levels of nitrite/nitrate and in the levels of peroxynitrite at 18 h after zymosan challenge. Immunohistochemical examination demonstrated a marked increase in the immunoreactivity to nitrotyrosine and to poly ADP-ribose synthetase (PARS) in the lung, liver, and intestine of zymosan-treated iNOS +/+ mice. The intensity and degree of nitrotyrosine and PARS were markedly reduced in tissue section from zymosan-iNOS -/- mice. Zymosan-treated iNOS -/- mice showed a significantly decreased mortality and inhibition of the development of peritonitis. In addition, iNOS -/- mice showed a significant protection on the development of organ failure since tissue injury and MPO were reduced in lung, small intestine, and liver. Furthermore, a significant reduction of suppression of mitochondrial respiration, DNA strand breakage, and reduction of cellular levels of NAD+ was observed in ex vivo macrophages harvested from the peritoneal cavity of iNOS -/- mice subjected to zymosan-induced non-septic shock. In vivo treatment with aminoguanidine (300 mg/kg 1 and 6 h after zymosan administration) significantly prevents the inflammatory process. Taken together, our results clearly demonstrate that iNOS plays an important role in zymosan-induced non-septic shock.

Topics: Animals; Enzyme Inhibitors; Exudates and Transudates; Guanidines; Lipid Peroxidation; Liver; Lung; Macrophages, Peritoneal; Male; Mice; Mice, Knockout; Multiple Organ Failure; Nitrates; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Nitrites; Peritonitis; Peroxidase; Poly(ADP-ribose) Polymerases; Rhodamines; Shock; Tyrosine; Zymosan

The aim of the present study was to evaluate the effects of hyperbaric oxygen (HBO) therapy on multiple organ failure induced by zymosan. Administration of zymosan (500 mg/kg) in the rat induced neutrophil infiltration in the lung, liver, and intestine as evaluated by increase in myeloperoxidase (MPO) activity. Therefore, lipid peroxidation was significantly increased in zymosan-treated rats. This inflammatory process coincided with the damage of lung, liver, and small intestine. Immunohistochemical examination demonstrated a marked increase in the immunoreactivity to nitrotyrosine in the lung, liver, and small intestine of zymosan-shocked rats. HBO (2 absolute Atmosphere) exposure attenuates the increase in the tissue levels of MPO and malondialdehyde (MDA) caused by zymosan in the lung, liver, and intestine. In addition, HBO (2 absolute Atmosphere) was effective in preventing the development of lung, liver, and intestine injury. Taken together, the present results demonstrate that HBO may also be an efficacious treatment in multiple organ failure induced by zymosan.

Topics: Animals; Hyperbaric Oxygenation; Lipid Peroxidation; Male; Malondialdehyde; Multiple Organ Failure; Peritonitis; Peroxidase; Rats; Rats, Sprague-Dawley; Tyrosine; Zymosan

Despite recent investigations, the mechanisms responsible for intestinal epithelial injury during endotoxemia remain unclear. The present study tests the hypothesis that epithelial necrosis and/or apoptosis correlate with nitric oxide (NO) dysregulation in a nonischemic model of sepsis-induced ileal injury. To test this hypothesis, a well-established in situ, autoperfused, feline ileal preparation was employed. After endotoxin (lipopolysaccharide [LPS], 3 mg/ kg, intravenously; n = 9) or vehicle (control; n = 5) treatment, ileal segments were obtained at baseline, 2 and 4 h for simultaneous evaluations of cellular and mitochondrial ultrastructure, immunoprevalence of inducible nitric oxide synthase (iNOS) and 3-nitrotyrosine (a stable biomarker of peroxynitrite), and histochemical evidence of apoptosis. Epithelial necrosis was prominent by 2 h post-LPS, despite unaltered global ileal tissue oxygen content, blood volume, and blood flow. Significant evidence of apoptosis and increases in the immunoprevalence of iNOS and 3-nitrotyrosine were not evident until 4 h post-LPS. These results suggest that the early ileal mucosal necrosis may be due to LPS-induced activation of inflammatory pathways and/or microcirculatory disturbances, whereas NO dysregulation may participate in later events, including protein nitration and epithelial apoptosis.

Topics: Animals; Apoptosis; Cats; Ileum; Immunohistochemistry; Intestinal Mucosa; Lipopolysaccharides; Male; Mitochondria; Multiple Organ Failure; Necrosis; Nitric Oxide; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Oxygen Consumption; Sepsis; Tyrosine

An enhanced formation of reactive oxygen species contributes to the multiple organ dysfunction syndrome (MODS) caused by endotoxin. We have recently discovered that two cell wall components, namely lipoteichoic acid (LTA) and peptidoglycan (PepG) of the gram-positive bacterium, Staphylococcus aureus, synergize to cause shock and MODS in the rat. Here, we investigate the effects of a membrane-permeable radical scavenger (tempol) on the circulatory failure and MODS (kidney, liver, lung) caused by coadministration of LTA (3 mg/kg i.v.) and PepG (10 mg/kg i.v.) in the anesthetized rat.. Prospective, randomized study.. University-based research laboratory.. Thirty-four anesthetized, male Wistar rats.. After surgical preparation, anesthetized rats were observed for 6 hrs. Control rats were given vehicle (control plus saline, 2 mL/kg bolus injection, followed by an infusion of 1.5 mL/kg i.v., n = 6) or tempol (control plus tempol, 100 mg/kg i.v. bolus injection, followed by an infusion of 30 mg/kg i.v., n = 6). Gram-positive septic shock was induced by coadministration of LTA (3 mg/kg i.v.) and PepG (10 mg/kg i.v.) (LTA/PepG plus saline, n = 12). Another group of rats was pretreated with tempol before shock was induced (LTA/PepG plus tempol, 100 mg/kg i.v. bolus injection, 15 mins before LTA/PepG administration, followed by an infusion of 30 mg/kg i.v., n = 10).. Within 6 hrs, administration of LTA/PepG resulted in hypotension, acute renal dysfunction, hepatocellular injury, pancreatic injury, and increased plasma concentrations of nitrite/nitrate. Pretreatment of rats with tempol augmented the hypotension but attenuated the renal dysfunction and the hepatocellular injury/dysfunction caused by LTA/PepG. Tempol did not affect the increase in nitrite/nitrate caused by LTA/PepG.. These results imply that an enhanced formation of reactive oxygen species (including superoxide anions) contributes to the kidney and liver injury and dysfunction caused by LTA/PepG in the anesthetized rat.

Topics: Animals; Blood Pressure; Cyclic N-Oxides; Free Radical Scavengers; Kidney; Lipopolysaccharides; Liver; Lung; Male; Multiple Organ Failure; Multiple Trauma; Nitrates; Nitrites; Peptidoglycan; Random Allocation; Rats; Rats, Wistar; Shock, Septic; Spin Labels; Staphylococcal Infections; Teichoic Acids; Tyrosine

In the present study, we used IL-6 knock-out mice (IL-6KO) to evaluate a possible role of IL-6 in the pathogenesis of non-septic shock induced by peritoneal injection of zymosan. A severe inflammatory response characterized by peritoneal exudation, high peritoneal levels of nitrate/nitrite, and leukocyte infiltration into peritoneal exudate was induced by zymosan administration in wild-type control (WT) mice. This inflammatory process coincided with the damage to the lung and small intestine, as assessed by histological examination. Lung, small intestine and liver myeloperoxidase (MPO) activity, indicative of neutrophil infiltration and lipid peroxidation, were significantly increased in zymosan-treated WT mice. Peritoneal administration of zymosan in the WT mice also induced a significant increase in the plasma levels of nitrite/nitrate and in the levels of peroxynitrite, 18 hours after zymosan challenge. Immunohistochemical examination demonstrated a marked increase in the immunoreactivity to nitrotyrosine in the lung of zymosan-treated WT mice. Zymosan-treated IL-6KO showed significantly decreased mortality and inhibition of the development of peritonitis. In addition, IL-6KO mice showed significant protection from the development of organ failure, since tissue injury and MPO was reduced in the lung, small intestine and liver. Furthermore, a significant reduction of suppression of mitochondrial respiration, DNA strand breakage and reduction of cellular levels of NAD+ was observed in ex vivo macrophages harvested from the peritoneal cavity of IL-6KO mice subjected to zymosan-induced non-septic shock. In vivo treatment with anti-IL-6 (5,000 ng/day per mouse, 24 and 1 hour before zymosan administration) significantly reduced the inflammatory process. Taken together, the present study clearly demonstrates that IL-6 exerts a role in zymosan-induced non-septic shock.

Topics: Animals; Antibodies, Monoclonal; Ascites; Ascitic Fluid; DNA Damage; Energy Metabolism; Injections, Intraperitoneal; Interleukin-6; Intestine, Small; Leukocyte Count; Lipid Peroxidation; Liver; Lung; Macrophage Activation; Macrophages, Peritoneal; Mice; Mice, Inbred C57BL; Mice, Knockout; Multiple Organ Failure; NAD; Neutrophils; Nitrates; Nitrites; Oxidative Phosphorylation; Peritonitis; Peroxidase; Shock; Tyrosine; Zymosan

Reactive oxygen species (ROS) contribute to the multiple organ failure (MOF) in hemorrhagic shock. Here we investigate the effects of a membrane-permeable radical scavenger (tempol) on the circulatory failure and the organ injury and dysfunction (kidney, liver, lung, intestine) associated with hemorrhagic shock in the anesthetized rat. Hemorrhage (sufficient to lower mean arterial blood pressure to 500 mmHg for 90 min) and subsequent resuscitation with shed blood resulted (within 4 h after resuscitation) in a delayed fall in blood pressure, renal and liver injury and dysfunction as well as lung and gut injury. In all organs, hemorrhage and resuscitation resulted in the nitrosylation of proteins (determined by immunohistochemistry for nitrotyrosine) suggesting the formation of peroxynitrite and/or reactive oxygen species. Treatment of rats upon resuscitation with the membrane-permeable radical scavenger tempol (30 mg/kg bolus injection followed by an infusion of 30 mg/kg/h i.v.) attenuated the delayed circulatory failure as well as the multiple organ injury and dysfunction associated with hemorrhagic shock. Thus, we propose that an enhanced formation of ROS and/or peroxynitrite importantly contributes to the MOF in hemorrhagic shock, and that membrane-permeable radical scavengers, such as tempol, may represent a novel therapeutic approach for the therapy of hemorrhagic shock.

Topics: Animals; Cell Membrane Permeability; Cyclic N-Oxides; Free Radical Scavengers; Intestinal Mucosa; Intestines; Kidney; Liver; Lung; Male; Multiple Organ Failure; Rats; Rats, Wistar; Reactive Oxygen Species; Resuscitation; Shock, Hemorrhagic; Spin Labels; Tyrosine